A method for concentration of monosaccharide and removal of inhibitors during hydrolysate pretreatment for improved bioethanol production

Due to its renewable and clean characteristics, bioethanol is an advantageous alternative energy source to fossil fuels. Although crop straw is a suitable material for bioethanol production, the low-concentration of fermentable sugars and the presence of inhibitors such as furfural and acetic acid in straw hydrolysate are not conducive to ethanol fermentation and pose significant limitations. This work aims to facilitate the removal of furfural and acetic acid during sugar concentration. A reverse osmosis (RO) membrane was chosen for the simultaneous concentration of sugar and removal of inhibitors. Additionally, an ethanol promotion method was developed, the results from which indicated that the retentions of furfural and acetic acid were reduced in the RO process. In different synthetic solutions with ethanol, the retention of furfural decreased by 48.40% when the ratio of ethanol/furfural concentration was 12.10, and the retention of acetic acid decreased by 22.30% when the ratio of ethanol/acetic acid concentration was 5.80. The findings of this study showed that the method for inhibitor removal proposed in this study could promote the removal of furfural and acetic acid from hydrolysate and has great potential for use in bioethanol production. (C) 2020 Elsevier Ltd. All rights reserved.