Claims
- 1. A method for dehydrogenating a normal paraffin hydrocarbon containing 4 to 30 carbon atoms per molecule which comprises contacting the hydrocarbon, at dehydrogenation conditions, with a catalytic composite comprising a porous carrier material containing, on an elemental basis, about 0.01 to about 2 wt. % platinum group metal, about 0.05 to about 5 wt. % cobalt, and about 0.01 to about 5 wt. % bismuth, wherein the platinum group metal, catalytically available cobalt and bismuth are uniformly dispersed throughout the porous carrier material; wherein substantially all of the platinum group metal is present in the elemental metallic state; and wherein substantially all of the catalytically available cobalt is present in the elemental metallic state or in a state which is reducible to the elemental metallic state under dehydrogenation conditions or in a mixture of these states.
- 2. A method as defined in claim 1 wherein the normal paraffin hydrocarbon containing 4 to 30 carbon atoms per molecule is admixed with hydrogen when it contacts the catalytic composite.
- 3. A method as defined in claim 1 wherein the platinum group metal is platinum.
- 4. A method as defined in claim 1 wherein the platinum group metal is iridium.
- 5. A method as defined in claim 1 wherein the platinum group metal is rhodium.
- 6. A method as defined in claim 1 wherein the platinum group metal is palladium.
- 7. A method as defined in claim 1 wherein the catalytic composite is in a sulfur-free state.
- 8. A method as defined in claim 1 wherein the porous carrier material is a refractory inorganic oxide.
- 9. A method as defined in claim 8 wherein the refractory inorganic oxide is alumina.
- 10. A method as defined in claim 2 wherein the dehydrogenation conditions include a temperature of 700.degree. to about 1200.degree. F., a pressure of 0.1 to 10 atmospheres, a LHSV of 1 to 40 hr..sup.-1, and a hydrogen to hydrocarbon mole ratio of about 1:1 to about 20:1.
- 11. A method as defined in claim 1 wherein the composite contains on an elemental basis, about 0.05 to about 1 wt. % platinum group metal, about 0.1 to about 2.5 wt. % cobalt and about 0.05 to about 1 wt. % bismuth.
- 12. A method as defined in claim 1 wherein the metals content of the catalytic composite is adjusted so that the atomic ratio of bismuth to platinum group metal is about 0.1:1 to about 2:1 and the atomic ratio of cobalt to platinum group metal is about 0.1:1 to about 66:1.
- 13. A method as defined in claim 1 wherein substantially all of the bismuth is present therein in an oxidation state above that of the elemental metal.
- 14. A method as defined in claim 13 wherein substantially all of the bismuth is present in the catalytic composite as bismith oxide or bismuth aluminate.
- 15. A method as defined in claim 2 wherein substantially all of the catalytically available cobalt contained in the composite is present in the elemental metallic state after the method is started-up and lined-out at dehydrogenation conditions.
- 16. A method for dehydrogenating a normal paraffin hydrocarbon containing 4 to 30 carbon atoms per molecule which comprises contacting said hydrocarbon with a nonacidic catalytic composite comprising a porous carrier material containing, on an elemental basis, about 0.01 to about 2 wt. % platinum group metal, about 0.05 to about 5 wt. % cobalt, about 0.1 to about 5 wt. % alkali metal or alkaline earth metal, and about 0.01 to about 5 wt. % bismuth; wherein the platinum group metal, catalytically available cobalt, bismuth and alkali metal or alkaline earth metal are uniformly dispersed throughout the porous carrier material; wherein substantially all of the platinum group metal is present in the elemental metallic state; wherein substantially all of the catalytically available cobalt is present in the elemental metallic state or in a state which is reducible to the elemental metallic state under dehydrogenation conditions or in a mixture of these states; and wherein substantially all of the alkali metal or alkaline earth metal is present in an oxidation state above that of the elemental metal.
- 17. A method as defined in claim 16 wherein the normal paraffin hydrocarbon containing 4 to 30 carbon atoms per molecule is admixed with hydrogen when it contacts the catalytic composite.
- 18. A method as defined in claim 16 wherein the dehydrogenatable hydrocarbon is a normal paraffin hydrocarbon containing about 10 to about 18 carbon atoms per molecule.
- 19. A method as defined in claim 16 wherein the dehydrogenation conditions include a temperature of about 700.degree. to about 1200.degree. F., a pressure of about 0.1 to about 10 atmospheres, an LHSV of about 1 to 40 hr..sup.-1, and a hydrogen to hydrocarbon mole ratio of about 1:1 to about 20:1.
- 20. A method as defined in claim 16 wherein the contacting is performed in the presence of water or a water-producing substance in an amount corresponding to about 1 to about 1000 wt. ppm. based on hydrocarbon charge.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of my prior, copending application Ser. No. 602,935 filed Aug. 8, 1975 now U.S. Pat. No. 3,981,795, issued Sept. 21, 1976. All of the teachings of this prior application are specifically incorporated herein by reference.
US Referenced Citations (6)
Continuation in Parts (1)
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Number |
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602935 |
Aug 1975 |
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