Conclusion
In this study, seven DESs were synthesized and evaluated in the pretreatment of CS. ChCl:formic acid, DES with acidic hydrogen donor, could increase cellulose accessibility by removal of hemicellulolose and lignin, leading to a high CrI of 57.1. In butanol fermentation using DES pretreated hydrolysates by Clostridium saccharobutylicum DSM 13864, butanol yield of 0.17 g g−1 total sugar and productivity of 0.12 g L−1 h−1 were attained without apparent inhibitory effect. Taken together, this work demonstrates that DESs pretreatment is a promising and biocompatible procedure in the biofuel production from lignocellulosic biomass.