Selective separation of hemicellulose from poplar by hydrothermal pretreatment with ferric chloride and pH buffer

Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors

The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals.

Improvement in caffeic acid and ferulic acid extraction by oscillation-assisted mild hydrothermal pretreatment from sorghum straws

This work investigated the effect of oscillation-assisted hydrothermal process on extraction of caffeic acid and ferulic acid from sorghum straws. The results showed that the oscillation-assisted hydrothermal process efficiently improved extraction of caffeic acid and ferulic acid. The oscillation-assisted hydrothermal process resulted in the extraction rates of 1275.48 and 1822.64 mg/L.h for caffeic acid and ferulic acid, respectively. Moreover, the oscillation-assisted hydrothermal process exerted destructive effects on hemicellulose, lignin and the amorphous regions of cellulose, contributing to the release of caffeic acid and ferulic acid in pretreated sorghum straws. The scavenging activities for hydroxyl, 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid radicals of the caffeic acid and ferulic acid extracts obtained by the oscillation-assisted hydrothermal process were determined to be 83.69 %, 84.17 % and 88.45 %, respectively.