Fast Disassembly of Lignocellulosic Biomass to Lignin and Sugars by Molten Salt Hydrate at Low Temperature for Overall Biorefinery.

Abstract

Lignocellulose is a complex of cellulose, hemicellulose, and lignin, whose overall conversion is still a challenge, especially by a fast and efficient method. Here, a very simple method has been developed using acidic molten salt of zinc chloride hydrate as the solvent and catalyst for complete disassembly of lignocellulose at 95 °C and atmospheric pressure in 12 min. The major products are lignin and monosaccharides, such as glucose and xylose. It was found that high-purity lignin in yield of about 20 wt % can be obtained with various biomass, and the maximum yield of glucose from bamboo is 40.56 wt % and that of xylose from wheat straw is 16.82 wt %. Importantly, zinc chloride can be recovered through precipitation by ammonia and reused for next cycles. It provides a simple route to separate and efficiently convert lignocellulose, especially high-grade feedstock for biorefinery.