Patent ID: 7708877
Filing Date: 2010-05-04
Classification: C10G

Abstract:
1. A process for the hydroconversion of heavy oils with an active slurry catalyst composition admixed in a hydrocarbon oil, which results in almost complete removal of sulfur or nitrogen from the final product, said process employing at least two upflow reactors in series with a separator located in between each reactor, said process comprising the following steps: (a) providing the active slurry catalyst composition admixed in a hydrocarbon oil, formed by combining a slurry comprising Group VIB and Group VIII metals and a hydrocarbon oil having a viscosity of at least 2 cSt (or 32.8 SSU) @212° F.; (b) combining a heated heavy oil feed, the active slurry catalyst composition admixed in the hydrocarbon oil and a hydrogen-containing gas to form a mixture; (c) passing the mixture of step (b) to the bottom of the first reactor, which is maintained at slurry hydroconversion conditions, including elevated temperature and pressure; (d) removing a vapor mixture containing product, gases, unconverted material and slurry catalyst from the top of the first reactor and passing it to a first separator; (e) in the first separator, removing a vapor stream comprising product and gases overhead to a lean oil contactor and passing a liquid bottoms material, comprising unconverted material and slurry catalyst, to the bottom of the second reactor, which is maintained at hydroconversion conditions, including elevated temperature and pressure; (f) removing a vapor mixture containing product, gases, unconverted material and slurry catalyst from the top of the second reactor and passing it to a second separator; (g) in the second separator, removing a vapor stream comprising product and gases overhead to the lean oil contactor and passing a liquid bottoms material, comprising unconverted material and slurry catalyst to further processing; (h) contacting the vapor stream comprising product and gases countercurrently with lean oil in a lean oil contactor wherein entrained catalyst and any unconverted material is removed by contact with a lean oil which exits as bottoms while products and gases are passed overhead; (i) passing the overhead material of step (h) to a hydroprocessing unit for the removal of sulfur and nitrogen, wherein greater than 99% sulfur and nitrogen removal and 98% conversion to lighter products is achieved; hydroprocessing conditions employed in each reactor comprise a total pressure in the range from 1500 through 3500 psia and temperature from 700 through 900 F; and hydrofinishing conditions in the hydroprocessing unit comprise temperatures in the range from 400 and 800 F, space velocities in the range from 0.1 to 3 LHSV, and pressures in the range from 200 to 3000 psig wherein the active slurry catalyst composition is formed by the following steps: (a) mixing a Group VIB metal oxide and aqueous ammonia to form a Group VIB metal compound aqueous mixture; (b) sulfiding, in an initial reaction zone, the aqueous mixture of step (a) with a gas comprising hydrogen sulfide to a dosage greater than 8 SCF of hydrogen sulfide per pound of Group VIB metal to form a slurry; (c) promoting the slurry with a Group VIII metal compound; (d) mixing the slurry of step (c) with hydrocarbon oil having a viscosity of at least 2 cSt 212° F. to form an intermediate mixture; (e) combining the intermediate mixture with hydrogen gas in a second reaction zone, ruder conditions which maintain the water in the intermediate mixture in a liquid phase, thereby forming an active catalyst composition admixed with a liquid hydrocarbon; and (f) recovering the active catalyst composition.