Choline chloride-based deep eutectic solvents for efficient delignification ofBambusa bambosin bio-refinery applications

The use of choline chloride-oxalic acid (CO) and choline chloride-urea (CU) green solvents as mediator for delignification ofBambusa bambosstem (BS) has been studied. The optimal delignification of BS obtained at 120 degrees C and 4 h of DESs (deep eutectic solvents) treatment process. The morphological structure of raw BS and treated BS was analyzed by SEM, XRD, and FTIR. The results showed that the crystallinity index increased from 43.8 in raw BS, to 44.3%, and CUT-BS and 46.4 in COT-BS. The surface elemental composition of BS was estimated by photoelectron spectroscopy (XPS). The carbon and oxygen elemental contents in the biomass surface were determined by XPS survey, C1s, and O1s spectra. The delignification using CO system (25.4%) more easily digested the BS biomass compared to CU system (19.4%). The use of acid DES can be an effective pretreatment process compared to basic treatment processes for biomass fractionation in bio-refinery applications.