Mechanism analysis of NaOH-urea binary low-temperature high-solid pretreatment of corn stover and application in cellulosic ethanol production

Water and chemical overconsumption is one of the technical challenges for cellulosic ethanol production. To address this issue this study developed a NaOH-urea binary low-temperature high-solid pretreatment technology that addresses the high temperature, pollution, and costs associated with traditional methods (acid, organic solvent pretreatment, etc.). Brunauer-Emmett-Teller (BET) surface area measurements and atomic force microscopy (AFM) tests showed that the porosity, specific surface area, and surface roughness of CS pretreated with the NaOH-urea combination increased by 55.32 %, 56.12 %, and 529.66 %, respectively. Additionally, urea was demonstrated to promote the removal of lignin during the pretreatment process. Before enzymatic hydrolysis and fermentation, the traditional method of washing the pretreated materials was discarded and pressure filtration method (PFM) was used for dehydration. At 30 % solids loading, the concentration of glucose after enzymatic hydrolysis was 98.15 mg/mL, and Saccharomyces cerevisiae 1308 reached an ethanol titer of 42.54 mg/mL with a yield of 91.10 % within 24 h of fermentation. This research supports the low-pollution and low-cost development and application of biomass energy.