Xylan and xylose decomposition during hot water pre-extraction: A pH-regulated hydrolysis

Xiheng Kang; Yun-Yan Wang; Shuangfei Wang; Xueping Song

doi:10.1016/j.carbpol.2020.117391

Xylan and xylose decomposition during hot water pre-extraction: A pH-regulated hydrolysis

Carbohydr Polym. 2021 Mar 1:255:117391. doi: 10.1016/j.carbpol.2020.117391. Epub 2020 Nov 9.

Authors

Xiheng Kang¹, Yun-Yan Wang², Shuangfei Wang¹, Xueping Song³

Affiliations

¹ School of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China; Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning 530004, PR China.
² Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, 37996, USA.
³ School of Light Industry and Food Engineering, Guangxi University, Nanning 530004, PR China; Guangxi Key Laboratory of Clean Pulp & Papermaking and Pollution Control, Nanning 530004, PR China; Center for Renewable Carbon, Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, 37996, USA. Electronic address: sx_ping@gxu.edu.cn.

PMID: 33436220
DOI: 10.1016/j.carbpol.2020.117391

Abstract

One of the key issues in the development of biofuels using lignocellulosic feedstocks is to increase the yield of fermented sugar, and simultaneously decrease the generation of fermentation inhibitors. Therefore, it is essential to understand the degradation mechanism of xylan during hot-water pretreatment. We analyzed the hydrothermal degradation products of xylan and xylose under different conditions. Results showed that furfural and formic acid formed from xylose reached a maximum value of 32.56 % and 35.14 %, respectively. By increasing the initial pH of the xylan solution, the furfural concentration can be reduced effectively to 2% and the formation of formic acid was preferred under alkaline conditions. On this basis, we proposed a new hydrothermal degradation pathway of xylan in alkaline solution. The in-depth understanding of xlyan degradation during hot water pre-treatment will be beneficial for improving the efficiency of biofuel production.

Keywords: Degradation pathways; Hydrothermal degradation; Xylan; Xylose; pH regulation.