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

A novel approach using a biphasic system consisting of a molten lithium bromide hydrate solution (LiBr center dot 3H(2)O) and an organic solvent was developed to efficiently produce furan-based chemicals from cellulose and lignocellulosic biomass. At 125 degrees 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 similar to 70% and similar to 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 beta-aryl ether linkages and separated with high purity for potential coproducts.