Rapid and effective molten oxalic acid dihydrate pretreatment to enhance enzymatic saccharification for biohydrogen production by efficient coextraction of lignin and hemicellulose in wheat straw

Biohydrogen production from lignocellulose presents an enduring challenge due to the tough, rigid, and complex structure that endows the lignocellulose with high resistance to biodegradation. In the present work, a rapid and effective pretreatment method employing molten oxalic acid dihydrate (OAD) was proposed to enhance enzymatic saccharification for biohydrogen production through efficient coextraction of wheat straw. The molten OAD pretreatment at 110 °C achieves a 95 % cellulose retention, 95 % hemicellulose removal, and 81.3 % delignification within 5 min. Furthermore, an 85 % enzymolysis conversion rate and 114.04 mL/g total solids (TS) fermentative hydrogen yield can be obtained. The OAD pretreatment enhanced the feasibility of biomass refining and paves the way for a novel, fast and high-efficiency pretreatment method for advancing the productivity stage toward biohydrogen production from lignocellulosic biomass.