Hydrogenation of naphthalene on nickel phosphide supported on silica

摘要

The reduction of polycyclic hydrocarbon in middle distillates has received considerable attention because of the stringently environmental regulations. Aromatic saturation was run in the conventional hydroprocessing. However, aromatic hydrogenation is more difficult than hydrodesurfurization and hydrodenitrogenation under conditions that are normally used for hydrotreating. In addition, there are thermodynamic equilibrium limitations on aromatic hydrogenation within the normal conditions. A well-understanding of the effects of process variables, catalyst types and thermodynamic equilibrium in the feedstock is necessary for the optimum operating strategies. In this work, the nickel phosphide supported on silica was prepared by the temperature-programmed hydrogen reduction of nickel phosphate, and its catalytic properties for hydrogenation of naphthalene were investigated.The nickel phosphides supported on silica were prepared by temperature-programmed reduction in hydrogen. The reaction conditions of naphthalene hydrogenation such as temperature, press, volume of H2/liquor and WHSV were tested. The hydrogenation of naphthalene produces mixtures of cis- and trans-decalin through the intermediate of tetrahydro-naphthalene. The conversion and selectivity to decalin reach the maximum at 340°C, due to thermodynamic equilibrium limitation. A high pressure of H2 promoted naphthalene hydrogenation. Volume ratio of H2/liquor almost had no effect on hydrogenation.