title: A novel mechanism and kinetic model to explain enhanced xylose yields from dilute sulfuric acid compared to hydrothermal pretreatment of corn stover.
abstract: Pretreatment of corn stover in 0.5% sulfuric acid at 160 °C for 40 min realized a maximum monomeric plus oligomeric xylose yield of 93.1% compared to a maximum of only 71.5% for hydrothermal (no added mineral acid) pretreatment at 180 °C for 30 min. To explain differences in dilute acid and hydrothermal yields, a fast reacting xylan fraction (0.0889) was assumed to be able to directly form monomeric xylose while a slow reacting portion (0.9111) must first form oligomers during hydrothermal pretreatment. Two reactions to oligomers were proposed: reversible from fast reacting xylan and irreversible from slow reacting xylan. A kinetic model and its analytical solution simulated xylan removal data well for dilute acid and hydrothermal pretreatment of corn stover. These results suggested that autocatalytic reactions from xylan to furfural in hydrothermal pretreatment were controlled by oligomeric xylose decomposition, while acid-catalytic reactions in dilute acid pretreatment were controlled by monomeric xylose decomposition.
authors.affiliation: Center for Environmental Research and Technology, Bourns College of Engineering, University of California, 1084 Columbia Avenue, Riverside, CA 92507, USA. shenj417@yahoo.com
authors.forename: Jiacheng
authors.initials: J
authors.lastname: Shen
authors.forename: Charles E
authors.initials: CE
authors.lastname: Wyman
mesh_terms: D056804:Biofuels; D006358:Hot Temperature; D006868:Hydrolysis; D007700:Kinetics; D008956:Models, Chemical; D018547:Plant Stems / Q000737:chemistry*; D011134:Polysaccharides / Q000378:metabolism*; D013464:Sulfuric Acids / Q000737:chemistry*; D014994:Xylose / Q000096:biosynthesis*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D056804:Biofuels; D011134:Polysaccharides; D013464:Sulfuric Acids; C007916:hemicellulose; D014994:Xylose; C033158:sulfuric acid