U.S. flag

An official website of the United States government


Main content area

Alkali combined extrusion pretreatment of corn stover to enhance enzyme saccharification

Zhang, Shujing, Keshwani, Deepak R., Xu, Yixiang, Hanna, Milford A.
Industrial crops and products 2012 v.37 no.1 pp. 352-357
adsorption, alkalis, biomass, cell walls, corn stover, dyes, enzymes, extrusion, glucose, hydrolysis, saccharification, surface area, temperature, washing, xylose
Because of good adaptability, high throughput and continuous feature, twin-screw extrusion has been shown to be a promising pretreatment method for biomass to open the cell wall at the microscopic scale. This greatly increases the specific surface area for enzyme adsorption regardless of crystallinity. The objective of this study was to investigate the effectiveness of alkali-assisted extrusion for improving corn stover digestability. The glucose and xylose sugar yields for combined process were 86.8% and 50.5%, respectively, at an alkali loading of 0.04g/g dry biomass, a screw speed of 80rpm, temperature of 140°C and washed with water. The average residence time for extrusion is 27min for 100g corn stover. These yields were 3.9 and 13.3 times higher than their untreated counterparters. The crystallinity index was not related with hydrolysis yields. Congo red dye adsorption indicated that alkali-assisted extrusion produced significantly more pores at the meso and large scales compared to untreated material, which significantly improved the sugar yields.