Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
269 words
In a hydrodesulfurization process wherein a metal- and sulfur-containing petroleum liquid residuum feedstock is treated in a hydrodesulfurizing step by feeding the residuum together with hydrogen upwardly into a desulfurization reaction zone maintained under ebullated bed hydrodesulfurization conditions with a temperature between about 700° and about 825°F and a pressure between about 1000 and about 3000 psig, while maintaining in said desulfurization zone a high density, substantially non-porous particulate solid catalyst selected from the group consisting of cobalt molybdate on alumina and nickel molybdate on alumina in random motion in the liquid, said catalyst having a porosity not greater than 0.1 cc/g of cumulative pore volume for pores having diameters larger than 250A to recover a reiduum containing less than one percent sulfur; the improvement which comprises: pretreating the metal-containing residuum before substantial desulfurization to remove vanadium or nickel by feeding said residuum with a hydrogen-containing gas to a pretreatment zone maintained at a temperature between about 700° and 825°F and a pressure between 1000 and 3000 psig; maintaining in said pretreatment zone a bed of particulate contact solids containing at least 75 weight percent porous alumina and containing about 71/2 to 22 weight percent metal oxide promoter consisting essentially of a mixture of Fe 2 O 3 , TiO 2 and SiO 2 , and mixtures thereof; feeding said contact solids to the reaction zone at a rate sufficient to achieve at least 40 percent removal of vanadium, said contact solids being maintained in random motion in the liquid by the residuum feed and hydrogen-containing gas, whereby the desulfurization catalyst has increased life and sulfur removal is enhanced.
Claim 2
Dependent Claim
269 words
In a hydrodesulfurization process wherein a metal- and sulfur-containing petroleum liquid residuum feedstock is treated in a hydrodesulfurizing step by feeding the residuum together with hydrogen upwardly into a desulfurization reaction zone maintained under ebullated bed hydrodesulfurization conditions with a temperature between about 700° and about 825°F and a pressure between about 1000 and about 3000 psig, while maintaining in said desulfurization zone a high density, substantially non-porous particulate solid catalyst selected from the group consisting of cobalt molybdate on alumina and nickel molybdate on alumina in random motion in the liquid, said catalyst having a porosity not greater than 0.1 cc/g of cumulative pore volume for pores having diameters larger than 250A to recover a reiduum containing less than one percent sulfur; the improvement which comprises: pretreating the metal-containing residuum before substantial desulfurization to remove vanadium or nickel by feeding said residuum with a hydrogen-containing gas to a pretreatment zone maintained at a temperature between about 700° and 825°F and a pressure between 1000 and 3000 psig; maintaining in said pretreatment zone a bed of particulate contact solids containing at least 75 weight percent porous alumina and containing about 71/2 to 22 weight percent metal oxide promoter consisting essentially of a mixture of Fe 2 O 3 , TiO 2 and SiO 2 , and mixtures thereof; feeding said contact solids to the reaction zone at a rate sufficient to achieve at least 40 percent removal of vanadium, said contact solids being maintained in random motion in the liquid by the residuum feed and hydrogen-containing gas, whereby the desulfurization catalyst has increased life and sulfur removal is enhanced.
Claim 3
Dependent Claim
29 words
The process of claim 1 wherein more than 65 percent of the sulfur in the feedstock is removed; wherein the feedstock before pretreatment contains at least 100 ppm vanadium.
Claim 4
Dependent Claim
244 words
In a hydrodesulfurization process wherein a metal- and sulfur-containing petroleum liquid residuum feedstock is treated in a hydrodesulfurizing step by feeding the residuum together with hydrogen upwardly into a desulfurization reaction zone maintained under ebullated bed hydrodesulfurization conditions with a temperature between about 700° and about 825°F and a pressure between about 1000 and about 3000 psig, while maintaining in said desulfurization zone a high density, substantially non-porous particulate solid catalyst selected from the group consisting of cobalt molybdate on alumina and nickel molybdate on alumina in random motion in the liquid, said catalyst having a porosity not greater than 0.1 cc/g of cumulative pore volume for pores having diameters larger than 250A to recover a residuum containing less than one percent sulfur; the improvement which comprises: pretreating the metal-containing residuum before substantial desulfurization to remove vanadium or nickel by feeding said residuum with a hydrogen-containing gas to a pretreatment zone maintained at a temperature between about 700° and 825°F and a pressure between 1000 and 3000 psig; maintaining in said pretreatment zone a bed of particulate contact solids consisting essentially of porous alumina and containing about 5 weight percent SiO 2 promoter; feeding said contact solids to the reaction zone at a rate sufficient to achieve at least 40 percent removal of vanadium, said contact solids being maintained in random motion in the liquid by the residuum feed and hydrogen-containing gas, whereby the desulfurization catalyst has increased life and sulfur removal is enhanced.
Claim 5
Dependent Claim
244 words
In a hydrodesulfurization process wherein a metal- and sulfur-containing petroleum liquid residuum feedstock is treated in a hydrodesulfurizing step by feeding the residuum together with hydrogen upwardly into a desulfurization reaction zone maintained under ebullated bed hydrodesulfurization conditions with a temperature between about 700° and about 825°F and a pressure between about 1000 and about 3000 psig, while maintaining in said desulfurization zone a high density, substantially non-porous particulate solid catalyst selected from the group consisting of cobalt molybdate on alumina and nickel molybdate on alumina in random motion in the liquid, said catalyst having a porosity not greater than 0.1 cc/g of cumulative pore volume for pores having diameters larger than 250A to recover a residuum containing less than one percent sulfur; the improvement which comprises: pretreating the metal-containing residuum before substantial desulfurization to remove vanadium or nickel by feeding said residuum with a hydrogen-containing gas to a pretreatment zone maintained at a temperature between about 700° and 825°F and a pressure between 1000 and 3000 psig; maintaining in said pretreatment zone a bed of particulate contact solids consisting essentially of porous alumina and containing about 5 weight percent SiO 2 promoter; feeding said contact solids to the reaction zone at a rate sufficient to achieve at least 40 percent removal of vanadium, said contact solids being maintained in random motion in the liquid by the residuum feed and hydrogen-containing gas, whereby the desulfurization catalyst has increased life and sulfur removal is enhanced.
Claim 6
Dependent Claim
30 words
The process of claim 3 wherein more than 65 percent of the sulfur in the feedstock is removed; wherein in the feedstock before pretreatment contains at least 100 ppm vanadium.