title: Optimization of supercritical phase and combined supercritical/subcritical conversion of lignocellulose for hexose production by using a flow reaction system.
abstract: A flow reaction system was utilized to investigate lignocellulose conversion using combined supercritical/subcritical conditions for hexose production. Initially, investigation of cellulose hydrolysis in supercritical water and optimization of reaction parameters were done. Oligosaccharide yields reached over 30% at cellulose concentrations of 3-5 gL(-1) and reaction times of 6-10s at 375 °C, and 2.5-4 gL(-1) and 8-10s at 380 °C. Temperatures above 380 °C were not appropriate for the supercritical phase in the combined process. Subsequently, conversion of lignocellulosic materials under combined supercritical/subcritical conditions was studied. Around 30% hexose was produced from corn stalks under the optimal parameters for supercritical (380 °C, 23-24 MPa, 9-10s) and subcritical (240 °C, 8-9 MPa, 45-50s) phases. Flow systems utilizing the combined supercritical/subcritical technology present a promising method for lignocellulosic conversion. The results of this study provide an important guide for the operational optimization and practical application of the proposed system.
authors.affiliation: School of Environment, Beijing Normal University, Beijing 100875, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Lu
authors.forename: Hua-Yong
authors.initials: HY
authors.lastname: Wu
authors.forename: Jin-Wen
authors.initials: JW
authors.lastname: Liu
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Wang
mesh_terms: D019149:Bioreactors; D002482:Cellulose; D006601:Hexoses / Q000096:biosynthesis*; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism*; D009844:Oligosaccharides / Q000096:biosynthesis; D012212:Rheology / Q000295:instrumentation / Q000379:methods*; D062611:Solid Waste / Q000032:analysis; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry*; D003313:Zea mays / Q000737:chemistry
chemical_list: D006601:Hexoses; D009844:Oligosaccharides; D062611:Solid Waste; D014867:Water; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin