Pretreatment and Conversion of Shrimp/Crab Shells into High-Value Products with Ionic Liquids

Due to unique hydrogen bond network and excellent chem-physical properties, ionic liquids (ILs) including deep eutectic solvents (DESs) show great potential in the biomass dissolution and conversion. In this entry, the performance of ILs toward the utilization of shrimp/carb shells is briefly presented. Specifically, the separation and functionalization of chitin, an important component in the waste shrimp/crab shells, are mainly summarized and described. To figure out a comprehensive understanding for chitin utilization from shrimp/crab shells, a schematic structure of shrimp shells is illustrated firstly. And then, some typical methods for chitin preparation via shell treatment with ILs were compared, which are divided into extraction and pulping strategies. As an important precondition for chitin conversion, some progresses related to high solubility of chitin in ILs are also summarized. Finally, this entry provides the conversion of chitin to high-value chemicals using ILs with chitin and shrimp shells as the raw materials. This entry aims to show that ILs including DESs have great potential in waste shrimp and crab shell direct utilization. And with well addressing some existing issues or challenges, the corresponding technologies are expected to achieve widespread and larger-scale applications in the near future.