2nd gen biofuel

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Rapeseed residues utilization for energy and 2nd generation biofuels

A. Zabaniotou * , O. Ioannidou, V. SkoulouChemical Engineering Department, Aristotle University of Thessaloniki, Un. Box 455, 54124 Thessaloniki, Greece

Received 24 June 2007; received in revised form 28 August 2007; accepted 4 September 2007Available online 29 September 2007

Abstract

Lignocellulosic biomass is an interesting and necessary enlargement of the biomass used for the production of renewable biofuels. It isexpected that second generation biofuels are more energy efficient than the ones of rst generation, as a substrate that is able to com-pletely transformed into energy. The present study is part of a research program aiming at the integrated utilization of rapeseed suitableto Greek conditions for biodiesel production and parallel use of its solid residues for energy and second generation biofuels production.In that context, fast pyrolysis at high temperature and xed bed air gasication of the rapeseed residues were studied. Thermogravimetricanalysis and kinetic study were also carried out. The obtained results indicated that high temperature pyrolysis could produces higheryields of syngas and hydrogen production comparing to air xed bed gasication. 2007 Elsevier Ltd. All rights reserved.

Keywords: Rapeseed residues; Biofuels; Pyrolysis; Gasication; Kinetics

1. Introduction

Directive 2003/30/EC of the European Parliament andthe Council of 8 May 2003 aims at promoting the use of biofuels or other renewable fuels to replace diesel or gaso-line for transport in each Member State, with a view tocontributing to objectives such as meeting climate changecommitments, as well as promoting environmental-friendlysecurity of supply and renewable energy sources. In thiscontext, Member States should ensure that a minimumshare of biofuels or other renewable fuels is placed on theirmarkets and, to that effect, they shall set national indicative

targets.However, the rst generation biofuels seem to createsome scepticism to scientists. There are concerns aboutenvironmental impacts and carbon balances, which set lim-its in the increasing production of biofuels of 1st generation .Additionally, both biodiesel and bioethanol are expensive

options for climate mitigation as compared to biomassfor heat and power generation.

Bomb et al. [1]claimed that environmental impacts asso-ciated with energy crops require sustained investigationsince the environmental impacts and carbon balances of biofuels depend on feedstocks and the way they are farmed,processed and distributed. Biodiesel and bioethanol in theEU has been calculated to result in 1570% greenhousegas savings when compared to fossil fuels [2], while bioeth-anol from Brazil results in over 90% greenhouse gas savings[3].

Frondel et al. [4] based on a survey of recent empirical

studies, found that the energy and greenhouse gas balancesof rapeseed-based biodiesel is clearly positive but it appearsto be unclear whether the overall environmental balance isalso positive. Additionally, they claimed that biodiesel isnot a cost-efficient emission abatement strategy. Thus, forthe abatement of greenhouse gases, they recommend moreefficient alternatives based on both renewable and conven-tional technologies.

Besides, the agricultural rapeseed production capaci-ties for example in Germany, which is the country withthe highest rapeseed production, are almost exhausted

0016-2361/$ - see front matter 2007 Elsevier Ltd. All rights reserved.

doi:10.1016/j.fuel.2007.09.003

* Corresponding author. Tel.: +30 2310 99 62 74; fax: +30 2310 99 6209.

E-mail address: [email protected] (A. Zabaniotou).

www.fuelrst.com

Available online at www.sciencedirect.com

Fuel 87 (2008) 14921502
mailto:[email protected]:[email protected]


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according to Bockey et al. [5]. During the recent years, Ger-many and Austria have been leading in the substitution of diesel with biodiesel and rapeseed-oil biofuels, whileFrance, Spain and Sweden mainly substitute petrol withbioethanol. The market penetration of biofuels addition-ally has been driven by increasing costs for crude oil and

fossil fuels. However, the increasing production clearlyshows its rst limits. In Germany, during 2005, about 1million of hectares were used for the cultivation of rapeseedfor the production of biodiesel [6]. To a certain extend theincreasing demand may be satised by importing feedstockor biodiesel but, in the long term, it is necessary to enhancethe diversity of raw materials [6].

Therefore, it seems that energy crops are technically pos-sible but that no single solution exists to cover every situa-tion [7], pointed out that from a wider viewpoint, choicesmust maximize income, yield, quality characteristics,energy and technical tool savings, manpower, effects onsoil, air and environment both at local and regional levels.In order to balance the cost of crops to biofuels options, itseems obvious that an aspect, which must be studied withparticular care, is the economic exploitation of energycrops by-products determined by multi-functionality of many species [7] Electricity generation on the basis of cropresidues for example, might be a relatively cheaper alterna-tive in terms of abatement cost and an alternative income[4].

It seems then evident that an understanding of the rela-tionship between production of grain and production of the biomass feedstock is important to support the emergingbioenergy technologies. Hoskinson et al. [8] have used a

model the DSS4Ag in order to begin to understandthe relationship between the production of grain and theproduction of biofeedstock, from the standpoint of the eco-nomics of simultaneously producing both. Many othercomputer models of bioenergy systems have been, also,developed. But none of them considered the economics of simultaneous production of an agricultural crop and itscrop residue biomass.

Summarising, it is obvious that:

(1) Besides the biofuels derived from oil crops, grain andsugar crops, which are commonly called biofuels of the 1st generation, lignocellulosic feedstock can offerthe potential to provide novel biofuels, the biofuels of the second generation (Table 1 ).

(2) Electricity generation on the basis of crop residues,might be a relatively cheap alternative in terms of abatement costs and an additional alternative incomesource and employment support measure for the agri-cultural sector.

In that respect, the present study being part of a researchprogram aiming at the integrated utilization of rapeseedinto Greece, attempting to contribute in the above prob-lematic for the biodiesel production and parallel use of

the residues for energy and 2nd generation biofuels produc-

tion. Experiments that took place in Mediterranean region(Greece, Italy, Spain) under the EU program during thelast decades showed positive results [9]. In Greece, rapeseedcan be cultivated as a winter or spring annual crop and at

the moment, its cultivation has been conducted on experi-mental and demonstration scale, with the rst attempt of cultivation at real farmers level through the proposedresearch program. The ability to grow at low temperatures,compared to the other oleiferous crops grown in Greece, isthe most important feature of rapeseed cultivation.

The present research was conducted towards thermo-chemical conversion of rapeseed residues by means of hightemperature pyrolysis and gasication for the productionof a gas suitable for further energy production exploitationor syngas production for second generation biofuels pro-duction. Thermogravimetric analysis was also carried outfor kinetic purposes.

2. Thermochemical conversion

There are two basic procedures to transform solid bio-mass into liquid or gaseous biofuels for the second genera-tion biofuels production ( Fig. 1). One aims at thethermochemical conversion of the total biomass into a highcaloric value synthesis gas with subsequent production of various liquid and gaseous fuels. The other is to transform

Table 1First and second generation biofuels from biomass

Firs t generation biofuels Second generation biofuels

Type Method-Source Type Method-Source

Bioethanol Conventional Bioethenol Lignocellulosic

Biodiesel (FAME/FAEE)

From energycrops

BTL Lignocellulosic

From waste Methanol Synthetic fuels

Pure vegetable oi ls Cold pressed DME LignocellulosicBiogas Conventional Biodiesel NExBTLBio-ETBE From energy

cropsBiohydrogen Lignocellulosic

Fig. 1. Biofuels production from lignocellulosic feedstock.

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parts of the high moisture feedstock material into products(biogas) with a high content of energy by microbiologicalfermentation. This can be attributed to the specic conver-sion of the polysaccharides into alcohols, like bioethanol orbiobutanol, or the conversion of digestible plant biomassinto biogas, which can be puried to biomethane to be

additionally supplied to the natural gas grid.As opposed to the biofuels of the rst generation, bothpathways aim to complete integrate the utilization of bio-mass for energy production purposes. Large by-productsquantities that are driven out of the process and left unex-ploited taking out of consideration of their attractiveenergy content (lignocellulosic biomass) could be an inter-esting and necessary unexploited energy container of thebiomass used for the production of renewable biofuels.New technologies of releasing this spare energy contenthas not been applied or if so, just in pilot-plant scale. Asno data are available for large-scale production, it is hardto get reliable cost estimates or to perform life cycle assess-ments for the various pathways [6].

Nevertheless, although a lot of effort has been focusedinto converting the lignocellulosic by-product materials tofermentable sugars and oils, this is unlikely to ever becomea practical means of utilization of those materials due tothe intractable and complex nature of lignocellulose, whichcontains relatively large amounts of biochemically resistantlignin. This gives the go-ahead to the thermochemical pro-cesses as the means of exploiting these materials. Convert-ing the lignocellulosic by-products materials into energythrough the thermochemical processes emerges as the bestway, as it maximizes production of elemental carbon.

The enormous increase in the production of rst gener-ation biofuels such as ethanol starting with corn grain as araw material and biodiesel from rapeseed, not only gives alittle or no net production of energy overall from thisapproach, it is also causing distortions in the markets forsupplying food products. Crop lignocellulosic by-products,on the other hand, produced in massive quantities world-wide and are readily obtained because it has to be handledanyway in the acquisition of grain [10].

Nevertheless, thermochemical processing of crop by-product residues, found in massive amounts of lignocellu-lose material, has not received the attention that itdeserves. There are few literature data concerning theexploitation of rapeseed residues for energy productionpurposes, although they present very high oileic content.

Haykiri-Acma and Yaman [11] studied rapeseedthrough TG analysis under various dynamic atmospheres,showing the importance of the reactive atmosphere. Rape-seed stalks and straws were, also, studied from Karaosma-noglu et al. [12] using a slow pyrolysis, tubular reactor inorder to study the liquid product. Additionally, Onayand Kockar [1315] studied rapeseed pyrolysis for bio-oilproduction in a xed bed reactor. Finally, Predel andKaminsky [16] studied rapeseed in a uidized bed reactorin order to examine if the valuable contents of this grain

can be obtained under an inexpensive and simpler way.

3. Experimental

3.1. Rapeseed residues

The raw material used for experimentation was solidresidues, remaining on elds from rapeseed cultivation in

real elds being cultivated by Pioneer Hi-Bred HellasS.A. in the region of Western Macedonia in Greece. Priorto use, samples washed from dust, grounded to desirableparticle size (by a small laboratory scale mill) and sievedto powder of


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Chemical formula of the rapeseed solid residues wasbased on their ultimate analysis and was found to be:C1 H 1.49 O0.83 N 0.01 . Based on the chemical formula of rape-seed residues it can be seen at Fig. 3, rapeseed residues are

placed after the solid carbon regarding the decrease of CO 2emissions as a function to C/H ratio of the fuel, eventhought it advantages in all other environmental aspects.

3.2. Fast pyrolysis in a captive sample reactor

The experimental apparatus for fast pyrolysis perfor-mance included a wire mesh sample reactor consisted of two electrodes, an electrical circuit, a water cooling coil,

a trap for moisture, two lters for liquid hydrocarbons, asystem for gas collection and a system of gas analyses(GC). The sample was weighted approximately $ 0.3 gand placed in an envelope of stainless steel 100 mesh. Athermocouple inside the sample, connected with a com-puter through program, provided the relation between tem-

Fig. 2. Decreasing CO 2 emissions in function to the C/H ratio in fuels.

Table 2Ultimate and proximate analysis of rapeseed residues

Proximate analysis (% w/w, dry) Ultimate analysis (% w/w)

Rapeseed residuesMoisture 5.86 C 44.52Ash 3.95 H 5.53Fixed carbon 23.04 O a 49.37Volatiles 73.01 N 0.58Molar type C 1 H 1.49 O0.83 N 0.01

a Calculated by difference.

Table 3Comparison of literature data over elemental analysis and HHV calculation of rapeseed residues (where daf:dry ash free)

C H N O HHV (MJ kg 1 ) HHV calculation Reference

41.1 daf 6 daf 5.1 daf 47.8 19.4 ASTM [11]45.17 df 5.15 df 0.75 df 42.92 17.64 n.a. [12]

44.52 df 5.53 df 0.58 df 49.37 16.8 Calculation [17] Present study



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perature and time (heating rate). Fig. 4 shows the experi-

mental set up of fast pyrolysis [21]. The experiments werecarried out in a temperature range of 480790 C, with aheating rate of 48 C s1 , under atmospheric pressure andhelium atmosphere. The reaction products included char,gas and volatile compounds.

The produced gas was analyzed in a gas chromatograph(6890N, Agilent Technology). The two columns used werePlot Q and Molesieve, with helium as carrier gas. The tem-perature prole of the gas chromatograph was isothermal,at 40 C, and the retention time of the whole analysis was38 min. The standard gas mixture used for the calibrationof the method was CO, CO 2 , H2 , CH 4 , C2 H 4 and C 2 H 61% (v/v) balanced in helium and the volume concentration

was calculated by an external standard method. Gas com-position and yields were resulted based on a linear relation-ship between the concentration and area measured by theprogram. The produced gas composed mainly by CO,CO 2 , H2 , CH 4 , and less by light hydrocarbons (C 2 H 4 andC2 H 6 ). The GC system comprised two detectors, where

thermal conductivity detector (TCD) used for CO, CO 2 ,H 2 , CH 4 , C2 H 4 and C 2 H 6 analysis, and the ame ion detec-tor (FID) for CH 4 , C2 H 4 and C 2 H 6 .

3.3. Gasication in a xed bed reactor

The gasication experiments, with air as a gasicationmedium, performed in a batch, laboratory scale, xedbed reactor, as shown in Fig. 5. The experimental facilityconsisted of ve main parts: (a) the atmospheric downdraftxed bed reactor (b) the air providing section, (c) the gascleaning and sampling section, (d) the temperature control

section, and (e) a gas offline analysis section. The reactorwas constructed from a 316-stainless steel tube and is sur-rounded by an individually controlled electric heater (heat-ing rate $ 15 C min

1 ) that aims at supplying heat for startup and counter heat losses during reactors operation. Thevolume of the reactor is 63 cm 3 and biomass feeding isbatch, performed by hand after appropriate dismantlingof the reactor tube. The temperature is being controlledby a K-type thermocouple placed vertically inside the reac-tor. Air at ambient conditions is introduced into the reac-tor moving downwards to the xed biomass particles.

During experimentation, produced gas exited the reac-tor from the top and passed through a cold trap (ice), a

Fig. 3. TGA of rapeseed residues.

Fig. 4. Schematic diagram of experimental set-up of the laboratory captive sample reactor.

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glass wool lter and a moisture trap (silica gel) and nallywas collected in a bottle from were a sample was taken inorder to proceed the gas composition analysis.

At the start-up of each experimental run, a calculationof the air ow rate was simply determined using a chro-nometer and a volumetric cylinder. Reactor was placedvertically into the furnace and heating was turned on bysetting the controllers at the selected operating tempera-tures of 750950 C in 50 C increments.

After the reactor was placed inside the furnace, the bedtemperature controller was set on and the air ow was,also, turned on. When the bed temperature reached thedesired levels, the experiment stopped. Typically, it tookalmost 20 min for each test to reach the end. A gas samplewas taken and when the reactor was cooled down the charresidue was weighted. Under normal conditions eachexperiment was repeated two times, after thorough clean-ing for eliminating possible memory effects and tar foulingdangers and the results showed a good agreement.

After the experiment stopped clean and dry gas wassampled using airtight gas sampling bags and immediatelyanalyzed on a gas chromatograph (Model 6890N, Agilent

Technologies), with helium as carrier gas, to detect perma-nent gases (H 2 , CH 4 , CO, CO 2 , C2 H 4 and C 2 H 6 ).

4. Results and discussion

4.1. Temperature effect

4.1.1. Fast pyrolysis experimentsPyrolysis products are gaseous, liquid and solid. Yields

of these products are, generally, determined by differentfactors, among which temperature is of high importance.Pyrolysis experiments were carried out in a captive sample

reactor under the temperature range of 480790 C and a

heating rate of 48 C s1 . It was observed ( Figs. 68) thatby increasing the temperature of the reactor, released vola-tiles from biomass particles, and increased the yield of thegaseous products, while decreased char yield. This trendbecomes more perceptible above 650 C. The higher gasyield in this study was 26.79 wt% at 790 C, while the max-

imum char yield reached 28.61 wt% at 480 C.Figs. 912 reveal the effect of temperature on pyrolysisgas composition. Imposing higher temperatures the H 2 per-centage increased and CO 2 decreased. The amounts of CO

Fig. 5. Schematic diagram of experimental set-up of the laboratory xedbed gasier.

Fig. 6. Comparison of the produced char via pyrolysis and gasication.

Fig. 8. Comparison of the produced liquids via pyrolysis and gasication.

Fig. 7. Comparison of the produced gas via pyrolysis and gasication.



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and CH 4 were not affected considerably with temperatureranges. The component with the highest yield in pyrolysisgas was carbon monoxide reaching 44.1% (v/v) at 620 C,while hydrogen reached 45.8% (v/v) at 790 C. Carbondioxide reached $ 11% (v/v), while methane gave a percent-age of 13.62% (v/v). Traces of ethylene and ethane were

also determined but in very low quantities.

The low heating value of the gas was calculated by usingthe following equation [22,23]:

LHV 30:0 CO 25:7 H2 85:4 CH 4

151:3 CnHm 4:2 KJ MJ m 3 2The LHV of the gaseous product was not really affected

by temperature increases. It was uctuated around14 MJ m3 (Fig. 13). The highest LHV observed at620 C where CO and CH 4 reached their maximum yieldand at 790 C because of the high H 2 content. Accordingto Yang et al. [22] such gas belongs to the medium levelgaseous fuels and could be directly used in engines, tur-bines and boilers for power production.

Concerning char analysis, the amount of carbon did notshow particular affection with temperature, while its hydro-gen content decreased ( Fig. 14) as temperature increased.The high and low heating values of char are depicted inFig. 15. It is obvious that there is not much differencebetween the two heating values and there are almost con-stant with temperature. According to the regulation normsfor domestic briquettes [24] (Fig. 14), the pyrolysis char hasa trend to fall in category B, which represents briquetteproduction with carbon content 69% before agglomera-tion. As shown in Fig. 14, the maximum carbon content(65.63%) in pyrolysis experiments was found in char pro-duced at 790 C.

Fig. 10. Comparison of the produced H 2 via pyrolysis and gasication.

Fig. 11. Comparison of the produced CH 4 via pyrolysis and gasication.

Fig. 12. Comparison of the produced CO 2 via pyrolysis and gasication.Fig. 9. Comparison of the produced CO via pyrolysis and gasication.

Fig. 13. LHV of pyrolysis and gasication gas.



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4.1.2. Fixed bed gasication experimentsThe main gasication product was the producer gas.

Pyrolysis experiments were carried out in a captive samplereactor under the temperature range of 750950 C and a

heating rate of $ 15 C s1 . It was observed ( Figs. 68) that

by increasing the temperature of the reactor increased theyield of the gaseous products, while char, liquid yielddecreased. The higher gas yield in this study was27.19 wt% at 950 C, while the lower char and tar yieldreached 20.06 and 27.54 wt% at 950 and 800 C,

respectively.Temperature effect over the producer gas quality is alsodepicted in Figs. 912, under steady oxidizing conditions.Fig. 9 indicates that CO production reached a maximum,at the highest gasication temperature, of 24.48% (v/v).From Fig. 10, it can be clearly seen that H 2 concentrationincreased with temperature and reached a maximum of 28.77% (v/v) at 900 C, while the content of CH 4(Fig. 11) showed an almost stable production trend of $ 8% (v/v).

The above trends could be simply explained as it iswidely known that high temperatures favour the reactantsin exothermic gasication reactions, while in endothermicreactions favour the products, respectively. Therefore, asgasication is a complex process occurring through a num-ber of endothermic and exothermic reactions that strength-ened or became weaker, respectively, with increasing

Fig. 14. Effect of temperature on the wt% C and wt% H of the pyrolyticchar in the captive sample reactor, C/H ratio and categories A and B of regulation norms for xed carbon of charcoal according to Schenkel andGuyot [24].

Fig. 15. LHV of pyrolysis gas and char.



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temperature the evaluation of each gaseous component areexplained.

As it concerns LHV of gasication gas LHV (Eq. (2)) itincreased with temperature as depicted in Fig. 13. LHVwas estimated that follows a slight increasing trend as tem-perature increases reaching at high temperature

10.13 MJ m3

.This could have a strong relationship tothe fact that higher temperatures were more favourablefor raising hydrogen and CO percentage in the gaseousmixture and as a result better heating value gas wasproduced.

4.1.3. Comparison of pyrolysis and gasication resultsComparing the two thermochemical methods it can be

said that high temperature fast pyrolysis showed generallybetter results than gasication. Although the gas yield washigher during the xed bed gasication ( Fig. 7) the gaswas classied as a low heating value gas, while the one

obtained from the fast pyrolysis as a medium heatingvalue gas (Fig. 13). This could be attributed to the factthat as air was used in the gasication, slight oxidizingreactions to CO 2 and H 2 O products were inevitable, com-paring to the completely inert atmosphere where high tem-perature pyrolysis took place and resulted in volatilesrelease. The lower amounts of CO and higher amount of CO 2 in gasication producer gas, in comparison topyrolysis gas, could be an also evidence of the fact thatprobably gasication at even lower oxidizing conditionswould led to more CO production and even more reducedCO 2 emissions.

Temperature increase had an advantageous effect onsyngas (CO + H 2 ) yield, as well. At all gasication temper-atures (% v/v) percentages of syngas was lower that thatproduced by high temperature pyrolysis ( Fig. 16), but tem-perature increases generally seemed to maximize syngasproduction in both processes.

Besides, a gas (from either pyrolysis or gasication) witha yield of (H 2 + CO) (% v/v) >0.8 has a strong reducingpower and could be used as a reducing medium in makingiron sponge (porous iron), a raw material in electric arc fur-

naces [25]. The produced syngas from pyrolysis, in the pres-ent study, showed a sum of (H 2 + CO) varying around 0.8,which makes it appropriate for reduction medium on thecontrary of gasication gas.

Studying the effect of temperature on the H 2 /CO molarratio ( Fig. 17), it would also revealed that the ability to uti-lize such biogas (1 < (H 2 /CO) < 2) for chemical syntheseslike methanol and pure naphtha production [25], FisherTropsh synthesis (ratio $ 2) and even oxo-synthesis pro-cesses (ratio $ 1) is evident [26]. In the present study thegasication produced gas showed an almost constant ratioof H 2 /CO $ 1.2 indicating that this biogas is good not onlyfor Fisher Tropsh synthesis, methanol production, butalso, for oxo-synthesis processes.

In Fig. 17, the molar ratio CO/CO 2 veries the occur-rence of CO 2 as the main product of oxidation reactionsthat embodied to gasication process, while in pyroly-sis at high temperatures CO production is stronglyfavoured.

The main conclusion from the comparison of the twomethods (high temperature pyrolysis vs. gasication of rapeseed residues) is that hydrogen and syngas productionare favoured through high temperature fast pyrolysis oralternatively gasication at very small oxidizing conditions,in order to be used in fuel cells and FT technologies,

respectively.Fig. 16. Comparison of the produced syngas via pyrolysis and

gasication.

Fig. 17. Comparison of the H 2 /CO and CO/CO 2 ratios via pyrolysis andgasication.



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5. Kinetics

The kinetic parameters, activation energy and frequencyfactor could be predicted via non-isothermal thermogravi-metric technique. Thermogravimetric data were used toderive DTG (derivative thermogravimetry) curve whichwas used to calculate the activation energy values of rape-seed residues by the method of CoatsRedfern [27].

The initial equation that many researchers use is by thefollowing equation:

dadt

K i 1 a n

K i k 0i e E i RT

3

Assuming a single and a rst order reaction ( n = 1) themethod that Coats and Redfern suggest is expressed byEq. (2) below

log log1 a

T 2 E 2:303 R 1T log k 0 RqE 4where a = ( m0 mt )/m0 , where m0 the initial mass of the

sample and m t the current mass, and q is the heating rate.The Arrhenius kinetic parameters k 0 , E , were estimatedby the slope and intercept of the line. The slope is theamount ( E /2.303R) where the activation energy was esti-mated, and the intercept was the amount log ( k 0 R /qE )where the pre-exponential factor was estimated. Table 4shows the results of the kinetic parameters.

6. Conclusion

In order to balance the cost of crops to biofuels options,it seems obvious that an aspect, which must be studied withparticular care, is the economic exploitation of by-prod-ucts. With respect to the sustainability, it has also to beproved if other pathways with higher energy efficiency forthe conversion of lignocellulosic biomass exist, e.g. heatand electricity production in heat and power plants. Withinthe energy sector biomass in stationary applications likepower and heat offer best energy efficiency and green housegases emission avoidance.

The attempt to study thermochemical methods as a wayof facing the rapeseed residues as an energy value prod-uct, lead to the conclusion that high temperature fast pyro-lysis, compared to gasication, indicated the suitability of such thermochemical process in terms of syngas and hydro-

gen production.

In the present study, the gasication produced gasshowed an almost constant ratio of H 2 /CO $ 1.2 indicatingthat this biogas is good not only for Fisher Tropsh synthe-sis, methanol production, but also, for oxo-synthesisprocesses.

Acknowledgments

Authors are thankful to European Commission, GreekMinistry of Development-General Secretariat of Research& Technology and Pioneer Hi-Bred Hellas S.A. Companyfor funding this research under PABET2005 program.They also thank Mr. N. Mariolis and G. Zanakis from Pio-neer Hi-Bred Hellas S.A. Company ( www.pioneer.com ) forproviding the rapeseed residues and the laboratory of Chemical Process Engineering for hosting the gasicationexperiments. Special thanks to Dr. G. Stavropoulos.

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Table 4Kinetic parameters of rapeseed pyrolysis

T (K) E (kJ mol1 ) k 0 (s1 )

308373 12.74 0.87473593 58.50 64.1 103

673773 15.31 2

http://www.pioneer.com/http://www.ufop.de/http://www.cres.gr/kape/default_uk.htmhttp://www.cres.gr/kape/default_uk.htmhttp://[email protected]/http://[email protected]/http://www.cres.gr/kape/default_uk.htmhttp://www.cres.gr/kape/default_uk.htmhttp://www.ufop.de/http://www.pioneer.com/


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