Fractionation of the main components of corn stover by formic acid and enzymatic saccharification of solid residue

In this work, three main components (cellulose, hemicellulose, and lignin) of corn stover were fractionated effectively by formic acid. The effects of reaction temperature and time on the fractionation were investigated. It was found that the suitable conditions for the fractionation of corn stover were: the formic acid concentration was 88 wt.%, the ratio of solid to liquid was 1:13, and the treatment temperature was 80 C with the duration of 3 h. Under such conditions, the retention yield of cellulose, extraction yields of hemicellulose and lignin were 89.5%, 79.8% and 65.6%, respectively. Subsequently, the enzymatic hydrolysis of the solid residue was conducted by using the enzyme mixture of cellulase (20 FPU/g dry substrate) and beta-glucosidase (10IU/g dry substrate). The enzymatic hydrolysis rate of glucan and xylan could reach 62.8% and 79.4%, respectively. In addition, to study the property changes of corn stover before and after treatment, SEM, XRD and TGA analyses were performed, and the lignin extracted bylformic acid was also characterized by TGA and GPC. (C) 2013 Elsevier B.V. All rights reserved.