Single and binary sulfur removal components from model diesel fuel using granular activated carbon from dates' stones activated by ZnCl2

Samples of granulated activated carbon (GAC) produced from dates' stones as adsorbent by chemical activation using ZnCl2 as an activator were used in desulfurization of a model diesel fuel composed of n-decane (n-C10H22) and 4,6-dimethyl dibenzothiophene (4,6-DMDBT) as sulfur containing compound. The adsorption data were fitted to both Freundlich and Langmuir isotherms to estimate the adsorption parameters. The optimum operating conditions for GAC preparation based on high adsorption capacity using ZnCl2 are T-carb = 600 degrees C, theta(carb) = 3.0 h and R = 0.5. Comparison with dibenzothiophene (DBT) adsorption using the same GAC showed that 4,6-DMDBT has a lower adsorption capacity than DBT due to steric effects caused by the existing two methyl groups. Finally adsorption of binary mixtures of DBT and 4,6-DMDBT on GAC were experimentally obtained, fitted and analyzed using extended Langmuir, extended Freundlich and ideal adsorption solution theory, IAST, models. (C) 2009 Elsevier B.V. All rights reserved.