Choline chloride/polyacid-based deep eutectic solvents for efficient cellulose extraction from sugarcane bagasse

t:

Deep eutectic solvents (DESs) are green, environmentally friendly solvents formed by mixing a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA) in specific proportions to create a eutectic mixture. This study focuses on the preparation of various choline chloride (ChCl)-based DESs using ChCl as the HBA and polyacids, oxalic acid (OA), malonic acid (MA), and succinic acid (SA), as the HBDs. The efficiency of these DESs in extracting cellulose from sugarcane bagasse (SCB) was investigated. The effects of different ChCl to polyacid ratios (1:1, 1:2, 1:3, 1:5, 2:1, 3:1, and 5:1), extraction times, and temperatures on the lignocellulose compositions were examined. The chemical compositions of SCB after pretreatment were analyzed using high-performance liquid chromatography (HPLC) following the National Renewable Energy Laboratory (NREL) method and confirmed by thermogravimetric analysis (TGA) and Fourier transform spectroscopy (FTIR). The results showed that the ChCl/OA-based DES with a 1:1 ratio pretreated the SCB at 80°C for 2 hours achieved the highest efficiency with nearly 100% removal of hemicellulose, 37% removal of lignin, and almost 51 % retention of cellulose.