Fabrication of silica aerogel and carbon–silica composite for dynamic adsorption of benzene from dry and wet gas streams

Abstract

ABSTRACT In the present study, the white kaolin-derived silica (SA) and silica-carbon aerogel composite (CSA) were successfully synthesised as useful adsorbents for the effective removal of benzene from dry and wet gas streams. The physicochemical features of the adsorbents were characterised using SEM, BET, XPS, and TGA, and the adsorption properties of benzene were investigated through breakthrough time curves and equilibrium study. The specific surface areas of SA and CSA were 628 and 783 m2 g−1, respectively, demonstrating the high porosity of the synthesised adsorbents. The dynamic adsorption and isotherm performances of SA and CSA confirmed that both adsorbents have superior adsorption properties and Khan isotherm for both developed adsorbents were the fittest model among the two- and three-parameter isotherm models studied and provided a maximum adsorption capacity of 366.2 and 224.4 for SA and CSA mg g−1, respectively. Furthermore, the reusability tests revealed that the SA and CSA could be efficiently recovered at 180°C. Our experimental outcomes indicated that the prepared SA and CSA can be applied as efficient and inexpensive adsorbents for the removal of benzene from gaseous streams.