Structural evolution during corn stalk acidic and alkaline hydrogen peroxide pretreatment

Abstract

Oxidative pretreatment is a promising strategy for biomass utilization due to its excellent performance and economic costs. Insights into lignocellulose recalcitrance are essential to further develop biomass manufacture. To understand structural recalcitrance, we performed systematic characterizations after mild hydrogen peroxide pretreatment in alkali or Lewis acid environments, followed by enzymatic hydrolysis to obtain higher glucose yields than raw materials. Results indicated that hydrogen peroxide pretreatment in saturated calcium hydroxide solution effectively removed lignin through cleavage of the lignin-carbohydrate complex and part C-C linkages in the middle lamella. The ferrous sulfate solution induced hemicellulose solubility, and the partially oxidized lignin was depolymerized under hydrogen peroxide pretreatment. The solvent could then be used for subsequent hydrolysis and cellulose conversion. It was demonstrated that hydrogen peroxide pretreatment is an effective and promising method for refining lignocellulose under an alkaline environment and is suitable for subsequent cellulose conversion in ferrous sulfate solution.