Efficient fractionation of reed biomass by inorganic salt-driven seawater/ethanolamine pretreatment for fermentable sugars and N-containing lignin

ETA/SW pretreatment fractionated reed into fermentable sugars and N-containing lignin. • Achieved 82.20% lignin removal under optimized pretreatment conditions • Glucose and xylose hydrolysis efficiencies reached 84.72% and 66.70%, respectively. Exploring low-cost, low-energy-consumption methods to efficiently disassemble waste biomass and achieve full utilization of multi-components in lignocellulose has always been a significant challenge in the field of biomass pretreatment. In this study, a new strategy of high-solids inorganic salt-driven seawater/ethanolamine pretreatment was proposed. During pretreatment, inorganic salt ions in seawater induce cell wall swelling, which enhances the diffusion of ethanolamine into the fiber matrix. Acting as a basic nucleophile, ethanolamine promotes lignin depolymerization while simultaneously enabling amination modification. This process effectively suppresses lignin condensation and redeposition, resulting in improved cellulose preservation. Consequently, the treated biomass exhibits enhanced cellulose accessibility and significantly improved enzymatic hydrolysis efficiency. Under the favorable conditions, the glucan retention rate and lignin removal rate reached 94.29% and 82.20% respectively. Subsequent hydrolysis with cellulase (25 FPU/g) and hemicellulase (120 IU/g) gave glucose and xylose hydrolysis efficiencies of 84.72% and 66.70%, respectively. This strategy enabled the concurrent production of fermentable sugars and N-containing lignin. Moreover, the idea of using seawater instead of freshwater to pre-treat waste biomass and realize the productization of all components provides a promising route for the advancement of biomass pretreatment technologies. Download: Download high-res image (270KB) Download: Download full-size image