A batch reactor study to determine effectiveness factors of commercial HDS catalyst

In this work we present a series of experiments in order to determine effectiveness factor of commercial hydrodesulfurization (HDS) catalysts. All the tests were carried out with straight-run gas oil (SRGO) and CoMo/γ-Al2O3 catalyst in a batch reactor at 54 kg/cm2 pressure, 320–380 °C reaction temperature, 1000 rpm stirring and reaction times between 1 and 6 h. Four sizes of catalyst were employed for HDS experiments: (1) Commercial size, average particle size dp = 2.5 mm, (2) dp = 0.833 mm (20 mesh), (3) dp = 0.369 mm (40 mesh), and (4) dp = 0.246 mm (60 mesh). Before HDS tests all the samples were loaded to a continuous high-pressure reactor, then dried, soaked and sulfided with a mixture of SRGO and dimethyl disulfide (DMDS, 1 wt.% sulfur) at typical activation conditions. The effects of reaction temperature, reaction time, and catalyst particle size on hydrodesulfurization are discussed and reaction order, kinetic constants, effectiveness factors and activation energies are calculated for each particle size. The values of effectiveness factors are within those reported in the literature.