Analysis of corn-to-ethanol process for automotive applications.

摘要

This study analyzes the technical feasibility of using corn-to-ethanol as an alternative for conventional fuel in automotive applications. The process of growing corn and its conversion to ethanol is studied to find the stoichiometric yield of ethanol under idealized conditions. Because carbon dioxide is a greenhouse gas, the fate of carbon dioxide through the process is traced. The total energy required for this process is estimated. A sensitivity study is carried out to assess the impact of inefficiencies at each major process step on the overall process. Finally, the energy to generate ethanol from corn is compared to that for generating gasoline. According to the results in this thesis, it would take 0.86 equivalent gallons of ethanol to produce 1 gallon of ethanol product. While the net energy is positive, which implies that this process is feasible, this is clearly not a very efficient process. Distillation of ethanol from a 10% fermentation broth to 99.9% pure ethanol takes up a major portion (67%) of the total energy in the corn to ethanol process even under idealized conditions. Furthermore, the land area available in the United States is not sufficient to grow enough corn to replace current gasoline usage with ethanol produced from corn.