Deep eutectic solvent with Lewis acid for highly efficient biohydrogen production from corn straw

Abstract

To boost saccharification and biohydrogen production efficiency from corn straw, Lewis acid enhanced deep eutectic solvent (DES) pretreatment using choline chloride/glycerol was developed. A notable enhancement of the enzymatic hydrolysis efficiency from 26.3 % to 87.0 % was acquired when corn straw was pretreated with aqueous DES at 100 °C for 5 h using 2.0 wt% AlCl₃. A maximum biohydrogen yield of 114.8 mL/g total solids (TS) was achieved in the sequential dark fermentation stage, which was 2.1 times higher than that of the raw feedstock (37.1 mL/g TS). The enhanced efficient conversion was ascribed to the effective removal of lignin and hemicellulose, which led to the bio-accessibility of the straw. This work provides new sights for the rational design of efficient AlCl₃-aided aqueous DES system toward biohydrogen production from lignocellulosic biomass.

Keywords: Biohydrogen; Corn straw; Dark fermentation; Deep eutectic solvent; Enzymatic saccharification.