Production of levulinic acid from glucosamine by dilute-acid catalyzed hydrothermal process

Glucosamine is a basic unit of the chitin/chitosan structure, which is derived from crustacean (e.g. crab, shrimp) and insect shells. In this study, the production of levulinic acid (LA) from glucosamine via dilute-acid-catalyzed hydrothermal hydrolysis was investigated. Among the reaction conditions, reaction temperature, reaction time, and substrate concentration were more effective than catalyst concentration. The optimal conditions for LA production, as determined by the response-surface methodology (RSM), were as follows: 188 °C reaction temperature, 4 wt% catalyst concentration, 49 min reaction time, 120 g/L substrate concentration. Under these conditions, the LA yield was 30.3 g/L (25.3 wt%), while the 5-HMF concentration was zero. These results might provide basic knowledge essential to the production of valuable chemicals derivable from renewable marine resources and utilizable as fuel additives and polymer building blocks.