Life Cycle Assessment of Biofuels Paolo Masoni ENEA

Life Cycle Assessment of Biofuels Paolo Masoni ENEA – LCA & Ecodesign Lab (ACS PROT – INN) paolo. masoni@bologna. enea. it UNESCO Rome, 2007 18 th January

Table of Contents • Why LCA of biofuels? – Positive and negative effects on the environment – Key impacts • Key methodological issues • Conclusions

Purpose of the lesson • Explain why it is necessary to carry out LCA study of biofuels • Give an overview of the LCA methodological problems to be addressed • Provide a list of main conclusions from existing LCA studies • Give some examples of results from LCA of biofuels

Why LCA of biofuels? • Starting question: Are biofuels positive for the environment? • Annex to Communication from the Commission “An EU Strategy for Biofuels” IMPACT ASSESSMENT: – “Extending the use of biofuels can reduce net greenhouse gas emissions… “ Positive – “The cultivation of energy crops can also impact on biodiversity, soil and water resources. ” Negative – “The positive and negative effects of biofuels on exhaust emissions must be carefully monitored” Uncertain

LCA confirmed as appropriate tool • Public consultation from EC on biofuel directive: – “Stakeholders generally agree that a well to wheel environmental evaluation from a broad, macro perspective is the most appropriate view to these issues, including also for example byproducts and their use, and the net demand for external resources such as clean water and fertilizers” – “It is suggested that an international CO 2 calculation tool should be developed”

Biofuel life cycle Fertiliser Fuel Pesticides Competitive land use Agriculture Co-products Processing Distribution Use Residues from other life cycles Alternative use of residues

Key impacts: GHG emissions CO 2 CH 4 emissions from use of fossile fuels Fertiliser Fuel N 2 O emissions from use of fertilisers in crops cultivation Pesticides Relevant GHG gases: CO 2 (GWP =1) CH 4 (GWP =23) N 2 O (GWP =296) Competitive land use Agriculture Co-products Processing CO 2 CH 4 avoided emissions for production of coproducts Distribution Use Residues from other life cycles Alternative use of residues “recycling” of CO 2 emitted when biofuels are consumed Attention! Biofuels are NOT carbon neutral

Key impacts: feedstock cultivation • Land use: – Biodiversity – Soil quality – Avoiding land abandonment • Change in crops – Water quantity – Improve in rotation – Social aspects (from food to energy) • Chemicals – Soil and water quality

Key impacts: using biofuels • Need of monitoring • High EU vehicle emission standards: the impact of existing biofuels on exhaust emissions is expected low • Biodiesel: reduction of CO emissions, NOx, HC and PM negative effects • BTL: expected lower pollutant emissions (no S, no aromatics)

Main methodological issues for LCA of biofuels • Attributional or consequential study • System boundaries • Complexity of feedstock production stage – – N 2 O emissions: crucial but very difficult to quantify Land use Effect on biodiversity Alternative uses of feedstock • Time and scale effects • Allocation of co-products

Attributional or consequential study? • Attributional study: describes the environmental properties of a system. – Goal: optimize a system in an existing technological environment – Use of average data • Consequential LCA: describes the effects of changes within the life cycle. – Large-scale changes in technological systems – Use of marginal data – Decision makers want to be informed on consequences of their choices – Difficulties on completeness, accuracy and relevance

Difficulties for consequential LCA • Completeness – Future uncertain – Data gaps • Accuracy – The effects of changes depend on economic mechanisms: dynamic and equilibrium models might help – Rebound effects • Relevance

Feedstock production • Energy crops – Different agricultural systems – Comparison with alternative use of land • Functional unit • Include soil within the system boundary – Inventory • Emissions quantification: NH 3 to air from chemical fertiliser and animal manure NO 3, PO 4, K+ to water, N 2 O, NOx to air and N, P, K balance in soil, • Allocation • Residues from other life cycles – Comparison with alternative use of the residues

Different agricultural reference systems Source: IFEU 2001

Effects of different agricultural systems Source: IFEU 2001

Time and scale effects • Time frame gives room for technical development – Functional unit – Choice of performance data – Selection of technologies under study • Background systems as heat and power production change over time – Major effects on GHG emissions and agricultural land use • Allocation of environmental impact between product and co-products depends on markets for co-products – Example: current key markets for ethanol co-products in EU-15 correspond to an ethanol production of 2% of liquid fuels, well below the 2010 target

Background systems Process energy: C = coal M = mixed N 2 O W = wood Transport fuel: D = diesel B = biofuel Adapted from: Jonasson, Sanden, 2004

Co-product allocation Market limit for soya meal Adapted from: Jonasson, Sanden, 2004 Substitution of soya meal Heat production replacing natural gas

Effects of co-product allocation Avoided production of soya meal Adapted from: Jonasson, Sanden, 2004 Heat production

Conclusions • LCA is a necessary tool to assess the potential benefits and problems of biofuels • The results depend on the specific realisation of the system • The nature of the problem requires to address several methodological problems