Changes in apparent reaction order and activation energy in the hydrodesulfurization of real feedstocks

In this work we present experimental information about the effect of feed properties on apparent reaction order and activation energy in the hydrodesulfurization of middle distillates. Experiments were carried out in a pilot reactor at the following operating conditions: reaction temperature of 340, 350, and 360 °C; liquid hourly space-velocity of 1.5 and 2.0 h^-1; reaction pressure of 54 kg/cm² and hydrogen-to-oil ratio of 2000 ft³/bbl. Apparent reaction orders were in the range of 1.70-1.98, while apparent activation energies varied in the range of 14-42 kcal/mol. Reaction orders showed an increase as molecular weight of feed was increased. Activation energies were similar for feedstocks with same reaction order.