Net energy analysis of sugarcane based ethanol production
Mahesh Shelar, Vilas K. Matsagar, Vijay S. Patil, Sanjay D. Barahate
Abstract
Ethanol is being projected as a renewable future biofuel to be a total substitute for gasoline by policymakers in India. Today it is used in blended form with gasoline. Ethanol in India is produced from sugarcane in distilleries and most of those are integrated with sugar industries. Anecdotal evidence suggests that sugarcane production in India consumes lot of water and for irrigating the crop electricity is consumed. Electricity is produced from fossil fuel mainly coal in India. Quantifying the energy input that goes into sugarcane production and ethanol processing is therefore relevant. This paper reports the findings from field investigations into the energy use practices of sugarcane production in a sugarcane belt of Maharashtra and a study of energy use in sugar industry. Net energy value is reported in MJ per litre of Ethanol and is found to be 40% surplus. Similar studies are reported for Brazilian Ethanol by investigators. The key differences in net energy value in India and Brazil arise from the assumptions regarding cane growing practices including power required in pumped irrigation and fertilizer application per litre of ethanol production. Net energy analysis of biofuels depends on the data assumed by the researchers regarding input of energy use, source of energy, energy value of co-products and land and water productivity of sugar cane. Sensitivity analysis is therefore included to account for all these parameters.