LCA of biofuels: developments and constraints

Transcription

1 LCA of biofuels: developments and constraints Dr. Julio C. Sacramento Rivero Faculty of Chemical Engineering Universidad Autonoma de Yucatan 1

2 Contents Scope of this presentation Brief overview of LCA methodology Quick critical review of LCA of biofuels in Latin America Challenges for LCA standardisation (biofuels in LA) LC Inventories & system boundaries LC Impact Assessments Co-product allocation 2

3 Scope Shed some light on biofuels LCA s common practices in the Americas Aiming to provide standardised guidance of LCA methodology, for greater: Accuracy Transparency Comparability 3

4 Overview of biofuels LCA LCA: evaluation of inputs, outputs, and impacts in all stages of the product/service life cycle. Most used tool for Environmental performance comparison of biofuel alternatives More than 30 years old: started as an energy optimisation tool Current standard framework: ISO series (since 1997) 4

5 Overview of biofuels LCA Raw materials extraction Processing Resources: materials and energy Transport Manufacture Usage Emissions and impacts i.e. water, air, soil Waste management 5

6 Overview of biofuels LCA KAMMEN et al (2007) Energy and greenhouse impacts of biofuels: a framework for analysis, Organization for Economic Co- Operation and Development (OECD), Berkeley, USA: International Transport Forum 6

7 Overview of biofuels LCA 1. Define goal and scope Functional unit System boundaries (space and time) 4. Results Interpretation 2. Inventory Analysis 3. Impact Assessment Classification / Characterisation Data quality Representativeness Methodology selection Categories Selection Allocation method Normalisation* 7

8 Analysis of biofuels LCAs in LA Sources: International Scientific Journals Papers from the last 10 years Total of 32 relevant LCAs selected for the analysis Available USA and EU studies are far more, mainly on 1st generation biofuels 8

9 Overview of biofuels LCA 1. Define goal and scope Functional unit System boundaries (space and time) 4. Results Interpretation 2. Inventory Analysis 3. Impact Assessment Classification / Characterisation Data quality Representativeness Methodology selection Categories Selection Allocation method Normalisation* 9

10 Analysis of biofuels LCAs in LA Functional unit (depends on the goal of the study) System boundaries 10

11 Overview of biofuels LCA 1. Define goal and scope Functional unit System boundaries (space and time) 4. Results Interpretation 2. Inventory Analysis 3. Impact Assessment Classification / Characterisation Data quality Representativeness Methodology selection Categories Selection Allocation method Normalisation* 11

12 Analysis of biofuels LCAs in LA LCI database 12

13 Overview of biofuels LCA 1. Define goal and scope Functional unit System boundaries (space and time) 4. Results Interpretation 2. Inventory Analysis 3. Impact Assessment Classification / Characterisation Data quality Representativeness Methodology selection Categories Selection Allocation method Normalisation* 13

14 Analysis of biofuels LCAs in LA Impact Assessment Methodology 14

15 Analysis of biofuels LCAs in LA CML Impact Categories 15

16 Impacts Resources Analysis of biofuels LCAs in LA Primary energy consumption Abiotic Resources Depletion Water consumption Land Use Biotic Resources Depletion Global Warming Eutrophication Acidificación Human toxicity Photochemical ozone formation Terrestrial Eco-toxicity Ozone Layer Depletion Freshwater Eco-toxicity Marine water Eco-toxicity Biofuels win Biofuels lose Varies 16

17 Challenges in LCEB: CO 2 accounting Are biofuels really carbon neutral? 17

18 Challenges in LCEB: CO 2 accounting Are biofuels really carbon neutral? Fossil Energy! Fossil Energy! Fossil Energy! Fossil Energy! 18

19 Challenges in LCEB: CO 2 accounting Are biofuels really carbon neutral? N 2 O Fossil Energy! Fossil Energy! Fossil Energy! Fossil Energy! 19

20 Challenges in LCEB: CO 2 accounting Fertilizer use is responsible for 1/3 of N 2 O impacts Large uncertainties in current LCA databases Data for South America sugarcane varies from kg/ha/a Same region, for african palm: kg/ha/a SMEETS et al (2009) Contribution of N 2 O to the greenhouse gas balance of first-generation biofuels. Global Change Biology, 15(1): Assumption of % of N volatilised: 0.5 5% CRUTZEN et al (2007) N 2 O release from agro-biofuel production negates global warming reduction by replacing fossil fuels. Atmospheric Chemistry and Physics Discussions, 7(4):

21 Challenges in LCEB: LUC dluc iluc Are biofuels really carbon neutral? N 2 O Fossil Energy! Fossil Energy! Fossil Energy! Fossil Energy! 21

22 Challenges in LCIA: Others Same issues than in GHG emissions accounting, but in several categories of concern: Human and ecological toxicity Acidification and Eutrophication potentials Land use/indirect food competition 22

23 Challenges in LCIA: Allocation How do we split the bill? Allocation method for coproducts: Energy (simple; Lower Heating Values) Mass (Bias with high added-value products) Market value (Subject to arbitrary external changes; very dynamic) Different methods give very different results 23

24 Challenges in LCIA: Allocation Case study: LCA of Green Jet fuel production from jatropha oil (Prof. David Shonnard, MTU-SFI) Jatropha Cultivation Harvesting Jatropha Biomass Transport Jatropha Oil Extraction Jatropha Oil Transport Jatropha GJ Production Green Jet fuel Plantation area: 55,000 ha Production: 10 ton/ha/a wet seed 24

25 Challenges in LCIA: Allocation Energy Allocation US DoE 63% 47% 37% 53% 25

26 Challenges in LCIA: Allocation Energy Allocation EU RED 0% 47% 100% 53% 26

27 Challenges in LCIA: Allocation Energy Allocation EU RED 0% 47% 100% 53% Process Modifications according to the demands of the certification schemes! 27

28 Challenges in LCIA: Allocation Displacement Allocation US EPA 28

29 Challenges in LCIA: Allocation GHG Emissions (g CO2 eq/mj of GJ) Fossil Jet* US DoE US EPA EU RED Jatropha Cultivation/Harvest (RMA) Jatropha Seed, Shell Transport (RMT) Combined Seed,Shell,Oil Transport Jatropha Oil Extraction Jatropha Oil Transport GJ Production from Jatropha Oil (LFP) Combined Oil Extraction and GJ Production Co-Product Credit Extraction Stage Co-Product Credit GJ Production Stage -70 Final Product Transport 1 Fossil Jet Fuel Combustion 77.7 Direct Land Use Change (dluc) Total Savings, % US DoE: Energy allocation US EPA: Displacement allocation EU RED: Energy allocation; no credit for electricity cogeneration * From Skone and Gerdes, 2008, Development of Baseline Data and Analysis of Life Cycle Greenhouse Gas Emissions of Petroleum-Based Fuels, DOE/NETL-2009/1346, November 26, RMA = Raw Material Acquisition, RMT = Raw Material Transport, LFP = liquid fuel production 29

30 Closing Remarks LCA allows for quantification of several environmental impacts over the life cycle of biofuels. Needs a careful interpretation of results based on the study assumptions LCA-framework fails to include important issues of sustainability, such as: Avoided land use from co-products iluc Water use Costs (production vs market prices) Social issues and thus requires complementary analyses. 30

31 Closing Remarks LCA evaluates potential impacts, which sum up from emissions produced in different places, at different times. Main sources of inconsistencies in currently published biofuels LCA: N 2 O emissions through volatilisation dluc (what s to be used as former land use?) Analysed Impact Categories Allocation! 31

32 Closing Remarks 32

33 Any questions? Dr. Julio C. Sacramento-Rivero Facultad de Ingeniería Química Universidad Autónoma de Yucatán +52(999) x1129 Producción de biocombustibles y su impacto, oct 2012, Mérida, México