Effect of hydrogen sulfide on the hydrotreating of middle distillates over Co–Mo/Al2O3 catalyst Original Research Article

In this work we report the experimental results obtained in an isothermal fixed-bed hydrotreating reactor using an industrial feedstock consisting of a blend of 85 vol% of straight-run gas oil and 15 vol% of light cycle oil. All tests were carried out with a commercial Co–Mo/Al2O3 catalyst at a total pressure of 54 kg/cm2, LHSV of 1–2 h−1, temperature of 350–370°C and constant hydrogen-to-oil ratio of 2000 ft3/bbl. The effect of hydrogen sulfide concentration in gas on sulfur, nitrogen and aromatics in product was studied in the range 0–10 mol%. The experimental results show that the inhibiting effect of hydrogen sulfide on sulfur, nitrogen and aromatics contents is lower at high temperature. Other product properties, such as cetane index and API gravity, showed relatively little changes when the hydrogen sulfide concentration in gas was increased.