Thermodynamic modeling of adsorption of dimethyl sulfide on raw and modified activated carbon by simplified local density model

Abstract

The simplified local density (SLD) model was employed to analyze the experimental results of the adsorption of dimethyl sulfide (DMS) from a model fuel (n-hexane) on raw and modified walnut shell activated carbon (WSAC) with different impregnated amounts of silver ions (Ag-2, 4, 6, 8, and 10 mass percent). Modified Peng–Robinson equation of state was used in the liquid phase and the 6-12 Lenard Jones (LJ) potential function was implemented to represent the solid-fluid interactions. The LJ parameters for pure DMS and n-hexane were obtained from the Tsonopoulos correlation for the Second Virial coefficient data. Published experimental results of DMS and n-hexane adsorption were used for the physical properties and the molecular parameters needed in SLD model. Excess adsorption amounts of DMS were then calculated and compared with the experimental data. The average absolute deviations (AAD) between the experimental data and calculated results were 0.0072, 0.0727, 0.0377, 0.0601, 0.0605, and 0.0634 mmol/gr adsorbent for WSAC, WSAC-Ag-2, WSAC-Ag-4, WSAC-Ag-6, WSAC-Ag-8, and WSAC-Ag-10, respectively. For the same adsorbents the percent average absolute relative deviation (AARD%) were 14.11, 15.50, 7.70, 15.48, 16.16, and 29.09, respectively. The applicability of the SLD model in liquid-phase adsorption is validated.