New perspectives for maximizing sustainable bioethanol production from corn stover

In Egypt, the production of second-generation bioethanol from agricultural waste is a thriving method to compensate the excessive usage as a consequence of the outspread of Covid-19. The profusion and renewability of lignocellulosic biomass urge its utilization as a promising feedstock for bioethanol production. However, functional delignification without affecting the cellulose matrices remains the major obstacle to achieving effective enzyme accessibility. This paper highlights a novel physio-chemical combination for corn stover (CS) pretreatment for bioethanol production. The optimum pretreatment condition was achieved using a mixture of 5% maleic acid (MA) and 3% citric acid (CA) for 30 min at an autoclave temperature of 110 degrees C leading to produce a pretreated CS (MAC) with 99% hemicellulose removal, 90% cellulose recovery, and 80% lignin removal. Characteristics analyses such as; SEM, FTIR, TGA, EDX, elemental, proximate, ultimate, higher heating value (HHV), and functionalization analyses were performed to emphasize the property and structure change of CS before and after the pretreatment. Then, MAC was hydrolyzed by cellulase enzyme and produced 13.5 g/L glucose yield which was fermented by Saccharomyces cerevisiae and produced 10 g/L bioethanol.