Net Energy Gain and Water Footprint of Corn Ethanol Production in Thailand

Abstract

Abstract: The aims of this research are to study and compare energy efficiency or Net Energy Gain (NEG) and Water Footprint (WF) of corn-based 99.5% purified ethanol production with different kinds of raw materials for ethanol production using the Life Cycle Assessment (LCA) technique. 1 L of corn-based ethanol product was set as a functional unit. System boundary was considered from corn plantation, ethanol production, transportation, and using. For the energy analysis, the results show that corn-based ethanol production has lower energy efficiency than sugarcane, cassava, and molasses-based ethanol about 3.72, 3.48 and 1.82 times, respectively. The WF in the whole life cycle of corn-based ethanol production chain is 3.67 m3 per L ethanol, wtih the green contribution of 53.7%, the grey contribution of 43.8, and the blue contribution of 2.4%. The amount of water consumption to meet the capacity in year 2013 of bioethanol (949.1 millions L) in Thailand in scenarion 1 (72% sugarcane, 18% cassava and 10% corn) and scenario 2 (62% sugarcane, 28% cassava and 10% corn) are lower than basecase (72% sugarcane and 28% cassava) by 8.7% and 3.4%, respectively. Because corn-base ethanol production has lower WF than sugarcane and cassava-based ethanol production about 1.65 and 2.71 times, respectively.