title: Fermentable hexose production from corn stalks and wheat straw with combined supercritical and subcritical hydrothermal technology.
abstract: Lignocellulosic wastes, including corn stalks and wheat straw, were pretreated and hydrolyzed with combined supercritical and subcritical hydrothermal technology. Soluble sugars were collected by pre-washing the crushed materials before hydrolysis. The effects of solid-liquid ratio, temperature, and reaction time on oligosaccharide production were investigated and the optimum supercritical conditions were found to be 20 mg/2.5 ml water, 384 degrees C, 17 s for corn stalks and 20 mg/2.5 ml water, 384 degrees C, 19 s for wheat straw. Subsequent subcritical processing of the hydrolyzate (with or without the water extract) from supercritical treatment was guided by a previous analysis of cellulose hydrolysis kinetics. The highest yield of fermentable hexoses from corn stalks (27.4% of raw material) was obtained at 280 degrees C, 27 s, and from wheat straw (6.7% of raw material) at 280 degrees C, 54 s. This study provides novel key parameters for fermentable hexose production from lignocellulosic feedstocks using combined supercritical and subcritical hydrothermal treatment.
authors.affiliation: Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Wen-Jing
authors.initials: WJ
authors.lastname: Lu
authors.forename: Hong-Tao
authors.initials: HT
authors.lastname: Wang
authors.forename: Jin-Long
authors.initials: JL
authors.lastname: Yang
mesh_terms: D019149:Bioreactors; D002482:Cellulose / Q000737:chemistry*; D004736:Energy-Generating Resources; D005285:Fermentation; D005947:Glucose / Q000737:chemistry; D006601:Hexoses / Q000737:chemistry*; D006868:Hydrolysis; D007700:Kinetics; D008031:Lignin / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry; D013696:Temperature; D014908:Triticum / Q000378:metabolism*; D014867:Water / Q000737:chemistry; D014994:Xylose / Q000737:chemistry; D003313:Zea mays
chemical_list: D006601:Hexoses; D009844:Oligosaccharides; D014867:Water; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin; D014994:Xylose; D005947:Glucose