Energy and GHG balances

Estimating Energy and Greenhouse Gas Balances of Biofuels

Concepts and Methodologies

From a methodological point of view, several estimations of the reduction of greenhouse gas (GHG) emissions from biofuels lead to a large variability of results even if they address the same biofuel pathway. It has been shown that the methods used and the assumptions on data inventories, system boundaries, allocation of resources and emissions may significantly impact the results.

However evaluating GHG balances of biofuels is not straightforward. This paper aims at investigating the main assumptions made in the literature when estimating the reduction of GHG emissions of biofuels in comparison with their fossil competitors.

LASEN working paper No. 437.100

Life cycle assessment of soybean-based biodiesel in Argentina for export

Luis Panichelli & Arnaud Dauriat & Edgard Gnansounou, International Journal of Life Cycle Assessment, online first.

This work aims at analyzing the environmental impact of soybean-based biodiesel production in Argentina for export. The relevant impact categories account for the primary non-renewable energy consumption, the global warming potential, the eutrophication potential, the acidification potential, the terrestrial ecotoxicity, the aquatic ecotoxicity, the human toxicity and land use competition. The paper tackles the feedstock and country specificities in biodiesel production by comparing the results of soybean-based biodiesel in Argentina with other reference cases. Emphasis is put on explaining the factors that contribute most to the final results and the regional specificities that lead to different results for each biodiesel pathway.

See the article on Springerlink

Energy and greenhouse gas balances of biofuels: biases induced by LCA modelling choices

E Gnansounou, A Dauriat, L Panichelli and J Villegas, Journal of Scientific & Industrial Research, Vol. 67, November 2008, pp.885-897.

This paper investigates extent to which these choices influence the results. After performing a comparison and constructive criticism of various modelling choices, life cycle assessment (LCA) of wheat-to-bioethanol was used as an illustrative case where bioethanol was blended with gasoline at various percentages (E5, E10 and E85). A large difference was observed in reduction of GHG emissions with a high sensitivity to method used to allocate impacts between co-products, type of reference systems, choice of functional unit and type of blend. The study recommends for basing estimation of energy and GHG balances of biofuels on principles of transparency, consistency and accuracy.