Claims
- 1. A process for treating a gas stream having at least about 90 volume percent of H2, based on the total volume of all constituents comprising said gas stream, at least one halogen-containing compound and a total concentration of S-containing compounds less than about 2 ppm by volume, based on a mono-sulfur compound equivalent, said process comprising:
(a) contacting said gas stream with a nickel catalyst composition at a temperature greater than 850° F. (454° C.) but less than or equal to about 1050° F. (566° C.), wherein said halogen-containing compound contacts said nickel catalyst composition so that a substantial portion of said halogen-containing compound is reduced, said catalyst composition comprising a source for nickel in a zero oxidation state, Ni0, selected from the group consisting of
(i) at least about 5 weight percent Ni0, (ii) a Ni0 precursor having Ni+n, where 1≦n≦4, that can produce at least about 5 weight percent Ni0 under substantially reducing conditions, and (iii) combinations thereof, said Ni0 weight percent being measured as a percentage of the total weight of all constituents comprising said nickel catalyst composition; and (b) producing a nickel catalyst-treated gas stream, wherein substantially all halogen-containing compounds are de-halogenated.
- 2. The process of claim 1, wherein the gas stream further comprises O2.
- 3. The process of claim 2, wherein the mole ratio of H2 to O2 in said gas stream is at least about 10 to 1.
- 4. The process of claim 2, wherein the mole ratio of H2 to O2 in said gas stream is in a range of from about 10 to 1 to about 100,000 to 1.
- 5. The process of claim 1, wherein the total concentration of S-containing compounds is less than about 1 ppm by volume, based on a mono-sulfur compound equivalent.
- 6. The process of claim 1, further comprising pre-treating said gas stream by contacting said gas stream with a pre-treatment material comprising zinc oxide so that at least a portion of any sulfur-containing compounds in said gas stream is removed.
- 7. The process of claim 6, further comprising, prior to the pre-treating step, removing at least a portion of zinc oxide poisons present in said gas stream by contacting said gas stream with an adsorbent bed.
- 8. The process of claim 7, wherein said zinc oxide poisons are selected from the group consisting of HCl, HF, HBr, Hl and combinations thereof.
- 9. The process of claim 1, wherein the nickel catalyst-treated gas stream is substantially free of halogen-containing compounds and comprises H2O, a halogen-containing acid and a saturated hydrocarbon having from 1 to about 3 carbon atoms.
- 10. The process of claim 9, further comprising removing said halogen-containing acid by contacting said nickel catalyst-treated gas stream with a pre-treatment bed selected from the group consisting of an adsorbent bed, a chemical neutralizing bed, and combinations thereof.
- 11. The process of claim 10, wherein the adsorbent bed comprises a material selected from the group consisting of alumina, calcium oxide, and combinations thereof.
- 12. The process of claim 1, wherein said gas stream further comprises oxygen-containing compounds.
- 13. The process of claim 12, wherein said oxygen-containing compounds are selected from the group consisting of CO, CO2, O2, N2O, NO, NO2, HNO3 and combinations thereof and CH4, H2O, NH3 and combinations thereof are produced from said nickel catalyst-treatment.
- 14. The process of claim 1, wherein said gas stream further comprises amines.
- 15. The process of claim 14, wherein said amines are selected from the group consisting of R1NH2, R1R2NH, R1R2R3N, and combinations thereof and NH3 is produced when said gas stream is contacted with said nickel catalyst composition, where R1, R2 and R3 are independently selected from the group consisting of C1 to C3 hydrocarbyl groups.
- 16. The process of claim 2, wherein at least a portion of said halogen-containing compounds and at least a portion of said O2 are reduced substantially concurrently.
- 17. The process of claim 1, wherein said nickel catalyst composition comprises said nickel source and a support for said nickel source.
- 18. The process of claim 17, wherein said support is inert with respect to hydrodehalogenation and halo-compound by-product reactions.
- 19. The process of claim 17, wherein said support is selected from the group consisting of aluminum oxide, magnesium oxide, calcium oxide and combinations thereof.
- 20. The process of claim 19, wherein the concentration of said support is in a range of from about 35 to about 95 wt. % in said nickel catalyst composition.
- 21. The process of claim 1, wherein the concentration of H2 in said gas stream is at least about 95 volume percent.
- 22. The process of claim 1, wherein the concentration of Ni0 or Ni0 precursor is in a range of from about 5 to about 65 weight percent.
- 23. The process of claim 1, wherein the concentration of Ni0 or Ni0 precursor is in a range of from about 10 to about 50 weight percent.
- 24. The process of claim 1, wherein the concentration of Ni0 or Ni0 precursor is in a range of from about 15 to about 25 weight percent.
- 25. The process of claim 1, wherein said nickel catalyst composition further comprises a promoter in a concentration of from about 0.1 to about 5 weight percent.
Parent Case Info
[0001] This application claims the benefit of copending U.S. patent application Ser. No. 09/689,354, filed in the names of Bhadra S. Grover and Henrik W. Rasmussen on Oct. 12, 2000.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09689354 |
Oct 2000 |
US |
Child |
10378806 |
Mar 2003 |
US |