Sustainability assessment of biodiesel produced from Jatropha curcas using life cycle assessment approach

Transport sector in India is heavily dependent on fossil fuels and ~75% of the demand is met by import. National Biofuel Policy, 2009 focused on production of biodiesel from non-edible oil seeds. We assessed the sustainability of biodiesel produced from Jatropha curcas, using the life cycle assessment approach. India specific inventory data for biodiesel production was collected by extensive literature review. GaBi software was used to model the life cycle of biodiesel. The environmental impacts are compared for different blends of biodiesel with reference to diesel in four impact categories: Global Warming Potential, Acidification Potential, Eutrophication Potential, and Human Toxicity Potential. Using the biodiesel may reduce the global warming potential by 64.6% as compared to fossil diesel; while eutrophication potential, acidification potential, and human toxicity potential impacts may increase by 61.3%, 36.5%, and 52.5% respectively. A trade-off between impact categories is seen for biodiesel. Sensitivity analysis was done to identify most sensitive parameters in biodiesel life cycle. Use of electricity, life cycle span of Jatropha, seed yield, methanol, urea fertilizer, NOx emission factor, and steam are found to be highly sensitive in biodiesel life cycle. Scenario analysis was done to analyse the effect of change in seed yield, life span, and emission intensity of Indian electricity grid. Even low yield of Jatropha provides reduction in global warming potential (~27.7%) but in other impact categories significant increase is expected. Impacts could be further minimized if the emissions from grid are minimized in future.