title: Acetic acid-catalyzed hydrothermal pretreatment of corn stover for the production of bioethanol at high-solids content.
abstract: Corn stover (CS) was hydrothermally pretreated using CH3COOH (0.3 %, v/v), and subsequently its ability to be utilized for conversion to ethanol at high-solids content was investigated. Pretreatment conditions were optimized employing a response surface methodology (RSM) with temperature and duration as independent variables. Pretreated CS underwent a liquefaction/saccharification step at a custom designed free-fall mixer at 50 °C for either 12 or 24 h using an enzyme loading of 9 mg/g dry matter (DM) at 24 % (w/w) DM. Simultaneous enzymatic saccharification and fermentation (SSF) of liquefacted corn stover resulted in high ethanol concentration (up to 36.8 g/L), with liquefaction duration having a negligible effect. The threshold of ethanol concentration of 4 % (w/w), which is required to reduce the cost of ethanol distillation, was surpassed by the addition of extra enzymes at the start up of SSF achieving this way ethanol titer of 41.5 g/L.
authors.affiliation: Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780, Athens, Greece.
authors.forename: Constantinos
authors.initials: C
authors.lastname: Katsimpouras
authors.affiliation: Biochemical and Chemical Process Engineering, Division of Sustainable Process Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, 97187, Luleå, Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Christakopoulos
authors.affiliation: Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens, 9 Iroon Polytechniou Str., Zografou Campus, 15780, Athens, Greece. vtopakas@chemeng.ntua.gr.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Topakas
mesh_terms: D000085:Acetates / Q000737:chemistry*; D002384:Catalysis; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D008855:Microscopy, Electron, Scanning; D014783:Viscosity; D003313:Zea mays / Q000737:chemistry*
chemical_list: D000085:Acetates; D000431:Ethanol
keywords: Corn stover; Enzymatic liquefaction; Ethanol fermentation; Pretreatment; Response surface methodology