Sugarcane straw as feedstock for 2G ethanol: Evaluation of pretreatments and enzymatic hydrolysis

The potential of sugarcane straw (SCS) as feedstock for 2G ethanol production was investigated. Three different pretreatments (hydrothermal, ultrasound and acid) and the enzymatic hydrolysis of SCS were evaluated. Pretreated materials were delignified with NaOH and after that the enzymatic hydrolysis of all materials was conducted. The best conditions for hydrothermal pretreatment removed a massive amount of hemicellulose (about 60%), preserving the most portions of lignin and cellulose. In general, ultrasound pretreatment was not very effective in removing the cell wall components. Acid pretreatment was able to remove high amounts of hemicellulose (77%) and lignin (54%). After NaOH treatment, a low quantity of lignin remained. The enzymatic hydrolysis achieved high conversion for the combinations hydrothermal + NaOH (84%) and acid + NaOH (86%). These results show that hydrothermal and acid pretreatment were more suitable in the process of ethanol obtainment of from SCS.