Electro-driven deep eutectic solvent pretreatment of wheat straw with enhancive component fractionation and hydrogen evolution at room temperature

Deep eutectic solvent (DES) pretreatment is attractive for the delignification of lignocellulosic biomass, while unable to circumvent the trenchant demand for the higher-temperature operating conditions. Herein, an electro-assisted DES (choline chloride/ethylene glycol = 1:2) strategy was developed for wheat straw pretreatment at room temperature. The rate of lignin removal, hemicellulose removal, cellulose recovery, and cellulose saccharification reached 68.1%, 60.8%, 95.1%, and 82.5%, respectively, which were comparable or superior to the reported efficiency of traditional DES pretreatment methods. The destruction of lignin by electricity and in-situ dissolution of released lignin components with DES enabled effectively the separation of the full components. Notably, the evolution rate of hydrogen in-situ produced during electro-driven DES pretreatment of wheat straw was 50 μmol cm⁻² h⁻¹, and 4.6 g/100 g lipids could be obtained with Trichosporon cutaneum grown on the fractionated cellulose and hemicellulose components. The electro-assisted DES process offers a potential platform for lignocellulosic biomass fractionation at ambient conditions. According to the life cycle cost analysis (LCCA), the estimated cost of producing hydrogen from 100 g of wheat straw is only $37.24, demonstrating its potential for commercial viability.