wood energy final
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wood energyTRANSCRIPT
April 2004 ISSN 1239-1336ISBN 952-457-151-X
National Technology AgencyP.O. Box 69, (Kyllikinportti 2), FI-00101 Helsinki, Finland
Tel. +358 105 2151, fax +358 9 694 9196e-mail: [email protected]
www.tekes.fi
Developing technology for large-scale production of forest chipsWood Energy Technology Programme 1999–2003
Final Report
Tekes• D
eveloping technology for large-scale p
roduction of forest chip
s – Wood
Energy Technology P
rogramm
e 1999–2003
Final Rep
ort
6
04
Developing technologyfor large-scale productionof forest chipsWood Energy Technology Programme1999–2003
Final ReportTechnology Programme Report 6/2004
Developing technology for large-scaleproduction of forest chips
Wood Energy Technology Programme1999–2003
Final Report
Pentti HakkilaVTT Processes
National Technology Agency
Technology Programme Report 6/2004Helsinki 2004
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ISSN 1239-1336ISBN 952-457-151-X
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Foreword
Finland is the world leader in utilization of bioenergy. The role of wood as a sourceof energy is more important than in any other industrialized country, as 20 % of theprimary energy consumed is derived from wood-based fuels.
The goal is to further increase the use of wood fuels because the mitigation of cli-mate change requires the reduction of CO2 emissions. In Finland, one of the majormeans to meet the challenge is to replace fossil fuels with forest biomass. The targetof the Finnish energy and climate strategies is to raise the annual production of for-est chips to 5 million m3 or 0.9 Mtoe by 2010.
In 1999, the National Technology Agency Tekes established a five-year Wood En-ergy Technology Programme to develop efficient technology for the large-scaleproduction of forest chips for consumption by heating and power plants. In 2002,the programme was extended to include a sub-programme on small-scale produc-tion and use of wood fuels. This final report summarizes the results of theprogramme, excluding the sub-programme, which will continue to the end of 2004.
As of January 2004, the programme consisted of 44 research projects, 46 industrialprojects and 29 demonstration projects, in which 27 research organizations and 53enterprises participated. Close collaboration between researchers and practitionersenabled the programme to focus on key problems, to build-up know-how and to fa-cilitate its rapid application in practice.
Throughout the programme, the operating environment changed. Today, much ofthe population, and decision-makers in government and industry support the in-creased use of forest energy wholeheartedly. Forest industry has adopted a pioneer-ing role, the engineering industry has developed innovative technology and equip-ment, and heating and power plants have adapted their fuel handling and combus-tion facilities for wood fuels. The capacity of these plants is sufficient to consume allavailable wood fuels, as long as the cost is competitive. Furthermore, reliable deliv-ery organizations for forest chips are now in place, and the harmful variation of chipquality has been reduced, although not totally eliminated. At first, the cost of forestchips was lowered, but an increase in the demand for forest chips and lengtheninghauling distances are increasing the cost of production. During the five-year periodof the programme, the use of forest chips was quadrupled.
Finland has strengthened its position among the forerunners in the field of wood en-ergy. This positive development is a result of many factors, and the Wood EnergyTechnology Programme has been one of the links in the chain. Tekes wishes to thankall the parties who contributed to the programme. Special thanks are extended to the
Executive Board for its strong support and supervision, and the coordinating team atVTT Processes: Programme Manager Pentti Hakkila, Product Manager EijaAlakangas and Programme Coordinator Kati Veijonen.
Helsinki, April 2004
Tekes, the National Technology Agency
Summary
The national Wood Energy Technology Pro-gramme was carried out by Tekes during the period1999–2003 to develop efficient technology forlarge-scale production of forest chips fromsmall-sized trees and logging residues. This is thefinal report of the programme, and it outlines thegeneral development of forest chip procurementand use during the programme period. In 2002, asub-programme was established to address small-scale production and use of wood fuels. This sub-programme will continue to the end of 2004, and itis not reported here.
The programme was coordinated by VTT Pro-cesses. As of January 2004, the programme con-sisted of 44 public research projects, 46 industrialor product development projects, and 29 demon-stration projects. Altogether, 27 research organiza-tions and 53 enterprises participated. The total costof the programme was 42 M€ of which 13 M€ wasprovided by Tekes. The Ministry of Trade and In-dustry provided investment aid for the new tech-nology employed in the demonstration projects.
When the programme was launched at the end ofthe 1990s, the major barriers to the use of forestchips were high cost of production, shortage of re-liable chip procurement organizations, and the un-satisfactory quality of fuel. Accordingly, the pro-gramme focused largely on these problems. In ad-dition, upgrading of the fuel properties of bark wasalso studied.
The production of forest chips must be adapted tothe existing operating environment and infrastruc-ture. In Finland, these are charaterized by rich bio-mass potential, a sophisticated and efficient orga-nization for the procurement of industrial timber, alarge capacity of heating and CHP plants to usewood fuels, the possibility to co-fire wood andpeat, and the unreserved acceptance of society atlarge. A goal of Finnish energy and climate strate-
gies is to use 5 million m3 (0.9 Mtoe) chips annu-ally by 2010.
The Wood Energy Technology Programme was animportant link in the long chain of activities that re-sulted in an unforeseen growth in the use of forestchips. The programme provided a frame and forumfor joint research and development efforts. The keyrole was played by the participating enterprises inthe fields of forest industries, production of fuelsand energy, and machine manufacturing. The roleof forest machine and timber truck entrepreneursalso was of utmost importance.
Forest chip production technology matured duringthe programme period. Chips from logging resi-dues from regeneration areas remained the cheap-est and most abundant source. In 2002 they cov-ered 63% of the total production of forest chips. Asthe demand for carbon-neutral wood fuels grew,industry sought for additional biomass sources andextended procurement operations to whole-treematerial from early thinnings and even stump androot wood from regeneration areas.
Special emphasis was placed on the developmentof system know-how. Baling technology revolution-ized the transportation of uncomminuted biomassand opened the way to centralized comminution atthe plant. Several large CHP plants installed a sta-tionary crusher that, in turn, made it possible toprocess stump and root wood. By 2004, some 24residue balers with a total annual capacity of 0.6million m3 were in operation in Finland. The newtechnology was found especially attractive with re-spect to the flexible process control of large-scaleprocurement of forest chips.
The traditional basic solution, comminution atlanding, still held its leading position. The intro-duction of new chipper-trucks helped to cool thehot chain that is normally a weakness of the sys-tem. In addition to its application to logging resi-
dues, this system is suitable for whole-tree chip-ping as well.
Regarding small-tree chips, the problem has beenlow productivity and the high cost of manual fell-ing. After a long period of slow development, theuse of accumulating felling heads is becomingcommon, and the production chain is becomingfully mechanized. Independent forest machine en-trepreneurs now have a possibility to produce chipsfrom young thinning stands independently of theharvesting of industrial timber.
New technologies, the refinement of procurementlogistics and learning through experience each re-duce the cost of production. However, as the pro-duction is increasing rapidly, the operations haveto be extended to more and more difficult standconditions and distant locations. The average costof forest chips has consequently increased in spiteof technical developments. In 2003, the price ofchips at the plant was 10 €/MWh.
Chip production organizations developed rapidly.Biowatti and UPM both produced 0.5 million m3
(1 TWh) forest chips in 2003. Forest chips becamea credible fuel even for large CHP plants. Never-theless, to increase competition small local pro-ducers are also needed, and forest machine entre-preneurs are examining the possibilities of net-working in order to build secure delivery options.
The use of forest chips is increasing in Finlandfaster than in any other country. The positive envi-ronment for growth has been a crucial factor for thedevelopment and deployment of new technology.It has given space to the industry to experiment andmotivated investments, and it has strengthenedFinland’s position as a pioneer.
When the Wood Energy Technology Programmewas launched in 1999, an unofficial goal was to in-crease the use of forest chips fivefold in five years,i.e. 2.5 million m3 in 2003. Consumption statisticsare not yet available, but it is estimated to be 2.1million m3. Thus, the goal will be achieved a yearlate of the schedule, but production will have in-creased fourfold. The official goal, 5 million m3 in2010, seems to be realistic, but the continuous ef-forts of enterprises, research organizations and thepublic sector will be needed to achieve this goal.
Table of contents
Foreword
Summary
1 Wood energy in Finland . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Present use of wood fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Wood in the energy strategy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 The Wood Energy Technology Programme . . . . . . . . . . . . . . . . . . . . . 72.1 The targets of the programme . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82.2 The organization of the programme . . . . . . . . . . . . . . . . . . . . . . . . 82.3 The projects of the programme . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.4 Sub-programme for small-scale production and use of wood fuels . . 102.5 The international dimension of the programme . . . . . . . . . . . . . . . 11
3 The operating environment of forest chip production . . . . . . . . . . . . 133.1 Management of forests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133.2 Procurement of industrial timber. . . . . . . . . . . . . . . . . . . . . . . . . . 163.3 Utilization capacity of forest chips . . . . . . . . . . . . . . . . . . . . . . . . 173.4 Co-combustion of wood and peat . . . . . . . . . . . . . . . . . . . . . . . . 20
4 Raw material base of forest chips . . . . . . . . . . . . . . . . . . . . . . . . . . . 214.1 Stemwood loss from logging operations . . . . . . . . . . . . . . . . . . . . 214.2 Biomass residues from final fellings . . . . . . . . . . . . . . . . . . . . . . . 234.3 Small trees from early thinnings . . . . . . . . . . . . . . . . . . . . . . . . . . 244.4 Stump and root wood from final fellings . . . . . . . . . . . . . . . . . . . . 244.5 Forest chip potential of the Finnish forests . . . . . . . . . . . . . . . . . . 26
5 Production technology of forest chips . . . . . . . . . . . . . . . . . . . . . . . . 295.1 Production systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295.2 Production organizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375.3 Production logistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405.4 Production equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425.5 Buffer and security storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475.6 Receiving and handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495.7 Production costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
6 Quality control of forest chips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.1 Moisture content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536.2 Other fuel properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
7 Use of forest chips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597.1 The driving forces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 597.2 The users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
8 Use of bark . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658.1 Barking residues as a fuel source . . . . . . . . . . . . . . . . . . . . . . . . . 658.2 Improving the fuel properties of bark . . . . . . . . . . . . . . . . . . . . . . 67
9 The impacts of forest chip production . . . . . . . . . . . . . . . . . . . . . . . . 699.1 Impacts on forest increment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 699.2 Impacts on the management of forests . . . . . . . . . . . . . . . . . . . . . 719.3 Socio-economic impacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
10 State of the art . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Appendix 1. The Executive Board of the Programme . . . . . . . . . . . . . . . . . 89
Appendix 2. The Projects of the Programme . . . . . . . . . . . . . . . . . . . . . . . 91
Tekes’ Technology Programme Reports . . . . . . . . . . . . . . . . . . . . . . . . . 99
1 Wood energy in Finland
The harsh climate, long transport distances, highstandard of living and the predominance of pro-cess-type industries raise the annual use of energyin Finland to 6.3 toe per capita. As there are no de-posits of fossil fuels and the country is rich in for-ests, large amounts of wood have traditionally beenused for the production of energy. Before industri-alization, wood crops were used mainly for fuel,charcoal and tar. During the 19th Century, theslash-and-burn agriculture also reduced the forestresources (Figure 1).
It was not until the second quarter of the 20th Cen-tury that more wood was used for raw material thanfor fuel. Even then, wood remained the primarysource of energy, and on the eve of the Winter Warat the end of the 1930s, wood accounted for 70 % ofall fuels in Finland. Fuelwood only lost its domi-nant position in the late 1950s.
1.1 Present use of wood fuels
The total consumption of wood in Finland is about 75mill. m3 annually. Per capita consumption is 20 timeshigher than the average in the EU countries (Figure2). Wood and the entire forest cluster have played avery significant role in the national economy.
At present, over 90 % of the wood harvest is used asraw material by the forest industries. Only 5 mill.m3 per annum is used directly for fuel, but muchmore energy is derived from forest industries´ pro-cessing residues. The proportion of the energycomponent in the timber flow is approximately asfollows:• In sawmilling 15–25 % (sawdust, debarking and
screening residues)• In plywood manufacturing 30–40 % (log ends,
waste from plies, dust, debarking and screeningresidues)
1
100
80
60
40
20
Structure of removal, %
1850
50
1.6
1900
50
2.7
1950
53
4.0
2000
70
5.2Population, mill.
Felling, mill. m /a3
Natural loss andlogging waste
Fuelwood andrural construction wood
Slash-and-burn,tar and charcoal
Export
Pulpwood
Sawlogs
Figure 1. Removal of stem wood from the Finnish forests since the mid-1800s(48, the figure has been extended to 2000).
• In mechanical pulping 10–15 % (debarking andscreening residues)
• In chemical pulping 50–60 % (black liquor, de-barking and screening residues). Black liquor isa lignin-rich byproduct of kraft pulping that con-tains more than a half of the initial heating valueof pulpwood. Black liquor is burnt for simulta-
neous recovery of energy and pulping chemi-cals. It is a significant fuel, particularly in Fin-land and Sweden, where most European kraftmills are located.
Process residues included, almost a half of thewood used in Finland ends up as fuel, either di-
2
2
4
6
8
10
12
14
16
Finland Sweden Austria France Germany Denmark U.K. Holland EUaverage
Net importsIndigenous wood
m / capita3
14.4
7.7
2.5
0.6 0.4 0.4 0.1 0.10.8
Figure 2. Consumption of roundwood per capita in selected EU countries in 1999(56).
5
10
15
20
25
30
Woodpulp
Sawngoods
Compositeboards
Otherproducts
Blackliquor
Sawdustetc.
Pellets,briquets
Bark Traditionalfirewood
Forestchips
25.9
13.3
1.90.3
17.7
8.6
3.1
0.05
5.4
1.7
Industrial end products 53 % Production of energy 47 %
Indirect use Direct use
Mill. m / annum3
Figure 3. The end use of wood in Finland in 2001 or 2002. Recycled wood ex-cluded (56, 80, 103).
rectly or indirectly (Figure 3). Consequently, 20 %of the total consumption of primary energy, corre-sponding to 6.7 Mtoe in 2002, and 11 % of the elec-tricity, is derived from wood-based fuels (Figure4). These shares are greater than in other industrial-ized countries. More than 20 % of the wood energy,however, is derived from process residues from im-ported wood.
Wood fuels thus come from a large number of in-digenous and foreign sources. By far the most im-portant wood-based fuel is black liquor that is ex-clusively used by the producer. Other large sourcesare debarking residues and the traditional firewoodin small-scale use. Forest chips are still a relativelymodest source of fuel, but it has considerablegrowth potential (Figure 5).
3
8.7
5.6
4.5
3.7
1.61.0
2.1
0.90.3
2.4
1.6
1.1
2
4
6
8
10
Oil Nuclearpower
Coal Naturalgas
Residuesfrom
importedwood
Importedelectricity
Peat Hydropower
Others Wood-basedfuels
5.1
Black liquor
Bark, sawdust, etc.
Traditional firewood
Mtoe / annum
Total consumption 33.5 Mtoe / 2002
Imported energy 75 % Indigenous energy 25 %
Figure 4. Consumption of energy by source in 2002.
15.3
4.5
2.5 1.60.7 0.1 0.1
10
2
4
6
8
10
12
14
16
Bark Sawdust Forestchips
Industrialchips
Recycledwood
Pellets andbriquets
Otherwood
Goal / 2010
Total 25 TWh / 2002
TWh / annum
Figure 5. Consumption of solid wood fuels in heating and power plants in 2002 (103).
1.2 Wood in the energy strategy
The objective of the Government´s energy policy isto ensure the availability of energy, to maintaincompetitive energy prices, and to enable Finland tomeet its international commitments with respect toemissions into the environment (44). As a MemberState of the EU, Finland´s obligation is to decreasethe average greenhouse gas emissions in the years2008–2012 to the level that prevailed in 1990, i.e.76.5 Mt of carbon dioxide equivalent. The targetlevel is currently exceeded by more than 10 %. Thegovernment has to find ways to replace fossil fuelswith renewable energy (95).
In 1999, the Ministry of Trade and Industry ap-proved the Action Plan for Renewable EnergySources (45). The goal is to bring an increase of 50% in the use of renewable energy by 2010, com-pared to the level of 1995. As much as 90 % of theincrease is to be derived from bioenergy, mainlywood-based fuels. The plan was revised in 2002, asthe operating environment was experiencing rapid
change. According to the revised plan, of the dif-ferent sources of renewable energy the growth is tobe fastest in the use of forest chips. In 2010, the en-ergy produced from forest chips will correspond to0.9 Mtoe (Table 1). This will require 5 mill m3 for-est biomass.
Energy derived from forest industry liquid andsolid process residues increased rapidly during thelate 1990s. This was possible because of thegrowth in capacity and wood consumption. How-ever, possibilities for a further expansion of the useof indigenous wood for industrial purposes arelimited and, therefore, additional wood energymust primarily be produced from low-quality re-sidual forest biomass. According to the plan, forestchips alone will cover one third of the increase inthe use of renewable energy during this decade.
The advantage of forest chips is that the input/out-put ratio of energy is 1/30. The entire energy con-tent of fuel can thus be used for replacing fossil fu-els, whereas the energy produced from industrial
4
Source of energy 1995 2001 2005 2010 2025
Use Mtoe/annum
Direct use of wood-based fuels
Traditional firewood, small scale 1.0 1.1 1.2 1.3 1.4
Forest chips, inc. small scale 0.1 0.2 0.5 0.9 1.5
Indirect use of wood-based fuels:
Black liquor 2.6 3.2 3.4 3.7 4.0
Solid processing residues 1.2 1.8 1.9 2.0 2.2
Wood-based, total 4.9 6.3 7.0 7.9 9.1
Recycled fuels 0.0 0.0 0.1 0.2 0.2
Biogas, agri-biomass, liquid biofuels 0.0 0.0 0.1 0.2 0.5
Hydro power 1.1 1.1 1.2 1.2 1.4
Wind power 0.0 0.0 0.0 0.1 0.4
Heat pumps, solar energy 0.0 0.1 0.1 0.2 0.5
Renewable, grand total 6.1 7.6 8.6 9.8 12.1
Table 1. The revised plan of the Ministry of Trade and Industry for renewable energy (46).
residues is actually needed primarily for the pro-cess itself. It is not available for replacing fossil fu-els elsewhere.
The Government’s aim is to make renewable en-ergy economically competitive on the open mar-kets. The following support measures are em-ployed:• Energy taxation of fuels used for heat produc-
tion. A carbon-based fuel tax was imposed in1990, but wood-based fuels are free of the taxbecause of their carbon neutrality. In the begin-ning of 2004, the energy tax on different fuelswas as follows: coal 6.3, light fuel oil 6.0, heavyfuel oil 5.3, natural gas 1.9 and peat 1.6 €/MWh.The energy tax changes the price ratios of fuels,greatly enhancing the competitiveness of woodin heat production (Figure 6).
• Support for electricity production. The car-bon-based fuel tax is limited to heating. It is notcollected if fuel is used for the production ofelectricity. Instead, a tax of 6.9 €/MWhe is leviedfrom consumers of electricity, independently ofthe source of energy. If the source of energy isforest chips or wind, the tax is refunded to theproducer.
• Support for the production of forest fuels. Whensmall-diameter fuelwood is harvested fromyoung thinning stands, a subsidy of about 5.5 €/MWh is paid to chip producers. The stands mustmeet specific silvicultural criteria. When stumpand root wood is harvested from regeneration ar-eas which have been logged in summer time, asubsidy of about 0.9 €/MWh is paid because thetreatment helps to protect the next tree genera-tion from root rot fungus. No direct support isawarded for the production of fuel chips fromlogging residues from late thinnings or final har-vest.
• Aid for investments. Financial aid can be grantedto promote the introduction of new technologyin the production of forest chips. For specialequipment, such as chippers, crushers, balers, ac-cumulating felling heads and biomass vehicles,the subsidy is typically 25 %. Projects involvinginnovative technology are given priority.
• Financial support for the development and com-mercialisation of technology. The primary chan-nel for funding applied R & D is the NationalTechnology Agency Tekes, which gives a highpriority to the use of renewable sources of en-ergy.
5
10
20
30
Heavyfuel oil
Naturalgas
Coalinland
Coalon the coast
Milledpeat
Fuelchips
Energy taxPrice without tax
Lightfuel oil
Price, / MWh€
28.9
19.8
16.1
12.7 11.79.6 10.2
Figure 6. Consumer prices of different fuels in heat production in August 2003.VAT not included (8).
2 The Wood Energy Technology Programme
The National Technology Agency Tekes is themain public investor in applied and industrial re-search and development in Finland. Renewable en-ergies, an essential issue of subtainable develop-ment, is one of the key strategic areas. About 50 %of Tekes’ funding is focused through technologyprogrammes. Several of the programmes havedealt with bioenergy technology, focusing on areassuch as production of fuels, combustion, conver-sion and environmental impacts (Figure 7).
The production of wood fuels was included for thefirst time in the research cluster under consider-ation in the Bioenergy Research Programme in1993–1998. The programme was aimed at the pro-duction, use and conversion of wood and peat fu-els. When the program was coming to an end, itwas concluded that (98):
• The great potential of bioenergy in Finland hadbeen demonstrated and recognized by the popu-lation at large, and by industry and decisionmakers.
• The use of bioenergy had started to grow.• In the development and application of wood en-
ergy technology Finland, together with Sweden,was among the forerunners.
It was agreed that ensuring further developmentand maintaining the research know-how required anew, coordinated programme. The forest indus-tries and large energy companies were ready to in-crease the use of forest fuels and participate in aforthcoming programme. As many changes wereoccurring in the operating environment, includingthe Kyoto Protocol, the programme had to be re-formed.
7
1990 1995 2000 2005
LIEKKI 2
Combustion
CODEModelling ofcombustionprocesses
Wood combustionin fireplaces
CLIMTECH
Energy formwaste and REF
Artificial dewateringof peat
Use + Conversion
WOOD ENERGYPeat
WoodBIOENERGY
SIHTI
SIHTI IIEnergy and environmental
technology
DENSYDistributedenergy systems
STREAMSWaste management
and recycling
Small-scale wood fuelproduction and use
FINEFine particles
Peat production basedon solar energy
Wood energy clinic Mitigatingof climatechange
JALOFuel conversion
LIEKKI 1
Combustiontechnology
Figure 7. Tekes’ programmes of bioenergy. The area of a rectangle indicates relativeexpenditure (Tekes).
The most abundant reserve of renewable energy isforest biomass, but its utilization was being con-strained by the excessive cost of recovery. Conse-quently, Tekes decided to focus on the develop-ment of production technology for forest chips.The new programme was called the Wood EnergyTechnology Programme, abbreviated in this reportto Wood Energy Programme.
2.1 The targets of the programme
The ultimate target of the Wood Energy Pro-gramme was to create favourable conditions for in-creasing the use of forest chips. Consequently, theprogramme was aimed at developing cost-compet-itive production technologies and procurement lo-gistics for recovering residual biomass. The em-phasis was on developing systems for large-scaleoperations in conjunction with combined heat andpower plants.
Preconditions for a rapid increase in the use of for-est chips are the reduction of costs, improved qual-ity of chips, and reliable delivery systems. Chipsmust also be produced by environmentally soundmethods that support sustainable forest manage-ment. The primary targets of the programme weretherefore:• To integrate energy production into conven-
tional forestry and the procurement of industrialtimber
• To develop production systems and procure-ment logistics suitable for the existing infra-structure
• To develop long-distance transport of chips,uncomminuted loose residues and compositeresidue logs
• To develop technology for receiving, comminuting,handling and storage of wood fuels at the plant
• To encourage the participation of forest machineand truck contractors in the wood fuel branch
• To develop quality control for forest chips andprocessing residues from the forest industries inorder to improve the useability and energy effi-ciency of the plant
• In 2002 a sub-programme was established to ad-dress small-scale production and use of woodfuels.
The programme set for itself an unofficial goal: toincrease the annual use of forest chips from 0.5million m3 in 1998 to 2.5 million m3 in 2003, i.e. afive-fold increase in five years. The final result ofthe consumption in 2003 is not available yet, butthe preliminary estimate is 2.1 million m3. Thismeans that the use of forest chips quadrupled butdid not quintuple during the program period. Thetarget will probably be achieved a year behind theschedule.
2.2 The organization of theprogramme
The programme period was 1999–2003. Theprogramme was composed of projects that typi-cally lasted from 1 to 3 years. There were threetypes of projects:• Projects undertaken by research institutes that
addressed common and general needs. In theseprojects research organizations collaboratedwith industrial partners. The results and know-how achieved are in the public domain.
• Projects dealing with product development, i.e.industrial projects, were related to practical ap-plications. They served specific needs of a sin-gle company or group of companies. Examplesinclude the development of a complete chip pro-curement system, less corrosive combustiontechnique for chips rich in needles, chipper, bun-dler, feller-buncher for small trees, forwarderfor biomass transport, special vehicles for trans-porting forest fuels, and fuel receiving and han-dling system at plant. An industrial project com-monly included co-operation with a research or-ganization. The results and experience fromcompany projects are not necessarily in the pub-lic domain.
• Demonstration projects were aimed to promotethe introduction and deployment of new tech-nologies. Funding was primarily investmentgrant-aid from the Ministry of Trade and Indus-try.
Several research organizations participated in theprogramme: VTT Processes, the Finnish ForestResearch Institute, Metsäteho Oy, University ofJoensuu, University of Jyväskylä, University of
8
Oulu, Helsinki University of Technology, TTS In-stitute, and the Radiation and Nuclear Safety Au-thority of Finland. Each research project had an ad-visory board composed of researchers and practi-tioners from participating organizations. Theboard typically met 2–4 times a year to discuss re-search needs, budget changes and major reportsand to monitor the work programme. The indus-trial projects could also have such a board, but itwas an internal company decision. Altogether, 27research units and 53 enterprises participated in theprogramme. At Tekes Tarja-Liisa Perttala, thenHeikki Kotila and since 2002 Marjatta Aarnialawere responsible for the programme.
The programme was coordinated jointly by MotivaOy and VTT Processes. The former signed the con-tracts and took care of accounting, and the latterwas responsible for daily conducting of the work.The Programme Managers at VTT Processes werein the beginning Satu Helynen and Pentti Hakkilajointly, and since 2000 Pentti Hakkila alone. Since2001, the Programme Coordinator was Kati Vei-jonen. Eija Alakangas was responsible for commu-nications with the interested parties.
Tekes nominated an Executive Board to direct thework. The board was chaired by Pekka Laurila,Managing Director of Biowatti, and cochaired bySeppo Paananen from UPM Forest. The ExecutiveBoard consisted of representatives of the majormarket actors in the forest fuel segment. The fol-lowing organizations were represented:• Biowatti Oy (production and distribution of
wood fuels)• BMH Wood Technology Oy (manufacturer of
receiving and handling equipment)• Forestry Development Centre Tapio (promotion
of private forestry)• Fortum Power and Heat Oy (production of elec-
tricity, heat etc.)• Kvaerner Power Oy (manufacturer of fluidized
bed boilers etc.)• Ministry of Agriculture and Forestry (forest
policy)• Ministry of Trade and Industry (energy policy,
funding of new technology demonstrations)• Pohjolan Voima Oy (production of electricity
and heat)
• Plustech Oy/Timberjack Oy (manufacturer offorest machines)
• Tekes (funding)• Trade Association of Finnish Forestry and Earth
Moving Contractors (forest machine contracting)• UPM Oyj (forest industry, procurement of timber
and wood fuels)• Vapo Oy (production and distribution of peat
and wood fuels)• VTT Processes (programme coordinator)
The total cost of the programme was 42 M€, ofwhich about 13 M€ was provided by Tekes. Themajority of funding was provided by enterprisesfor their own product development projects, andfor public research projects in which industry par-ticipated. Research institutes also provided funds.The Ministry of Trade and Industry promoted thedeployment of new technology by supportingdemonstration projects.
2.3 The projects of the programme
As of February 2004, the programme contained 44research projects, 46 industsry projects and 29demonstration projects. They were divided into 6subject groups (Table 2).• Planning and organization. The subject group
produced the basic information necessary forsystem development and planning of opera-tions. Examples are studies on technical loggingconditions and cost factors of chip procurement,organization of chip procurement, contractornetworks, scaling of fuelwood, and determiningthe boundary between pulpwood and fuelwood.
• Production systems and techniques. This sub-ject group was the core of the programme, and itincluded all demonstration projects. The em-phasis was in the development of machines, ve-hicles, work methods and entire procurementsystems for the production of fuel from forestbiomass.
• Quality control, handling and use. Major topicswere quality control of forest chips and debark-ing residues, the effect of fuel quality on theuseability of a plant, changes in fuel propertiesduring storage, development of fuel receiving
9
and handling technology at the plant, and co-fir-ing of wood fuels with peat.
• Impacts on environment and forestry. Amongthe subjects studied were the emissions fromforest fuel production, effect of intensive bio-mass recovery on the nutrient balance of forestsoils, quality control of forest fuel harvesting,and the impact of residue removal and stump ex-traction on the forest regeneration.
• An wood fuel clinic had been estabilished in1996 to transfer know-how from the BioenergyResearch Programme to small and medium-sized enterprises, and it was continued within theWood Energy Programme. The clinic formed arapid and flexible way to support small-scaleproduct development. Financial aid was given to29 small projects concering fuelwood produc-tion and use.
• Other subject groups listed in Table 2 are exam-ined in sub-sections 2.4 and 2.5.
2.4 Sub-programme for small-scale production and use ofwood fuels
The Wood Energy Programme was focused ini-tially exclusively on the large-scale production offorest chips. Once this work was up and running,Tekes considered it appropriate to extend projectactivities to small-scale production and use of
chips, chopped firewood and pellets. An additionalsub-programme was therefore estabilished in2001. Due to the delayed start, the sub-programmewill continue to the end of 2004, or a year longerthan the main programme. The estimated cost ofthe sub-programme is 5.2 M€, of which Tekes willprovide 2.9 M€.
The concept of “small scale” is applied flexibly,but in principle the sub-programme deals withboilers smaller than 1 MW. Small- and medium-sized companies’R&D needs are examined so as toencourage research and product development ac-tivities and to create national and internationalbusiness opportunities (26). Companies are en-couraged to implement product development pro-jects. Four target areas are identified, all character-ized by the small scale of operations:• Production and handling of chips and chopped
wood. The most important topics are the devel-opment of cost-effective technologies, the logis-tics of production chains, fuel quality, and thestorage and feeding of fuel.
• Production, distribution and use of pellets. Theaim is to create functional and comprehensiveheat production systems based on the use of pel-lets.
• Heating technology. The aim is to improve theefficiency of combustion and to reduce emis-sions to meet the Central European standard.The means to be applied are automation, mod-ern control systems, and modular solutions.
10
Subject group Researchprojects
Industrialprojects
Demonstrationprojects
Planning and organization 5 4
Production systems and techniques 6 17 29
Quality control, handling and use 14 9
Impacts on forestry 7 1
Small-scale production and use 7 14
International cooperation 5 1
Total 44 46 29
Table 2. The projects of the Wood Energy Programme by subject groups.
• Business and service concepts relating to all tar-get areas. Examples include the creation of heatentrepreneurship and energy service companies,and the development of customer-driven in-ternet sales of wood fuels. The networking ofcompanies is promoted.
As of February 2004, altogether 21 projects hadbeen started. Since most of them will continue tothe end of 2004, this final report of Wood EnergyProgramme does not present any results of thesub-programme concerning small-scale opera-tions.
2.5 The international dimension ofthe programme
Although the primary driving force behind thewood energy boom is the global climate change,the Wood Energy Programme and its targets wereessentially national. However, as wood energy ispromoted for the same reasons all over the world,international cooperation opens up useful channelsfor the exchange of information, transfer of tech-nology, and trade. From the Finnish viewpoint aproblem was that corresponding comprehensiveR&D programmes were not ongoing in other coun-tries at the same time. At the programme level itwas not possible to find a foreign partner that wasprepared to fund and carry out an extensive re-search programme concerning the development offorest chip production technologies.
The traditional cooperation partner has been Swe-den. Similarities between the two countries are ob-vious in climate, forest management, forest tech-nology, energy sector, infrastructure, and socio-economic environment. Conditions for profitablecooperation are favorable, as both Sweden andFinland are forerunners in the field of wood energy(7). However, during the programme period the re-search emphasis in Sweden was on environmentalissues such as the effect of biomass recovery on thebiodiversity of forests, whereas the Finnish pro-gramme was focused on the development of tech-nology. There was, therefore, no programme levelcooperation. The cooperation was limited to pro-
jects with Sveriges Lantbruksuniversitet (SLU),Växjö universitet and Värmeforsk.
Three persons from Finland also worked for a yearin the USA as visiting scientists within the frame-work of the programme. The topics studied werethe co-combustion of solid biofuels and coal, max-imum biomass use and efficiency in large-scaleco-firing, and technology transfer on the produc-tion of biofuels. The programme also participatedin the work of a number of international organiza-tions:• IEA Bioenergy Agreement, especially Task 18
(Conventional forestry systems for bioenergy)in 1998–2000 and subsequent Task 31 (Biomassproduction for energy from sustainable forestry)in 2001–2003.
• ALTENER bioenergy network: AFB-net, andsince 2000 the subsequent EUBIONET (Euro-pean bioenergy networks; http://eubionet.vtt.fi),for the exchange of commercial bioenergy in-formation and to spread knowledge of the Finnishbioenergy sector in participating countries. TheAFB-net and EUBIONET were coordinated byVTT Processes.
• OPET network (Organization for Promoting En-ergy Technology) for the exchange of informa-tion about bioenergy technology at internationallevel in cooperation with industry. The OPETFinland was coordinated by Tekes(www.tekes.fi/opet).
• EU cooperation in certain research and industryprojects. This included the preparation of thebioenergy IP project for the 6th frameworkprogramme of the European Commission.
Results were mainly published in Finnish. In addi-tion, results were made available in Englishthrough following means: the www pages of Tekes(www.tekes.fi/english/programm/woodenergy), aprogramme pamphlet, case cards on results, post-ers and a comprehensive interim report (18). Scien-tific articles were presented in international maga-zines, seminars and conferences such as Bioenergy2003 in Jyväskylä, where the programme organizeda specific session and study tour on the large-scaleproduction of forest chips.
11
3 The operating environment of forest chipproduction
In the interests of the Finnish national economy itis of great importance that timber crops are di-rected at forest industries. Export earnings from acubic meter of unbarked softwood is about 100 € ifthe product is sawn timber or kraft pulp, and muchmore if the product is paper or paper board. Thesurplus value is significantly smaller if the wood isused as fuel. The energy from a cubic meter ofwood corresponds to less than 0.2 tons of oil; a sav-ing in foreign exchange of only 30 €.
Energywood is actually a by-product, a leftoverfrom the more valuable industrial timber crops.Therefore, energywood must be harvested at theterms of industrial timber.
3.1 Management of forests
Private persons own 61 % of productive forestland, and 71 % of the annual increment occurs onprivate lands. There are 242 000 forest holdingslarger than 10 ha, and the average area is c. 40 ha.The majority of the domestic timber is thereforeharvested from private forests. The predominanceof non-industrial family forestry strongly influ-ences the care and intensity with which the forestsare managed and utilized. The fragmented natureof the ownership affects the requirements placedon forest machines with respect to their mobilityfrom site to site and friendliness to the forest envi-ronment. The small size of holdings strains the pro-ductivity of mechanized harvesting, increases thecosts and disturbs the logistics.
Thinnings are a standard silvicultural practice. Insouthern Finland, nearly all stands are thinnedcommercially from below twice or three times, andin northern Finland once or twice, during the rota-tion period. Commercial thinnings are preceded by
a pre-commercial thinning, from which timber isnot harvested because of the small tree size.
The correct timing of silvicultural activities is es-sential for maintaining the vitality of the foreststand, to accelerate the diameter growth of the treesand to improve the physical conditions for futuremechanized cuttings. However, where pulpwoodis in over-supply, the early thinnings are a problem.Compared to the final harvest, the productivity ofwork is low and mechanization more complicated.
Early thinnings are a particular challenge to forestowners, timber procurement organizations andmachine manufacturers alike. Demand for small-sized wood and the presence of a well developedand disciplined wood procurement organizationare preconditions for successful early thinning.
Young thinning stands are a potential source offuel. Currently, the richest fuel yields are found instands were silvicultural activities have been ne-glected. These stands are over-dense, and the treesthat have to be removed are too thin for industrialpurposes. As such they are attractive as a fuel har-vest, but if it is based on poor silviculture the avail-ability of fuel will not be sustainable. The FinnishForest Research Institute is therefore examining anew approach to the management of young forests:rescheduling the early tending operations in orderto gain a better and sustainable yield of fuel fromthe thinning treatment prior to the traditional firstcommercial thinning (83).
It is hoped that the use of low-quality biomass as asource of renewable fuel will promote managementof young forests. In later thinnings and regenera-tion cuttings no serious problems occur regardinglogging, but establishment of a new stand after re-generation cutting is also a cause of concern, sinceplanting is still performed manually and forest la-
13
bor is becoming scarce. The presence of abundantlogging residues is one of the factors constrainingthe mechanization of regeneration. Thus, the re-moval of logging residues and stumps for energyproduction could pave way for good post-harvest-ing management practice.
Table 3 presents an example of the management re-gime and biomass yield of coniferous forests insouthern Finland. The lower values of the biomass
residues refer to Scots pine and the higher values toNorway spruce. These biomass residues form thebulk of the energy potential of a stand during a ro-tation period. An additional source is stump androot wood.
The richest sources of energy are whole-three bio-mass from early thinnings and logging residuesand stump and root wood from regeneration cut-tings of spruce (Figures 8–10). As pine was the
14
Treatment Stand ageyears
Yield of timberm3/ha
Biomass residues
m3/ha toe/ha
Precommercial thinning 10–20 – 15–50 3–9
1st commercial thinning 25–40 30–80 30–50 6–9
2nd commercial thinning 40–60 50–90 20–40 4–8
3rd commercial thinning 50–70 60–100 20–40 4–8
Final harvest 70–100 220–330 70–130 13–24
Total during rotation 360–600 155–310 30–58
Table 3. A typical management regime of a southern Finnish forest stand. Biomass does not includestump and root wood.
Figure 8. Small trees from an early thinning of pine. The removal from a young softwood-dominated stand is frequently composed of hardwoods (VTT).
15
Figure 10. Stump and root wood from a final cut of spruce (VTT).
Figure 9. Logging residues from a final cut of spruce (VTT).
preferred species of stand establishment in the1960s and 1970s, a large majority of young standsare dominated by pine (Figure 11).
3.2 Procurement of industrial timber
In 2001, the Finnish forest industries used 54 mill.m3 of indigenous and 13.5 mill. m3 of importedwood. About 83 % of the indigenous wood waspurchased from private forests, mainly on thestump but also delivered to road side by the forestowner.
Three large forest industry companies, Stora Enso,UPM and Metsäliitto-Yhtymä are responsible forthe procurement of more than 80 % of all commer-cial timber. They operate nationwide and performtheir wood procurement through special forestrydepartments that contract the implementation toindependent entrepreneurs. Cutting and off-roadhaulage are included in a single logging contract,whereas secondary transport is subject to a sepa-rate contract. A contractor typically owns 1–4 for-est machines or trucks.
The technology of wood procurement is based ex-clusively on the mechanized cut-to-length system.
Both the delimbing and cross-cutting of stems arecarried out with one-grip harvesters at the stump.An exception is early thinnings where cutting isstill commonly performed with a chainsaw. Tim-ber is transported to the landing with load-carryingforwarders. This Nordic technology differs con-siderably from the North-American technology, anessential feature of which is haulage of wholeundelimbed trees or delimbed stems to the roadside. Conditions for biomass recovery are there-fore very different in the two regions, and this mustbe taken into account when technology is trans-fered.
Figure 12 shows the number of harvesters, for-warders and 60-ton timber trucks employed in2001. The rate of employment varied considerablyover the year. Under-employment in the summertime indicates that machine contractors may haveseasonal capacity for biomass harvesting (23).
The Finnish timber procurement system is effi-cient and cost-competitive, and it is well suited foroperating in small private forests. Due to mechani-zation, sophisticated logistics and motivated ma-chine entrepreneurs, the nominal cost of procure-ment is lower than 15 years ago. The current aver-age is 14 €/m3 from stump to mill.
16
0.5
1
1.5
2
2.5
1.9
2.3
1.71.9
1.7
0.9
0.30.2
1-20 21-40 41-60 61-80 81-100 101-120 121-140 141+
Small trees frompine stands
Logging residues andstump wood from spruce stands
Hardwood-dominatedSpruce-dominatedPine-dominated
Area, mill. ha
Age, years
Figure 11. The age structure and species dominance of the southern Finnishforests according to the 9th National Forest Inventory (Metla).
This is the operating environment of timber pro-curement in Finland. Since forest biomass is to berecovered as a by-product of industrial timber, theintegration of operations is the natural solution. Itfollows that of the utmost importance is the moti-vation of the forest industries to produce and useforest chips. An exception is the early thinningswere fuel is the primary product and pulpwoodonly a side product, if it is recovered at all. In theseyoung stands, machine contractors can operate in-dependently of the forest industry timber procure-ment organizations and form networks for deliver-ing forest chips to local heating and power plants.
3.3 Utilization capacity of forestchips
A precondition for the successful use of forestchips is that the fuel handling and combustion tech-niques of a plant are adapted for the specific prop-erties of the fuel. Two alternative combustion tech-nologies are available for the large-scale conver-sion of forest biomass to heat and electricity.
The traditional grate combustion method is com-petitive when boiler capacity is less than 5–20MW. The Biograte technology of Wärtsilä Bio-power, based on a rotating grate boiler, is also suit-able for wet biomass, such as debarking residuesfrom sawmills.
Larger plants employ the fluidized bed combustion(FBC) technology. In FBC boilers, fuel is fed into afluidized bed of hot sand, which is circulated by astream of high velocity air from below. Combustiontakes place either in a bubbling fluidized bed(BFB) at low air velocity, or in a circulating fluid-ized bed (CFB) at a higher air velocity. As the bedmaterial is massive relative to the amount of fuel,the combustion process is effectively stabilizedand control of burning and pollutants is greatly fa-cilitated.
The majority of the global FBC boiler productionis in the hands of two globally operating Finnishcompanies, Foster Wheeler Energia Oy and Kvaer-ner Power Oy. The technology was originally de-veloped for the combustion of non-homogenous
17
Figure 12. The number of harvesters, forwarders and timber trucks employed incommercial roundwood production in 2001 (56).
biofuels with difficult properties such as unevenparticle size and high moisture content. The FBCprovides the ability to burn low-grade fuels andon-line fuel switching, and reduces the output ofharmful emissions such as NOx and SO2.
A wide range of fuels can be accommodated withhigh efficiency: wood chips, bark, peat, sludge, in-dustrial and municipal waste, coal, oil and naturalgas. The FBC technology is therefore commonlyemployed in new large plants, and a considerablenumber of traditional grate boilers and pulverizedpeat and coal boilers have been converted tofluidized bed technology. In addition, the receiv-ing, handling and feeding techniques have beenadapted for wood fuels. This has significantly in-creased the potential for using biofuels in Finland.
In heating plants where forest fuels are used forheat production only, 85–88 % of the energy con-tent of the fuel is recovered. Typically, heatingplants are smaller than 10 MW. In condensingpower plants designed for electricity generationonly, about 40–45 % of the input energy is recov-ered in the form of electricity, while the remainingheat is lost in cooling water and flue gases. Forestchips are not competitive in these plants because of
their high price and the low overall efficiency of theprocess.
Combined heat and power (CHP) production orco-generation is a single process of a back-pres-sure power plant. Power is generated as in a con-densing plant, but heat is recovered and used in anindustrial process or for the heating of a nearbycommunity. Under conditions of a high all-year de-mand for heat it is often possible to achieve goodfuel efficiency and a high product value by com-bining power and heat production. The annualpeak load time of industrial CHP plants is about6 000 h (full capacity). As the need for space heat-ing is low in the summer time, the peak load time ofdistrict heating CHP plants is only 4 500 h.
CHP plants have an overall efficiency of 85–90 %.About 20–30 % of the energy input is converted toelectric power and 55–70 % to heat. CHP plants areresponsible for 32 % (Figure 13) of the electricitysupply and 75 % of the district heat in Finland. Al-most all large towns use CHP plants for districtheating. These plants are usually large, but theco-generation technology is now being scaleddown for plants with an electricity output of only5–10 MW or less.
18
5
10
15
20
25
30
Nuclearpower
26.9
CO -free production2
Proportion, %
Hydropower
Importedelectricity
Windpower
Districtheating
Industry Condensingpower
16.3
12.3
0.1
17.3
14.313.0
CHP
Use of forestchips possible
Production causingCO emissions2
Figure 13. The sources of electricity in 2001 (43).
Because of its high energy efficiency, CHP tech-nology is a powerful tool for the reduction of CO2
emissions. Therefore, the EU has set a goal to dou-ble the use of CHP during the period 1994 to 2010.However, as CHP technology is already widelyemployed in Finland, the possibilities to expandthe overall capacity are limited. But where an oldplant is being replaced, it may be feasible to shiftfrom fossil fuels to biofuels, even though total ca-pacity is not increased (25).
Pohjolan Voima Oy alone has recently invested620 M€ to biomass CHP plants with a total capac-ity of 559 MWe and 1 038 MWth. These invest-ments made possible the large-scale use of forestfuels. In 2004, the company’s use of forest chipswill exceed 1 TWh (Figure 14).
In the beginning of 2001, the electricity productioncapacity of the Finnish CHP plants was 5 200MWe. The share of district heating CHP was twothirds and industrial CHP one third (43). The totalcapacity of electricity production in Finland was14 990 MWe.
According to VTT, approximately 7 500 MW newelectricity generation capacity has to be installedby 2020 to meet the growth in energy demand or toreplace old plants. Although a 1 600 MW nuclearpower plant will start operating in 2009, a signifi-cant portion of the new capacity will employ CHPtechnology and co-combust peat and wood fuels(Figure 15). The share of forest chips in theseplants will entirely depend on their cost competi-tiveness and availability. It is obvious that the limitof growth will not be determined by the utilizationcapacity but rather the production capacity of for-est chips.
19
Recycled woodand agri-biomassForest chips
1.4
1.2
1.0
0.8
0.6
0.4
0.2
Use of forest chips,TWh / annum
2001 2002 2003 2004 2005
Materialized Prediction
Figure 14. Use of forest chips in the powerplants of Pohjolan Voima (PVO).
0
3 000
6 000
9 000
12 000
15 000
18 000
21 000
2000 2010 2020 2030
Demand of new capacityDemand of new capacityCHP, district heatOther condensingCoal-condensingNuclear powerHydro & wind power
7 500 MW
2040 2050
Nominal power (MW)
Figure 15. Estimated shutdown schedule of the present electricity generatingcapacity and demand for new capacity (99).
3.4 Co-combustion of wood andpeat
Peatlands cover one third of the land surface ofFinland. A half of this peatland area is in its naturalstate, while the other half has been drained for for-estry. About 1.4 % of the area has been designatedfor peat extraction. The area of the extractionworking is currently about 40 000 ha. Nationwide,the growth of peat far exceeds the harvest.
As there are no fossil fuels in Finland, peat playsan important role as an indigenous source of en-ergy. In fact, Finland is the world leader in the tech-nology of peat production and combustion. VapoOy annually produces over 20 mill. m3 and Turve-ruukki Oy about 2 mill. m3 loose peat fuel. In addi-tion, more than 200 small producers operate lo-cally. Some 90 % of the production is milled peatand 10 % sod peat.
Peat was scarcely used prior to the global energycrises in the 1970s. When the Government intensi-fied is support for the technological developmentof peat extraction in the 1980s, an epoch-makingchange took place. By 2001, the consumption offuel peat corresponded to 2.0 Mtoe or 6 % of the to-tal consumption of primary energy. It is usedmainly in back-pressure power plants for com-bined production of heat and power. About 18 % ofdistrict central heating and 5 % of electricity isgenerated from peat.
Large plants burn peat mainly in fluidized bed boil-ers at atmospheric pressure. They are typicallymultifuel boilers that also utilize other solid fuels,such as bark, sawdust, forest chips or coal. It fol-lows that in these plants fuel peat competes withwood fuels. On the other hand, peat and wood fuelsalso complement each other. In large plants, thefollowing benefits may be gained from the co-fir-ing of wood and peat:• The use of more than one type of fuel helps to re-
duce transport distances and costs.
• The inferior storage properties of wood chipsprevent a plant from keeping large inventories.Peat, on the other hand, is easy to store, and itcan be used for securing the fuel supply. In nor-mal conditions nationwide, the inventory of peatis large enough for a year’s consumption.
• The price of fuel peat is stable, and it is not af-fected by the fluctuation of international energymarkets.
• Peat has a rather constant moisture content,40–45 % in the winter time, whereas forest chipstend to be too moist during the winter when thedemand for energy is highest. Blending chipsand peat stabilizes the average moisture contentof the fuel.
• Corrosion problems caused by alkalis and chlo-rine from needle-rich forest chips can be re-duced when the chips are co-fired with peat, andsulphur emissions from peat are reduced inco-combustion due to favourable chemical reac-tions.
In large plants, fuel supply can seldom be based onwood alone. Availability and security are im-proved, and the cost of fuels and harmful environ-mental impacts are reduced, through the co-firingof wood and peat. For example, the world’s largestbiofuelled power plant, Alholmens Kraft in Pietar-saari on the west coast of Finland, uses a 50/50mixture of wood and peat, with 10 % of the totalenergy derived from forest chips. The capacity ofthe plant is 240 MWe power, 100 MWth processsteam for a pulp and paper mill, and 60 MWth dis-trict heat.
The combined use of wood and peat places specialrequirements on the supply logistics, handling andblending the fuels at the plant. Removing the bot-tlenecks from the receiving facilities and schedul-ing the arrival of wood, bark and peat trucks arecrucial issues.
20
4 Raw material base of forest chips
The annual increment of the Finnish forests is 78mill. m3 including bark. The drain, which is com-posed of fellings and natural mortality, is 65 mill.m3 per annum. The balance is positive, but as a partof the forest area is protected and many forest own-ers give priority to recreation and multiple use, thepossibilities for increasing fellings are quite lim-ited. There is potential, however, in young thinningstands where the silvicultural targets are notreached.
The fellings are composed of stemwood removalswhich are recovered, and stemwood losses whichare left in the forest. Removals are divided into in-dustrial wood and fuelwood. The traditional forestinventories are limited to stemwood only. Crownmass and stump and root wood are omitted (Figure16).
4.1 Stemwood loss from loggingoperations
A part of the stemwood drain fails to meet the qual-ity and diameter requirements of industrial wood.Figure 17 shows the proportion of stemwood left atsite as residue in commercial logging operations. Itcan be concluded that:• The proportion of residues is 20–30 % in the first
commercial thinning but only 4–5 % in the finalcutting. The smaller the trees, the greater is theloss.
• The proportion of residues is in spruce standshigher than in pine stands. This is because theminimum diameter requirement of pulpwood isstricter for spruce, and small undergrowth treesare more common in spruce stands.
21
Scots pine Norway spruceProportion, %
Stem 100 69 100 59Crown 23 16 45 27Stump and root 22 15 24 14Complete tree 145 100 169 100
Figure 16. Distribution of biomass between stem, crown and stump-rootsystem in final fellings.
• The primary source of stemwood loss is the un-der-sized tops, especially in the first thinning,where a large number of trees is removed and thestem tapers slowly.
In the integrated harvesting of pulpwood andfuelwood, the quality of both assortments is im-proved if the minimum diameter of pulpwood is in-
creased. The effect is opposite if the minimum di-ameter is decreased. This happened in 2001, as theminimum diameter of pine pulpwood was loweredto 6 cm.
The residual stemwood is potential fuel. The totalamount of stemwood residues from annual loggingoperations in Finland is 4–5 million m3, but as it is
22
0
5
10
15
20
25
30
Defected woodUnder sized topsSmall sized stems
-
-
Firstthinning
Secondthinning
Finalcut
Firstthinning
Secondthinning
Finalcut
Loss of stemwood, %
Pine stands Spruce stands
23
5
16
27
4
13
Figure 17. The relative loss of stemwood in commercial harvesting operations in 1997.
10
20
30
40
50
60
Crown mass / stem mass, %
Dead branchesLive branches
70
59
48
54
34
22 21
Pine stands Spruce stands
Firstthinning
Secondthinning
Finalcut
Firstthinning
Secondthinning
Finalcut
Figure 18. Crown mass in relation to stem mass. Dry weight basis.
scattered over an area of 600 000 ha, the yield persite is too low to make the salvage feasible. Profit-able harvesting for energy requires richer yields.This is achieved with simultaneous recovery of re-sidual stemwood and crown mass.
4.2 Biomass residues from finalfellings
As only stemwood has commercial value, crownmass and stump-root systems are not included inforest inventories. They are difficult to measure,and therefore biomass data on these tree compo-nents tend to be vague.
Crown mass refers to branches with leaves, liveand dead. In conjunction with timber harvesting,the amount of crown mass residues is estimatedusing empirical crown mass/stemwood ratios.When crown mass is used for energy, it is feasible tocompare dry mass rather than volume. Since the ba-sic density of branchwood is higher than that ofstemwood, the ratio is higher on the mass basis. Thecrown mass/stemwood ratio is typically 40–60 %for spruce and 20–30 % for pine (Figure 18).
Although the recovery of stemwood residues is notfeasible as such, it becomes more attractive whenthe recovery of crown mass and stemwood resi-dues are combined. Under Finnish conditions,80–90 % of this mix is crown mass and the remain-ing 10–20 % is stemwood. The presence of stem-wood facilitates the loading, feeding and baling of re-sidual forest biomass. When the mix is comminutedwith a chipper or crusher, the product is called log-ging residue chips.
The availability of logging residue chips is, inpractice, not as plentiful as Figure 18 seems to sug-gest. Some of the logging sites are out of questiondue to small size, long distance, difficult terrain orecological restrictions, and in all cases it is recom-mended that 30 % of logging residues are left atsite. If residues are left to season and shed part ofthe needles before haulage to road side, the yield ofbiomass is further reduced.
According to a common rule of thumb, the recov-ery of logging residue chips from regeneration ar-
eas of spruce is 0.5 MWh per m3 stemwood re-moved, and in pine stands 0.25 MWh correspond-ingly. In typical regeneration cuttings, the averageyield of fuel from logging residues in 100–120MWh/ha for spruce and 50–60 MWh/ha for pine.
Figure 19 shows the logging residue potentialwithin a 100 km radius of plants in different partsof Finland. The national frontiers, coast lines, wa-ter systems, road networks, age structure of forestsand species dominance cause great regional differ-ences in the availability. In the central parts of thecountry, the availability of logging residue chips to agiven location is more than 800 GWh per annum,unless there are competing users. Nationwide, thetechnical availability of logging residues from finalharvests is about 11–12 TWh per annum, of which6–8 TWh is presently economically harvestable.
23
Figure 19. Logging residue potential from finalfellings within a 100 km transport distance, andoptimal location of power plants with an annualconsumption of 300 GWh of forest chips. Small-tree chips and stumpwood chips are not in-cluded (73).
4.3 Small trees from earlythinnings
The production of forest chips for fuel was startedin the mid-1950s. The primary raw material wasthen small trees from young thinning stands. Treeswere carefully delimbed, and the product was ofhigh quality as required by the then existing chipfeeding and combustion techniques.
As the cost of labor increased, the competitivenessof stemwood chips suffered, and the use of chipsstagnated. The introduction of hydraulic crane inthe 1970s made multi-tree handling possible. Onlythen could the production of small-tree chips be ra-tionalized and delimbing was abandoned. The ap-pearance of a new concept, whole-tree chips, re-sulted in many changes:• The yield of chips increased 15–50 %• The productivity of harvesting increased 15–40 %• The cost of procurement was reduced 20–40 %• The loss of nutrients from forest soil reduced
50–150 %• The particle size distribution and other quality
properties of chips suffered• The machines had to be more robust.
The cost of small-tree chips nevertheless remainedhigh. Production was subsidized for silviculturalreasons, but in the 1990s logging residue chips oth-erwise became more competitive. The increase inuse was restricted exclusively to logging residuechips due to their cheaper cost, but a number of rea-sons have gradually appeared for extending theraw material base to young thinning stands:• Tending of young forests needs to be intensified• Broadening the raw material base improves the
availability of forest fuels and shortens transportdistances
• Independence of the timber markets assists theacquisition of fuel during times of depression inthe forest industries when the production ofother wood fuels is reduced
• Independent chip producers who are not in-volved in the harvesting of industrial timberhave an easier access to raw material in youngthinning stands
• Seasonal fluctuation of employment may be lev-elled by performing small-tree harvesting in thesummer time when pulpwood and sawlog oper-ations slow down
• Diameter requirements of pulpwood can bemade more elastic to response the fluctuation ofdemand, if pulpwood and fuelwood are parallelproducts
• Small-tree chips are of better quality comparedto logging residue chips. Small trees are easier tostore and season, and they produce drier chipswith a lower needle content. This is important,especially for small heating plants
• Small-tree operations create more jobs whichare definitely needed in rural areas. However, inthe long term the availability of labor is expectedto decrease, and a higher need for labor may ac-tually become a problem unless the operationsare fully mechanized.
Under-sized small-tree material is available mainlyin young stands where good tending practices havebeen neglected. Two types of fuel harvesting oper-ations occur. If fuel is the primary product, thetreatment is called energywood thinning. If the re-moved trees are thick enough to allow pulpwood tobecome the primary product, with fuelwood as aby-product, the treatment is called first thinning. Inboth cases, technical logging conditions are diffi-cult because of the small size of the trees. Improve-ments in logging conditions by concentrating ofoperations were examined in the programme (82,84).
4.4 Stump and root wood fromfinal fellings
The stump-root system is defined as all wood andbark of a tree below the stump cross-section. Theuse of stump and root wood for fiber and fuel wasstudied actively in Finland and Sweden during the1970s and 1980s, but the cost was found to be ex-cessive. UPM recently started to again develop theproduction of stump wood for fuel, and progresshas been rapid.
24
Stump-root systems can only be salvaged fromclear-cutting areas. Uprooting is carried out withheavy machines and, therefore, only stumps fromsaw timber-sized trees can be accepted. Moreover,thin roots break and stay in the ground. Sand andstones prevent comminution with sharp knives andso crushers are used instead of chippers.
According to the earlier studies by the Finnish For-est Research Institute, the harvestable dry mass ofa stump-root system is 23–25 % of the stem mass,when sideroots thinner than 5 cm are not recov-
ered. In 2003, UPM harvested stump and rootwood from an area of almost 1000 ha. The yield offuel exceeded the FFRI research findings becausestump height has increased following the replace-ment of manual felling by harvesters. A part of theroot section thinner than 5 cm is also recovered.
Figure 20 shows the dry mass and energy contentof a stump-root system as a function of tree size.For example, if the breast height diameter of a treeis 30 cm, the stump-root system corresponds inpine stands to an energy content of 0.35 MWh and
25
40
60
20
80
10 3020 40
kg
Norway spruce
Scots pine
5 cm
5 cm
5 cm
5 cm
0.2
0.3
0.1
0.4
10 200 30
MWh
Stump diameter, cm
Breast height diameter, cm
Figure 20. Dry mass and heating value of a stump-root system as a function ofstump diameter. Stump cross-section at root collar height, under 5 cm root sec-tions excluded (16).
Scots pine Norway spruce
12
StumpSide roots
5 cm 10 cm 20 cm 5 cm 10 cm 20 cm
% %
15 2053
16 27 25
32
Side roots StumpSide roots Side roots
Figure 21. Distribution of dry mass in a stump-root system of sawtimber-sizedtrees. Under 5 cm root sections excluded (16).
in spruce stands 0.40 MWh. If the number of treesis, say, 400 per hectare, the amount of harvestableenergy is 140–160 MWh/ha.
There is an important difference in the structure of astump-root system between pine and spruce (Figure21). Wet peatlands and the northernmost Finlandexcluded, pine typically has a taproot, and only ahalf of the total mass is composed of lateral roots.Spruce, on the other hand, has no taproot at all, butthicker lateral roots. In spruce, therefore, the cen-tral section of the stump-root system covers onlyone third and the lateral roots two thirds of the totalmass. The difference between the species affectsthe techniques of uprooting and splitting. A sprucestump is easier to harvest and causes only a shallowhole in the ground.
The removal of stump-root systems facilitates sitepreparation for regeneration. It also involves an op-portunity to exterminate the root rot fungus fromthe stand, since the fungus survives in a regenera-tion area in the stumps and gradually infects thetrees of the new generation. Removal of stumpsprevents the root-rot fungus from spreading andheals the infected site.
4.5 Forest chip potential of theFinnish forests
Inventory data on forest resources are importantfor the planning of capacity, product lines and loca-tion of new forest industries. A national forest in-ventory has been carried out nine times since theearly 1920s, and precise knowledge is available ofstemwood resources.
The need for basic forest data now includes notonly stemwood but all forest biomass because en-ergy producers are prepared to invest in wood-firedheating and CHP plants, fuel producers are com-peting for market shares of raw material, and pol-icy-makers are setting new targets for renewableenergy. Forest biomass, although it is renewable, isnevertheless a limited resource, and its use must bebuilt on a sustainable basis.
Estimations of availability begin from the theoreti-cal maximum potential. This is composed of twomajor sources. First, it includes all residual bio-mass left in the forest in conjunction with timberharvesting. Secondly, it includes the small-tree bio-mass which is removed, or should be removed, forsilvicultural reasons in precommercial thinnings ofyoung stands. The former is dependent on the mar-kets of forest products, whereas the latter is free ofmarket fluctuations.
Only a part of the maximum biomass potential isrecoverable. Many technological, socio-economicand environmental factors affect the availability:• Price development of alternative fuels, taxes and
subsidies• Development of procurement technology and
logistics• Motivation of forest machine and truck contrac-
tors to participate• Development of the quality requirements of for-
est chips. For example, will the foliage be takenor left?
• The acceptance of private forest owners, whichis affected by the price paid for biomass
• The energy and climate policies at the nationaland EU levels. The trade of CO2 emissions willbe of utmost importance.
In Figure 22, the technological and environmentalfactors have been taken into account, but no priceassumptions have been applied. The technicallyharvestable potential is estimated separately forfive different types of logging operations:• Energywood thinnings are tending operations in
young stands in which the owner has earlier ne-glected good forest management. Because of thesmall size of the trees, the primary product isfuel. The age of the stands is typically 15–25years and a majority are dominated by pine, butthe removals may be composed of hardwoods.The cost of harvest is high, and subsidies arenecessary to make the recovery possible.
• First thinnings refer traditionally to the firstcommercial logging operation of a stand, nor-mally at the age of 25–40 years. Pulpwood is theprimary product, but as 20–30 % of the stem-wood drain does not meet the minimum dimen-sions of pulpwood, first thinnings may also yieldsubstantial quantities of fuelwood.
26
27
Energywood thinning
First thinning
Late thinnings
Final harvest
Stump and root wood,all operations
3 + 1
3 + 3
1 + 5
2 + 12
15 + 0
100 %
Stump and root woodfrom final harvest
1.5 + 0.5
2 + 1
0.5 + 0
1 + 6.5
2 + 0
33 %
Energywood thinning andfirst thinning
Final harvest
1.6
3.4
The goal of energyand climate strategies
for 2010 5
11 %
The goal of Wood EnergyProgramme for 2003
2.55.5 %
Production of forestchips in 2003
2.1
4.7 %
Energywood thinning andfirst thinning
Final harvest
0.6
1.5
Mill. m / annum3
Technially harvestablebiomass potential
7 + 8 = 15
Theoreticalbiomass potential24 + 21 = 45
Energywood thinning
First thinning
Late thinnings
Final harvest
Figure 22. The biomass potential of the Finnish forests. The first part ofthe series of numbers refers to stemwood and the second part to crownmass (mill. m3/annum).
• Later thinnings leave only small amounts ofstemwood at the site. Residues contain mainlycrown mass, the separate recovery of whichwould cause logging damage to standing treesand unnecessary nutrient loss at a critical devel-opment phase of the stand. Production of forestchips is not recommended at this stage.
• Logging residues from final harvest are com-posed largely of crown mass which is abun-dantly available, especially in spruce stands.Logging residue chips are therefore producedmainly from the crown mass of spruce. Condi-tions of recovery are favourable. No subsidiesare available.
• Stump and root wood from final harvest can besalvaged from clear-cut areas of mature sprucestands. Typically, logging residues have alreadybeen collected from the same site.
A summary of the amount and structure of thetechnically harvestable biomass reserve is pre-sented in Figure 23. More than a half of the har-vestable reserve is crown mass including foliage. Ifthe targets set for forest chips are to be met, crownmass must be accepted as a source of fuel despiteits inferior quality and accelerated nutrient loss.The technology of harvesting must be developed tokeep needle removal at an acceptable level.
28
2
4
6
8
10
Energywoodthinning
4 TWh
Crown massStem mass
Mill. m /annum3
Whole tree chips-
Firstthinning
Finalharvest
Stumps fromfinal harvest
6 TWh
16 TWh
4 TWh
Residuechips
Crushedstump chips
Figure 23. Technically harvestable biomass potential of the Finnish forests.
5 Production technology of forest chips
The Wood Energy Programme aimed at the devel-opment of efficient technology for large-scale pro-duction of forest chips. To increase the flow ofchips tenfold in ten years will require sophisticatedand cost-competitive procurement systems.
A prevailing feature of the programme was its sys-tem approach. The concept of system developmentwas understood in its broad sense, including as-pects such as procurement organization, logistics,machinery used in the production, receiving andhandling of fuel at the plant, and storage as a bufferin the chain. Chapter 5 deals with these issues pri-marily from the viewpoints of technology, reliabil-ity and costs.
5.1 Production systems
A forest chip production system consists of a se-quence of individual operations performed to pro-cess biomass into commercial fuel and to transportit from source to plant. The main phases of chipprocurement are purchase, cutting, off-road trans-port from stump to roadside, comminution, mea-surement, secondary transport from roadside tomill, and receiving and handling at the plant. Thesystem offers the organization, logistics and toolsto control the process.
The efficiency of a procurement system is highlydependent on the environment and infrastructurein which it is operating. Economic, social, ecologi-cal, industrial and educational factors, as well aslocal traditions, also have an effect. Consequently,no single production system is optimal in all coun-tries, or in all conditions within a given country.Under Finnish conditions, the operating environ-ment of forest chip procurement is characterizedby the following attributes:• The majority of the forests belongs to private
non-industrial owners, the size range of hold-ings being typically 20–200 ha. This means
small sales volumes, cramped landing areas atnearby road sides, and frequent shifting of ma-chines from site to site. These drawbacks in-crease the cost of transactions and the scaling ofbiomass, decrease the operational availability ofmachines and so place considerable demandsupon control of large-scale chip procurement.
• Up to 90 % of the potential is linked to the har-vesting of industrial roundwood. The bulk ofproduction must therefore be integrated with theexisting timber procurement system, but the de-gree of integration may vary. In addition, smallindependent contractors and their networks areneeded locally to increase competition.
• All logging machines and timber trucks areowned by contractors. The production of forestchips therefore rests on private contractors andthe profitability of their enterprises.
• The demand for chips varies seasonally, espe-cially in the case of smaller heating plants,which causes fluctuations in employment. Inlarge industrial CHP plants, the demand forchips is more stable.
• Only small plants can base their fuel supply ex-clusively on forest chips. To secure fuel avail-ability, to reduce the costs, and to level out qual-ity variation, larger plants burn forest chipsmixed with bark, sawdust, peat or coal. To keepthe fuel blend constant, chip arrivals at the plantmust be strictly scheduled. This requirementcomplicates the logistics of forest chip procure-ment.
• The Finnish forests belong to the Pan-EuropeanForest Certification System (PEFC). Good for-est management practices are essential also forthe production of forest fuels.
A forest fuel production system is built around thecomminution phase. The position of the chipper orcrusher in the procurement chain largely deter-mines the state of biomass during transportationand, consequently, whether subsequent machinesare dependent on each other, i.e. whether the sys-
29
tem is hot or cool. Comminution may take place atthe road side or landing site, at the source, at a ter-minal, or at the plant where the chips are to be used.
Comminution at landing(Figures 24–26)
Comminution at a landing is the traditional optionof forest chip production. The biomass is hauled byforwarders to the landing and bunched into 4 to 5 mhigh piles. The forwarder operates independentlyof the chipper. Comminution is performed at thelanding using farm tractor-driven chippers insmaller operations and heavy truck-mounted chip-pers or crushers in large-scale operations.
Chips are blown directly into a 100 to 130 m3
trailer truck, a process that makes the system hot andvulnerable, i.e. subsequent machines are dependenton each other. The close linkage of comminutionand trucking results in waiting and stoppages andthus reduces the operational efficiency. A consider-able part of the time consumption of a chipper orchip truck may be wasted in waiting. A smooth in-teraction of comminution and trucking is the mostdemanding phase of the system.
Another problem is that a wider landing area is re-quired than in the alternative systems. This is be-cause of the large road-side inventories of biomassand the simultaneous presence of the chipper andthe truck.
Landing chippers do not operate off road and cantherefore be heavier, stronger and more efficientthan terrain chippers. They are reliable, their tech-nical availability is high, an they have a longlife-span. If the biomass, such as stump and rootwood, is contaminated by stones and soil, it is pos-sible to use crushers that are more tolerant thanchippers.
To avoid the system from over-heating, the truck-mounted chipper and chip truck can be replaced bya single chipper truck. This blows the chips di-rectly into a container and then hauls the load to theplant. As the chipper truck is equipped with its ownchipping device and crane, load capacity suffersand the operation radius around the plant is re-duced. On the other hand, as only one single unit isneeded, the chipper truck is suitable for small worksites and for delivering chip to small heatingplants. This alternative was developed in the
30
Figure 24. Forest fuel production system based on comminution at a landing. Small trees from earlythinning, truck-mounted chipper (VTT).
programme jointly by Biowatti Oy, a large woodfuel producer, Oy Sisu-Auto Ab, a truck manufac-turer, and Heinola Sawmill Machinery, a chippermanufacturer.
Comminution in the terrain(Figure 27)
Comminution in the terrain, or at the source, re-quires a highly mobile chipper suitable forcross-country operations and equipped with atippable 15–20 m3 chip container. The chippermoves in the terrain on strip roads and transfers the
biomass with its grapple loader to the feeder of thechipping device. The load is hauled to the road sideand tipped into a truck container, which may be onthe ground or on a truck trailer.
Because a single machine carries out both thecomminution of biomass and the off-road transportof chips, the cost of shifting machines from site tosite is reduced, and smaller logging sites becomecommercially viable. The use of containers re-duces the interdependence between the chipperand the truck, although it is not entirely removed,and the system remains somewhat hot. Large land-
31
Figure 25. Forest fuel production system based on comminution at a landing. Loggingresidues from final harvest, truck-mounted chipper (VTT).
Figure 26. Forest fuel production system based on comminution at a landing. Loggingresidues from final harvest, chipper-truck (VTT).
ing areas are not required, but a level and firm siteis necessary for the truck containers.
For off-road operation, the chipper must be as lightas possible, although lightness causes its strengthand stability to suffer. Even so, terrain chipperstend to be too heavy for use on soft soils, while theuse of crushing equipment in terrain is out of ques-tion. A terrain chipper requires flat and evenground and, because of its small load size and slowspeed, its range is less than 300–400 m. Snowcauses problems in the winter and results in an in-creased moisture content of chips, unless the ter-rain chipper operates at a landing.
When large volumes of forest fuels are produced,the terrain chipping system becomes difficult tocontrol. At present, the role of this system is dimin-ishing. In the Wood Energy Programme, the terrainchipping system was developed jointly by BiowattiOy, a wood fuel producer, and S. Pinomäki Ky, aforest machine manufacturer.
Comminution at a plant(Figures 28 and 29)
Communition at a plant makes the chipper andchip truck independent of each other. The technicaland operative availability of the equipment in-creases, control of the procurement process is fa-cilitated, demand for labor is decreased, and thecontrol of fuel quality is improved. Mobile chip-
pers can be replaced by heavy stationary crusherswhich are suitable for comminuting all kinds ofbiomass, including stump and root wood and recy-cled wood.
The larger is the fuel flow, the more obvious be-come the advantages. Since the investment cost ishigh, only large plants can afford a stationarycrusher.
When comminution is performed at the plant,truck transportation of biomass takes place in theform of loose logging residues, whole trees orpieces of stump and root wood. The low bulk den-sity of the biomass is the weak link in the system.The development of the truck transportation ofuncomminuted biomass was therefore one of thekey areas of the programme.
It is necessary to increase the bulk density of resi-dues, and for this an interesting prototype baler,Fiberpac, had been introduced earlier in Sweden.Experiences with the technique were encouraging,but it did not achieve wide acceptance at a timewhen the use of forest biomass was not growingand there was little room or need for new produc-tion capacity. The situation was reverse in Finlandwhere the use of forest chips had started to growrapidly. Consequently, Timberjack purchased therights to the Fiberpac technology and developedthe technology further. The project resulted theTimberjack 1490D residue baler.
32
Figure 27. Forest fuel production system based on comminution in the terrain. Loggingresidues from final harvest (VTT).
In this new system, logging residues are com-pressed and tied into 70 cm diameter, 3.2 m longbales or composite residue logs. A bale of greenresidues weighs 500 kg and has an energy contentof about 1 MWh. Bales are transported to the roadside using a conventional forwarder (Figures 30and 31) and on to the plant using a conventional
timber truck. About 12 bales form one forwarderload, and 65 bales or 30 tons form one truck load.
The real advantages of the system did not show upas long as the profitability of the baling techniqueswas evaluated simply by adding successively costsfrom separate work phases of the chain. In a holis-
33
Figure 28. Forest fuel production system based on comminution at a plant. Logging residuesfrom final harvest (VTT).
Figure 29. Forest fuel production system based on comminution at a plant. Stump and rootwood from final harvest (VTT).
34
Figure 30. Timberjack 1490D baling logging residues of spruce (Timberjack).
Figure 31. Conventional Timberjack 1710 forwarder unloading compacted residue logs atroad side (Timberjack).
tic systems analysis, the new technology compareswell with the traditional alternatives, because at-tention is also given to logistics, operative avail-ability, process control, reliability, scaling and en-vironmental impacts:• The machines involved operate independently of
each other making the system cool and reliable.• The integration of bundle production in the pro-
curement of industrial roundwood is simple, asoff-road and on-road transportation can be per-formed with standard equipment.
• The baler produces accurate real-time informa-tion about the daily production and inventories.Scaling becomes cost-free.
• The storage of bales is simple: storage space re-quirement is reduced, little loss or deteriorationof biomass occurs, and long-term storage for thewinter season is easy.
• The noise, dust and litter problems, which mayoccur in conjunction with comminution at alanding, are avoided.
• The reliability of the fuel deliveries is greatlyimproved, while the overhead costs are reduced.
• Bales can be unloaded from a vehicle and storedat any stage of the production chain. This possi-bility, as well as reliable information about thebiomass inventories, create excellent conditionsfor efficient process control.
The system based on residue bales and comminutionat a plant was developed jointly by UPM, PohjolanVoima, Alholmens Kraft and Timberjack to supplyforest biomass to the world’s largest biofuel-firedCHP plant (Figure 32). Since then, more largeplants have installed a stationary crusher andstarted to apply the same technology. At the begin-ning of 2004, 24 residue balers already operated inFinland. Their total capacity was 0.6 mill. m3 or 1.2TWh per annum, corresponding to one third of theforest chips used by all heating and CHP plants.The organizations responsible for the procurementof raw material to the forest industries have found
35
Figure 32. Compacted residue logs in front of the crushing station of Alholmens Kraftpower plant (E.V.A.).
the baling technology an attractive way to integratefuel production in their operations.
Although baling is a proven technology, it still hassignificant development potential. Among the pos-sibilities are:• Improved productivity of baling by making the
feeding and compressing functions faster, andforwarding more efficient through enlargenedload space
• Broadening the application area from loggingresidues to small-tree material. The problem isthe narrow working space in young thinningstands rather than the baling process itself
• Use of mobile chippers and crushers for com-minution of residue bales at small plants or ter-minals where the use of a stationary crusher isnot economical
• Solving some minor problems: keeping stonesout of the bales, use of rear and side walls intrucks for traffic safety, and tangling of cordswith the axles of crushers and disc screens.
Over short distance, it may still be economical totransport logging residues to the plant as unpro-
cessed loose material (Figure 33). The stationarycrushers currently in use are capable of comminutingloose logging residues, although the productivity isnot as high as for baled material. An ongoing pro-ject of the programme aims to developed an en-larged load space and compressing techniques forresidue trucks (93).
Comminution at a terminal
Comminution at a terminal is a compromise be-tween comminution at a landing and at the plant.Biomass is hauled uncomminuted to the terminalfor size reduction, and then transported to the plantas chips.
If the network of terminals is dense, the distancefrom the logging site to the terminal remains short.The system does not differ much from the tradi-tional option where comminution is carried out at alanding. Vapo Oy has developed an operation pat-tern where the farm tractor-diven HavuHukkatrailer is used first for off-road transport from log-ging site to road and, subsequently, for on-road
36
Figure 33. Loading unprocessed logging residues into a biomass truck (Metsäteho).
transport to a terminal over a distance less than 10km (81). The load capacity of the trailer is in-creased with an enlargening load space which canbe compressed (Figure 34). The system is not gain-ing ground, as it lacks flexibility.
If a fuel producer operates only few terminals andthey are located far from the biomass sources,off-road transport with a forwarder and on-roadtransport with a truck are separate operations. Thesize of the terminal is larger, and the system doesnot differ greatly from comminution at plant. Theterminal may be paved, and the use of a crusher ispossible. Large terminals are operated by BiowattiOy at Janakkala and Hyötypaperi Oy at Valkeala.
A terminal is a tool for controlling the procurementprocess. Biomass can be stored at the terminaluncomminuted and processed during the winterseason when the demand for fuel is high and work-ing conditions at the forest end are difficult. The ar-rangement makes it possible to apply baling tech-nology for supplying forest chips to small plantsthat do not have a stationary crusher.
5.2 Production organizations
The availability of fuel must be ensured in all con-ditions irrespective of weather, equipment failure,labour disputes or depression in the markets of for-est products. Insecurity of fuel supply was a barrierto the use of forest chips in large plants in the late1990s.
The supply of fuel has to be robust. In the case offorest fuels, proving the robustness of supply is adifficult task, because the fuel is collected from alarge number of harvesting operations, fuel inven-tories are small, and working conditions are unfa-vourable during the peak demand in mid winter.
The majority of forest chips are derived from log-ging residues from industrial timber harvesting. Itfollows that fuel and raw material should be har-vested as integrated operations. This is possibleonly if the forest industries are motivated to do so.In Central Europe, the forest industries are con-cerned about a possibly undesirable effect of forestfuel markets on the availability and price develop-
37
Figure 34. Load-compacting HavuHukka forwarder for transporting logging residuesfrom stump to satellite terminals (Vapo).
ment of pulpwood. Conversely, the Finnish forestindustries see many reasons for being actively in-volved and for adopting a pioneer role, because:• Demand for small-sized wood results in im-
proved silviculture and increases the long-termyield of industrial wood
• Removing excessive biomass residues is atrump card in the timber trade because it bringsindirect silvicultural advantages to the forestowners
• Traditionally, the forest industries control theraw material flow, and so it is natural that theyalso wish to control the fuel flow, since the gen-eral trend is for the integration of operations
• Renewable energy enhances the green image ofthe forest industries – an advantage in exportmarkets
• Harvesting biomass residues may provide moreeven employment for contractors. Energywoodharvesting takes place in the summer time whenthe cutting of industrial timber is at a minimum
• Forest chip production is becoming a profitablebusiness due to green certificates and CO2 emis-sions trading in the EU.
There are three large forest industry enterprises inFinland: UPM, Stora Enso and Metsäliitto-
Yhtymä. They all have an advantage over otherfuel producers in the access to biomass sources ofprivate forests in conjunction with the normal tim-ber trade. The fourth major actor is Vapo, the lead-ing producer and developer of technology of fuelpeat. Each of them has organized the production offorest chips in its own way:• Metsäliitto-Yhtymä. The forestry department of
this concern is responsible for the purchase andharvesting of biomass. At the road side, the bio-mass is handed over to a subsidiary company,Biowatti, which is responsible for comminutionat the road side and delivering of the fuel to thecustomers. In 2003, the wood fuel deliveries ofBiowatti amounted to 4 TWh. Forest chips alonecorresponded to 1 TWh, and together with pel-lets they were the fastest growing assortment inthe company’s fuel selection (Figure 35).
• UPM. The procurement of forest chips belongsentirely to the company’s forestry department,and it is integrated with the procurement of in-dustrial raw material. In 2003, the production offorest chips was 1 TWh, most of which was de-livered to CHP plants owned by PohjolanVoima. Five of these plants are equipped with astartionary crusher for comminution of residuelogs and stump and root wood.
38
TWh / annum
0.5
1.0
1.5
2.5
2.5
3.0
3.5
4.0
1994 1996 1998 2000 2002
Forest chipsIndustrial chipsSawdustBarkOtherPellets
Figure 35. Wood fuel deliveries of Biowatti.
• Stora Enso. Compared to the volume of timberharvesting, the scale of forest chip production ismodest. The company’s forestry department isresponsible for production, which amounted to0.1 TWh in 2003.
• Vapo. As a peat producer Vapo lacks a forestrydepartment and direct access to biomass sources.Synergy is sought by integrating wood fuel pro-curement with the peat business. Vapo is also apellet producer and an owner of heating andCHP plants.
These four companies control three quarters of thecommercial production of forest chips. Strong ac-tors are creating the foundation for a robust supplyregime. They can benefit from the large scale andthe logistics systems available. However, as a largepart of the chips is actually used by these producersthemselves, competition is reduced.
Instead of working as contractors for the largecompanies, some forest machine and truck entre-preneurs act as independent fuel producers, eitheralone or through a network. Because of the smallsize of the enterprises, they operate only locally.Nevertheless, they have a positive effect on compe-
tition in the field. The Trade Association of FinnishForestry and Earth Moving Contractors encour-ages its members to sign independent chip deliverycontracts by promoting networking (78). TheWood Energy Programme examined possibilitiesto use an internet-based information and marketingsystem to promote the mobilization of the small-tree reserves of young thinning stands, and to im-prove the operating environment of small local fuelproducers (35, 37). Kotimaiset Energiat Ky, Metsä-energia Ky (Figures 36 and 37) and LähienergiaOy are pioneers among the independent chip entre-preneurs in Finland.
In addition to the fuel producers mentioned above,172 small heat entrepreneurs operated in Finlandat the end of 2002. They were either private per-sons such as farmers, or co-operatives or limited li-ability companies that were responsible for bothfuel supply and heating of rural buildings, and theywere paid for the heat rather than fuel. The averagesize of a boiler was 0.48 MW. The total capacity ofthe boilers was 83 MW, the annual consumption offorest chips 80 000 m3, and the turnover 5 M€ (54,86).
39
Figure 36. Moha chipper-truck unloading at a small heating plant (TradeAssociation of Finnish Forestry and Earth Moving Contractors).
5.3 Production logistics
Production logistics refers to the control of fuelflow from stump to plant. Developing the logisticsis aimed at improving the operational availability,rather than the technical availability, of machinesdeployed by a fuel procurement system.
The majority of the procurement costs is caused byterrain and road transport. Therefore, the core offorest chip logistics is in the control of transporta-tion. Converting the biomass into transportableform with a chipper, crusher or baler also is an es-sential part of the logistics system, as chips have tobe loaded directly from a chipper into a truck orcontainer. The link between the chipper and thetruck is the Achilles heel of the traditional technol-ogy. For a number of reasons, the large-scale pro-duction of forest chips is a demanding task fromthe viewpoint of logistics:• Biomass has to be collected from a large num-
ber of timber sites. Conditions of harvesting andstorage at the road side are directed by the indus-trial timber, since biomass is only a low-valuebyproduct from industrial logging operations.Obtaining of biomass is difficult for a fuel pro-ducer who does not participate in the harvestingof pulpwood and sawlogs.
• Small size of sales. The yield per site is low. Thismeans the frequent moving of machines fromsite to site, guiding contractors to new sites, andthe underutilization of truck capacity.
• Scattered location of work sites. Varying dis-tance to the plants continuously changes the pro-ductivity ratios between the subsequent opera-tions in the system. Issues such as the concentra-tion of work sites, scheduling trucks, and ex-change of raw material between fuel producersmust be given due attention.
• Variation of biomass properties. The raw mate-rial base is composed of small trees, logging res-idues, and stumps and roots. Each biomasssource may require the use of specific machines,and each source produces a different kind offuel. The variation of chip properties must belevelled.
• Change in quality. Comminuted wood fuels de-teriorate rapidly during storage, whereas thedrying and purification of uncomminuted stumpand root wood in piles improves the quality. Theform and duration of storage have to be designedto ensure the quality of chips.
• Small inventories. Due to the risk of quality loss,buffer storages of forest chips tend to be small.For the peak season in winter, biomass is stored
40
Figure 37. Valtra farm tractor-based residue forwarder of Metsäenergia with enlargeningload space (TTS Institute).
at the road side or at terminals in an uncom-minuted state.
• Blending of fuels. The supply of forest chips isseldom sufficient to meet the fuel needs of alarge plant. Therefore, forest chips are cofiredwith bark, sawdust and peat. For the useabilityof the plant, efficiency of combustion and con-trol of emissions, it is important to keep the fuelblend constant (49). The arrivals of fuel trucksmust be scheduled accordingly.
Achieving the benefits of the economy of scale isnot, therefore, a simple task. However, the integra-tion of fuel production in the timber procurementorganizations of the forest industries creates manyadvantages in the purchase of biomass, the use ofinformation systems, knowledge of local condi-tions, the use of existing equipment when appro-priate, and in the supervision of work.
The Wood Energy Programme placed strong em-phasis on the development of logistics. Movingcomminution to a plant or terminal was found to bean effective measure for enhancing the reliabilityof the procurement system. Residue bales help to
smoothen the logistics: the system becomes lessvulnerable, waiting times between machines areeliminated, winter storage is facilitated and the en-tire process becomes easier to control (70, 71, 94).The current baling technology is only suitable forlarge-scale operations, and a precondition is acrusher at the plant. The crusher makes it possibleto receive stump and root wood as well, and the rawmaterial base and fuel supply are consequentlybroadened. Large 150 m3 truck-and-trailer vehi-cles have been built to transport loose logging resi-dues, residue bales, undelimbed tree sections andstump and root wood to the plant, separately ormixed (Figure 38).
It nevertheless remains more common that forestfuels arrive at a plant as chips. If the distance isshort, the landing site crowded or reception at aplant limited, the truck does not use a trailer. Themaximum load volume is then 60 m3. Otherwisethe truck is equipped with a trailer and the load vol-ume is typically 100–130 m3. In one of the pro-jects, it was found that compared with blowing ofchips into the truck, the use of a belt conveyorequipped with a mechanical ejector increased the
41
Figure 38. Hauler truck of a 150 m3 truck-and-trailer unit for transportinguncomminuted biomass. The extendable trailer is not in the picture (Kome)
bulk density and reduced the consumption of en-ergy (74).
Queuing of fuel trucks is an unnecessary cost factorwhich should be eliminated. Queuing may occur atlarge plants especially in cold winter weather whenthe need for fuel is high. The peak time of arrivalsis typically in the morning. To avoid queuing, bot-tlenecks should be removed from the receivingsystem, and the arrivals should be scheduled.
The use of an internet-based, general-purpose lo-gistics control system applying mobile terminalswas studied in the programme. Among the aspectsinvestigated were vehicle control and terminal lo-gistics, navigation of vehicles, work planning, andinstructions for deliveries by internet to mobile ter-minals. The advantages mentioned by the partici-pants of the project included paper free truck cabin,decrease of cellular phone calls, and GIS/GPS sup-ported navigation. Technology should be devel-oped further to support the whole business processof the truck entrepreneur so that the informationneeded in planning, operative work and invoicingcould be monitored by the system (74, Figure 39).
5.4 Production equipment
In 2001, about 44 mill. m3 of industrial wood washarvested from the Finnish forests, the deliverysales of self-employed forest owners excluded.The equipment used by different contractors isfully compatible, allowing for organizational flexi-bility.
Unfortunately, little machine compatibility hasbeen achieved in the procurement of forest chips,even though the annual production remains lessthan 2 mill. m3, small-scale use excluded. The lackof compatibility is because the logging conditionsvary from the early uncommercial thinning ofyoung stands to the final harvest of mature stands,and because the technology is still new. Several al-ternative production systems are in use, and eachsystem employs special equipment that is not nec-essarily compatible with other systems. This diver-sity causes problems in practice:• The contractors’ flexibility is restricted and in-
vestments become risky when technology pre-vents changing from one system to another.
42
Figure 39. An internet-based logistics system helps to control the fuel flow (Biowatti).
• Machine markets are fragmented, manufacturein series is not possible, and machine prices re-main high.
Whenever possible, it is preferable to use conven-tional equipment for the harvesting and transporta-tion of forest biomass. However, special equip-ment is needed in many phases of the chain, andthey were given an important role in the Wood En-ergy Programme. Although the system approachwas central to the programme, some projects fo-cused on narrower topics with the aim of develop-ing and demonstrating new machine solutions andremoving specific bottlenecks in a system. Resultsfrom these product development projects are asfollows:• The Kome biomass truck is designed specificly
for transportation of stump and root wood, but itis also suitable for logging residues and residuelogs. The load volume is up to 150 m3. The totallength of the truck and trailer is 25 m. The traileris extendible to enable the crane to reach the rearof the trailer when loading and unloading. Theload space also has walls made of special steel(Figure 38).
• Pika Loch 2000 is an 8-wheeled terrain chippermanufactured by S. Pinomäki Ky. The cabin isleveled automatically and slews 330 degrees.The weight is 23 tons, including the 10-m-reach
Loglift 71 FT 100 crane, the Bruks 604 CT drumchipper with a 60 x 36 cm feed opening, and 20m3 chip space. Unloading takes place from 4.2 mheight, and so it is not necessary to lower atruck’s chip containers to the ground for loading(Figure 40).
• The TT-97RM made by Heinola Sawmill Ma-chinery is a medium-sized drum chipper with a90 x 40 cm feed opening. It is designed primarilyto operate at landing sites and small satellite ter-minals. The basic model is equipped with abogie axle, and it is driven by a 100–140 kWfarm tractor (model TT-97RMT). The weight is7.5 tons without the tractor. It can also bemounted on a truck (model TT-97RML). Thepower source is then a 225–375 kW auxiliaryengine, or the engine of the truck.
• The truck-mounted Giant chipper from LHMHakkuri is designed to operate at landing sites.The power source is a 367 kW auxiliary engine.The reach of the Loglift 95 crane is 10 m. Thedrum chipper has a 140 x 60 cm feed opening,and it can be fed from both sides. It is equippedwith a litter screw for salvaging loosened finematerial from the feeding table. The total massof the unit is 32 tons. High efficiency makes theGiant chipper suitable for large-scale opera-tions, but flexible mobility allows also shuttlingand small-scale chipping on farms (Figure 41).
43
Figure 40. Pika Loch 2000 terrain chipper (S.Pinomäki Ky).
• The Sisu chipper truck performs both chippingat the landing and transportation of chips to thecustomers. As the same unit carries out two sub-sequent work phases, the production chain re-mains cool. The base components are the SisuE14 truck, the Loglift 75ZT crane, the TT-
97RMS drum chipper from Heinola SawmillMachinery, three chip containers with a total ca-pacity of 100 m3, and Multilift LHS 260.5 sys-tem for moving the containers. Seven Sisu chip-per trucks worked for Biowatti at the beginningof 2004 (Figure 42).
44
Figure 41. Truck-mounted Giant chipper (LHM Hakkuri).
Figure 42. Sisu chipper-truck (Biowatti).
• The Timberjack 1490D residue baler is used forbaling logging residues and small-sized trees inclear-cut areas. The total mass, including the10-m-reach crane, is 32 tons. The revolving bal-ing device is fed from the side. The bale isformed by compressing and tieing with cord.The process is continuous, and the bales arecross-cut with a chainsaw, normally to 3.2 mlengths to fit ideally with the measurements ofthe vehicles used for transportation. The struc-ture of the base machine is designed for workingin terrain, but one baler has been mounted on atruck for Central European conditions. At thebeginning of 2004, altogether 27 balers were inoperation, 20 of them in Finland (Figure 43).
• Driven by logistic advantages and improved re-liability of fuel deliveries, baling technology hasdeveloped rapidly, and new manufacturers haveappeared. For example, S. Pinomäki Ky has de-veloped RS2000 residue baler, which is mountedon Pika Combi 828 harwarder. The 21 ton unitcan be converted easily to forwarder for theoff-road transportation of the bales (Figure 44).
• Timberjack 720 and 730 accumulating fellingheads allow the multi-tree handling in young
stands. Any harvester suitable for thinning, suchas Timberjack 770, may act as the base machine.The felling head replaces the conventional har-vester head. Trees are cross-cut by shearing, themaximum stem diameter being 20 cm for theformer and 30 cm for the latter. The feller-headautomatically collects several small trees at atime to reduce the movements of the crane and toimprove productivity. The two felling headsweigh 340 and 620 kg respectively (Figure 45).
• The fuel receiving systems of BMH Wood Tech-nology, when a crusher is included, are capableof handling all kinds of forest fuels. AlholmensKraft’s power plant has a rapidly rotating sta-tionary Saalasti Crusher with 180 x 120 cm feedopening, powered by two 500 kW engines. Thecapacity is 160 m3 loose/h. Jämsänkoski powerplant has a slowly rotating 2-drum ECO Crusherwith a 330 x 420 cm feed opening. The capacityis 50–180 m3 loose/h, depending on the proper-ties of the biomass. Figure 46 shows the fuelhandling system of Kymin Voima. The powerplant does not have a crusher, and therefore theforest fuels have to arrive as chips.
45
Figure 43. Timberjack 1490D residue baler mounted for a truck for Central Eu-ropean conditions (Timberjack).
Although the Wood Energy Programme is ending,Tekes’ support for product development will con-tinue. Among the machines under development are
stump harwarders for combined uprooting, split-ting and forwarding stump and root wood with asingle wheeled machine (69).
46
Figure 44. RS2000 residue baler mounted on a Pika Combi harwarder(S.Pinomäki Ky).
Figure 45. Timberjack 770 harvester equipped with the accumulatingTimberjack 730 feller head for small-tree operations (Timberjack).
5.5 Buffer and security storage
A fuel delivery system must be designed to over-come both anticipated and unexpected distur-bances. The larger is the flow of forest fuels, andthe higher is their share in a plant’s fuel blend, themore important are the precision and reliability ofthe deliveries. Disturbances may occur for manyreasons:• The need for fuel increases during the winter
season, but then ice and snow hamper chip pro-duction and may lead to the breakdown of ma-chinery
• The availability of bark, sawdust, and residuesfrom final felling suffers in times of economicdepression in the sawmill industry. The produc-tion of processing residues is also reduced dur-ing holidays.
• Small fuel delivery organizations that are basedon a single machine chain are particularly vul-nerable to illness, labor disputes or machinemalfunction.
• Excessive moisture content of chips causes aloss in efficiency and an increase in emissions.
Storage can be used for decreasing and levelingthe moisture content.
• Disturbances may occur in the global markets offossil fuels and electricity.
As long as the use of forest chips was only experi-mental and took place on a small scale, this prob-lematic was essentially theoretical. Rapid in-creases in the use of wood fuels is changing the sit-uation. As the system’s resistance to shocks can bestrengthened by means of buffer storage, the needfor storage was studied in the programme (72).
Short-term buffer storage is aimed to secure con-tinuous fuel supply at night, during weekends andholidays, in extreme weather conditions, and incase of machine breakdowns. For comminutedbiomass, the volume of the storage pile or silo isdetermined by the energy density of chips, 0.7–0.9MWh/m3 loose.
Seasonal storage aims at controlling the moisturecontent of forest fuels that are to be burnt in thewinter time, and to move work from difficult win-
47
Figure 46. Fuel receiving and handling system of Kymin Voima (61).
ter conditions to easier summer ones. Since forestchips deteriorate during storage and the loss of drymatter amounts to 1–3 % per month, only un-comminuted biomass is stored over periods of sev-eral months (Figures 47 and 48). The need of dis-trict heat is seven times greater in the winter than inmid summer.
Long-term security storage is fixed by law for fos-sil fuels, but no statutory obligations have beenprescribed for indigenous fuels. Nevertheless, innormal conditions the inventories of fuel peat arelarge enough to cover the consumption of an entireyear. As long-term storage of wood fuels is notpossible on a large scale, shortages are normally
48
Figure 47. Road side storage of small trees for the winter season (Biowatti).
Figure 48. Road side storage of residue logs for the winter season (VTT).
compensated with peat. Consequently, large CHPplants seldom rely on wood fuels alone. They areprepared to receive, handle and co-combust woodand peat, and the fuel blend can be changed accord-ing to conditions. In countries were peat is notavailable, wood can be co-combusted with coal orother locally available fuels.
5.6 Receiving and handling
Wood fuels differ from peat and coal with respectto their handling properties, such as particle sizedistribution, bulk density, moisture content andfluidity. Differences also occur amongst the woodfuels. For example, forest chips and debarking res-idues behave differently. Diversity and variableproperties of wood fuels must be given proper at-tention in planning. Unfortunately, this is not al-ways recognized.
Receiving, handling, blending and feeding woodfuels are problematic where the plant is not pre-pared for the special properties of chips and chiptrucks. As these operations are an essential func-tion of a forest fuel production system, they weregiven an important position in the Wood EnergyProgramme (34, 61, 62). The following topicswere addressed:• Development of inbound logistics of arriving
chip trucks in order to reduce the time used forqueuing and unloading.
• Modifying plants designed for peat trucks un-loading sidewards to accept chip trucks unload-ing backwards.
• Making a homogenous blend from a variety offuels. Blending is usually performed at the re-ceiving station of the plant, but it may also takeplace in conjunction with intermediate fuel stor-age when loading or unloading silos.
• Modifying handling equipment, such as discscreens and conveyors, to cope with chips con-taining over-sized particles, impurities and ex-cessive moisture.
• Developing comminution of forest biomasswith high-capacity stationary crushers at theplant.
Proportioned to the boiler capacity of a plant, theinvestment for the receiving and handling system
is roughly 20 000 €/MW at the district heatingCHP plants and 30 000 €/MW at the industrialCHP plants, i.e. about 9 % of the total investmentof a new plant. This proportion is increasing ratherthan decreasing in order to remove bottlenecks andimprove the useability of the plant, as well as tohandle uncomminuted wood fuels (Figure 49). Thefollowing findings are based on a survey of the bot-tlenecks in fuel handling at large CHP plants (39).
A receiving station must apply technology that en-ables fast and undisturbed unloading of fuel trucks.The system should be scaled to handle materialswith a low energy density. For forest chips, theminimum capacity is 3 m3 loose/h/MW of fuel ca-pacity of the boiler. If the receiving capacity is in-sufficient, the unloading time of trucks increases,resulting in queuing and additional costs.
A stationary crusher should be capable of com-minuting all kind of biomass delivered to the plant:loose and baled logging residues, undelimbedtree-sections, recycled wood, and stump and rootwood. The cost of investment is 1–2 M€, and there-fore only large plants can afford a crusher. Onlyfive CHP plants were equipped with a stationarycrusher in 2003.
A disc screen, and crusher for reducing the over-sized particles from screening to an acceptablesize, are required to improve the fluidity of the fueland prevent breakage and blockage of conveyors.Small heating plants do not always have a screenand an accompanied crusher. This forces them touse high-quality chips and pay a higher price.
A buffer storage is required to ensure the fuel sup-ply during weekends etc. It may be a rectangularA-building, circular silo or open field. Coveredchip stores are typically large enough for 10–20hours’ consumption.
Experience has taught that due consideration mustbe given to the properties of forest chips and thespecific demands of the fuel trucks. The fluency offuel deliveries and useability of the plant will oth-erwise suffer. When old technology is replaced, ora greenfield plant is built, participation of theforthcoming chip procurement organization in theplanning is essential. Since the mid-1990s, a large
49
number of heating and CHP plants have been refit-ted with the technology required to use forestchips. This has greatly increased the utilization ca-pacity of forest fuels in Finland.
5.7 Production costs
While fossil fuels occur in large deposits and canbe produced at a constant cost, forest fuels are scat-tered and must be collected from a large number oflocations. Technical logging conditions varywidely, and the variations are reflected in the pro-ductivity and cost of work.
Knowledge of the cost factors of forest chip pro-duction has been vague. When the Wood EnergyProgramme was established, this lack of elemen-tary knowledge was a serious shortcoming fromthe viewpoint of technology development. The ef-fect of factors such as stand conditions and haulingdistances should be known in order to:• Identify the most advantageous stands for chip
production• Estimate the change in the cost when the de-
mand for chips increases or when the quality re-quirements of the fuel are tightened
• Focus on the key problems in machine andmethod development
• Collect basic knowledge needed by decisionmakers who direct subsidies to the production offorest chips.
The effect of cost factors associated with the oper-ating environment depends on the scale of opera-tion, the technology applied, the source, and thequality requirements placed upon the biomass. Ex-amples of the findings of the programme are (3, 6):• The cost of recovery depends on the yield of bio-
mass per hectare. The recovery of logging resi-dues from the final cut of mature spruce stands istypically 20 % of the recovery of roundwood.For pine, the corresponding figure is little morethan 10 %. Halving the recovery raises the costof off-road transport by 10 %. The cost of har-vesting is thus lowest in spruce-dominatedstands, and the availability of forest fuels is mostabundant in regions where spruce is the domi-nating species.
• The proportion of foliage in logging residuesfrom mature stands is 30 % for spruce and 20 %for pine. The yield of chips decreases if the resi-dues are left to season on the site to defoliate so
50
Figure 49. Fuel receiving and handling system of Jämsänkoski power plant (VTT).
as to improve the quality of fuel and reduce theloss of nutrients from forest soil. The reductionin biomass recovery, the delay in the harvestingschedule, and accompanied logistical disadvan-tages raise the cost of procurement,
• If a plant’s demand for logging residues in-creases, the average cost of procurement in-creases as well, because the operations must beextended to less favourable stands and at greaterdistances. Considerable regional differences inthe availability and costs arise from differencesin the structure of forests and species domi-nance.
• The small size of timber sales from private forestholdings is also a serious cost factor. Proper tim-ing and coordination of operations with neigh-bouring holdings could increase the harvestablefuel in a region by more than 10 % and reducethe average costs by 4 to 6 % (82).
A significant gap exists between cost of fuel fromthe early thinnings and that from final cuttings.The gap is caused by the high cost of cutting andbunching of small-sized trees from thinnings,whereas in the other phases of the procurementchain cost differences are modest. If no stumpageis paid, the cost level is 10 €/MWh for logging resi-due chips and 15 €/MWh for whole-tree chips(Figure 50). The former meets the solvency of theusers, but the latter exceeds it by some 5 €/MWh.This is why whole-tree chips are subsidized butlogging residue chips are not.
Average costs may be misleading, since costs varyconsiderably. Figure 51 shows how a single pro-ductivity factor, stem volume, affects the cost ofcutting and, consequently, the cost of the entireprocurement chain. The effect is steeper in mecha-nized than in manual cutting.
Production costs and chip prices should not be con-fused. A goal of the Wood Energy Programme wasthe reduction of costs, not necessarily a reductionof prices. Cost reduction leaves room to ma-noeuvre in less favourable stand conditions, im-proves the profitability of forest machine enter-prices, and makes it possible to pay stumpage toforest owners. Price reduction tends to have a re-verse effect, although it improves the competitive-ness of chips against alternative fuels.
The average market price of forest chips decreasedin the 1990s, partly because of a shift fromwhole-tree chips to logging residue chips. The lowpoint was reached in 2000, since when the averageprice has increased by almost 20 %. This happeneddespite the development of technology and logis-tics, as the increasing use of wood fuels forced theproduction organizations to extend their opera-tions to more difficult and distant stands (Figure52). The price paid by small heating plants is alsoabove the average because of their stricter qualityrequirements.
51
2
4
6
8
10
12
14
16
Logging residuechips
Whole-treechips
OverheadsTruck transportChipping and landingOff-road transportCutting
Cost, / MWh€
10
15
Figure 50. Cost structure of forest chips from logging residues andsmall whole trees.
Although the prices of wood fuels are increasing inFinland, they are still substantially below theSwedish level. During the third quarter of 2003, theaverage price of forest chips at a Swedish heatingplant was 14.2 €/MWh (130 SEK/MWh), valueadded tax excluded, or 39 % higher than in Finland
(9). Fossil fuels used for heating are taxed moreheavily in Sweden, and therefore the price level ishigher. In Finland, the lower prices are explainedpartly, but not entirely, by lower stumpage prices ofbiomass, investment aid for production machinery,and production support for small-tree chips.
52
CuttingOff-road transportChipping at landingTruck transportOverheads
Mechanized cuttingManual cuttingCost, / MWh€
20
15
10
5
5045403530252015105 5045403530252015105Stem volume, dm3 Stem volume, dm3
35
30
25
20
10
5
40
15
Figure 51. Cost structure of whole-tree chips as a function of stem volume (5).
Bark Sawdust Forest chips
Price, /MWh€
5.5 5.3
11.0
6.0 6.3
8.8
5.96.5
8.6
6.8 6.9
9.0
7.67.1
9.4
2
4
6
8
10
12
1995 1999 2000 2001 2002 19951995 1999 2000 2001 2002 1999 2000 2001 2002 2003*
10.2
Figure 52. The price of solid wood fuels at the plant, excluding VAT (19, 103, 8).
6 Quality control of forest chips
The quality of forest chips is dependent upon thesource of the biomass and the techniques em-ployed for comminution, handling and storage.Consistent particle size, low contents of moistureand foliage, and low ash production improve theuseability of the plant and efficiency and economyof combustion.
Different boilers demand different fuel properties.The larger the plant, the more tolerant it usually isof random variations in fuel properties. Even so,knowledge of fuel properties and careful control ofquality are essential to the operational reliabilityand efficient combustion of all boiler systems,large CHP plants included. The role of quality be-comes more pronounced as the production of forestchips increases.
Problems may occur when a peat-fired plant startsto use chips (89). Such problems are solved by re-arranging the fuel handling system, limiting theproportion of forest chips in the fuel blend, or bymeans of quality control that must be extended toall phases of fuel procurement, starting from standselection. Very little can be done after the fuel hasarrived at the plant.
The quality of chips is affected by many propertiessuch as moisture content, heating value, energydensity, foliage content, ash content, specific emis-sion of CO2, and particle size. It is not only the av-erages that matter. Perhaps even more important isthe random variation of properties. Variation oc-curs within a truck load, between truck loads, andaccording to the season. An important goal of qual-ity control is to reduce such variations.
The Wood Energy Programme contained severalprojects that dealt with chip quality issues. Exam-ples of these projects are listed below. Some ofthem deal with processing residues from forest in-dustries:
• Quality control of logging residues and small di-ameter trees by means of seasoning (27, 28)
• Critical properties of wood fuels with respect toboiler corrosion and power plant useability (31,66, 67, 68)
• Chemical changes in wood fuels during storageand thermal drying, and the effects of thechanges on fuel properties, occupational healthhazards and emissions during storage (10, 11)
• Flue gas emissions from co-firing by-productsfrom the plywood and particle board industries(96)
• Improving the combustion properties of bark:reduction of moisture content prior to storage,removal of impurities, and optimizing storage(Section 8.2)
• Improving the particle size of chips throughchipper development (79)
• Suitability of small-diameter wood for pulping,and establishing boundaries between pulpwoodand fuelwood (36, 42)
• Effect of radioactivity of wood fuels on the useof ash (97).
6.1 Moisture content
The most important single quality factor is themoisture content of chips. Moisture content is a di-rect cost factor, and it is taken into account in thepricing of the fuel. An excessive moisture contentresults in a price reduction, while a low moisturecontent brings a bonus. It affects the heating value,storage properties and transport costs of the fuel:• Effective heating value. Vaporization consumes
0.7 kWh heat energy per a kilogram of water. Ifthe moisture content of fresh softwood is re-duced from 55 % to 40 %, the initial amount ofwater is reduced by half, and the effective heat-ing value increases 8 %
• Efficiency of combustion. Moist wood tends tocombust incompletely, and a part of the heat en-ergy of the fuel is then lost. This is a problem
53
particularly in small boilers where the tempera-ture remains too low if the fuel is moist
• Emissions. Incomplete combustion results in in-creased emissions of carbon monoxide, hydro-carbons and fine particles
• Storage properties. Chemical and biochemicalreactions take place during the storage of chips,particularly if the biomass contains active nutri-ent-rich material such as foliage. Dry matter losscan be avoided only when the moisture contentis less than 25 %
• Handling problems. In winter, moist chips mayfreeze in a truck load or silo causing blockagesand damage to the fuel handling system of aplant.
Large plants are more tolerant of high and variablemoisture content of chips, because they apply FBCtechnology and co-combust chips with peat. Any-how, excessive moisture content strains the energyefficiency even of a large plant. The moisture con-tent of wood fuels should not be too high, and itshould not vary randomly from load to load.
The moisture content of fresh biomass must be re-duced in order to obtain the full energy potential.Moisture is a critical fuel property, especially in thewinter time, as a reduction in the moisture contentoccurs only during the summer. Maintaining thereduced level of moisture during the autumn rainsrequires the careful planning and timing of opera-tions. During recent years, the procurement orga-
54
10
20
30
40
50
60
1 2 3 4 5 6 7 8 9 10 11 12
100
200
300
400
500
1 2 3 4 5 6 7 8 9 10 11 12
10
20
30
40
50
Month / 2001
M.C.%
Waterkg / m3
Moisture content, %Large power plants, average 48.3 %
Small heating plants, average 38.4 %
Large power plants, average 392 kg/m3
Small heating plants, average 262 kg/m3
Figure 53. Monthly variation of the moisture content of forest chips in 2001.Averages of 4 large power plants and 7 small heating plants (33).
nizations have managed to achieve greater controlof the moisture content, and truck loads of chipswith an excessive 55–60 % moisture content are nolonger common. Nevertheless, energy is still lostbecause biomass arrives at the plant with an excessof moisture.
A common goal is to maintain the moisture contentof forest chips below 50 % at large plants and be-low 40 % at small plants. In 2001, average mois-ture contents remained considerably below thesetarget limits during the summer, but during thewinter the limits were exceeded slightly. The an-nual average was 48 % and 38 % for large andsmall plants respectively (Figure 53).
6.2 Other fuel properties
Energy density refers to the amount of energy perunit volume of load space in a truck or storage pile.The energy density of wood fuel is determined by:• The basic density of wood, bark and needles (kg
dry mass/m3 solid). It is typically 450–500 kg/m3
for small-sized birch and 370–410 kg/m3 forother tree species in Finland. The lowest basicdensity, only 270 kg/m3, is found in pine bark
• Effective or lower heating value (kWh/kg fuel)depends on the chemical content and moisturecontent of wood. Lignin has a higher heatingvalue than carbohydrates, and softwoods there-fore have a higher heating value than hard-woods. However, the effect of moisture contentis stronger than the effect of wood properties(Figure 54)
• Bulk density (m3 solid/m3 loose) refers to the ra-tio of solid and loose volumes of fuel. For exam-ple, the bulk density of uncomminuted loggingresidues is 0.15–0.20, but comminution raises itto 0.36–0.46. The common conversion factor forforest chips is 0.40. Compressed residue logshave about the same bulk density as chips in atruck load.
In 2001, the average energy density of forest chipsarriving by truck at large power plants was 0.77MWh/m3 loose. Variations in moisture contentcaused seasonal fluctuations (Figure 55).
Compared with other fuels, the space requirementof forest fuels is large (Figure 56). Forest chips aretherefore typically a local fuel. If internationaltrade of forest fuels becomes common in the futureand forest fuels are transported over long dis-
55
Heating value, MJ/kg
20
15
10
5
20 40 60 80
Moisture content, %
Lower heating valueper total mass
Lower heating valueper dry mass
Higher heating valueper dry mass
Freshforest chips
Dry forestchips
Wetbark
Figure 54. The effect of moisture content on the effective heating value of wood.
tances, it may become profitable to refine biomassinto pellets or liquid fuels.
Forest chips may contain large quantities of nee-dles. If no needle loss takes place in conjunctionwith harvesting, the proportion of needles inwhole-tree chips is 5–9 % for pine and 10–18 % forspruce. In logging residue chips the correspondingshares are 15–20 % for pine and 20–35 % for
spruce. Although twigs and needles are shed at var-ious phases of the procurement process, needlesstill remain a nuisance in the combustion process.
The contents of metal alkaloids and chlorides inneedles are unusually high. Depending on thecombustion conditions, the alkali metals can be ox-idized or they can form sulphates or chlorides. Ifonly wood chips are burned, the sulphur content is
56
1 2 3 4 5 6 7 8 9 10 11 12
Month / 2001
Large power plants, average 0.77 kg/m3
0.6
0.7
0.8
0.9
Energy density MWh / m loose3
Figure 55. Monthly variation of energy density of forest chips in 2001.Averages of three large plants (33).
5
10
15
20
25
30
Space requirement, m / toe3
Oil Coal Sodpeat
Milledpeat
Woodpellets
Birchbark
Loggingresiduechips
Pinebark
Residuelogs
Loggingresiduechips
Looseloggingresidues
Fres
h
Dry
Wet
Fres
h
Fres
h
Fres
h
Figure 56. Space requirement of selected fuels in truck transport.
low and chlorides are formed. The chlorides thentend to condense on heat transfer surfaces of theboiler, slowing down the heat transfer and causingthe risk of high-temperature corrosion. If the sul-phur content of the fuel is increased, e.g. by blend-ing peat with chips, sulphates are formed instead ofchlorides, and the risk of corrosion is avoided. Un-less the needle problem in combustion is solved,forest chips cannot be allowed to have a high nee-dle content. Reducing the amount of needles slowsdown the procurement process causing friction inthe logistics and increased costs. This topic wastherefore given considerable emphasis in theprogramme (65).
The content of ash is less than 0.5 % in woodproper, but in bark 6–7 times and in foliage 6- 11times as much. The content of pure ash is thusabout 1 % in whole-tree chips and 2 % in loggingresidue chips, or 4–6 kg/m3 and 8–12 kg/m3 fuelrespectively. In practice, the yield of crude ash ishigher, as forest chips contain impurities such assand, and the ash may also contain char. Since ashcauses costs and landfill problems, biomass shouldbe as clean as possible when harvested. This is fa-cilitated by the use of load-carrying forwarders foroff-road transport, a characteristic feature of theNordic logging technology. In countries wheretrees or stems are dragged to road side with askidder, the biomass is soiled and the yield of crudeash tends to be higher. In Finland, the amount ofimpurities is especially high in stump and rootwood.
The specific emission of CO2 of a fuel indicates thegeneral level of emissions that are produced incombustion. The combustable elements are carbonand hydrogen. In complete combustion carboncombines with oxygen releasing energy and car-bon dioxide, and hydrogen combines with oxygenreleasing energy and water. From the viewpoint ofclimate change it is of great significance whetherthe energy is derived from carbon or hydrogen. Ifthe carbon to hydrogen ratio of a fuel is high, theamount of CO2 emissions is also high.
For different fuels the specific emission of CO2 isas follows: natural gas 202 g/kWh, heavy fuel oil277, coal 342, peat 382 and wood of 40 % moisturecontent 396 g/kWh. However, if the biomass is aproduct of sustainable forestry, carbon circulatesin a closed system without increasing the carbondioxide content of the atmosphere. Under theseconditions, biomass is almost a carbon-neutralfuel, as only the fuel and lubricants used in the pro-curement cause CO2 emissions. The input/outputratio of energy is low 1:30 (58). In conditions ofemission trade this is a huge advantage, as CO2
emissions from fossil fuels become liable tocharge.
57
7 Use of forest chips
Wood fuels play an important role in Finland’s en-ergy and climate strategies. One of the targets is toraise the annual consumption of forest chips to 5 mill.m3 by 2010. To direct the energy policy, decisionmakers need information about development trendsand barriers constraining the implementation.
Reliable statistics on forestry and forest industriesare published annually in the Statistical Yearbookof Forestry. The statistics include detailed informa-tion on the consumption of wood by the forest in-dustries, but use of wood residues for the produc-tion of energy has been monitored only occasionally(17, 19, 40). Since such statistics were found neces-sary for directing research, the Wood EnergyProgramme carried out a survey on the use of forestchips in 1999 (20). In 2000, the Finnish Forest Re-search Institute began to regularly monitor the con-sumption of solid wood fuels (101–103). In addition,use of forest chips by heat entrepreneurs (86) andsmall farms (80, 87) has been surveyed separately.
A considerable part of industrial processing resi-dues is used directly at source, so that the fuel neverenters the market. On the other hand, forest chips istypically a commercial product. Consequently for-est chips play a more visible role in the wood fueltrade than the consumption statistics might sug-gest. Furthermore, as the price of forest chips ishigher than that of bark and sawdust, forest chipshave a greater share in the market value than inheating value of wood fuel trade. Table 4 refers tosolid wood fuels used by heating and power plantsin 2002.
The total value of forest chip trade was 23 M€ or 22% of wood fuel markets to consumers other thansmall-houses and farms in 2002. The aim is to raisethe use almost fourfold by 2010. As the use andtrade of processing residues, i.e. bark and sawdust,will not grow substantially, forest chips will be theprimary article in the markets for unrefined woodfuels in the future.
7.1 The driving forces
Figure 57 shows the development in the use of for-est chips since the late 1950s. In the early days offuel chip technology tending of young forests andcreating of jobs were the primary drivers. Whenbirch became a pulpwood species in the 1960s, thedemand for low-quality hardwood improved andthe urgent silvicultural incentive for forest chipproduction almost disappeared. The businessfaded.
Interest revived in the mid 1970s as a result of theglobal energy crises. The major driving force wasthen the need to increase energy self-sufficiency, asthe high price and uncertain availability of fossilfuels had become serious threats to the nationaleconomy and security. Unfortunately, much of thetechnical readiness and skill acquired earlier hadbeen lost, and despite the efforts of the Govern-ment, it took several years before the use of forestchips began to increase. The peak was reached inthe early 1980s, when the price of oil collapsed andinterest in forest fuels again disappeared, and theuse of chips declined.
59
Share of forestchips, %
All solid wood fuels
– Heating value 10.2
– Market value 13.2
Commercial wood fuels
– Heating value 17.0
– Market value 21.9
Table 4. The share of forest chips of solid woodfuels used by heating and power plants in 2002.
The deep economic depression of the early 1990s,as well as the mechanization of timber harvesting,aggravated rural unemployment. With the conse-quent reduction in the demand for wood fromthinnings, attention once again shifted to forest fu-els. Simultaneously, society began to take notice ofissues related to climate change. Gradually, theglobal environmental threat became the prevailingdriving force of forest fuels. The rationale seems tobe lasting, and so the industry is in a safer positionthan before when investing in know-how, machineconstruction and the utilization of forest biomass.
Since 2000, the average growth rate in the use offorest chips has been 320 000 m3 per annum, prob-ably faster than in any other country in Europe.This has been possible due to a number of advan-tages offered by natural conditions, the structure ofthe industry and the high priority set by the Gov-ernment to renewable energy. Some key drivingfactors are listed below.
Massive biomass reserves. The potential of techni-cally harvestable biomass is 3 m3 or 0.5 toe energy
per capita per annum. This is a huge resource com-pared to other European countries (Section 4.5).
Attitudes. It is generally agreed that the use of re-sidual forest biomass for the production of renew-able energy has to be increased. The strategic goalsset by the Government are supported unanimouslyby all actors: the forest owners, forest industries,energy sector, environmentalists, policy makersand the general public.
Governmental support. The competitiveness offorest chips has been improved through the intro-duction of a carbon-based fuel tax, by refundingthe electricity tax, by support for the production offuels from young thinning stands, and through aidfor investments (Section 1.2).
Support to R&D. Research into biomass utilizationand bioenergy both have long traditions in Finland.Several successive national programmes have re-sulted in the accumulation of basic knowledge.Close cooperation between researchers and practi-tioners in the programmes has greatly aided thetransfer of knowledge to practice (Section 2).
60
3
1
2
1960 1970 1980 1990 2000 2010
Self-sufficiency
Use, mill. m / annum3
Silvicultureemployment
Employmentsilviculture
Use for pulpUse for fuel
Small whole treesSmall delimbed stems
Logging residues
Stumps
Climate change
Figure 57. Use of forest chips since the mid-1950s (20, 103).
Advocacy of the forest industries. In many Euro-pean countries, the forest industries have asceptical attitude towards the use of forest fuels. InFinland, no conflict exists between the pulp andenergy industries concerning the use of low-qual-ity wood. The Finnish forest industries are, in fact,a strong advocate for forest energy. This has beenthe foundation of the successful development(Section 5.2).
Utilization capacity. A large number of heatingand CHP plants have been modified and refittedwith the technology required to handle andcombust large amounts of forest fuels, and totallynew plants have been established (Figure 58, Sec-tion 3.3).
Availability of peat. Fuel peat is abundantly avail-able in many regions of Finland at a stable price.Blending peat and wood fuels helps to overcomeproblems caused by variable properties, hightransport costs and lack of secure inventories offorest fuels (Section 3.4).
Machine manufacturing. A majority of the globalproduction of forest machines used for thecut-to-length technology in timber harvesting, andthe production of FBC boilers, are in the hands ofFinnish companies. The presence of leading manu-facturers, and their active support for and participa-tion in the development work, has greatly promotedthe forest fuel boom in Finland (Section 5.4).
61
Figure 58. Use of forest chips at heating and power plants in 1999 and 2002 (20, 103).
7.2 The users
In 1998, before the Wood Energy Programme waslaunched, the total use of forest chips was esti-mated to be roughly 500 000 m3, small-scale useincluded. The next five years brought an unfore-seeable growth in the field of forest energy (Figure58).
In 2002, forest chips were burnt by 365 plantslarger than 0.4 MW. In the geographic areas of the13 Forestry Centers, Central Finland (area 8) wasthe forerunner and leading user. The region hasplenty of mature spruce stands that are being re-generated, several local CHP plants have been re-fitted to handle and combust forest fuels, and theregion is the heart of bioenergy research in Fin-land. Another advanced area is the Pohjanmaa For-estry Center on the western coast. In the northern-most part of Finland, the use of forest chips is mod-est because of the scarce population, long dis-tances, unsupportive structure of forests, and forestconservation issues (Figure 59).
Earlier, forest chips were mainly used for heat pro-duction. However, excluding small-scale use, thecombined production of heat and power is cur-rently more important. Growth is fastest in co-gen-eration, which is in agreement with the Finnish en-ergy policy goal, and the proposal for an EU direc-tive on the promotion of co-generation (Figure 60).
The source of forest chips is important when con-sidering its impacts on forestry, integration of op-erations, machine selection, job opportunities, fuelquality, and the need for subsidies. In the mid1990s, the main source was early thinnings. Sincethen, technological development has been rapidconcerning logging residue chips but slower withrespect to small-tree chips. The latter has becomemore competitive and its use has increased rapidly,whereas the use of small-tree chips has more orless stagnated (Figure 61). However, in 2003 the
production of whole-tree chips began to recoverdue to the mechanization of cutting. Biowatti aloneemployed 20 and Vapo 10 fellers-bunchers orharwarders to harvest fuel from young stands.Moreover, the use of stump and root wood for fuelis expected to increase rapidly, although it cannotyet be seen in the statistics for 2002.
62
Figure 59. Use of forest chips by forestry cen-tres in 2002 (103).
63
15
546
390
218
150
854
656
920
100
200
300
400
500
600
700
800
900
1000
2001 1999 2002 1999 2002 1999 2002 1999 2002
Annual use1000 m GWh3
Heat production CHP production
763
100
200
300
400
500
2001
2001
2001
2001
Small houses Heatentrepreneurs
Large houses,district heating
Districtheating plants
Forestindustries
Figure 60. The users of forest chips in 1999 and 2002 (20, 103). Small houses in 2001 (80).
100
200
300
400
500
600
700
800
900
1995
139
49 50102
233
806
142
1995199519952002 20022002 2002
1000 m / annum3
Delimbed stems Whole trees Logging residues Decayed wood etc.
2001
2001
2001
2001
Young stands Mature stands
65
Figure 61. The sources of forest chips in 1999 and 2002 (19, 103). Small-scale use excluded.
8 Use of bark
Under earlier conditions of undeveloped road net-work and an inefficient truck fleet, the weight oftimber was lightened through debarking and dry-ing prior to long-distance transport. Not until theearly 1960s was debarking moved completely toplant in order to speed up the flow of wood, im-prove timber quality, and reduce costs. Debarkingresidues therefore accumulated at the plants, butonly a part of them could be utilized.
Even in the early 1970s, for some mills bark wasstill only a waste product. The global energy crisesfinally solved the problem, and even old, decom-posed bark mountains were salvaged and used forthe production of energy. Bark became a valuedby-product. However, the use of bark may still beinefficient.
The Wood Energy Programme focused strictly onthe production of forest chips. An exception wasthe debarking residues from the forest industries;their quality improvement and a more efficient uti-lization of their heating value. Section 8 examinesdebarking residues as a fuel source and the find-ings of the relevant projects of the programme.
8.1 Barking residues as a fuelsource
The use of roundwood by the Finnish forest indus-tries is 65–70 mill. m3 per annum. The proportionof bark in this raw material is about 12 % or 8 mill.m3. Although the goal is to use bark efficiently, lossof dry matter and energy takes place throughout theprocurement chain:• Bark loss in timber harvesting. The feeding rolls
and delimbing blades of a harvester break andpeel bark. Bark is also loosened when timber ishandled by the grapple loaders. The loss is esti-mated at 10 % or 0.8 mill. m3 annually.
• Soiling of bark at sawmills. Logs are soiledwhen stored and handled on unpaved timber
yards at sawmills. Contaminated bark is not suit-able for fuel, and it is taken to landfill areas orcomposted. The loss may be up to 5 % of thebark volume at sawmills (60), i.e. more than 0.1mill. m3 annually.
• Incomplete debarking. When roundwood isbarked, a small fraction of the bark remains onthe logs. If the average bark content of pulpwoodchips is 0.7 %, the annual yield of bark fuel is re-duced by 0.3 mill. m3. However, a majority ofpulp chips are used for sulphate pulping. Thebark is then dissolved and recovered for energywhen the black liquor is burned.
• Use of bark for other purposes. Small quantitiesof bark are used as a ground cover and soil im-provement agent. This proportion is estimated tobe less than 5 % of the total volume of the barkpotential.
• Reduced heating value. Floating, water storage,debarking with water in wet drums, meltingfrozen wood with steam before debarking in drydrums, snow and ice on the log mantle, and thewetting of bark piles by rain water and snow allaffect negatively on the heating value of bark.
• Dry matter loss in storage. Chemical and bio-chemical reactions start causing dry matter lossin bark piles after storage times of only 3–4weeks.
Thus, a considerable part of the bark potential islost. On the other hand, this loss is compensated bywood loosened in the debarking process. If the av-erage wood loss in debarking is 1.5 %, as much as 1mill. m3 wood is mixed with bark. To be precise,the fuel produced is debarking residue with a10–15 % mix of wood, rather than bark.
In 2002, about 8.6 mill. m3 bark was burnt, mainlyby large CHP plants, corresponding to 15.3 TWhenergy (103). Bark accounted for 4 % of the totalconsumption of primary energy, and 13 % of theindigenous energy in Finland.
65
Problems of bark utilization are usually linked toquality issues rather than costs. To improve thefluidity of bark, it is usually crushed before utiliza-tion (Figure 62). Most of the bark is used at sourceby the producer. In 2002, only 3.6 mill. m3 or 42 %of the bark residues were sold. Market bark origi-nates mainly from sawmills, which burn only a partof the bark for their own needs. It is possible thatsawmills will increase the use of bark and sawdustfor the production of heat, electricity or refinedmarket fuels in the future. This may become attrac-tive because of the low market price of bark. Thecheaper price is not unreasonable, since the qualityof bark causes problems particularly in small-scaleuse. Typical fuel properties of bark are listed below:• Effective heating value (kWh/kg). The differ-
ence between wood and bark is insignificant inpine and spruce, but in birch bark the heatingvalue is 21 % higher than in birch wood (63).
• Basic density (kg dry mass/m3). The differencebetween wood and bark is small in the case ofspruce and birch, but in pine the bark is unusu-ally light. The basic density of pine bark is 30 %lower than that of pine wood. It is 20 % lowerthan in spruce bark and 40 % lower than in birchbark (Figure 63).
• Moisture content. Differences between woodand bark are minor at the time of felling, but dur-ing the production process moisture tends to in-crease in the bark. Excessive moisture content isa serious problem of bark fuels.
• Particle size. Long and thin strips of bark causehandling problems and bridging. Such problemsare typical of spruce bark especially in thespring time, and they may occur also in crushedbark.
• Energy density. The properties mentioned abovehave a negative effect on the energy density ofbark, resulting in extra costs in transportationand handling, and loss of boiler capacity in com-bustion. Figure 64 shows an example of the sea-sonal variation in the moisture content and en-ergy density of bark. The energy density variedfrom 0.5 to 0.7 MWh/m3 loose, whereas the cor-responding values of forest chips are typicallyfrom 0.7 to 0.9.
• Share of ash. The ash content of bark is highcompared to bark-free wood. The proportion ofpure ash is 2–4 % and that of crude ash, inor-ganic impurities of bark included, occasionallymore than 5 %.
66
Figure 62. Uncrushed (left) and crushed debarking residues (VTT).
8.2 Improving the fuel properties ofbark
Each handling phase of timber procurement chaincauses a loss of bark, especially during the sap sea-son in the spring when the bond between wood andbark is weak. The peeling of bark is affected byharvester head geometry, the sharpness of blades,
feeding speed and, above all, by the pressure di-rected to the feeding rolls and delimbing blades.Good maintenance of equipment and careful han-dling of logs reduce bark losses (55).
An excessive moisture content of bark results inhandling and boiler problems: bridging and freez-ing, incomplete combustion, increase in emissions
67
100
200
300
400
500
600
Firstthinning
Finalharvest
Firstthinning
Finalharvest
Firstthinning
Finalharvest
Basic density, kg/m3Wood
390
270
430
310
360340
380 380
470 480510
540
Pine
Birch
Spruce
Bark
Figure 63. The basic density of wood and bark.
July September October November March April
10 20 30 40 50
Moisture content
Energy density
70
60
50
40
30
20
10
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
Moisture content, % Energy density MWh / m loose3
Consecutive number of load measured
Figure 64. Seasonal variation of the moisture content and energy density of bark at asawmill (32).
and the need to blend bark to dryer and more ex-pensive fuels. Seasoning in piles is often thought toreduce the moisture content of bark. Chemical andbiochemical reactions release energy from the bio-mass during storage and the temperature inside thepile may rise in a few days to 60–70 °C. Watervapour moves upwards but condenses in the coolersurface layers, creating zones of dry and wet barkwith abrupt boundaries. Moldy bark appears at theboundries of the zones (Figure 65). The effect ofseasoning on the average moisture content of a pileis not very significant, and the possible increase inthe effective heating value of bark may be lost later.Furthermore, the reactions cause loss of dry matter,formation of fines, an increase in ash content, and adecrease of volatile materials. It was concludedthat long-term storage of bark should be avoided.A sawmill survey indicated that 17 % of sawmillshave bark inventories older than 1 month and 10 %have inventories older than 2 months (47).
The pulp industry removes water from wet bark bycompressing. If the moisture content is initiallyvery high, it can be decreased to 55–60 % in soft-wood bark and 45–55 % in birch bark. For com-pression the temperature must be above 15 de-grees, long bark strips should be avoided, and thewater removed must be treated. For these reasons,and because of the high investment costs, compres-sion techniques are not applied in the sawmill in-dustry (32).
Thermal drying, or the use of heat for vaporizingwater from bark, is another but seldom used alter-native to reduce the moisture content of bark. Heatenergy is taken from flue gas, steam or waste heat.With this method it may be feasible to lower themoisture content of bark by 10 percent units. Ther-mal drying is used to some extent in Sweden. InFinland, where the price of wood fuels is lower,thermal drying is not profitable (12, 32). Multi-stage drying was developed at the Helsinki Univer-sity of Technology to utilize secondary heat fromintegrated pulp and paper mills (2, 88).
VTT’s studies indicate that woody materials canbe dried artificially without excessive harmfulemissions if the temperature is below 200 °C, dry-ing takes place in a bed, and the released vapour isnot condensed. In these conditions pyrolysis, i.e.the thermal decomposition of the biomass, is pre-vented. The released organic compounds are thennot different from those initially present in bio-mass. The amount of the releasing organic constit-uents is 0.2–0.3 % of dry matter in logging residuechips, and 0.2–0.8 % in pine and spruce bark. Thus,they remain at a level that is commonly accepted innatural drying (11).
68
5650
5129
5156
4932
5775
5659
50-
5831
5958
5420
6026
5633
Heig
ht 4
m
Moist zoneDry zoneMoldy zone
Initial MCFinal MC
Figure 65. Moisture zones at a cross section of a bark pile. The upper numbersrefer to the initial and the lower numbers to the final moisture content (47).
9 The impacts of forest chip production
The fundamental rationale for the promotion offorest energy is the reduction of greenhouse gasemissions. Forest biomass is an almost carbon-neutral fuel, as the carbon circulates in a closedsystem, and the input energy is only 3 % of the out-put energy (85). The official production target forforest chips, 5 million m3 in 2010, corresponds to10 TWh energy.
If oil is replaced with forest chips, the reduction ofCO2 emissions will be 2.7 Mt. If coal is replaced,the reduction will be 3.3 Mt. The former is 3.5 %and the latter is 4.3 % of the national level of green-house gas emissions in 1990. Forest chips maytherefore play a significant role in Finland’s effortsto meet its international obligation to return itsemissions to the 1990 level.
The primary driver of forest energy development isthe protection of the environment. The productionof forest fuels must therefore be in agreement withgood forest management practice and sustainableforestry; both the environmental and socio-eco-nomic aspects of sustainability included.
9.1 Impacts on forest increment
Proving the effects of intensive biomass removalon forest increment requires long-term biologicalexperiments and permanent sample plots in the for-ests. This is beyond the scope of short-term techno-logical projects. However, credibility of the systemdevelopment presupposes that its impacts aretaken into account and evaluated. The goal must beprevention of, or at least the minimization of, pos-sible harmful effects.
The greatest concentration of plant nutrient ele-ments occurs in the parts of the tree, such as fo-liage, where essential life processes take place. It is
inevitable that intensive extraction of biomass willresult in an increase in nutrient loss from the forest;more in fact than the increase in biomass yieldwould suggest (59). In comparison with conven-tional stem-only harvesting, each percentage in-crease in biomass recovery from crown mass withfoliage incurs an increased nutrient loss amountingto 2–3 % for pine, 3–4 % for spruce, and 1.5 % forleafless hardwoods. Yet, particularly in managedforests, crown mass represents such a large pro-portion of the fuel potential that large-scalebioenergy production would not be feasible with-out it.
Yield studies on the effect of crown mass removalon the forest growth are meagre. In a joint Nordicstudy, 8 young pine stands and 4 spruce stands inSweden and Finland were monitored. Whole-treeharvesting caused a 7 % growth reduction in pinestands and 12 % in spruce stands during the next 10years after the thinning (64). However, these scien-tific experiments do not exactly correspond to ev-ery-day management practice in the following re-spects: removal of stemwood was above the aver-age; crown mass was completely removed from theexperimental stands, which would never beachieved operationally; the growth loss caused by4 m wide strip roads in thinnings was not taken intoconsideration; and in the control plots representingstem-only logging, residual biomass was distrib-uted manually and evenly across the site in an idealway, which is not the real case in mechanized cut-ting operations. Removals from the softwood plan-tations of the experiment were composed of theneedle-rich dominant species, but in practice themajority of removals may actually be composed ofleafless hardwoods. The results published fromthese scientific experiments include no allowancesfor the differences between experimental treat-ments and actual harvesting practices, and this hascaused confusion among forest owners.
69
The results of yield studies should be proportionedto the removal of crown mass or foliage. TheMOTTI stand simulator of the Finnish Forest Re-search Institute can be used to estimate the effect ofdifferent treatments of young stands on the total in-crement and net incomes during the entire rotationperiod. The simulation model shows that when thecurrent technologies are applied, the loss caused bywhole-tree harvesting is considerably less than thatreported earlier. When stem-only harvesting is re-placed by whole-tree harvesting, future stumpageincomes are reduced by less than 3 % in pine standsand less than 4 % in spruce stands. On the otherhand, if this early thinning is neglected, the loss ofincomes is 11–12 % (Figure 66). Thus, if energy-wood thinning can promote the tending of youngforests, in many cases it will actually increase theforest owners’ future incomes.
Nutrient losses affect differently in regenerationareas. There are no trees to benefit from releasednutrients. Further, before the ground vegetation re-covers, some of the nutrients may be lost through
leaching. Salvaging the crown mass slows downleaching.
Very few research results are available on the effectof crown mass removal on the growth of the newtree generation. No significant growth reductionhas been found in the regeneration areas of pine,but young spruce trees seem to be less tolerant. Aloss corresponding to the increment of more thantwo years during a 30-year period has been re-ported after the complete removal of residues (53).In reality, the decline is considerably smaller, as30 % of the crown mass is left typically at the site.If transpiration drying takes place in the residues,crown mass is partially defoliated before extrac-tion, and no significant growth reduction occurs.
An abundant bed of logging residues can delay theestablishment of a new stand by one year. This timecan be saved if the residues are removed. As shownin Section 9.2, the removal of logging residues alsoproduces direct cost savings in site preparation andplanting (77). These advantages more than com-
70
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Fiber only Fiber andfuel
No tending
Yield of industsrial woodEarnings
Proportion,%
Pine stands Spruce stands
100100 10010098.2 97.6 97.7
89.2
97.1 96.4 96.1
88.2
Fiber only Fiber andfuel
No tending
Figure 66. Relative revenues from pine at a dry site and spruce at a fresh site during the entirerotation period of a stand. Three alternative thinning schedules, interest rate 3 % (29).
pensate for the growth loss that can be expected inthe regeneration areas of spruce.
Even though the risk of growth reduction may havebeen exaggerated, the problem nevertheless is real.The control of nutrient loss remains an importantaspect of the development of harvesting tech-niques. For example, the following possibilities arepresented:• No technology is able or intended to remove all
crown mass from the site. For example, the sal-vage of logging residues from the final harvest,irrespective of the system applied, accounts foronly some 70 % of the crown mass.
• Summertime transpiration drying is an effectiveway of achieving the simultaneous reduction inmoisture content and partial defoliation in smallwhole trees and logging residue heaps on thesite. However, the flow of fuel from the loggingsite to the energy plants is sloved, and the recov-ery of biomass is reduced.
• In small-tree operations, especially in youngpine stands, topping the trees means compro-mising the principle of whole-tree logging, but iteffectively reduces the loss of nutrients. If a 3 mtop from a pine tree is left on the site in an earlythinning, needle recovery is reduced by 52 % butthe overall recovery of whole-tree chips is re-duced by only 8 %.
9.2 Impacts on the management offorests
As some 86 % of Finland’s land area is under for-ests, forestry has a social obligation to participatein the production of renewable energy. Forest en-ergy brings a new dimension to forestry. One of thetasks of the Wood Energy Programme was the inte-gration of the concept of forest energy in the ev-ery-day forest management with timber harvestingpractices. A necessary precondition for this is thatthe timber procurement organizations of the forestindustries add forest chips to their produce, to-gether with sawlogs and pulpwood. During theprogramme period, this condition was fulfilled anda valuable synergy was created through the use ofexisting personel and machine resources.
The production of forest chips in the future will re-quire large amounts of forest machines and trans-port vehicles. The majority of the equipment willbe destined for off-road and on-road transportationof biomass, comminuted or uncomminuted. In Ta-ble 5 an estimation is given of the equipment thatwill be in use in 2010 given the assumption that theproduction is as follows: 2.5 mill. m3 logging resi-due chips, 1.5 mill. m3 stump chips, and 1 mill. m3
whole-tree chips. Compared to the vehicle fleetused for transporting industrial wood, the produc-
71
Machine Productivity, m3 Number
Feller-buncher 10 000 90
Stump harvester 17 000 114
Baler 25 000 50
Mobile chipper 30 000 67
Stationary chrusher 120 000 25
Forwarder 30 000 167
Biomass truck 25 000 70
Chip truck 25 000 80
Timber truck 25 000 50
Carriage truck to move machines 141
Table 5. An estimate of the equipment needed for the production of forest chips in 2010 (4).
tion of forest chips will increase the number of for-warders by 10 % and the number of trucks by 14 %.The ratio of mobile chippers and balers is totallysubject to technical development of alternativesystems.
By 2010, the annual turnover of forest chip produc-tion will be 110 M€ if the present cost structureprevails. As the turnover of industrial roundwoodproduction is 600 M€ per annum, forest chips willbring a 20 % increase in business. This is of impor-tance from the contractors’ viewpoint, becausepossibilities to increase the production of indus-trial wood are slight.
The operating environment of stand establishmentis also changing. Salvaging logging residues andstump and root wood is no longer a mere harvestingoperation. It is also the first phase of regenerationwork, i.e. the starting shot of site preparation andplanting. For example, a combi-machine has beendeveloped for simultaneous site preparation and the
collection of residues (23, 52). Site preparation isalso combined with stump extraction. Moreover, theremoval of logging residues paves the way for themechanization of planting (76), which is an urgentissue in Finnish forestry as the availability of man-ual labor is decreasing (Figures 67–69).
The production of forest chips also promotes thetending of young stands. Currently, the stands underconsideration are a product of neglected silviculture.Several hundred thousand hectares of ill-managedyoung forests urgently require thinning, and the pro-duction of forest chips will help to cover the costs,partly or totally. However, in the long term this doesnot provide a sustainable basis for the production oflarge amounts of small-tree chips for fuel. Conse-quently, new forest management models for youngforests are being examined. Energywood harvestingprior to the traditional first commercial thinningcould perhaps become a target-oriented stage ofgood forest management practice. Currently,energywood harvesting is only an emergency mea-sure to correct earlier failures (83).
72
Figure 67. A forwarder equipped with a mounter between the front and rear bogieson both sides, and with an enlargening load space, for simultaneous site preparationand residue collection (Metla).
73
Figure 68. Tenkanen’s stump harvesting head on an excavator for simultaneousuprooting, splitting and site preparation (Metla).
Figure 69. Bräcke planting machine mounted on a harvester in a regeneration area. Loggingresidues have been salvaged (Metla).
The recovery of forest chips from regeneration ar-eas and young thinning stands gives, in addition todirect cost savings, qualitative benefits such asmore even spacing of seedlings, and benefits in for-est protection. Especially important is the possibil-ity to annihilate through stump extraction the rootrot fungus that has infested large areas of sec-ond-generation spruce stands in southern Finland.
Estimating the total economic value of the advan-tages and disadvantages is a difficult task as theyare not commensurable. An orienting calculationof the direct and indirect effects of forest chip pro-duction on the profitability of forestry has never-
theless been attempted, because this knowledge isneeded in systems analyses (Table 6).
Forest chip production affects the profitability ofprivate forestry in two ways: cost savings and addi-tional incomes in the future. A part of the incomesare absorbed by the increment reduction caused bythe accelerated loss of nutrients and the possiblecost of compensating fertilization, but the total ef-fect remains positive. The sum of cost savings andincomes in 2010 is estimated at 11 M€. On aver-age, the forest owners gain 2 €/m3 biomass, most ofwhich is derived from the energywood thinning ofyoung stands.
74
Cost or income factor Loggingresidue chips
Stumpchips
Whole-treechips
Forest chipstotal
Benefit M€/annum
Direct cost savings
Clearing the area – – 0.5 0.5
Site preparation 1.0 0.8 – 1.8
Planting 1.2 0.4 – 1.6
Supplement planting 0.1 ∆ – 0.1
Weeding -0.4 -0.1 – -0.5
Tending of young stands - - 6.0 6.0
Total 1.9 1.1 6.5 9.5
Additional incomes
Improved regeneration result 0.6 – – 0.6
Faster regeneration 0.6 – – 0.6
Reduced risk of damage – 1.6 ∆ 1.6
Nutrient loss and fertilization -2.2 -0.4 -0.9 -3.5
Tending of young stands - 2.4 2.4
Total -1.0 1.2 1.5 1.7
Grand total 0.9 2.3 8.0 11.2
Table 6. Forest owners’ direct cost savings and future additional incomes resulting from the productionof forest chips in 2010. Production of chips 5 mill. m3, rate of interest 3 % (21, 22).
Table 6 does not include the stumpage price whichpossibly is paid to the forest owner. Presently it isquite low, and often no stumpage price is paid atall. For most forest owners the cost savings and in-crease in future incomes are a sufficient incentive,but some are not ready to surrender the right of bio-mass extraction without stumpage. Achieving theproduction target of 5 mill. m3 requires the partici-pation of all forest owners, and this puts pressureon the stumpage price development (57).
9.3 Socio-economic impacts
In Finland, the productivity of timber procurementhas increased tenfold in a few decades. Epochalchanges took place in the operating environmentdue to mechanization, the delegation of work to in-dependent contractors, building up a dense net-work of all-year forest roads, and moving workphases such as debarking from forest to mill. As inthe other areas of primary production, the numberof jobs has decreased. In 2001, the total perfor-mance in forestry corresponded to 23 000 workyears, including 4 000 forest workers, 5 000 har-vester and forwarder operators, and 3 000 timbertruck drivers (56).
Unemployment is a serious problem in rural com-munities. Production of forest fuels creates newjobs, but it is not immune from the general trend ofjob-losses, as competitiveness of forest fuels re-quires an increase in productivity. The employ-ment effect of forest chip production will thereforenot be as high as was expected earlier. Neverthe-less, the production of forest fuels in rural areasmay have a stimulating effect on local employ-ment.
In large-scale operations, energywood is no longerhandled manually. The only exception is cuttingand bunching of small trees in early thinnings, buteven this last manual phase of forest chip produc-tion is being mechanized. In 2003, more than 30feller-bunchers were employed in fuelwood har-vesting.
The employment effect depends on many factors:source of biomass, technical logging conditions,quality requirements of fuel, and the scale of pro-duction. The latter largely determines the systemand equipment selected. Although the productionof forest chips is a round-the-year process, singlejobs are typically seasonal. The diversity, seasonalnature of jobs, and the integration of the procure-
75
1.4
1.2
1
0.8
0.6
0.4
0.2
Employmentwork years / 1000 m3
0.3 0.3
1.4
0.8
0.6
0.5
Indirect, other FinlandIndirect, localDirect
Logging residue chips
Whole-tree chips
PietarsaariResidue
logs
OuluChippingat landing
RuukkiChippingat landing
PietarsaariMechanized
cutting
RuukkiManualcutting
PerhoHeat
entrepreneurs
Figure 70. Employment effect of alternative chip production systems (1).
ment of industrial wood and fuelwood make it dif-ficult to estimate the number of new jobs at the na-tional level.
The Thule Institute of the University of Oulu eval-uated the socio-economic impacts of forest chipproduction. A case study was carried out at fourplants (Figure 70):• In Perho, a co-operative organization of forest
owners is responsible for the fuel supply and op-erating the heating plant. The annual use of for-est chips is about 2 900 m3. The source of chips issmall trees that are cut manually.
• In Ruukki, the local forest management associa-tion supplies the chips, 4 800 m3 per annum, butit does not participate in the maintenance of theplant. Here, too, chips are produced from smalltrees that are felled manually.
• In Oulu, the Toppila power plants use annually28 000 m3 forest chips that are supplied by threemajor producers. Logging residues are the pri-mary source of chips.
• In Pietarsaari, Alholmens Kraft’s power plantaims to use at least 200 000 m3 of forest chips an-nually. The primary source is logging residues
that arrive at the plant in the form of residue logs.Small-tree chips are produced using fully mech-anized technology, i.e. cutting is carried out withaccumulating feller-bunchers.
The relative employment effect was highest inPerho, 1.4 man-years per 1 000 m3 chips, due to thesource of biomass, small scale of operations, andmanual cutting. In Pietarsaari the productivity washigh because of advanced technology: 0.3 man-years per 1 000 m3 if the source was of logging resi-dues, and 0.6 man-years per 1 000 m3 if the sourcewas small trees from thinnings.
The case studies give a firm basis for estimating thedirect employment effect of forest chip productionin 2010. In the following estimate, it is assumedthat logging residues and stump and root wood arerecovered using present day’s most advanced tech-nology, whereas the production of small-tree bio-mass from early thinnings is based only partly onmechanized cutting. On average, the production offorest chips requires 0.45 man-years per 1 000 m3
chips. Accordingly, the total effect is estimated at 2 275 man-years in 2010 (Table 7).
76
Product Production1000 m3
Man-years/1000 m3
Man-years/annum
Small-tree chips
– Whole-tree chips, mechanized cutting 600 0.6 360
– Whole-tree chips, manual cutting 200 1.2 240
– Stemwood chips, self-employed forest owners 200 2.0 400
Logging residue chips 2 500 0.30 750
Stump chips 1 500 0.35 525
Forest chips, total 5 000 0.45 2 275
Table 7. An estimate of the employment effect of forest chip production in 2010.
The Thule Institute also estimated the disposableincomes from forest chip production, and the arealallocation of incomes to the local communities,other regions in Finland, government and foreigncountries. In large-scale operations, a quarter and,in small-scale operations, up to a half of the dispos-able incomes will remain in the local economy tobenefit households, firms and municapilities. Fig-ure 71 is interpreted as follows:• The net incomes to the government are com-
posed of savings, fees and taxes, excludingadded value tax. Below the x-axis are the nega-tive effects of investment aid and the subsidiespaid for the production of small-tree chips.
• The net incomes that remain in the local econ-omy are divided into two parts. The upper sec-tion refers to stumpages, wages and subsidies toforest owners. The lower part refers to the otherincomes that remain in the local economy, in-cluding the wages paid to forest workers, ma-chine operators and entrepreneurs.
• The part of the incomes allocated to foreigncountries is composed mainly of fuel and lubri-cants, trucks, machines and spare parts.
77
-15
-10
-5
0
5
10
15
20
25
30
35
40
Net income, / m€ 3
Income earnerForeign countriesLocal communitiesOther parts of FinlandState, incomeState, subsidies
18
-0.4 -0.2
18
24
29
-11 -11 -11
3538
Logging residue chips
Whole-tree chips
PietarsaariResidue
logs
OuluChippingat landing
RuukkiChippingat landing
PietarsaariMechanized
cutting
RuukkiManualcutting
PerhoHeat
entrepreneurs
Figure 71. Net incomes from the production of forest chips and their areal distribu-tion. Explanations in Figure 74 (1).
10 State of the art
Finnish society strongly supports the use of resid-ual forest biomass as a source of renewable energy.All major actors are in agreement concerning boththe climate and energy policy implications. How-ever, the common good as such is not necessarily asufficient incentive for all actors. They must alsoachieve personal benefits.
The problem of forest fuels is that their use is bene-ficial to the national economy, but it has not neces-sarily been a profitable business. To improve thecompetitiveness of forest fuels, the costs of otherfuels have been increased through carbon-basedenergy taxes, and the cost of forest chips has beenreduced through incentives and the development oftechnology.
Only few years ago, forest fuels were given a sub-ordinate position in forest management and inte-grated harvesting operations. This may still be truein many cases, but a change is taking place. Theforest sector is gradually learning to appreciateforest fuels as a natural and relevant product ofsustainable forestry. The status of renewable en-ergy has risen, and the production and use of forestchips are today acceptable and valued activities(90, 92). There are now a number of signs that sug-gest that forest energy is already established as anelement of Finnish forestry:• The use of bark, sawdust, recycled wood, pellets
and forest chips for energy is monitored regu-larly. Reliable statistical data are published an-nually concerning the use of forest chips,sources of biomass, and the prices. This informa-tion is useful for various actors and decision mak-ers because it helps to monitor the fuels’develop-ments. Such comprehensive and up-to-date infor-mation is not available in other countries.
• The Forestry Development Center Tapio, the or-ganization responsible for the development ofprivate forestry in Finland, now considers theproduction of forest fuels as a daily routine of
forestry. It has published two guides for goodmanagement practice in conjunction with the re-covery of biomass (13, 14). It is also extendingthe monitoring of the quality of logging work inprivate forests to fuelwood operations (15).
• Forest management planning. Most forest own-ers have a management plan for their forestholdings. The plans promote good silvicultureand the utilization of forest resources. However,they currently fail to include forest energy. Pos-sibilities to include the fuel concept in the planare being studied in order to promote the use offorest fuels (91).
• Young stands as a source of fuel. Currently, therecovery of small-tree biomass from earlythinnings takes place in stands where fuel is onlyavailable due to earlier failures to carry on goodmanagement practices. However, if poor tend-ing practices continue to be a precondition forthe availability of forest fuel, the supply of fuelis not sustainable. Therefore, management mod-els in which the recovery of fuel is a purposefultarget of an early energywood thinning are beingexamined.
• The readiness of forest machine contractors.The Trade Association of Finnish Forestry andEarth Moving Contractors is developing thereadiness of its members to participate in theforest fuel business. The association has pub-lished guidelines for cutting and forwardingenergywood (100), a guide book for qualitystandards for forest machine contractors (50),and a guide book for quality standards for chipcontractors (49). It is also promoting the net-working of contractors in order to form localchip production organizations (38).
• Approval of environmentalists. Although envi-ronmentalists generally adopt a sceptical atti-tude towards intensive forestry, they have ac-cepted the targets and technology developmentfor the production of fuel from forest biomass inFinland.
79
Despite the low market value, forest chips are nowrecognized as one of the natural and conventionalproducts of Finnish forestry. Production of renew-able energy helps to justify the present forest man-agement practice, it improves the green image offorest procurement organizations, and it is becom-ing a profitable and attractive business. Many bar-riers have disappeared. However, all problemshave not been solved:• Cost of production. A considerable cost reduc-
tion took place during the 1990s as a result ofchanges in the operating environment: themechanization of cutting, the deployment ofmore efficient chippers, the possibility to em-ploy equipment to its full capacity, the replace-ment of costly small-tree chips with cheaperlogging residue chips, and the development ofprocurement logistics. In 2000, the prices of for-est chips began to increase as growing demandforced the producers to extend their operationsto increasingly difficult and remote stands. Al-though the technology has developed rapidlyand the biomass base has broadened, high costscontinue to constrain chip production.
• Loss of nutrients. Studies of the effect of inten-sive biomass recovery on the increment of for-ests are few and largely theoretical. They do notconnect the effects of forest chip productionwith real-world conditions. Comprehensive andlong-lasting experiments are needed, while re-sults from the theoretical experiments must berelated to actual harvesting practices, and tech-nology must be developed to reduce the loss ofnutrients.
• Recycling of ash. Nutrient loss caused by inten-sive biomass recovery can be offset by the recy-cling of ash, the loss of nitrogen excluded. Aprecondition for feasible ash recycling is properash management at the plant. Cofiring of bio-mass with fossil fuels, municipal waste or peatresults in a dilution of the nutrient content, oreven the contamination of the ash, and conse-quently a part of the ash becomes inuseable. Onthe other hand, large quantities of bark ash areavailable. Technology and logistics of ash recy-cling should be developed (Figure 72).
80
Figure 72. Ash recycling technology needs to be further developed (Metla).
• Stumpage price. In 2004, only about 15 % of thetechnically harvestable logging residues wererecovered. The 2010 goal implies that about onethird of the technically harvestable potential isto be recovered. If forest owners do not realize theindirect cost saving and silvicultural benefits ofresidue extraction by then, the availability of for-est chips may be at risk. If the average stumpageprice of forest biomass increases from the pres-ent zero level to, say, 2 €/m3 solid, it will mean a10 % increase in the price of forest chips but lessthan a 1 % increase in the total stumpage sumpaid by the forest industries from pulpwood andsawlogs. The stumpage price of forest biomassis therefore more a matter of principle.
• Forest management associations. The promo-tion of private forestry in Finland rests primarilywith forest management associations. They arethe prime movers in the management of forestsand timber trade at the local level. They also playan important role in forest fuel production. Inparticular, their role is essential in the produc-tion of fuel from young thinning stands, an areawhere the wood procurement organizations nor-mally do not operate.Although there are exceptions, the participationof forest management associations in the pro-duction of forest fuels has been disappointing.Their primary goal has been the tending ofyoung stands rather than the extraction oflow-value biomass. The simple thinning opera-tion becomes much more demanding if smalltrees are recovered for energy. There is an obvi-ous risk that the forest management associationsmay loose their leading position in stand estab-lishment and tending work in private forests un-less they become actively involved in the forestfuel business.
• Scaling of energywood. Fuelwood, forest chipsincluded, is not covered by the Law ConcerningTimber Measurement. This is partly because thetrade of fuelwood has not been common, partlybecause of the wide variation in scaling proper-ties, and partly because of the relatively lowvalue. Undeveloped scaling methods and lack ofreliable conversion factors constrain the tradeand weaken confidence. Only residue logs arean exception, as the baler produces accurate
real-time information about the number of logsproduced. The Wood Energy Programme in-cluded two projects aimed at solving problemsof measurement (41, 75), but many problems re-main.
During the programme period, the general atmo-sphere was favourable for forest fuels. Due to threestrong producer organizations, forest chips became acredible option for large CHP plants. The forest in-dustry adopted a pioneer role in the development oftechnology and in the production and use of forestchips. In 2003, Biowatti and UPM both produced 1TWh of forest chips, 50 % of the Finnish total.
The Wood Energy Programme focused on the de-velopment of large-scale procurement systems forforest chips. New advanced technology was devel-oped and transferred into practice:• Residue log technology promoted the integra-
tion of fuel production in the industrial timberprocurement systems. The control of the pro-curement chain was raised to an industrial level.Due to its flexible logistics, reliability and clean-liness, the residue log system is preferred by for-est owners, contractors and supervisors. How-ever, at the moment this technology is only fea-sible in large-scale operations. The capacity ofthe 24 balers operating in Finland in early 2004is sufficient for processing a half of the loggingresidue recovery.
• Stationary crushers made it possible to receivesolid biomass fuels in almost any form, i.e. resi-due logs, uncomminuted loose residues,undelimbed tree-sections, stump and root wood,and recycled wood. It became possible tobroaden the raw material base, streamline theprocurement logistics, and move work from theforest end to easier conditions at the plant. Inearly 2004, six Finnish CHP plants had a station-ary crusher.
• Stump and root wood was not considered to be arealistic option for fuel production when theprogramme was launched. However, it rapidlybecame a preferred fuel at the CHP plants thatpossess a stationary crusher. The technology isnew, and it has considerable development poten-tial (Figure 73).
81
82
Figure 73. Stump and root wood has become a realistic and abundant fuel source (VTT).
Figure 74. Harvesting fuel from early thinnings is becoming a fully mechanized operation.
• Comminution at landing is still the prevailingsystem for the production of chips from loggingresidues and whole trees. No totally new techni-cal solutions were introduced during the pro-gramme period. Nevertheless, truck-mountedchippers and chipper-truck technology pro-gressed, the techniques of biomass storage at theroad side were improved to allow faster chipperoperation and better control of moisture content,and the procurement logistics was refined.
• Cutting has been a prohibitive cost factor for theproduction of small-tree chips in early thinnings,but new technology is being developed (30). Theuse of accumulating feller-heads has improvedthe productivity of work and has paved the wayfor cost reductions (Figure 74). This technologyseems to offer a cost-competitive solution forenergywood harvesting from young standswhere the tree size is not too small. A precondi-tion is that the production support for small-treechips is maintained at the present level.
The atmosphere of growth has created favourableconditions for the development and introduction ofnew technology. Demonstration projects and in-vestment aid from the Ministry of Trade and Indus-try have speeded up the process. Broadening theraw material base has required refining and up-grading the receiving and handling systems at theplant.
In accordance with the initial plan, the programmefocused on the development of system know-how.The holistic approach and participation of severalglobally known machine manufacturers hasstrengthened Finland’s position among the tech-nology leaders in the field of wood energy.
During 1999–2003, the average growth rate in theproduction of forest chips was 320 000 m3 per an-num; a fast enough rate to allow the introduction ofnew technology, but not fast enough to permit themass-production of equipment. Without mass-pro-duction the technology is doomed to remain ex-pensive.
The official goal of forest chip production, 5 mill.m3 in 2010, requires an increased growth rate.From 2004 on, the annual increase should be400 000 m3 each year of this decade. Attaining thegoal is possible, but it is also necessary to continuedevelopment work in the future.
83
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31. Hämäläinen, J., Orjala, M., Järvinen, T., Kärki, J. &Vainikka, J. 2003. Variation, effect and control offorest chips quality in CHP. Bioenergy 2003. Pro-ceedings: 225–232. Finbio.
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67. Orjala, M., Kärki, J., Ingalsuo, R., Oksa, M. &Paakkinen, K. 2002. Kerrostumien muodostuminenja niiden vaikutus lämmönsiirtoon ja käytettävyy-teen 84 MW kiertoleijukattilassa; voimalaitosmit-taukset. VTT Prosessit. Tutkimusselostus PRO/T6031/02.
68. Orjala, M., Kärki, J., Mäkipää, M., Oksa, M. &Häsä, H. 2004. Puupolttoaineiden vaikutus voima-laitoksen käytettävyyteen. VTT Prosessit. Projekti-raportti PRO2/PGO11/03.
69. Paananen, S. 2004. Kantopuun korjuu ja metsäpolt-toaineiden prosessointi - PUUY36. Puuenergianteknologiaohjelman vuosikirja. VTT Symposium231: 109–115.
70. Poikola, J. 2003. Practical experiences of large-scale production of forest chips. Bioenergy 2003.Proceedings: 233–235. Finbio.
71. Poikola, J. Backlund, C., Korpilahti, A., Hille-brand, K. & Rinne, S. 2002. Risutukkitekniikan edel-lytykset suurimittaisessa puupolttoainehankinnassa –PUUT19. Puuenergian teknologiaohjelman vuosi-kirja. VTT Symposium 221: 141–156.
72. Ranta, T. 2003. Puupolttoaineen varmuus- ja pus-kurivarastointi. VTT Prosessit. ProjektiraporttiPRO2/6022/03.
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74. Ranta, T., Asikainen, A., Lehikoinen, M., Väätäi-nen, K., Halonen, P. & Frilander, P. 2002. Metsä-hakkeen autokuljetuksen logistiikka. VTT Proses-sit. Tutkimusselostus PRO/T6042/02.
75. Rieppo, K. 2002. Hakkuutähteen metsäkuljetus-määrän mittaus. Metsätehon raportti 129.
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77. Saksa, T., Tervo, L. & Kautto, K. 2002. Hakkuutäh-de ja metsänuudistaminen. Metsäntutkimuslaitok-sen tiedonantoja 851.
78. Salo, T., Ahlgren, N., Puhakka, A. & Huovinen, J.2003. Bioenergiayrittäjyyden uudet toimintamallit.Hankeraportti.
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80. Sevola, Y., Peltola, A. & Moilanen, J. 2003. Poltto-puun käyttö pientaloissa 2000/2001. Metsäntutki-muslaitoksen tiedonantoja 894.
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82. Sirén, M. (toim.). 2002. Ensiharvennusten korjuu-olot ja niiden parantamismahdollisuudet. Loppura-portti. Metsäntutkimuslaitoksen tiedonantoja 837.
83. Sirén, M. & Hynynen, J. 2003. Energiapuuharven-nus osaksi kasvatusketjua. Tutkimussuunnitelma.
84. Sirén, M., Tanttu, V. & Ahtikoski, A. 2004. Ener-giapuun korjuun tehostaminen nuorista metsistä –osaprojekti. Puuenergian teknologiaohjelman vuo-sikirja. VTT Symposium 231: 39–52.
85. Soimakallio, S. & Wihersaari, M. 2002. Puupoltto-aineiden tuotannon ja käytön vaikutukset kasvi-huonekaasupäästöihin ja niiden rajoittamiseen.VTT Prosessit. Projektiraportti PRO4/T7509/02.
86. Solmio, H. 2001. Lämpöyrittämisen nykytila ja po-tentiaali. Työtehoseuran metsätiedote 3/2001.
87. Solmio, H. & Valkonen, J. 2002. Hakkeen käyttö jahaketekniikan kehitystarpeet maatiloilla. Työte-hoseuran raportteja ja oppaita 3.
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97. Vetikko, V., Valmari, T., Oksanen, M., Rantavaara,A., Klemola, S. & Hänninen, R. 2004. Puupolttoai-neiden radioaktiivisuuden vaikutus tuhkan käyt-töön – PUUT23. Puuenergian teknologiaohjelmanvuosikirja. VTT Symposium 231: 265–282.
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Appendix 1
The Executive Board of the Programme
Biowatti OyPekka Laurila, [email protected]
Ministry of Trade and IndustryMika [email protected]
Fortum Power and Heat OyDan Blomster – 5.3.2002
Kyösti Rannila 5.3.2002 –[email protected]
Forestry Development Centre TapioKari Mielikäinen – 3.5.2000Tage Fredriksson 3.5.2000 –[email protected]
Ministry of Agriculture and ForestryMatti [email protected]
Trade Association of Finnish Forestry and EarthMoving ContractorsRisto Kilkki – 19.1.2000Simo Jaakkola 19.1.2000 –[email protected]
TekesTarja-Liisa Perttala – 3.5.2000Heikki Kotila 3.5.2000 – 18.9.2002Marjatta Aarniala 18.9.2002 –[email protected]
TekesMauri Marjaniemi 6.9.2001 –[email protected]
BMH Wood Technology OyAntti [email protected]
Vapo OyTero Vesisenaho – 6.2.2001Timo Nyrönen [email protected]
UPM ForestSeppo Paananen, Vice [email protected]
Pohjolan Voima OyJuha Poikola 12.10.2000 –[email protected]
Kvaerner PowerMatti [email protected]
Plustech Oy/TimberjackArto [email protected]
VTT Processes, Programme LeaderPentti [email protected]
VTT Processes, CoordinatorSatu Helynen – 30.6.1999Ismo Nousiainen 30.6.1999 – 30.6.2000Satu Helynen 30.6.2000 – 6.2.2001Kati Veijonen 6.2.2001 –[email protected]
Stora Enso OyjArto Huurinainen – [email protected]
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The Advisory Board of the Sub-programme forSmall-scale Production and Use of Wood Fuels 2002–2004
Joensuu Regional DevelopmentCompany Josek LtdKeijo Mutanen, [email protected]
Farmer OyAri [email protected]
FinproVeli-Matti [email protected]
HT EngineeringHannu [email protected]
Junkkari OyMarko [email protected]
Jyväskylä Science Park Ltd/Central Finland En-ergy AgencyMikko [email protected]
Maaselän Kone OyJari Lö[email protected]
Motiva OyOsmo [email protected]
Rakennustempo OyAri [email protected]
TekesMarjatta [email protected]
TekesMauri [email protected]
Veljekset Ala-TalkkariAntti [email protected]
VTT ProcessesKati [email protected]
VTT ProcessesPentti [email protected]
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Appendix 2
The Projects of the Programme
1 Planning and organisation
PUUT01 Cost factors and large-scale procure-ment of logging residues (F)Antti AsikainenUniversity of JoensuuJoensuu Research StationE-mail: [email protected]
PUUT02 Energy wood procurementin connection with conventional woodprocurement (F)Pekka MäkinenFinnish Forest Research InstituteVantaa Research StationE-mail: pekka.makinen@ metla.fi
PUUT03 Estimation of the amount of loggingresidues in a harvester’s data system (F)Pertti HarstelaUniversity of JoensuuE-mail: [email protected]
PUUT04 Wood energy harvesting conditionsin first thinnings, and possibilities for theirimprovement (F)Matti SirénFinnish Forest Research InstituteVantaa Research StationE-mail: [email protected]
PUUT28 Development of chip productionfrom young forestsKari HillebrandVTT ProcessesE-mail: [email protected]
PUUY11 Distinction-making betweenmerchantable wood and energy wood (F)Hannu KiveläJP Management Consulting (Europe) OyE-mail: [email protected]
PUUY15 Networked contractorsin chip production (F)Tomi Salo/Simo JaakkolaTrade Association of Finnish Forestry andEarth Moving ContractorsE-mail: [email protected]
PUUY22 Determining the output andperformance in forest haulage oflogging residues (F)Kaarlo RieppoMetsäteho OyE-mail: [email protected]
PUUY23 Pre-feasibility study of e-businessapplication for the energy wood market (F)Petri VasaraJP Management Consulting (Europe) OyE-mail: [email protected]
2 Production systems and techniques
PUUT05 Production of mixed fuels at theterminal – an integrity of projects (F)Arvo LeinonenVTT ProcessesE-mail: [email protected]
PUUT12 Developing a two-stage crusher forcomminution of forest biomass (F)Arvo LeinonenVTT ProcessesE-mail: [email protected]
PUUT13 Development of chip procurement,short-distance haulage and storage of woodchips (F)Teuvo RasimusOccupational Adult Education Centre ofSavonlinnaE-mail: [email protected]
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PUUT18 Improving the quality and produc-tion efficiency of wood fuels by developingchipping and crushing techniques (F)Veli SeppänenVTT ProcessesE-mail: [email protected]
PUUT20 Development of transportationeconomy and logistics of forest chips (F)Ismo TiihonenVTT ProcessesE-mail: [email protected]
PUUT40 Development of the quality andproduction efficiency of wood fuels bydeveloping a compacting load space systemIsmo TiihonenVTT ProcessesE-mail: [email protected]
PUUY01 Method for thinning young stands(F)Jarmo HämäläinenMetsäteho OyE-mail: [email protected]
PUUY02 Wood fuel production based onchipping at plant (F)Antti KorpilahtiMetsäteho OyE-mail: [email protected]
PUUY03 Development of a special chipperfor industrial use of forest residues (F)Tommi LahtiLHM-Hakkuri OyE-mail: [email protected]
PUUY04 Crushing of logging residues atthe use site of fuel (F)Seppo PaananenUPM OyjE-mail: [email protected]
PUUY05 Tractor-operated drum-chipper forlogging residues (F)Ari MelkkoHeinolan Sahakoneet OyjE-mail: [email protected]
PUUY06 Technology for producing forestchips at the terminal (F)Jaakko SilpolaVapo OyE-mail: [email protected]
PUUY07 Clinic for wood fuel technologies (F)Dan AsplundJyväskylä Science ParkE-mail: [email protected]
PUUY12 Forest biomass as a real choice ofrenewable energy (F)Arto TimperiTimberjack OyE-mail: [email protected]
PUUY13 Development of a new all-terrainchip harvester (F)Sakari PinomäkiSakari Pinomäki KyE-mail: [email protected]
PUUY14 Trailer combination for transportinglogging residues (F)Jaakko SilpolaVapo Oy EnergiaE-mail: [email protected]
PUUY16 Development of a bundler forlogging residues (F)Fredrik PresslerBiowatti OyE-mail: [email protected]
PUUY18 Design and manufacture ofchipping equipment (F)Jorma IssakainenKesla OyjE-mail: [email protected]
PUUY19 Bundling system for large-scaleutilisation of forest energy (F)Juha PoikolaPohjolan Voima OyE-mail: [email protected]
PUUY21 Combining forest residue transportsand soil preparation (F)Timo HartikainenJoensuu Science ParkE-mail: [email protected]
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PUUY31 Development of a two-stage crusherfor comminution of forest biomass (F)Heikki Paalanen/Juha KorpiJoutsan Konepalvelu OyE-mail: [email protected]
PUUY36 Harvesting of stumps andprocessing of forest fuels (F)Seppo PaananenUPM Oyj, MetsäEmail: [email protected]
PUUY37 Automatic equipment for stumppullingReijo SaarioHykomet OyE-mail: [email protected]
3 Quality control, handling and use
PUUT06 Utilisation of first-thinning wood (F)Raimo AlénUniversity of JyväskyläE-mail: [email protected]
PUUT07 Processing of debarking residuesto fuels (F)Risto ImpolaVTT ProcessesE-mail: [email protected]
PUUT08 Fluidised-bed combustion offorest chips in big power plants (F)Markku OrjalaVTT ProcessesE-mail: [email protected]
PUUT09 Quality management of wood fuels,effect of storage techniques on drying ofwood fuels and on quality control fromstump to combustion (F)Kari HillebrandVTT ProcessesE-mail: [email protected]
PUUT15 Upgrading of combustion-technicalproperties of by-products from wood-processing industries (F)Raija RautiainenVTT ProcessesE-mail: [email protected]
PUUT17 Enhancement of back-pressurepower production in pulp and paper mills (F)Pekka AhtilaHelsinki University of TechnologyE-mail: [email protected]
PUUT19 Receiving and handling systemsfor wood fuels (F)Risto ImpolaVTT ProcessesE-mail: [email protected]
PUUT24 Effect of wood fuels on powerplant availability (F)Markku OrjalaVTT ProcessesE-mail: [email protected]
PUUT25 Flue gas emissions from co-firing ofby-products of plywood and particle boardindustries (F)Raili VesterinenVTT ProcessesE-mail: [email protected]
PUUT29 Chemical changes in wood fuelsduring storage and drying (F)Leena FagernäsVTT ProcessesE-mail: [email protected]
PUUT35 Reduction of bark loss in harvesterloggingAntti AsikainenFinnish Forest Research InstituteJoensuu Research StationE-mail: [email protected]
PUUT37 Chemical effects of the pretreatmentof wood fuelsPaterson McKeoughVTT ProcessesE-mail: [email protected]
PUUT38 Increasing the availability ofwood-fired power plants by improvingwood fuel controlMarkku OrjalaVTT ProcessesE-mail: [email protected]
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PUUT39 Improving the availability of fuelhandling equipment at heating power plantsMartti FlyktmanVTT ProcessesE-mail: [email protected]
PUUY08 Development of storage, materialflow equalising, quality control and boilerfeeding systems for solid biofuels (F)Antti NurmiBMH Wood Technology OyE-mail: [email protected]
PUUY09 Further development of atmosphericCFB gasification technology to improve itssuitability for straw and other agrobiofuels(F)Matti HiltunenFoster Wheeler Energia OyE-mail: [email protected]
PUUY10 Delivery, handling, mixing andfeed of multi-fuels - MF2 (F)Timo JärvinenVTT ProcessesE-mail: [email protected]
PUUY20 Oy Alholmens Kraft Ab:sdevelopment programme for procurement,receiving and storage of solid biofuels andfor an advanced adjustment system forthe boiler (F)Juha PoikolaPohjolan Voima OyE-mail: [email protected]
PUUY24 Development of hopper dischargingcontrol (F)Esko SaarelaRaumaster OyE-mail: [email protected]
PUUY28 Effect of co-combustion of woodand sludges on boiler corrosionAri FrantsiStora Enso Publication Papers Oy LtdE-mail: [email protected]
PUUY29 On-line measuring of moisturecontent and quality of wood fuelsSauli JänttiOy Merinova AbE-mail: [email protected]
PUUY32 Development of receiving andhandling system for loose and bundledforest residuesAntti NurmiBMH Wood Technology OyE-mail: [email protected]
PUUY40 Intelligent feeding system forinhomogeneous biofuelsJari ErkkiläTuotekehitys Oy TamlinkE-mail: [email protected]
4 Impacts on forestry
PUUT10 Effects of slash removal on forestregeneration (F)Timo SaksaFinnish Forest Research InstituteSuonenjoki Research StationE-mail: [email protected]
PUUT11 Environmental aspects of woodenergy chains (F)Helena MälkkiVTT ProcessesE-mail: [email protected]
PUUT14 Effects of intensified recovery ofbiomass in forests (F)Juha NurmiFinnish Forest Research InstituteE-mail: [email protected]
PUUT22 Wood energy and greenhousegases (F)Sampo SoimakallioVTT ProcessesE-mail: [email protected]
PUUT23 Radioactivity of wood fuels and ash,and implications for the use of ashes (F)Virve VetikkoRadiation and Nuclear Safety Authority ofFinlandE-mail: [email protected]
PUUT32 Effect of slash and stump removalon soil preparation and plantingPertti HarstelaUniversity of JoensuuE-mail: [email protected]
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PUUT36 Development of quality control formechanical harvesting of energy woodTage FredrikssonForestry Development Centre TapioE-mail: [email protected]
PUUY17 Environmentally sound afforestationof cut-away peatlands by fixing it up as a newcarbon sink and controlling the impacts (F)Pirkko SelinVapo Oy EnergyE-mail: [email protected]
5 International projects
PUUT16 Competitiveness of new bioenergytechnologies - IEA/Bioenergy (F)Yrjö SolantaustaVTT ProcessesE-mail: [email protected]
PUUT21 Co-combustion of solid biofueland coal (F)Veli-Pekka HeiskanenVTT ProcessesE-mail: [email protected]
PUUT27 Technology transfer on biofuelsbetween USA and Finland (F)Arvo LeinonenVTT ProcessesE-mail: [email protected]
PUUT31 Maximum biomass use andefficiency in large-scale co-firingAnne SuomalainenVTT ProcessesE-mail: [email protected]
PUUT33 Preparation of new bioenergyprojects for the 6th Framework Programmeof European Commission (F)Kai SipiläVTT ProcessesE-mail: [email protected]
PUUY25 Quality determination ofwood fuels used in the Far East (F)Dan AsplundJyväskylä Science ParkE-mail: [email protected]
6 Small-scale production and use
PUUT30 Distribution, handling and qualityimprovement of wood fuels for small-scale useAri ErkkiläVTT ProcessesE-mail: [email protected]
PUUT34 Customer-oriented network tradeand logistics of firewoodLauri SikanenFinnish Forest Research InstituteJoensuu Research CentreE-mail: [email protected]
PUUT41 Drying of wood chips as a part ofheat entrepreneurshipJukka YrjöläSatakunta Polytecnic, Research andDevelopment O’SataE-mail: [email protected]
PUUT42 Drying and quality control offirewoodKari HillebrandVTT ProcessesE-mail: [email protected]
PUUT43 Masonry fireplaces 2001Reijo KarvinenTampere University of TechnologyE-mail: [email protected]
PUUT44 Harvesting alternatives andcost factors of delimbed energy woodAntti AsikainenFinnish Forest Research InstituteJoensuu Research StationE-mail: [email protected]
PUUY26 Palax 450 firewood processor (F)Jaakko ViitamäkiYlistaron Terästakomo OyE-mail: [email protected]
PUUY27 Quality control of wood pelletsin small-scale distribution and handlingSeppo TuomiWork Efficiency InstituteE-mail: [email protected]
95
PUUY30 Quality control and development ofchopped firewoodAki JouhiahoTTS-InstituteE-mail: [email protected]
PUUY33 New generation sauna stovePertti HarviaHarvia OyE-mail: [email protected]
PUUY35 Development of small-scalefluidised boilerKari HämäläinenNew Fire OyE-mail: [email protected]
PUUY38 Development of bioenergy logisticsSampo HumalainenJST-KoneE-mail: [email protected]
PUUY41 Chipping stationVilho WidingLava ja Huolto Heinonen OyE-mail: [email protected]
PUUY42 Development of a combustionbracket for briquettesEsko HukkaPTI-Metalli OyE-mail: [email protected]
PUUY43 A new furnace typeIlkka PaateroKerman Savi OyE-mail: [email protected]
PUUY44 Clean combustion of wood fuelsin a small fireplaceJari ValtonenNarvi OyE-mail: [email protected]
PUUT45 Reduction of emissions fromsmall-scale wood burningHeikki OravainenVTT ProcessesE-mail: [email protected]
PUUY45 Development of a small-scalepelletisation lineAnssi KokkonenJPK-Tuote OyE-mail: [email protected]
PUUY46 Palax Power 100 wood chopperAnssi KoskiYlistaron Terästakomo OyE-mail: [email protected]
PUUY47 Drying and quality control offirewoodJyrki KoukiTTS-InstituteE-mail: [email protected]
7 Surveys financed by the executiveboard
PUUJ01 Guidebook for harvestinglogging residue chips (F)Tage FredrikssonWood Energy AssociationE-mail: [email protected]
PUUJ02 Survey of the use of forest chips (F)Pentti HakkilaVTT ProcessesE-mail: [email protected]
PUUJ03 Survey of research, developmentand use of wood energy in EU (F)Pirkko VesterinenVTT ProcessesE-mail: [email protected]
PUUJ04 A pre-study of using stumps androots as fuel (F)Ari ErkkiläVTT ProcessesE-mail: [email protected]
PUUJ05 Effect of wood fuels on theoperational economy of power plants (F)Jouni HämäläinenVTT ProcessesE-mail: [email protected]
PUUJ06 Production costs of pellets fordifferent plant integrates (F)Martti FlyktmanVTT ProcessesE-mail: [email protected]
PUUJ07 Guidebook for harvesting chipsfrom young forestsTage FredrikssonThe Forestry Development Centre TapioE-mail: [email protected]
96
PUUJ08 Quality survey of forest chips (F)Risto ImpolaVTT ProcessesE-mail: [email protected]
PUUJ09 Buffer stockpiling of wood fuels (F)Arvo LeinonenVTT ProcessesE-mail: [email protected]
PUUJ10 Feasibility of fuel drying at heatingand power plants (F)Martti FlyktmanVTT ProcessesE-mail: [email protected]
PUUJ11 Forest chips and forestry (F)Pertti HarstelaFinnish Forest Research InstituteSuonenjoki Research StationE-mail: [email protected]
PUUJ12 Bottlenecks in receiving, handlingand feeding systems of wood fuels (F)Timo JärvinenVTT ProcessesE-mail: [email protected]
PUUJ13 Changes in the competitiveness ofbioenergy in Europe (F)Pirkko VesterinenVTT ProcessesE-mail: [email protected]
8 Demonstration projects
PUUD1 Short-distance hauling of loggingresidues, and storage containerSavonlinna Vocational Institute
PUUD2 Truck for loose logging residuesHaulage Contractors Hakonen ja Pojat
PUUD3 Biomass balerRis-Esset Ab Oy
PUUD4 Production of forest chips atterminalsVapo Oy Energy
PUUD5 Giant chipperKotimaiset Energiat Ky
PUUD6 drum chipper TT-1310RMLTmi Hake-Energia Kari Vainikka
PUUD7 Long-distance transport of loggingresiduesVapo Oy Energy
PUUD8 Chipper-trucksBiowatti Oy
PUUD9 Biomass balerMachine Service Hölrin Oy
PUUD10 Drum chipper TT-1310 RMLChipping Group Kankaanmäki
PUUD11 Pika terrain chipperBiowatti Oy
PUUD12 Stationary biomass crusherOy Alholmens Kraft Ab
PUUD13 Biomass balerTmi Matti Sadeharju
PUUD14 Biomass balerH & H Ala-Korpi
PUUD15 Giant chipperKotimaiset Energiat Ky
PUUD16 Compaction device for loggingresidue truckBiowatti Oy
PUUD17 Biomass balerHaulage Company J. Kakko Ky
PUUD18 Biomass balerMachine Contractors Viitanen Oy
PUUD19 Harvester for small-dimensionedwoodMachine Contractors Autio Oy
PUUD20 Biomass balerMika Ruokola Ky
PUUD21 Biomass balerMika Ruokola Ky
PUUD22 Biomass balerForest Vihavainen Ky
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PUUD23 Mobile two-stage crusherFore Energia Oy
PUUD24 Biomass balerTenho Pulkkinen
PUUD25 Biomass balerEarthworks Jouko Laakso Oy
PUUD26 Biomass balerMika Ruokola Ky
PUUD27 Biomass balerForest Vihavainen Ky
PUUD28 Chipper-trucksBiowatti Oy
PUUD29 Biomass balerOtava Pauli
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Tekes’ Technology Programme Reports
99
6/2004 Developing Technology for Large-Scale Production of Forest Chips – WoodEnergy Technology Programme 1999–2003. Final Report. 98 p. Pentti Hakkila
5/2004 Puuenergian teknologiaohjelma 1999–2003 – Metsähakkeen tuotanto-teknologia. Loppuraportti. 134 s. Pentti Hakkila
4/2004 Diagnostiikka-teknologiaohjelma 2000–2003.
3/2004 Metallurgian mahdollisuudet 1999–2003. Loppuraportti.
2/2004 Moottoritekniikan teknologiaohjelma – ProMOTOR 1999–2003.
Loppuraportti. 110 s.
1/2004 Polymeerit tulevaisuuden rakentajina, Potra 2000–2003.
23/2003 Prosessiteollisuuden online-mittaustekniikat -teknologiaohjelman 1999–2002arviointi. Arviointiraportti. 15 s. Kalle Laine
22/2003 Presto – future products. Added Value with Micro and Precision Technology1999–2002. Final Report. 110 p.
21/2003 Evaluation of the EXSITE Programme. Evaluation Report. 72 p.Risto Louhenperä, Olle Nilsson
20/2003 Climtech-ohjelman toimintamallin arviointi ja kansallisen ilmasto- jateknologiastrategian ennakoiva arviointi. Arviointiraportti.
19/2003 USIX – Uusi käyttäjäkeskeinen tietotekniikka 1999–2003. Loppuraportti.71 s.
18/2003 Toimialoja kehittävien ohjelmien – KIVI, Divan, SPIN – arvionti.Arviointiraportti.
17/2003 Divan – Huonekalualan teknologia- ja kehittämisohjelma 1999–2002.
Loppuraportti. 20 s. Leila-Mari Ryynänen
16/2003 Kiviteollisuuden teknologia- ja kehittämisohjelma 1999–2002. Loppuraportti.67 s.
15/2003 Ohjelmistotuotteet – SPIN 2000–2003 -teknologiaohjelma. Loppuraportti.174 s.
14/2003 Jätteiden energiakäyttö -teknologiaohjelma. Loppuraportti. 148 s.
13/2003 Targeted Technology Programmes: A Conceptual Evaluation – Evaluation ofKenno, Plastic processing and Pigments technology programmes.Evaluation Report. 104 p. Erkko Autio, Sami Kanninen, Bill Wicksteed
12/2003 Muuttuva insinöörityö- ja ajattelutapa. Polttoprosessien mallinnus CODE-teknologiaohjelman vaikuttavuuden arviointi. Arviointiraportti. 32 s.Lasse Kivikko
11/2003 Osaamisen ja tiedonsiirron merkitys teknologiaohjelmissa – STAHA-,PRESTO- ja VÄRE-teknologiaohjelmien arviointi. Arviointiraportti.
10/2003 VÄRE – Control of Vibration and Sound Technology Programme 1999–2002.Final Report.
9/2003 Terve talo -teknologiaohjelma 1998–2002. Loppuraportti. 121 s.
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