Life Cycle Assessment of Second Generation Bioethanol from Sorghum and Pearl Millet Feed Stocks in India
Fossil fuels depletion has attracted increasing attention to blending bio-fuels worldwide. India’s energy demand is expected to grow at an annual rate of 4-5 times over the next couple of decades. With self sufficiency levels in crude oil becoming a distant dream, there is growing interest to look out for alternative fuels and the biofuels are an important option for policy makers in India. In this context, this paper reviews the experiences in India in the last two decades with respect to bio-fuels cultivation and its impact on land use, environment and impact on the livelihoods of rural communities. The objective of this paper is to assess the performance of Sorghum and Pearl millet feed stocks for biofuel production in India using a Life Cycle Analysis(LCA) approach. Baseline study was conducted during the year 2013 in the Madhya Pradesh state of India covering five districts and 333 sample farmers to understand the farmers perception about the various issues related to the production of biofuels using Indian staple food crops Sorghum and Pearl millet. Empirical data from the multi-locational trials conducted during the years 2014-15 and 2015-16 in farmers’ fields was used to conduct the LCA analysis. Sorghum and Pearl millet feed-stocks which are rainfed crops are considered for bioethanol production with different pre-treatment methods. Net Energy Ratio (NER), Net Energy Balance (NEB), Net Carbon Balance (NCB) and % Carbon reduction were some of the key parameters used for analysis and the results are evaluated based on the environmental impacts through the Life Cycle Assessment at 5% blending. Findings reveal that, dilute alkali pre-treatment process is most energy intensive due to consumption of alkali consumption. Whereas dilute acid pre-treatment has higher conversion efficiency than the other pre-treatment processes which is due to higher glucan and xylan conversion efficiencies. The study concludes that Sorghum feedstock is more energy intensive than Pearl millet feedstock due to higher water requirement and yield.
Key words - Biofuels, Energy and Life Cyle Analysis