title: Topochemical pretreatment of wood biomass to enhance enzymatic hydrolysis of polysaccharides to sugars.
abstract: The surface chemistry of milled birch and pine wood pretreated by ionic liquid, hydrothermal and hydrotropic methods, followed by enzymatic hydrolysis was studied in this work. Surface coverage by lignin was measured by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to describe the surface chemical composition after pretreatment in detail, and the morphology after pretreatment was investigated by FE-SEM. Ionic liquid (1-ethyl-3-methylimidazolium acetate, 1-butyl-3-methylimidazolium chloride) pretreatment at room temperature made the samples swell but did not dissolve the wood. Comparing the surface coverage by lignin, both in the case of birch and pine wood, hydrotropic worked best to remove the lignin hampering enzymatic hydrolysis. ToF-SIMS supported this finding, and showed that in birch, the carbohydrates were degraded more than in pine after hydrotropic pretreatment. The glucose yield of birch was improved by hydrotropic pretreatment from 5.1% to 83.9%, more significantly than in case of pine.
authors.affiliation: Laboratory of Fibre and Cellulose Technology, Åbo Akademi University, Porthansgatan 3, FI-20500 Turku, Finland. mhy-yifei@163.com
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Mou
authors.forename: Elina
authors.initials: E
authors.lastname: Orblin
authors.forename: Kristiina
authors.initials: K
authors.lastname: Kruus
authors.forename: Pedro
authors.initials: P
authors.lastname: Fardim
mesh_terms: D018533:Biomass; D002241:Carbohydrates / Q000096:biosynthesis*; D004798:Enzymes / Q000378:metabolism*; D006868:Hydrolysis; D052578:Ionic Liquids; D008031:Lignin / Q000378:metabolism; D008855:Microscopy, Electron, Scanning; D056951:Photoelectron Spectroscopy; D011134:Polysaccharides / Q000378:metabolism*; D014934:Wood
chemical_list: D002241:Carbohydrates; D004798:Enzymes; D052578:Ionic Liquids; D011134:Polysaccharides; D008031:Lignin
keywords: Biomass pretreatment; Enzymatic hydrolysis; ToF-SIMS; Topochemistry; XPS