Chromium-containing hydrofining catalysts

Claim 1

A HYDROCARBON COVERSION PROCESS FOR TREATING A HYDROCARBON OIL CONTAINING NITROGEN COMPOUNDS, WHICH COMPRISES PASSING SAID OIL AND EXCESS HYDROGEN AT ELEVATED PRESSURE AND AT A TEMPERATURE BELOW 900*F. INTO CONTACT WITH AN ACTIVE HYDROFINING CATALYST COMPOSED AS THE ESSENTIAL ACTIVE COMPONENTS OF SULFIDES OF BOTH CHROMIUM AND MOLYBDENUM SUPPORTED ON A REFRACTORY POROUS OXIDE CARRIER, AND RECOVERING AS A PRODUCT OIL REDUCED IN NITROGEN CONTENT; SAID CATALYST HAVING BEEN PREPARED BY IMPREGNATING ALUMINA WITH SOLUTIONS OF A MOLYBDENUM COMPOUND AND OF CHROMIC SULFATE, DRYING THE IMPREGNATED ALUMINA BELOW THE TEMPERATURE AT WHICH DECOMPOSITION OF CR2(SO4)3 OCCURS, TREATING THE DRIED IMPREGNATED MATERIAL WITH FLOWING HOT GAS COMPRISING HYDROGEN AT BETWEEN 500*F. AND 1000*F., AND TREATING WITH FLOWING HOT SULFIDING MEDIUM AT BETWEEN 400*F. AND 900*F. UNTIL BOTH CHROMIUM AND MOLYBDENUM ARE PRESENT PREDOMINANTYL AS SULFIDES.