Rapid, selective, and room temperature dissolution of crystalline xylan by a hydrotrope

Selective dissolution of industrial biowaste is of significant importance for the valorization of biomass. Especially, fractionation of polysaccharides with similar structures is more challenging. Herein, a new kind of cationic hydrotrope, tetraethylammonium hydroxide (TEAH), has been developed for rapid, efficient, and selective dissolution of industrial biowastes-xylan type hemicelluloses from viscose fiber mills. When the concentration of TEAH is 15 wt%, the solubility of industrial crystalline xylan reaches to 13.39 wt% at room temperature. Crystalline or amorphous xylan can be regenerated by adding water or ethanol, with 57.98 % and 95.45 % yields, respectively. Additionally, we showcase hemicelluloses were near-completely extracted from holocellulose without degrading cellulose under ambient temperature by simply adjusting the concentration of TEAH, demonstrating the advantage of the hydrotropic feature. This hydrotrope solvent system features selective, rapid, and room temperature dissolution polysaccharides, which will shed new light in technological applications of the industrial spinning or biorefining processes.