Biobutanol production from cellulose-rich sugarcane bagasse and hard aspen wood residue

• Two-stage mild acid-organosolv pre-treatment processes on agro-based waste were established. • Sugarcane bagasse and Aspen wood biomass were successfully pretreated with little fermentation and saccharification inhibitors released. • The hydrolysate did not need detoxification to support fermentation. • ABE fermentations were successfully carried out on the hydrolysate to produce biobutanol. This study investigated the impact of a two-stage pre-treatment process of sugarcane bagasse (SB) and aspen wood (AW) biomass to produce biobutanol. Mild acid and organosolv pre-treatment were combined to pre-treat the biomass and recover lignin. The pre-treated biomass was used for enzymatic saccharification. The total reducing sugars yield per 100 g of pre-treated biomass was 29.29 g/L (13.8 g/L glucose) and 27.79 g/L (12.45 g/L glucose) from AW and SB at 150 °C and 160 °C respectively. Both samples gave a lignin recovery of 15 %. The highest phenolic content obtained from the hydrolysates was 6.55 and 4.53 mg/L for SB and AW at 170 °C and 160 °C, respectively. The highest biobutanol concentration obtained was 7.08 and 8.65 g/L for SB and AW respectively after 72 h. Therefore, the two-stage pre-treatment process was successfully applied to obtain solid residues rich in cellulose as well as lignin, that could be fermented to produce biobutanol.