IN-SITU WASHING PROCEDURE TO RECOVER THE CATALYTIC ACTIVITY OF A DEACTIVATED HYDRODESULFURIZATION CATALYST

The present invention is an in-situ cleaning procedure for the recovery of catalytic activity of a based alumina HDS catalyst, molybdenum, nickel coated coke and contaminants and it has an HDS activity seriously diminished. The catalyst under study had between 13 and 18 wt % total carbon. Reformate, half the total volume, industrial toluene=35 volume % and Iso-propylic alcohol, 15 volume %, in order to reactivate a deactivated catalyst, a solvent mixture with the following volumetric ratio is prepared. Or it can also be used only reformate (100% volume). The solvent mixture is passed using a LHSV of 2 hr−1 for 72 hours at 50° C. or also using a recirculating three 24-hour cycles at 50° C. Option lasts 24 hours pure reformate LHSV=2h−1 to 50° C. The washed catalyst is fed back to the load reaction conditions maintained for 36 hours at 340° C., to initiate HDS activity balances. During this treatment oxides of molybdenum and nickel in the active phase are re-sulfided by increasing the HDS activity. The In-Situ Cleaning procedure to reactivate deactivated hydrotreating catalysts used to partially remove the carbon and increase the active phase of molybdenum di-sulphide, and also retrieve specific area, and hydrogenation sites that promote higher hydrodesulfurization activity of gasoil after this treatment.