Conversion of chitin biomass into 5-hydroxymethylfurfural: A review

5-hydroxymethyfurfural is an important platform chemical, which can be produced by hydrothermal conversion of chitin biomass. 5-Hydroxymethyfurfural can be converted into value-added chemicals and liquid fuels. Thus, the utilization of chitin biomass will help consume crustacean waste and reduce environmental problems caused by the overuse of fossil resources. This review summarizes the recent process in the production of 5-hydroxymethyfurfural from chitin biomass in solvent-catalytic systems. The topics mainly include solvent systems, catalysts, and conversion mechanisms. Suitable solvent system can improve the conversion of chitin biomass into 5hydroxymethyfurfural. Especially, the strong solubility of concentrated salt solution resulted in mild reaction temperature. Mechanism studies based on solvent system will be helpful to the products control. The catalysts are very important in producing 5-hydroxymethyfurfural from chitin biomass. Catalyst design and related reaction mechanism research will be necessary to improve the selectivity of the 5-hydroxymethyfurfural. Future research will focus on finding a catalyst-solvent combination system that improves the solubility and conversion of chitin biomass, especially on cheap and easily available solvents such as deep eutectic solvents, high-temperature water and inorganic salts such as aluminum chloride, ferrous chloride, etc.