Production of bioethanol and value added compounds from wheat straw through combined alkaline/alkaline-peroxide pretreatment

• DOI: 10.1016/j.biortech.2018.03.044
• Publication Date: 2018-03-18T20:58:18Z
• Authors: Zhaoyang Yuan; Yangbing Wen; Guodong Li
• Keywords: Ethanol; Hydrolysis; Fermentation; 0202 electrical engineering, electronic engineering, information engineering; Hydrogen Peroxide; 02 engineering and technology; Lignin; Triticum; 6. Clean water

An efficient scheme was developed for the conversion of wheat straw (WS) into bioethanol, silica and lignin. WS was pre-extracted with 0.2 mol/L sodium hydroxide at 30 °C for 5 h to remove about 91% of initial silica. Subsequently, the alkaline-pretreated solids were subjected to alkaline hydrogen peroxide (AHP) pretreatment with 40 mg hydrogen peroxide (H2O2)/g biomass at 50 °C for 7 h to prepare highly digestible substrate. The results of enzymatic hydrolysis demonstrated that the sequential alkaline-AHP pretreated WS was efficiently hydrolyzed at 10% (w/v) solids loading using an enzyme dosage of 10 mg protein/g glucan. The total sugar conversion of 92.4% was achieved. Simultaneous saccharification and co-fermentation (SSCF) was applied to produce ethanol from the two-stage pretreated substrate using Saccharomyces cerevisiae SR8u strain. Ethanol with concentration of 31.1 g/L was produced. Through the proposed process, about 86.4% and 54.1% of the initial silica and lignin were recovered, respectively.