Advancing circular economy: Biorefinery of agri-waste via green multicomponent deep eutectic solvent pretreatment
Han Gao, Jinliu Xiao, Yun Wang, Yunkai Yu, Junzhang Wu, Jian Zhang, Zhiwei Wang, Shuangfei Wang, Qingshan Luo
Abstract
An effective, economical, and eco-friendly pretreatment of lignocellulosic biomass is crucial for advancing biorefinery as a sustainable solution to fossil fuel scarcity and to support a circular economy. This study introduces a multifunctional deep eutectic solvent (multi-DES) system, created by combining analog volatile fatty acids (analog-VFAs) as hydrogen bond donors with choline chloride, to pretreat agricultural waste (agri-waste) and facilitate the production of nano-lignocellulose materials. The multi-DES pretreatment was optimized for varying durations and temperatures, achieving a maximum lignin removal rate of 74.1 % at 150 °C over 3 h. Subsequent ball milling yielded high-quality lignocellulosic nanofibers (LCNFs) with widths ranging from 10 to 15 nm and exhibiting excellent thermal stability and mechanical properties. A life cycle assessment (LCA) confirmed the environmental benefits and practical viability of this biorefinery process. This approach effectively upgrades agri-waste into valuable LCNFs, enhancing biomass utilization with minimal environmental impact, and advancing the competitiveness of biorefineries. • A multi-DES system using analog-VFAs and ChCl was developed for waste pretreatment. • An innovative biorefinery process was introduced to convert agri-waste into LCNMs. • The process produced LCNFs with high aspect ratio and robust properties. • LCA confirmed the environmental benefits and viability of the process.