Desulfurization of Real Diesel Fuel onto Mesoporous Silica MCM-41 Implementing Batch Adsorption Process: Equilibrium, Kinetics, and Thermodynamic Studies


In the current work, sulfur was removed from actual diesel fuel containing 1.2wt.% sulfur from the Al-Dura Oil Refinery (Iraq), which was studied usingadsorption desulfurization with the spherical mesoporous silica MCM-41. Thisstudy investigated the effects of different operating conditions, including the doseof MCM-41 (0.04-0.2 gm), time (60-180 min), and temperature (30-70°C). Theoptimal working conditions were determined to be 0.4 gm MCM-41, 180 min, and70°C. After exploring the isotherm models of Langmuir, Freundlich, and Temkin,Temkin models with a correlation coefficient (R2 = 0.9996) were selected to bestrepresent the stable data. The kinetics of sulfur components on MCM-41 werestudied using pseudo-first-order and pseudo-second-order kinetic models andintra-particle diffusion. A pseudo-first-order adsorption kinetic model with acorrelation coefficient (R2) of 0.9867 can accurately represent the adsorptionprocess. Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo) werecalculated as thermodynamic parameters. The adsorption of total sulfur-containingcompounds onto mesoporous silica was spontaneous, endothermic, and increasedthe irregularity of the sulfur compounds on the surface of the adsorbent. The totalsulfur content of actual diesel fuel was reduced from 1.2% to 0.84%,corresponding to a desulfurization efficiency of 29.72%. Consequently, thefindings of this study might be used as a starting point for future research.