Effective conversion of biomass into bromomethylfurfural, furfural, and depolymerized lignin in lithium bromide molten salt hydrate of a biphasic system

Abstract

A novel approach using a biphasic system consisting of a molten lithium bromide hydrate solution (LiBr$3H 2 O) and an organic solvent was developed to efficiently produce furan-based chemicals from cellulose and lignocellulosic biomass. At 125 C for 2 h, the yield of bromomethylfurfural (BMF) from cellulose reached >90% (molar yield), and the yields of furfural (FF) and BMF from real biomass (herbage, hardwood, and softwood) were $70% and $85%, respectively. The reaction mechanisms of the polysaccharides and lignin and the role of the molten salt hydrate were investigated and elucidated. In the biphasic system, hemicelluloses and cellulose of the biomass were dissolved, hydrolyzed, dehydrated and brominated to FF and BMF, respectively, in the aqueous phase, and the furan products were simultaneously extracted into and cumulated in the organic phase. Meanwhile, lignin in the biomass was significantly depolymerized through the cleavage of b-aryl ether linkages and separated with high purity for potential coproducts.

Hydrolysis of Hemicellulose and Derivatives—A Review of Recent Advances in the Production of Furfural

“…NaCl was also found responsible of all reactions such as hydrolysis, epimerization and dehydration involved in the processes at the higher temperature of 200°C. A production of furfural was set up in association with bromomethylfurfural (BMF) and HMF from cellulose and lignocellulosic biomass (Yoo et al, 2017 ). The biphasic system water-DCM (1:3, v/v) involving an organic solvent and a molten lithium bromide hydrate solution was heated for 2 h at 120°C and permitted to obtain furfural in 70% yield.…”

An uncondensed lignin depolymerized in the solid state and isolated from lignocellulosic biomass: a mechanistic study

“…A similar synergistic effect of the acid and LiBr trihydrate in ALBTH was reported in the hydrolysis and dehydration of polysaccharides to furfurals. 47,48 The structures of the GG products in ALBTH and NLBTH were further characterized by HSQC NMR analysis. HK and BD moieties were detected from the ALBTH-treated GG (Fig.…”

Structural changes of poplar wood lignin after supercritical pretreatment using carbon dioxide and ethanol–water as co-solvents

“…The 2D-HSQC NMR is a powerful analytic technique and can give detailed structural characterization of complex biopolymers such as lignin. 5,32,33 The 2D-HSQC spectra of EHL, SCEP-RL and SCEP-DL samples are shown in Fig. 1.…”