Biofuel and bioproduct environmental sustainability analysis.

Life cycle analysis (LCA) is a key tool in the evaluation of biofuel and bioproduct sustainability. Recent advances in these analyses include increased incorporation of spatially explicit elements of feedstock growth including changes in soil carbon and fertilization rates. Furthermore, new evaluations of processes to convert biomass to fuels (ethanol, algal-derived fuels, jet fuels, and others) and products have been conducted that examine emerging conversion technologies. Co-product allocation among co-produced biofuels and bioproducts continues to raise LCA methodological challenges; approaches to allocation can drive LCA results. Given the variations in feedstocks, spatially explicit factors, conversion process design, and LCA methodological choices (e.g. co-product allocation), transparency in reporting biofuel LCA methodology and results is critical to enable cross-comparison of studies.