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

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.