Characterization of CO2 mineral sequestration by wet carbonation of crustacean solid waste: a case study of crab shells

Crab shells, as the waste from seafood processing, are emerging as a valuable resource for recycling and environmental protection. By combusting the organic components of crab shells, the high-calcium crab shell ash (CSA) is produced. This ash serves as a promising raw material for CO 2 mineralization, contributing to energy conservation and emission reduction. In this study, the systematic mineralization experiment of CSA was conducted using wet carbonation, focusing on the effects of reaction temperature, liquid–solid ratio, particle size, and stirring speed on CO 2 mineralization. The optimal mineralization conditions were achieved at a temperature of 60 °C, a liquid–solid ratio of 10 mL/g, a stirring speed of 700 rpm, and a CSA particle size exceeding 200 mesh, resulting in a carbonation efficiency of 66.10%. Furthermore, we improved the mineralization process by modifying the CSA with Na 2 CO 3 and employing microwave treatment. The carbonation efficiency significantly increased to 71.80% with a Na 2 CO 3 concentration of 1.75 mol/L. Notably, microwave drying further enhanced the carbonation efficiency of CSA to 73.01%. Our findings contribute to a deeper understanding of CSA mineralization and establish a theoretical foundation and research direction for enhancing the carbon sequestration capacity and subsequent application performance of crustacean biomass ash.