Flow-Through Pretreatment of Corn Stover by Recycling Organosolv to Reduce Waste Solvent

In this study, the optimum conditions for pretreatment of corn stover using organosolv were determined. The predicted optimum conditions, determined using the response surface methodology, were ethanol concentration of 56.6 wt %, reaction temperature of 187.5 °C, and 320 mL of liquid throughput. Moreover, the pretreatment using recycled organosolv was carried out under the predicted optimum conditions. The pretreatment effect of the organosolv decreased as the organosolv was reused in the pretreatment process. When performing pretreatment with the initial organosolv, enzymatic digestibility for glucan was 71.0%. The digestibility was reduced as low as less than 66% in the first reuse process. Nevertheless, when repeatedly reusing the organosolv, the glucan digestibility remained mostly stable. It was confirmed that organosolv can be reused in the flow-through pretreatment of corn stover.