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US 5,181,941 AGranted
Membrane and separation process
AssigneeTexaco Inc.
InventorsMitri S. Najjar, Carl A. Hultman
Life of this patent
Estimating the term…
Abstract
A novel membrane system, including a layer of platinum or palladium on graphite, is used to separate hydrogen from a hydrocarbon stream.
Claims20
The method of separating a less permeable gas from a charge gaseous mixture containing a more permeable gas and a less permeable gas which comprises
- passing a charge gaseous mixture containing more permeable and a less permeable gas into contact with a thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body;
- maintaining a pressure drop across said thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body thereby forming a retentate containing a decreased content of said more permeable gas and a permeate containing an increased content of said less permeable gas;
- recovering said retentate containing a decreased content of said more permeable gas from the high pressure side of said thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body;
- and
- recovering said permeate containing an increased content of said more permeable gas from the low pressure side of said thin dense separating membrane layer containing Group VIII noble metal on a porous graphite body.
2 more elements
The method of separating hydrogen from a charge gaseous mixture containing hydrogen and a gaseous hydrocarbon which comprises
- passing a charge gaseous mixture containing hydrogen and a gaseous hydrocarbon into contact with a thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body;
- maintaining a pressure drop across said thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body thereby forming a retentate containing a decreased content of hydrogen and a permeate containing an increased content of hydrogen;
- recovering said retentate containing a decreased content of hydrogen from the high pressure side of said thin, dense separating membrane layer containing Group VIII noble metal on a porous graphite body;
- and
- recovering said permeate containing an increased content of hydrogen from the low pressure side of said thin dense separating membrane layer containing Group VIII noble metal on a porous graphite body.
2 more elements
A membrane, suitable for use in separating a mixture of more permeable gas and less permeable gas, prepared by the process which comprises
- maintaining, in a graphite container, at 500.degree. C.-1300.degree. C. a molten salt bath containing at least one halide of an alkali metal or an alkaline earth metal and a source of Group VIII noble metal;
- maintaining in said molten salt bath (i) an anode, submerged beneath the surface of said bath, and (ii) a porous graphite cathode;
- passing a direct current through said cathode, said bath, and said anode at cathode current density of 0.1-4 asd thereby depositing on said cathode a thin, dense membrane layer of Group VIII noble metal;
- and
- recovering said cathode bearing a thin, dense membrane layer of Group VIII noble metal.
2 more elements
The method of preparing a membrane suitable for use in separating a mixture of more permeable gas and less permeable gas which comprises
- maintaining, in a graphite container, at 500.degree. C.-1300.degree. C. a molten salt bath containing at least one halide of an alkali metal or an alkaline earth metal and a source of Group VIII noble metal;
- maintaining in said molten salt bath (i) an anode, submerged beneath the surface of said bath, and (ii) a porous graphite cathode;
- passing a direct current through said cathode, said bath, and said anode at cathode current density of 0.1-4 asd thereby depositing on said cathode a thin, dense membrane layer of Group VIII noble metal;
- and
- recovering said cathode bearing a thin, dense membrane layer of Group VIII noble metal.
2 more elements
The method of preparing a membrane suitable for use in separating more permeable gas from less permeable gas which comprises
- maintaining, in a graphite container, at 500.degree. C.-1300.degree. C. a molten salt bath containing a halide of an alkali metal or an alkaline earth metal;
- maintaining in said molten salt bath (i) an anode submerged beneath the surface of said bath and (ii) a porous graphite cathode and (iii) palladium fluoride;
- passing a direct current through said cathode, said bath, and said anode at cathode current density of 0.1-4 asd thereby depositing on said cathode a thin, dense membrane layer of palladium;
- and
- recovering said cathode bearing a thin, dense membrane layer of palladium.
2 more elements
The method of preparing a membrane suitable for use in separating a mixture of more permeable gas and less permeable gas which comprises
- maintaining in a graphite container at 600.degree. C.-800.degree. C. a molten salt bath containing a eutectic salt composition of lithium fluoride and sodium fluoride and a source of palladium;
- maintaining in said molten salt bath (i) an anode submerged beneath the surface of said bath and (ii) a porous graphite cathode;
- admitting inert gas through a graphite conduit to a point beneath the surface of said bath;
- passing a direct current through said cathode, said bath, and said anode at cathode current density of 0.1-4 asd thereby depositing on said cathode a thin, dense membrane layer of palladium metal;
- and
- recovering said cathode bearing a thin, dense membrane layer of palladium metal.
3 more elements
Dependencies are inferred from the claim text.