Thermostatic microwave-assisted pretreatment of corn stover at atmospheric pressure to enhance saccharification

A large amount of corn stover waste is produced from processing industries. In this study, the thermostatic microwave-assisted alkali pretreatment (TMAAP) of corn stover at atmospheric pressure was investigated to improve the utilization rate. The optimized conditions include pretreated time, NaOH concentration, temperature, initial power, and solid-liquid ratio. The pretreated corn stover samples for the enzymatic hydrolysis were studied on the crystallinity, surface microstructural changes, functional group changes and compositional analysis. The results showed cellulose recovery and lignin removal in the solid residue reached 87.39 % and 87.59 %, respectively when the corn stover was subjected for 45 min at a microwave reactor with an initial 600 W, 100 degrees C and 5 % NaOH. After TMAAP, the enzyme hydrolysis efficiency of the corn stove reached 85.40 %, which was higher than that of the untreated (59.96 %). The experiment can be carried out at atmospheric pressure without strict conditions. The techno-economic analysis predicts revenue of 22.82 USD by processing 100 kg of waste corn stover combined with enzyme cost analysis. To conclude, glucose (26.37 kg) and xylose (1.19 kg) were produced from corn stover (100 kg, 39.31 % glucan, 17.34 % xylan, 23.60 % lignin). The results can give insights into establishing an efficient alkali pretreatment of corn stove waste to produce glucose.