A comprehensive review on bioethanol production from corn stover: Worldwide potential, environmental importance, and perspectives

Corn is the second most abundant crop produced worldwide annually. Its residue, corn stover, is among the three most agricultural residues globally and the first one in the United States. The available corn stover in the world could be used to produce more than 45 million cubic meters of bioethanol (60% of the world production) instead of being mainly burnt on the fields. This practice could potentially reduce Green House Gases (GHGs) emissions by more than 150 million tonnes of CO₂ equivalent per year. A comprehensive review on pretreatment, saccharification and fermentation was performed in this study with investigating the effect of each of these steps on the whole process. The results showed that pretreatment is the most crucial step that hinders bioethanol production from corn stover, whereas newly developed methods like ionic liquids show promising results of 90% lignin degradation. A review on the techno-economic analysis performed in the literature indicated that the integrated biorefinery approach can be employed as an efficient strategy to cut the ethanol minimum selling price to half (0.27 $/L) with an average capital cost of 475 million dollars.