title: Alkaline-assisted screw press pretreatment affecting enzymatic hydrolysis of wheat straw.
abstract: Screw press processing of biomass can be considered as a suitable mechanically based pretreatment for biofuel production since it disrupts the structure of lignocellulosic biomass with high shear and pressure forces. The combination with chemical treatment has been suggested to increase the conversion of lignocellulosic biomass to fermentable sugars. Within the study, the synergetic effect of alkaline (sodium hydroxide, NaOH) soaking and screw press pretreatment on wheat straw was evaluated based on, e.g., sugar recovery and energy efficiency. After alkaline soaking (at 0.1 M for 30 min) and sequential screw press pretreatment with various screw press configurations and modified screw barrel, the lignin content of pretreated wheat straw was quantified. In addition, the structure of pretreated wheat straw was investigated by scanning electron microscopy and measurement of specific surface area. It could be shown that removal of lignin is more important than increase of surface area of the biomass to reach a high sugar recovery. The rate constant of the enzymatic hydrolysis increased from 1.1 × 10-31/h for the non-treated material over 2.3 × 10-31/h for the alkaline-soaked material to 26.9 × 10-31/h for alkaline-assisted screw press pretreated material, indicating a nearly 25-fold improvement of the digestibility by the combined chemo-mechanical pretreatment. Finally, the screw configuration was found to be an important factor for improving the sugar recovery and for reducing the specific energy consumption of the screw press pretreatment.
authors.affiliation: Aachener Verfahrenstechnik, Mechanical Process Engineering, RWTH Aachen University, Turmstr. 46, 52064, Aachen, Germany. qingqi.yan@avt.rwth-aachen.de.
authors.forename: Qingqi
authors.initials: Q
authors.lastname: Yan
authors.affiliation: Aachener Verfahrenstechnik, Enzyme Process Technology, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany.|DWI Leibniz Institute for Interactive Materials Research, Forckenbeckstr. 50, 52074, Aachen, Germany.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Chemical and Process Engineering, Thai-German Graduate School of Engineering, King Mongkut's University of Technology, North Bangkok, Bangkok, 10800, Thailand.
authors.forename: Wawat
authors.initials: W
authors.lastname: Rodiahwati
authors.affiliation: Aachener Verfahrenstechnik, Enzyme Process Technology, RWTH Aachen University, Worringer Weg 1, 52074, Aachen, Germany.|DWI Leibniz Institute for Interactive Materials Research, Forckenbeckstr. 50, 52074, Aachen, Germany.|Institute of Biochemical Engineering (IBVT), TU Braunschweig, Rebenring 56, 38106, Brunswick, Germany.
authors.forename: Antje
authors.initials: A
authors.lastname: Spiess
authors.affiliation: Aachener Verfahrenstechnik, Mechanical Process Engineering, RWTH Aachen University, Turmstr. 46, 52064, Aachen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Modigell
mesh_terms: D002480:Cellulase / Q000737:chemistry*; D006868:Hydrolysis; D008031:Lignin / Q000737:chemistry*; D011312:Pressure; D012972:Sodium Hydroxide / Q000737:chemistry*; D014908:Triticum / Q000737:chemistry*
chemical_list: C036909:lignocellulose; D012972:Sodium Hydroxide; D008031:Lignin; D002480:Cellulase
keywords: Enzymatic hydrolysis; Lignocellulose; Pretreatment; Screw press