Two-stage hydrodesulfurization process with hydrogen addition in the first stage

Claim 2

The process of claim 1 wherein desulfurization within the Hydrodesulfurization and desulfurization stages is carried out in liquid phase within a range of conditions substantially as described below: HydrodesulfurizationDesulfurization Stage Stage E.I.T. Temp., *F. Start-of-Run 625-710 675-730 End-of-Run 800765 Pressure, Psig 500-3000 150-1000 Inlet Gas, SCFB 1000-5000 Volume % Hydrogen 70-85 (% Purity) Feed Rate, V/Hr./V 0.5-2 0.5-2

Claim 3

The process of claim 1 wherein the catalyst is selected from the group consisting of a mixture of the oxides and sulfides of Group VIB and iron group metals.

Claim 4

The process of claim 4 wherein the catalyst is comprised of from about 1 to about 15 weight percent of nickel or cobalt sulfide, and from about 5 to about 25 weight percent of tungsten or molybdenum sulfide on an alumina support containing from about 1 to about 6 weight percent silica.

Claim 5

The process of claim 5 wherein the catalyst support has a surface area ranging in pores having a diameter of from about 30 to about 70 A diameter of at least about 100 square meters per gram.

Claim 6

The process of claim 1 wherein the sulfur-containing hydrocarbon feed is characterized as one wherein at least 50 weight percent thereof boils at a temperature of over 700* F.

Claim 7

The process of claim 7 wherein the sulfur content of said hydrocarbon feed ranges from about 2 to about 5 weight percent.

Claim 8

The process of claim 8 wherein the feed is a gas oil.

Claim 9

The process of claim 7 wherein the hydrocarbon feed is a petroleum residuum.

Claim 10

The process of claim 1 wherein the desulfurization stage is operated at pressures sufficiently low that hydrogen is released, and hydrogen partial pressures generated within the said stage are lower than employed in the initial hydrodesulfurization stage.

Claim 11

A process for desulfurizing a sulfur-containing hydrocarbon feed which, in combination, comprises: contacting the feed in an initial stage with a sulfur-resistant catalyst comprising a Group VI-B or iron group metal component, or mixtures of said metal components, including their oxides and sulfides, supported on a refractory inorganic oxide base, in the presence of hydrogen, to desulfurize from about 40 to 90 percent of the feed in a catalytic hydrodesulfurization reaction which produces hydrogen sulfide, light ends, and a partially desulfurized product, separating hydrogen, light ends, and by-product hydrogen sulfide from the partially desulfurized product, and then contacting the said partially desulfurized product in a subsequent stage with a sulfur-resistant catalyst comprising a Group VI-B or iron group metal component, or mixture of said components, including their oxides and sulfides, supported on a refractory inorganic oxide base, in the absence of added hydrogen, to produce a catalytic desulfurization reaction which effectively converts from about 40 to 90 percent of the remaining sulfur into hydrogen sulfide, said reactions being carried out within the range of conditions substantially as described: Hydrodesulfurization Desulfurization Stage Stage E.I.T. Temp., *F. Start-of-Run 625-710 625-800 End-of-Run 850 850 Pressure, Psig 300-5000 50-3000 Inlet Gas, SCFB 500-10,000 Volume % Hydrogen50-90 (% Purity) Feed Rate, V/Hr./V 0.1-100.05-10

Claim 12

The process of claim 12 wherein desulfurization within hydrodesulfurization and desulfurization stages is carried out in liquid phase within a range of conditions substantially as described below: Hydrodesulfurization Desulfurization StagE Stage E.I.T. Temp., *F. Start-of-Run 625-710 675-730 End-of-Run 800 765 Pressure, Psig 500-3000 150-1000 Inlet Gas, SCFB 1000-5000 Volume % Hydrogen 70-85 (% Purity) Feed Rate, V/Hr./V 0.5-2 0.5-2

Claim 13

The process of claim 12 wherein the catalyst is comprised of from about 1 to about 15 weight percent of nickel or cobalt sulfide, and from about 5 to about 25 weight percent of tungsten or molybdenum sulfide on an alumina support containing from about 1 to about 6 weight percent silica.

Claim 14

The process of claim 14 wherein the catalyst support has a surface area ranging in pores having a diameter of from about 30 to about 70 A diameter of at least about 100 m2/g.

Claim 15

The process of claim 12 wherein the desulfurization stage is operated at pressures sufficiently low that hydrogen is released, and hydrogen partial pressures generated within the said stage are lower than employed in the initial hydrodesulfurization stage.

Claim 16

The process of claim 12 wherein from about 60 to about 80 percent desulfurization is obtained in both the hydrodesulfurization and subsequent desulfurization stages, respectively.

Claim 17

The process of claim 12 wherein the sulfur-containing hydrocarbon feed is one wherein over 50 percent of the feed boils within a range of from about 700* F. to about 900* F., which contain from about 2 to about 5 percent sulfur; and including higher boiling materials and petroleum hydrocarbon residuum feedstocks which contain relatively large amounts of sulfur, asphaltenes, metals and ash.