Metal salt-assisted hydrogen peroxide-malonic acid pretreatment for effectively enhancing delignification and saccharification of rapeseed straw

To enhance enzymatic saccharification of rapeseed straw through the improvement of xylan elimination, cellulase accessibility and delignification, it is necessary to employ a highly efficient biomass pretreatment strategy. In this research, Manganese chloride (MnCl 2 )-catalyzed hydrogen peroxide (H 2 O 2 )-malonic acid (MA) (MA-H 2 O 2 -MnCl 2 ) treatment was built as an effectual way to alter the biomass structure and elevate enzymatic digestion of lignocellulose. Pretreatment of rapeseed straw at 80 °C for 15 min eliminated significant amounts of xylan and lignin. The reducing sugar yield of treated rapeseed straw (87.6 %) was 9.1-folds higher compared to untreated one. Cellulose accessibility elevated from 338.4 mg/g to 1235.8 mg/g and hydrophobicity declined from 4.2 g/L to 3.3 g/L. FTIR, SEM, and XRD that MA-H 2 O 2 -MnCl 2 resulted in a rough surface of RS, reduced crystallinity, and enhanced cellulase accessibility. The depolymerization of lignocellulosic biomass and the improvement of cellulose structure promoted the release of fermentable sugars. In this research, economic analysis, mass balance and energy balance were calculated to assess the treatment process in detail. MA-H 2 O 2 -MnCl 2 treatment was a green and effectual pretreatment strategy for enhancing enzymatic saccharification of lignocellulose. • MA-H 2 O 2 -MnCl 2 efficiently eliminated xylan and ligninin RS. • The relationship of RS structural changes and hydrolysis efficiency was explored. • The relationship of Lewis acid strength on the combination treatment was testified. • High accessibility (1235.8 mg/g) and low hydrophobicity (3.3 g/L) gave 87.6 % sugar yield. • Mass balance, energy balance and economic analysis of MA-H 2 O 2 -MnCl 2 were acquired.