Non-oxidative reprocessing and activity maintaining of hydrorefining catalyst - by mixing heavy oils and/or middle distillates with light cycle oil

Non-oxidative reprocessing and maintaining of the activity of hydrorefining-catalysts, pref. sulphurised CoO-MoO3/Al2O3 or NiO-MoO3/Al2O3, comprises using heavy oils and/or middle distillates pref. vacuum distillates as raw materials, whose content of undesired components esp. organometallic cpds. of vanadium and nickel, sulphur- and nitrogen cpds., and asphalts, is reduced by hydrogenation, and reducing the activity of the catalysts by catalytically initiated side-reactions and desorption, physiosorption and chemisorption of the high-boiling asphalts and resins and their decomposition prods.. The novelty is that 5-50 % light cycle oil from the catalytic splitting of vacuum distillates with the following properties: distn. range (K) of 430-650; density (g/cm3) of 0.82-0.96; viscosity (323 K) mm2 per sec. of 2.6; average molar mass of 170-190; total aromatic-content (wt.%) of 75-90; content of 1- and 2-ring aromatics (wt.%) of at least 75; is discontinuously mixed with the raw materials. After reaching the upper concn. limit of light cycle oil in the raw material after 20-40 hrs, the addn. is terminated or 0.5-50% light cycle oil is added continuously. ADVANTAGE - The loss of catalytic activity is prevented