Improving enzymatic hydrolysis of hybrid Pennisetum (Pennisetum americanum x P. purpureum) by dehydration combined with dry explosion pretreatment

Dry explosion (DE), a thermal-mechanical method based on explosive power, was introduced for pretreatment of biomass material. The effects of different dehydration combined with DE pretreatments (120, 140, and 160 degrees C) on color, pore characteristics, crystallinity, and enzymatic hydrolysis of hybrid Pennisetum (HP) were analyzed. The results showed that dewatering press (PD) removed more soluble substrate in HP than oven drying dehydration (OD). The instantaneous explosive decompression of the DE process significantly increased the explosion power density with the increasing severity factor and reached 45.50 MW.m(-3) at 160 degrees C. Moreover, dehydration combined with DE pretreatment broke the pore structure and destructed cellulose crystallization of HP. Also, it improved the cellulose accessibility and the surface exposure of cellulose, which enhanced the enzymatic hydrolysis yield. PD combined with 160 degrees C DE promoted the reducing sugar yield of HP to 443.0 mg/g and enzymatic hydrolysis to 70.2%. The correlation analysis showed that reducing sugar yield was significantly correlated with color L* and b* values, surface area, and crystal size. All in all, DE pretreatment is a green and effective method for biomass saccharification utilization.