Xylitol Production from Prehydrolysis Liquor of Kraft-based Dissolving Pulp by Candida tropicalis

Shanshan Liu, Huili He, Xin Fu, Tianzhong Yuan, Qiang Wang, Guihua Yang, Hui Zhang, Mingqi Ding, Changlyu Liao

Abstract


Xylitol production from the hemicelluloses of prehydrolysis liquor (PHL) is of practical interest from both economic and environmental standpoints. The removal of the inhibitors, e.g., lignin, acetic acid, and furfural, is the key to improving the conversion of xylose to xylitol when Candida tropicalis fermentation is used. For this purpose, a full chain process involving activated carbon adsorption, ion exchange resin treatment, acidolysis, and fermentation was considered in this work. The results showed that 72.6% of lignin and 67.1% of furfural were removed using an activated carbon dosage of 20 mg/g PHL. Additionally, 61.2% of acetic acid was also removed at a resin dosage of 100 mg/g PHL. Subsequently, acidolysis using sulfuric acid and pH adjustment with lime was performed on the treated PHL to convert the oligosaccharides into monosaccharides; a yield of 0.40 g xylitol/g xylose was achieved via treating the PHL with Candida tropicalis fermentation at 30 °C, 200 rpm, and 96 h. In addition, a material balance was determined for the full chain process.

Keywords


Xylitol; Prehydrolysis liquor; Fermentation; Activated carbon; Resin

Full Text: PDF

Welcome to BioResources! This online, peer-reviewed journal is devoted to the science and engineering of biomaterials and chemicals from lignocellulosic sources for new end uses and new capabilities. The editors of BioResources would be very happy to assist you during the process of submitting or reviewing articles. Please note that logging in is required in order to submit or review articles. Martin A. Hubbe, (919) 513-3022, hubbe@ncsu.edu; Lucian A. Lucia, (919) 515-7707, lucian.lucia@gmail.com URLs: bioresourcesjournal.com; http://ncsu.edu/bioresources ISSN: 1930-2126