Valorization of Crab Shells as Potential Sorbent Materials for Co2 Capture

Abstract

This study delves into the potential advantage of utilizing crab shells as sustainable solid adsorbents for CO2 capture, offering an environmentally friendly alternative to conventional porous adsorbents such as zeolites, silicas, MOFs, and porous carbons. The investigation focuses on crab shell waste, which exhibit inherent natural porosity and amide groups, making them promising candidates for CO2 physi- and chemisorption applications. Selective deproteinization and demineralization treatments were used to enhance textural properties, while preserving the natural porous structure of the crab shells. The impact of deproteinization and demineralization treatments on CO2 adsorption and speciation at the atomic scale, via solid-state NMR, and correlated these findings with textural properties and biomass composition were investigated. The best performing sample exhibits a surface area of 36 m2/g and a CO2 adsorption capacity of 0.31 mmol/g at 1 bar and 298 K, representing a gain of ~3.5 and 2, respectively, compared to the pristine crab shell. These results underline the potential of fishing industry wastes as a cost-effective, renewable, and eco-friendly source to produce functional porous adsorbents.

Keywords: Chitin, Crab shells, Solid-state NMR spectroscopy, Carbon capture, Porous material, Polysaccharides, Circular economy.