Abstract:
The aims of this chemical engineering project are to study and compare energy efficiency
or Net Energy Gain (NEG) and Water Footprint (WF) of com-based 99.5% purified ethanol
production with different kinds of raw materials for ethanol production using the Life Cycle
Assessment (LCA) technique. The LCA were done in accordance to the ISO 14040 (2006) and
ISO 14046 (2006). 1 liter of com-based ethanol product was set as a functional unit. System
boundary was considered from com plantation, ethanol production, transportation, and usage. The
results show that the WF of com-ethanol production was 4,407.45 liters/liter of ethanol or 0.1223
million krท/year or 0.243 percent of water availability in Thailand. These are corresponding to
2,719.61 liters/liter of ethanol of green water or 0.0755 milloin km3/year and 1,689.11 liters/liter
of ethanol of blue water or 0.0469 million km3/year. For energy efficiencies, the results show that
the NEG value of com ethanol production was 1.943 MJ/liter of ethanol. The highest energy was
from ethanol production or 15.24 MJ/liter of ethanol, followed by com plantation, and
transportation respectively. Considering the comparison com-ethanol production with various raw
materials for ethanol production, com-ethanol production has lower WF than cassava-ethanol
production about 1.8 times. Whereas, ethanol production from com has lower energy efficiency
than sugarcane, cassava, and molasses about 3.72 3.48 and 1.82 times respectively.
