An environmentally effective separation strategy of chitin from shrimp shells based on steam explosion and supercritical carbon dioxide

The development of an environmentally effective strategy for separating chitin from shrimp shells was carried out in this study. Steam explosion (SE) was first performed to increase the specific surface area of shrimp shells, which led to an improvement in the demineralization efficiency with supercritical carbon dioxide/ water and the deproteinization efficiency with high-temperature water. Comparing to shrimp shells without SE, the demineralization rate and deproteinization rate after SE increased by 12.23 % and 13.04 % respectively, and ultimately achieved high rates of demineralization and deproteinization (>95 %). The minimum selling price of chitin was estimated to be 303.95 CNY/kg by this strategy, which decreased by 35.06 % according to technical-economic analysis. Based on life cycle assessment, the carbon emissions per kilogram of processed shrimp shells were decreased by 38.74 %. This work provides a new perspective on the economic and green preparation of chitin and demonstrates considerable potential for large-scale development and application. • Steam explosion treatment improved separation efficiency of chitin significantly. • The rates of demineralization and deproteinization reached 95 % and 98 % respectively. • This strategy has obviously lower carbon emissions comparing to traditional strategy.