economic and technical aspects of biogases and their injection, growth potential for biomass/biogas...
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Economic and technical aspects of biogases and their injection,
growth potential for biomass/biogas in Germany
Uwe Klaas
DVGW e.V., Bonn, Germany
www.dvgw.de
European directive 2003/55/EC
Adopted on 26 June 2003 by the European parliament; Scope:
– natural gas
– liquefied natural gas
– biogas
– gas from biomass
– all other types of gases that can meet necessary quality requirements for access to the natural gas system.
Member States should ensure that, taking into account the necessary quality requirements, biogas and gas from biomass or other types of gas, are granted non-discriminatory access to the gas system, provided such access is permanently compatible with the relevant technical rules and safety standards.
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Gases within scope of the MARCOGAZ recommendation “Injection of Gases from Non-Conventional Sources into Gas Networks”
Gases from thermal or fermentation processes:– Biogas from agriculture;
– Sewage gas;
– Landfill gas;
Coal-bed methane and coal mine methane; Hydrogen-rich gases from gasification of e.g., biomass, or other
chemical processes– Gases (“Biosyngas”) from gasification processes based on biomass as
“energy plants”;
– But also the “classical” gasification of coal is a limit case: is that process still “conventional”?
Hydrogen produced from electrolysis (generally using renewable energy as e.g. hydro power, solar power or windmills).
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Indicative composition of different raw gases
Composition Units
Natural gas
(typical North Sea
H)
Biogas Coal-associatedgas
Biomassgasification
Anaerobic digester Landfill CMM CBM O2-fired Air-fired
Methane
mol%
88.8 (86.6 - 88.8)
65.0(50 - 80)
45.0(30 - 60) 65.0 90.0 15.6
(0 -18) 2.0
(1 – 10)
C2+ Hydrocarbons
8.3(8.3 – 8.5) - - 1.5 2.2 5.8
(0 - 5.8) (0 – 2)
Hydrogen - (0 - 2) 1.5(0 - 2) - - 22.0
(4 - 46)20.0
(10 – 25)
Carbon monoxide - - - - - 44.4
(13 - 70)20.0
(9 – 25)
Carbon dioxide
2.3(1.9 - 2.3)
35.0(15 - 50)
40.0(15 - 40) 16.0 3.3 12.2
(2 - 35)7.0
(7 – 16)
Nitrogen 1.1(0.9 - 1.1)
0.2(0 - 5)
15.0(0 - 50) 18.0 4.5 0
(0 - 7)approx.
50.0
Oxygen < 0.01 (0 - 1) 1.0(0 - 10) 0.5 - - -
Hydrogen sulfide
mg/m3
1.5(0 - 5)
< 600(100 - 10000)
< 100(0 - 1000) (0 - 5) (0 - 5)
Ammonia - 100(0 - 100)
5(0 - 5) - - - -
Total chlorine - (0 - 100) (0 - 800)
Total fluorine mg/m3 - 0.5(0 - 100)
10(0 - 800) - - - -
Siloxanes mg/m³ - 0 - 50 0 - 50 - - - -
Tar g/m³ - - - - - 0 - 5 0,01 - 100Source: MARCOGAZ recommendation
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Indicative properties of different raw gases
Properties Units
Natural gas
(typical North Sea
H)
BiogasCoal-associated
gasBiomass
gasification
Anaerobic digester
Landfill CMM CBMO2-
firedAir-fired
Gross calorific value (1)
MJ/m3 40 32 17 25 36 14 6
kWh/m³ 12 7 7 7 10 4 3
Net calorific value(1)
MJ/m3 35 22 21 23 32 13 9
kWh/m3 10 6 6 7 9 4 3
Wobbe Number (1)
MJ/m3 50 26 27 29 45 29 20
kWh/m3 15 8 8 8 13 8 6
Relative Density (1)
0.6 0.9 0.7 0.8 0.6 0.2 0.3
Density (1) kg/m3 0.7 0.8 0.8 0.8 0.7 0.3 0.3
MethaneNumber (2)
76 135 144 109 90 64 77
Sources: GERG-Report PC 1 "Biogas characterization WG 1.49" (2) calculated in accordance with AVL-List
Source: MARCOGAZ recommendation
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Treatment
Depending on the utilization of the gas its treatment is required. This will generally include:
• Drying of the gas (always);
• Desulfurization (nearly always);
• Removal of inert gases as CO2 (nearly always);
• for gases deriving from fermentative processes eventually removal of biogenic substances by filtration (often not specially required, being a side effect of desulfurization);
• for gases deriving from thermal processes often methanisation (final products of many thermal gas production processes are for the best part hydrogen and carbon monoxide);
• Odorization
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Injection of biogases
Bio- and sewage gases may be treated to be used either as augmentation gas or as exchange gas for natural gas. The technical conditions shall be laid down on national base, e.g. in Germany by DVGW code of practice 262.
To achieve this, the relevant characteristics of the base gas (natural gas) in the pipeline in which shall be injected shall be regarded. In Germany, these would be the values for natural gas H or L as given in DVGW code of practice G 260.
The injection of biogases and other non-conventional gases shall be performed indiscriminative in accordance to the existing legislative requirements.
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Gas meets specs? Or doesn‘t?
Biogases may be added in two different ways: As exchange gas: the biogas is treated to a quality equivalent or
near the quality of the natural gas, i.e. fully substitutable. Such treatment is of course more expensive, but offers the possibility of access to several biogas producers as long as the pipeline capacity allows.
As augmentation gas: the biogas is not fully treated, i.e. does not meet the specification of the natural gas. Still, for a single producer access may still be possible if the resulting gas mixture meets the specification, depending on agreement between biogas producer and grid operator. However, addition of another biogas off specs might result in the entire gas mixture to become off specs; thus, a case of discrimination would result.
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In addition to the requirements for natural gas as stated in DVGW code of practice G 260, the following requirements exist for the injection of biogases :
• From DVGW G 262: max. 6 Vol.-% CO2,
max. 5 Vol.-% H2;
• from DVGW G 685 (Gas billing), 5.4.2: Variation of the gross calorific value of the gas mixture over a billing period in a grid with more than one gas quality not exceeding 2 %;
• Proof of hygienic harmlessness;
• Pressure at the level of the pipeline into which is injected.
Utilization in gas supply (German case)
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Criteria for biogas injection
• Continual injection of gas shall be possible Limitations by minimum gas sales (seasonal differences)
• Taking the local structure of the gas grid into account (Mixing zones and zones with floating zero point?)
• Good blending of biogas and natural gas / Plug formation at zones with floating zero point
• Local clients of the gas (Sensible industrial clients?)
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Adding propane/air ?
• In order to adjust the Wobbe index and the calorific value it may be necessary, depending on the local gas quality, to add propane and/or air (CO2 removal may not be sufficient)
• Questions arising from addition of propane:
• Is condensation possible?
• Will the methane number change for gas engines?
• Remuneration?
• If the law does not provide remuneration:
•a) How can the addition of propane be measured?
•b) Is this energetic part marketed separately?
• In the nearer future, many grids operated on natural gas L will be transformed to deliver natural gas H– when installing an injection plant this should be considered early.
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Examples for the injection of biogasesIn south-western Sweden some biogas plants are operated by the regional gas supply company Sydgas. The treated gas is completely injected into the gas grid.
A Swiss company (Kompogas AG) offers biogas plants comprising a closed fermenter using the content of the “green bin” as substrate. Some of these plants are operated in Switzerland, others in Germany and other countries. In the Zurich area, the gas of three such plants is treated to a quality comparable to the natural gas in the grid and injected into the local gas grid.
Since December 2006 also in Germany 2 plants comprising injection into the natural gas grid are in operation (Pliening/Bavaria and Straelen/North Rhine region). A further dozen of plants is either under construction or in planning, mostly, but not exclusively on initiative of local gas supply companies.
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Biogas plant Pliening
Source: Own pictures Uwe Klaas
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Biogas plant Pliening
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Biogas plant Laholm/Sweden
Biogas production/ Grid access pipeline
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Okay, now we‘ve got that stuff in the grid. How much to expect?
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BGW/DVGW – study“Analysis and Evaluation of possibilities for utilization of biomass in Germany“ - Objectives and basic questions
• Evaluation of the biomass potential in Germany 2006 till 2030
• Techniques of production, treatment and injection of biogas
• Possibilities of gasification of wood as a source of bio-methane
• Costs evaluation of the utilization of biogas for the production of either electric power, heat or vehicle fuel in comparison to other uses of biomass
• Environmental effects of the use of biomass
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Usable acreage till 2030
Total agricultural acreage : approx. 11,8 Mio. ha (roughly constant)
Solid fuels or substrates* for biogas
Bioethanol
Used as such
RME/Biodiesel
*These acreages may be used either for growing solid fuels or for biogas substrates
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The situation today•Biogas production almost exclusively by fermentation (recently ca. 3500 plants in Germany)
•Acreage for plant cultivation for the production of biogas: 550 000 ha
•This includes for corn (45 t/ha) with a biogas yield of 180 m³/t with 55 % methane in the raw biogas a potential of 2,4 Bill. m³/a methane = 24 Bill. kWh/a (86,4 PJ/a) by reproducible raw materials
•Total potential 72,2 Bill. kWh/a (260 PJ/a)
Industrial and commercial waste material
5%
Municipal waste
11%
Energy plants
33 %
Harvest residues,
manure, straw, grass
51%
Biogas potential distribution according to origin
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Development of the biogas potential until 2030(Results of biomass study)
0
50
100
150
200
2005 2010 2020 2030
Po
ten
zia
l B
iog
ase
rze
ug
un
g +
Ein
sp
eis
un
g g
es. [M
rd. kW
h/a
]
Biogaspotenzialgesamt
Nawaro max.
Nawaro
GŸlle
sonst. Reststoffe
Gülle
Approx. 10% of expected German natural gas consumption in 2030
Wuppertal institute expects that approx. 60% of the technical potential may
be realized. Development path rather dependant from fixed conditions and subsidizing.
Conditions:•Complete use of the biogas potential for grid injection
Reasons for growth:
•Technical progress at plant level
•Increased acreage efficiency in agriculture
•Optimized fermentation of biomass
Tot
al p
oten
tial b
ioga
s pr
oduc
tion
and
inje
ctio
n (B
ill. k
Wh/
a)
Source: Study of Wuppertal institute
Total biogas potential
Energy plants max.
Energy plants
Manure
Other waste material
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Future cooperation of agriculture and gas industry required
Biogas production
Bio natural gasBio natural gas
(treatment + injection)(treatment + injection)
CHP
Direct power production
BiogasBiogas
(Direct power (Direct power production)production)
Input:-manure, sewage-agricultural raw material (e.g. corn)-organic waste
Biogas treatment
Natural gas pipeline
New utilization pathsutilization paths:
Biomethane
Fuel sector
Heating market
CHP
Expected biogas potential
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Expected biogas potential
Acreage competition
Biomass action plan: +in the beginning, sufficient potential for further growth is present.
+ potential not used so far must be developed – as e.g. derelict land, small private forests
+ industrialized countries with a large population will depend on imports from other EU member countries and from countries outside the EU.
ALARM! Beer prices already increased in Bavaria – barley being used for biogas production!
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Bio-natural gas: markets of use
Heating market
Power market
Fuel market
EIL* / CHP law
no support
Taxadvantage
Markets for utilizationRemuneration in
accordance of use
*EIL: Energy injection law
Bio-natural gas
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Back-up Klaas Biogas Paris
www.dvgw.deSource: Biopact, Brussels
Scheme of an biogas production plant
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Potential additional hazards of biogases
The following kinds of hazard have to be taken into account: hazards on human health of end-users and for employees of e.g. the
gas industry:– direct toxicity in case of leak in a semi-confined environment;
– indirect toxicity by combustion products;
– water pollution in case of injection in subterranean storage;
– air pollution;
hazards on gas networks integrity:– Corrosion;
– clogging of pipelines and safety devices;
hazards to the safe operation of gas appliances:– Corrosion;
– clogging of safety devices
– undue change of combustion properties.
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Schematic example for the injection of gases from non-conventional sources into natural gas networks
Cleaning +
Treatment
V
H-Gasor
L-Gas
H-Gasor
L-Gas
Local utilization
Production
EN ISO 13686Methods of treatment
for the respective type of NCS
V
Laws,
directives,
technical rulesand literature
Componentsand
processes
Gas supply
|-------------------------------->
Blender
Compressor
Compressor Control devices
Exchange gas
Augmentation gas
System barrier
Control devices H-Gasor
L-Gas
H-Gasor
L-Gas
H-Gasor
L-Gas
Safety data sheet for
natural gas
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Desulfurization
Regeneratively produced gases may also be desulfurized using well established methods as e.g. the use of gas cleaning mass (iron ore).
In agricultural biogas plants the major fraction of the sulfur is precipitated by injection of a certain volume of air into the gas volume of the fermenter.
More professional and applied in many smaller treatment plants is the reaction of hydrogen sulfide with oxygen and iodine doted active charcoal to result in elementary sulfur. However, after some time the charcoal needs replacement and safe disposal.
Another method applied is the dry desulfurization of the gas by reaction of hydrogen sulfide with iron hydroxide and oxygen which also yields elementary sulfur.
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Methane enrichment/ CO2-removal
Most applied methods are the pressurized washing with either water or organic solvents, and the pressure swing absorption (PSA).
Dry methods utilize molecular sieves, active charcoal or membranes for the removal of the inert gas components.
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Drying of the gas
For nearly all applications the gas needs to be dried, depending on the choice of the other treatment methods – if dry or wet method – either at the beginning or at the end of the treatment process. For smaller plants, often cryogenic methods are applied, for larger ones e.g. glycol washes.
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Additional potential hazards associated with landfill gas and countermeasures applied
Product SourceHazardous
componentsHazard for health
Hazard related to transmission,
distribution and useCountermeasure
BiogasLandfill gas
Halocarbons
Production of dioxins and furans under burner conditions
Corrosion
Sampling and analysis for halocarbons. Exclusion of sources of known halocarbon content.
Biological agents
Possible presence of pathogenic agents (need to be demonstrated)
Biocorrosion of gas networks
Hygienization of the substrateLong digester retention timeFiltration (see note below).
SiloxanesProduction of silica under burner conditions
Sampling and analysis for siloxanes. Exclusion of sources of known high silicon content. Removal of siloxanes from product.
Ammonia Toxic gas Corrosion Removal of ammonia
Polyaromatic hydrocarbons (PAHs)
Toxic, carcinogenAffects plastic and elastomere material; sooting when burnt
Permanent monitoring and removal
Source: MARCOGAZ recommendation
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Additional potential hazards associated with biogas and countermeasures applied
Product SourceHazardous
componentsHazard for health
Hazard related to transmission,
distribution and use
Countermeasure
BiogasDigester gas
SiloxanesProduction of silica under burner conditions
Sampling and analysis for siloxanes. Exclusion of sources of known high silicon content. Removal of siloxanes from product.
Biological agents
Possible presence of pathogenic agents (need to be demonstrated)
Biocorrosion of gas networks
Hygienization of the substrateLong digester retention timeFiltration (see note below).
Ammonia Toxic gas Corrosion Removal of ammonia
Halocarbons
Production of dioxins and furans under burner conditions
Corrosion
Sampling and analysis for halocarbons. Exclusion of sources of known halocarbon content.
Source: MARCOGAZ recommendation
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Development of energy potential of reproducible raw materials till 2030
• Assumed increase of productivity: 2% p.a.
• Acreage for the production of bio diesel is assumed as more or less constant (Cultivation of rape seed for the production of bio diesel)
• Acreage increase for the cultivation of wheat for the production of bio ethanol up to 250 000 ha until 2020
Renewables wood/straw corn rapeseed wheat others
total acreage Germany
acreagetsd. ha
potentialbill.
kWh/a
acreagetsd. ha
potentialbill. kWh/a
acreage potentialbill.
kWh/a
acreagetsd. ha
tsd. ha tsd. ha
thermochemical biochemical physicochemical
pausing acreageactive acreage 2005
550 28as thermo-chemical 24
342400 150 14 100
11.825 tsd. ha1.200 ha
pausing acreageactive acreage 2020
1.150 79 68400400 250 21 200 2.000 tsd. ha
pausing acreageactive acreage 2030
1.600 14 115400400 250 26 350 2.600 tsd. ha
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Specific requirements for NCS gas injection Austria France Germany Netherlands Sweden Switzerland
Property UnlimitedInjection
Limitedinjection
CH4> 96 % / - 85% >97% >96% >50%
CO2< 3 % <2,5% 6% / <3% <4% <6%
CO <2% / / / / /Total S < 10 mg/m³ < 30mg/m³ 30 mg/m³ <45 mg/m³ < 23 mg/m³ < 30mg/m³ < 30mg/m³
H2S < 5 mg/m³< 5 mg/m³
(H2S+COS) 5 mg/m³ < 5 mg/m³ 10 ppm < 5 mg/m³ < 5 mg/m³
Mercaptans < 6 mg/m³ <6 mg/m³ 15 mg/m³ / / / /O2
< 0,5 % <0,01% <0,5% <0,5% <1% <0,5% <0,5%
H2< 4 % <6% 5 % / <0,5% <5% <5%
H2OWater dew point
-8°C/40 barWater dew point<-5°C at MOP
Water dew point:Ground
temperature<32 mg/m³ <32 mg/m³ <60% <60%
Hydrocarbon dew point 0°C at OP <-2°C (1-70 bar) Ground
temperature / / / /
Wobbe index 13,3 – 15,7kWh/m³
13,64-15,7 kWh/m³ for H gas
12,01-13 kWh/m³ for B gas
10,5 – 15,7 kWh/m³ 43,6-44,41 MJ/m³
45,5-48,5 MJ/m³ 13,3-15,7 kWh/m³ /
Pressure Pressure of pipeline to be injected into
Gross calorific value
10,7-12,8kWh/m³
10,7-12,8 kWh/m³ for H gas
9,5-10,5 kWh/m³ for B gas
/ 35,1 MJ/m³ / 10,7-13,1 kWh/m³ /
Relative density 0,55-0,65 0,555-0,70 / / / 0,55-0,70 /
OdorantGas to be
odorized at consumer
15-40 mg THT/m³ Gas to be odorized at consumer
Gas to be odorized at consumer
/ 15-25 mg THT/m³ 15-25 mg THT/m³
Impurities Technically pure Technically pure Technically pure Technically pureHalogenated compounds 0 mg/m³ < 1 mg Cl /m³
< 10 mg F /m³ nil < 25 mg Cl/m³ / /
Ammonia Technically pure / / <3 mg/Nm³ <20 mg/Nm³ / /
Dust Technically pure / No dust No dust
Mercury < 1 μg/m³ / / / / /
Benzene
Siloxanes < 10 mg/m³
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Gas quality requirements in different countriesAT BE DK DE FR IT NL4 ES UK
Reference Temperature, °CVolumeEnergy
025/0 0
25/0025/0
025/0
00/0
1515/15
025/0
00/0
1515/15
GCV X X X X X X
Wobbe index X X X X X X
Density X X X X
Methane number
Hydrocarbon dew point X X X X X
Water dew point X X X X X X
Sulfur
Total X X X X X X X
H2S X X X X X X X X
Odorant2, 3 X X X
Mercaptan X X X
COS X
Other indices1
Comb. Potential
Lift Index
ICF X
Soot index X
CO X
Carbonyl metals
Impurities (liquids, solids) X X X X X
CO2X X
N2X
O2X X X X
H2X X
Aromatics5
NH3X X
Hg5 X
Source: MARCOGAZ recommendation
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Advantages of bio-natural gas in comparison with other regenerative energy resources
Sustainability The production of bio-natural gas offers a closed material circuit.
Low pollutant emissions Bio-natural gas burns just like natural gas and offers adequate emission advantages: very low NOx and CO values, no fine dust.
Versatile utilization The flexibility in the areas of utilization traffic, heating market and power production is outstanding.
Highest efficiency in traffic application
Compared with other biogenic fuels bio-natural gas offers the highest fuel harvest per acre. With bio-natural gas from 1 acre the mileage is triple than that of the bio diesel to be gained from an acre.
Suitable for base load The bio-natural gas from a biogas plant delivers steady energy for approx. 8.000 hrs/a.
Storable In conjunction with the natural gas grid and storages bio-natural gas becomes a storable energy.
Controllable Opposite to solar or wind power bio-natural gas is a controllable energy.
No additional logistics Bio-natural gas may be transported through the natural gas grid in a safe, environmental friendly and at reasonable costs. Means of transport as e.g. lorries are not required.
No depreciation of investment
The entire natural gas infra structure and the equipment at the user’s premises may be used without limitation. Thus, no investment depreciation.
Immediately useable The market penetration with efficient techniques of utilization enable already today the unrestricted use of bio-natural gas without additional investment for the natural gas/bio-natural gas client.
Low space requirements A storage for e.g. wood pellets or chippings at the user’s premises is not required. To store the energy content of 100 l heating oil in shape of wood chippings approx. 1 m³ is required.
Defined quality Bio-natural gas offers the same defined, constant quality as natural gas and shows no variation of quality as wood, wood chippings or pellets.
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Bio-natural gas for CHP - Specific greenhouse gas emissions in 2010
Power from mix
Power from natural gas
Power from biogas
Heat from mix
Heat from biogas
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Bio-natural gas: markets of use
Heating market
Power market
Fuel market
EIL* / CHP law
no support
Taxadvantage
Markets for utilizationRemuneration in
accordance of use
*EIL: Energy injection law
Bio-natural gas
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Bio-natural gas as vehicle fuel
Sustainability with bio-natural gas in traffic:Achievable kilometreage with the energy of one hectare
*Bio-natural gas from by-products (rapeseed cake, slurry, straw) vehicle fuel consumption: Otto engine 7,4 l/100 km, Diesel engine 6,1 l/100 km
BtL (Biomass-to-Liquid)4.030 l
Bio-natural gas3.560 kg
Rapeseed oil1.480 l
Bio diesel1.550 l
Bio ethanol (from grain) 2.500 l
Source: Fachagentur Nachwachsende Rohstoffe
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Bio-natural gas: markets of use
Heating market
Power market
Fuel market
EIL* / CHP law
no support
Taxadvantage
Markets for utilizationRemuneration in
accordance of use
*EIL: Energy injection law
Bio-natural gas
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Bio-natural gas as heating carburantSpecific costs of bio-natural gas to avoid CO2-emissions are significantly lower for new buildings
Specific costs to avoid CO2- emissions
Energy requirement/ Insulation level
Example: House equipped with natural gas recondensing boiler
Insulation: very high additional investments, long durability
Environmental heat (solar, heat pump): significant additional costs
Bio-natural gas: lowest costs despite higher carburant costs
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The German gas industry and biogas
The German gas industry is, in cooperation with agriculture, committed to create a competitive biogas market. This is also expressed in the declaration of commitment issued by the BGW, the German Association of the German gas and water industries, on 24 August 2007.
The objectives set by the politicians are: the share of renewables in energy supply of new private homes
shall be 20 %; the dependency from natural gas imports shall decrease; the emission of greenhouse gases shall be significantly reduced; the development of energy production from renewables will create
some 100.000 new jobs in the country.
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Bio-natural gas market – Preliminary conclusion
• Market predetermined by politics
• Fast growth possible
• Economical viable
• Existing support systems improvable
• Risk of political misguidance
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Biomass potential in Germany:systems
Biogeneticprimary energy Conversion Secondary energy Final utilization of
energy
Technical energy carrier potential Possible contribution of biomass to the supply of Energy
PressingEsterization etc.Rape seed Bio diesel (RME) Use as
vehicle fuel
Waste wood Chipping Wood chipsHeat production
MaisFertilization Biogas Power production
Examples:
Corn
Manure
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BGW/DVGW – study“Analysis and Evaluation of possibilities for utilization of biomass in Germany“
In January 2006 a study initiated by the associations of the German gas and water industry BGW and DVGW was published. The steering committee comprised besides representatives of the gas industry also the German biogas association (Fachverband Biogas e.V.), the German farmers association (Deutscher Bauernverband), the federal German ministry for the environment, the federal German ministry for consumer protection and agriculture and the states ministries for agriculture and for the economy and energy of Bavaria. The study was performed under conduct of the Wuppertal institute, split into work packages, by the institute for energetics (IE Leipzig), the Fraunhofer institute for the environment, safety and energy techniques (UMSICHT, Oberhausen) as well as the gas heat institute (Gaswärme-Institut GWI, Essen)