Molecular simulation of benzene adsorption on different activated carbon under different temperatures

Four different structure models of activated carbon were constructed here by molecular simulation method. The four models include three microporous structures with micropore sizes of 9-11 angstrom, 10-12 angstrom, and 13-16 angstrom, respectively, and one microporous-mesoporous structure with pore sizes of 15-17 angstrom and 21-24 angstrom. The microporous-mesoporous structure was easily adjusted by the introduction and deletion of single-wall carbon nanotubes (SWCNTs, 15, 15). The adsorption of benzene on different structure models at temperatures of 273.15, 288.15, 303.15 and 318.15 K were studied by Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) methods. Adsorption isotherms, average isosteric heats of benzene adsorption, porosity and pore volume change after benzene adsorption at different temperatures were analyzed. The radial distribution function, relative concentration distributions and diffusion coefficients of benzene molecules on different structure models were further studied. Comprehensive analysis results indicate that for low temperature, activated carbon with larger micropores and mesopores is favorable to adsorption of benzene. But for high temperature, activated carbon with smaller micropores is favorable to adsorption of benzene.