Fast Acidogenic Fermentation of Corn Stover Through a Two-Step Method: Nitric Acid Hydrolysis Combined with the Fermentation of Hydrolysate

Abstract

This study investigated a novel route for fast acidogenic fermentation of corn stover through a two-step method. Corn stover was first hydrolyzed by nitric acid, and the hydrolysate was then used for acidogenic fermentation. The results showed that the yields of soluble xylose, arabinose, and glucose in hydrolysate obtained from HNO3 hydrolysis of corn stover at the optimum condition achieved 96.86% of initial xylose, 98.54% of initial arabinose, and 18.58% of initial glucose, respectively. Acidogenic fermentation of hydrolysate proved to be effective, compared to acidogenic fermentation of raw corn stover; the production of volatile fatty acids (VFAs) increased by 54.8%, fermentation time decreased by 50%, and the distribution of VFAs was more suitable for subsequent methanogenic fermentation. This research provided an effective, suitable, and economical method for biogas production from corn stover.