Pretreatment combining ultrasound and sodium percarbonate under mild conditions for efficient degradation of corn stover

• Pretreatment using ultrasound and sodium percarbonate (US–SP) has been developed.
• US–SP pretreatment is quite effective for enhancing enzymatic digestibility.
• Higher degradation could be achieved by optimizing pretreatment conditions.
• Xylose could be effectively recovered from the pretreated biomass.

Ultrasound (US) can be used to disrupt microcrystalline cellulose to give nanofibers via ultrasonic cavitation. Sodium percarbonate (SP), consisting of sodium carbonate and hydrogen peroxide, generates highly reactive radicals, which cause oxidative delignification. Here, we describe a novel pretreatment technique using a combination of US and SP (US–SP) for the efficient saccharification of cellulose and hemicellulose in lignocellulosic corn stover. Although US–SP pretreatment was conducted under mild condition (i.e., at room temperature and atmospheric pressure), the pretreatment greatly increased lignin removal and cellulose digestibility. We also determined the optimum US–SP treatment conditions, such as ultrasonic power output, pretreatment time, pretreatment temperature, and SP concentration for an efficient cellulose saccharification. Moreover, xylose could be effectively recovered from US–SP pretreated biomass without the formation of microbial inhibitor furfural.