Effect of Supercritical Deposition Synthesis on Dibenzothiophene Hydrodesulfurization Over NiMo/Al2O3 Nanocatalyst

The synthesis of two NiMo/Al2O3 catalysts by the supercritical carbon dioxide/methanol deposition (NiMo-SCF) and the conventional method of wet coimpregnation (NiMo-IMP) were conducted. The results of the physical and chemical characterization techniques (adsorption-desorption of nitrogen, oxygen chemisorption, XRD, TPR, TEM, and EDAX) for the NiMo-SCF and NiMo-IMP demonstrated high and uniform dispersed deposition of Ni and Mo on the Al2O3 support for the newly developed catalyst. The hydrodesulfurization (HDS) of fuel model compound, dibenzothiophene, was used in the evaluation of the NiMo-SCF catalyst vs. the commercial catalyst (NiMo-COM). Higher conversion for the NiMo-SCF catalyst was obtained. The kinetic analysis of the reaction data was carried out to calculate the reaction rate constant of the synthesized and commercial catalysts in the temperature rang of 543-603 K. Analysis of the experimental data using Arrhenius' law resulted in the calculation of frequency factor and activation energy of the HDS for the two catalysts. (C) 2009 American Institute of Chemical Engineers AIChE J, 55: 2665-2674, 2009