High-purity lignin isolated from poplar wood meal through dissolving treatment with deep eutectic solvents.
Yujie ChenLili ZhangJuan YuYingzhao LuBo JiangYimin FanZhiguo WangPublished in: Royal Society open science (2019)
Deep eutectic solvents (DESs) have potential applications in biomass conversion and green chemicals due to their cost-effectiveness and environmentally friendly properties. This study reports on a feasible method of using DESs for lignin selective extraction from poplar wood meal. DESs obtained from various hydrogen-bond donors and acceptors were used to evaluate the dissolving capacity of lignin from poplar wood meal. Among the various DESs, lactic acid: choline chloride (9 : 1) exhibits the optimal extraction capacity, which is capable of selectively dissolving 95% of lignin from poplar wood meal at 120°C for 6 h. The purity of isolated lignin reaches 98% after regeneration in water. From Fourier Transform-IR, nitrobenzene oxidation and nuclear magnetic resonance analysis, the results demonstrate that the DESs can selectively cleave ether linkages and damage the non-condensation section of lignin, thereby facilitating lignin dissolution from wood meal. Thus, this study provides a promising route for the extraction of high-purity lignin from biomass materials.