Sustainability evaluation of biodiesel from Jatropha curcas L.

Transcription

1 October 18th, 2010 BIO 3 Hermosillo, Sonora, Mexico Arenberg Doctoral School of Science, Engineering & Technology Faculty Bioscience Engineering Department Earth and Environmental Sciences Sustainability evaluation of biodiesel from Jatropha curcas L. A life cycle oriented study Wouter ACHTEN

2 Jatropha curcas L. Was claimed: Not to compete with food (toxic) Not to compete for agricultural land (infertile, arid) Not to compete with nature (degraded, waste land) Enhance rural economic development Reduce greenhouse gases Achten et al. (2010) Biomass & Bioenergy

3 Introduction - Biodiesel By-products Oil extraction CO 2 CO 2 CO 2 CO 2 Biodiesel production CO 2 CO 2

4 Introduction - Biodiesel By-products Oil extraction CO 2 E E Biodiesel production E E CO 2 E

5 Problem statement Energy balance? Greenhouse gas balance? But also Other environmental impacts? Socio-Economy? What is Jatropha s performance? Compared to fossil diesel Compared to other biodiesels (Palm oil)

6 Materials and Methods Environmental impact!life Cycle Assessment is an appropriate tool LCA of Jatropha vs. Palm oil Biodiesel Generic LCA of Jatropha biodiesel Carbon debt due to land use change Economic performance!net present value of Jatropha production for farmers in Tanzania

7 Life Cycle Assessment Life cycle inventory Impact assessment Inputs Outputs Emissions to air CO 2 1! Fertilizer Transport Water Environmental interactions SO 2 23! Global warming potential (CO 2 eq) PO 4 By-products CH 4 297! Fossil Energy Water effluents N 2 O Energy use Machine MJ Source: Achten et al. (2007) BioFPR Products

8 Life Cycle Assessment Impact of 1 MJ Biodiesel: Fossil energy use Global warming potential Acidification and Eutrophication potential Land occupation / use change Ecosystem quality (Achten et al. (2009) LCAinFood) System boundaries Reference system Allocation Source: Achten et al. (2007) BioFPR

9 Jatropha versus Oil palm Jatropha in India Reference system Oil palm in Cameroon wasteland Cultivation System boundary expansion By-products Substitution Extraction System boundary expansion Substitution By-products Agricultural land Cultivation Seeds Crude Jatropha Oil Transesterification Biodiesel Biomass waste Oil extraction Seed cake Glycerol Glycerol Crude fossil oil Processing Fossil Diesel Palm Kernel Meal + animal feed Palm Kernel Oil + Alcohol Ethoxylates Crude Palm Oil Palm Kernel Meal Palm Kernel Oil Olein + Free Fatty Acids Fresh Fruit Bunches Extraction Crude Palm Oil Stearin Refinery POME Transesterification Biodiesel Engine combustion Engine combustion Engine combustion Achten et al. (2010) LCAinFood

10 Results Energy Balance Reduction: 79% Reduction: 45% Achten et al. (2010) Applied Energy Achten et al. (2010) ES&T

11 Results Global Warming Reduction: 55% Reduction: 77% Achten et al. (2010) Applied Energy Achten et al. (2010) ES&T

12 Results - Acidification Increase: 49% Reduction: 5% Achten et al. (2010) Applied Energy Achten et al. (2010) ES&T

13 Results - Eutrophication Increase: 430% Increase: 39% Achten et al. (2010) Applied Energy Achten et al. (2010) ES&T

14 Generic LCA of Jatropha Inventory analysis ( standard system) First hand factory and plantation data through questionnaires: Jatropha entrepreneurs over the world Literature data EcoInvent data base (background processes) Adapted from Trabucco et al. (2010) GCB Bioenergy, Thanks!

15 Results Non renewable energy use: Reduction of 87% compared to fossil diesel Global warming potential: Reduction of 45% compared to fossil diesel Acidification and Eutrophication: Increase of 741% compared to fossil diesel Almeida et al. (in preparation) Thanks!

16 Results

17 Environmental performance Jatropha biodiesel follows similar trends in environmental performance as other biodiesels Jatropha can attain GWP reduction potential, but among the lowest, compared to other biodiesels Jatropha = New system! improvement options: Jatropha cultivation is biggest contributor to impact! Agronomy & Cultivation: Fertilizer! Genetics (Achten et al. (2010) Biofuels) By-product use Achten et al (2010) Applied Energy & ES&T, Almeida et al. (in prepartation) But, what about Land use change? (Carbon debt)

18 Carbon debt & Repayment time GHG emissions Fossil Biodiesel Fossil Land use change: clearing land soil emissions CO 2 (Adapted from Vandenbempt 2008, Thanks!) x Time

19 Carbon debt & Repayment time GHG emissions Fossil Biodiesel Fossil Carbon debt (CO 2 eq per ha) Land use change: clearing land soil emissions CO 2 (Adapted from Vandenbempt 2008, Thanks!) x Time

20 Carbon debt & Repayment time GHG emissions Fossil Biodiesel Biodiesel Fossil Carbon debt (CO 2 eq per ha) LCA Biodiesel system reduces GHG emissions compared to fossil diesel (Adapted from Vandenbempt 2008, Thanks!) x Time

21 Carbon debt & Repayment time GHG emissions Fossil Biodiesel Biodiesel Carbon debt (CO 2 eq per ha) Fossil Repayment time (yr) (Adapted from Vandenbempt 2008, Thanks!) x y Time

22 Data sources Yield data (Trabucco et al 2010) Source: Trabucco et al. (2010) GCB Bioenery

23 Data sources Yield data (Trabucco et al 2010) GHG reduction Generic LCA Specific yield Specific transport distances Specific cultivation practices

24 Repayment time Repayment time of carbon debt by selling seeds after one time investment (years) Minimum 10 yr Six regions repay within first rotation (<20yr) Achten et al. (submitted)

25 Conclusions Jatropha system as such: Follows general biofuel results: E! GHG! Acidification" Eutrophication" Agricultural phase most impactful (Fertilizer) Jatropha system depends on yield Sufficient yield to attain GHG reduction (e.g. Tanzania: min. 750 kg per ha per yr) Yield has to be high enough to justify LUC (e.g. Tanzania: min kg per ha per yr)

26 Conclusions Sustainability is a geographic issue Relative high yields are necessary!jatropha yields are generally low (breeding, selection, cultivation practices can improve) (Achten et al. (2010) Biofuels)!Favorable climate and soils are necessary (Maes et al. (2009) B&B)!Potential carbon debt! (land use change)!potential impact on biodiversity "!Opportunity costs "!Probability of competition with food sector " Opportunities: Optimizing fertilizer use can further reduce GHG Use of By-products can further reduce GHG Achten et al (2010) Applied Energy & ES&T, Almeida et al. (in preparation) Small scale initiatives host opportunities (Agroforestry, Life fencing, ) Achten et al. (2010) JAE

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