Fuel combusting method

Patent metadata

Field	Value
Publication number	US-9938861-B2
Application number	US-201414175715-A
Country	US
Kind code	B2
Filing date	Feb 7, 2014
Priority date	Feb 21, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

The present techniques are directed to systems and a method for combusting a fuel in a gas turbine. An exemplary method includes providing a fuel to a combustor on a gas turbine, providing an oxidant to the combustor, and combusting the fuel and the oxidant in the combustor to produce an exhaust gas. At least a portion of the exhaust gas is passed through a water-gas shifting catalyst to form a low CO content product gas.

First claim

What is claimed is:

1. A method for combusting a fuel in a gas turbine, comprising:
providing a fuel to a combustor on a gas turbine;
providing an oxidant to the combustor;
combusting the fuel and the oxidant in the combustor to produce a combustor exhaust gas;
expanding the combustor exhaust gas in a turbine expander to produce an exhaust gas that comprises water vapor, carbon dioxide, and between 1,000 and 5,000 ppmv of each carbon monoxide and hydrogen;
passing at least a portion of the exhaust gas to a heat recovery unit that comprises a water-gas shifting catalyst; and
converting a portion of the carbon monoxide and water vapor within the exhaust gas passed through the heat recovery unit into carbon dioxide and hydrogen via a water gas shift reaction to form a low CO content product gas.

2. The method of claim 1 , comprising providing a diluent to the gas turbine and gas turbine combustor; and mixing a first portion of the diluent with at least one of the fuel, the oxidant, and the exhaust gas to cool the combustor, exhaust gas, or both.

3. The method of claim 2 , comprising:
extracting a second portion of diluent from the gas turbine or gas turbine combustor; and
delivering the said second portion of diluent to an oxidation catalyst unit configured to oxidize carbon monoxide, hydrogen and unburned hydrocarbons to carbon dioxide and water vapor and to produce a low oxygen content product gas.

4. The method of claim 1 , comprising:
compressing an oxidizing stream; and
providing a first portion of the oxidizing stream as the oxidant to the combustor.

5. The method of claim 1 , comprising:
compressing a fuel stream; and
providing a first portion of the fuel stream as the fuel to the combustor.

6. The method of claim 2 , comprising compressing the diluent prior to delivering the first portion of diluent to the combustor and extracting a second portion of the diluent.

7. The method of claim 5 , comprising providing a second portion of the fuel stream as a deoxidation fuel to an oxidation catalyst unit.

8. The method of claim 3 , comprising providing a second portion of the oxidant as an oxidizer to the catalyst unit.

9. The method of claim 4 comprising providing essentially ambient air as the oxidizing stream.

10. The method of claim 1 , comprising:
measuring a parameter of the exhaust gas; and
adjusting a fuel flow rate, an oxidant flow rate, or both to adjust the parameter to within a target set-point range.

11. The method of claim 1 , comprising:
measuring a parameter of the low CO content product gas; and
adjusting a fuel flow rate, an oxidant flow rate, or both to adjust the parameter to within a target set-point range.

12. The method of claim 1 , comprising measuring a parameter comprising oxygen concentration, carbon monoxide concentration, hydrogen concentration, unburned hydrocarbon concentration, nitrogen oxides or any combinations thereof in the exhaust gas, the low CO content product gas, or both.

13. The method of claim 12 , comprising determining an equivalence ratio from the parameter.

14. The method of claim 1 , comprising adjusting the ratio of the fuel to the oxidant to form a substantially stoichiometric mixture.

15. The method of claim 1 , comprising adjusting the ratio of the fuel to the oxidant to obtain an exhaust gas comprising between about 100 parts-per-million (ppm) of carbon monoxide (CO) and about 5000 ppm of CO.

16. The method of claim 1 , comprising:
cooling the low CO content product gas to remove water;
compressing the low CO content product gas;
recirculating the low CO content product gas to the combustor as a diluent; and
providing the diluent to the combustor separately from the oxidant and the fuel.

17. The method of claim 1 , comprising:
driving an expander turbine with the exhaust gas; and
generating mechanical power from the turbine expander.

18. The method of claim 1 , comprising passing the at least a portion of the exhaust gas through an oxidation catalyst bed configured to oxidize carbon monoxide, hydrogen and unburned hydrocarbons to carbon dioxide and water vapor.

19. The method of claim 1 , comprising injecting at least a portion of at least one of the low CO content product gas and low oxygen content product gas into a subterranean reservoir.

20. The method of claim 19 , comprising compressing the portion of the at least one of the low CO content product gas and low oxygen content product gas with a compressor prior to injecting the portion of the at least one of the low CO content product gas and low oxygen content product gas into the subterranean reservoir.

21. The method of claim 3 , comprising processing at least a portion of at least one of the low CO content product gas and low oxygen content product gas in a gas dehydration unit.

22. The method of claim 3 , comprising processing at least a portion of at least one of the low CO content product gas and low oxygen content product gas in a carbon dioxide separation unit to produce a lean carbon dioxide stream and a rich carbon dioxide stream.

23. The method of claim 22 , comprising injecting at least a portion of the lean carbon dioxide stream into a subterranean reservoir.

24. The method of claim 22 , comprising injecting at least a portion of the rich carbon dioxide stream into a subterranean reservoir.

25. The method of claim 22 , comprising providing at least a portion of the rich carbon dioxide stream to a carbon sequestration unit.

26. The method of claim 23 , comprising compressing at least a portion of the lean carbon dioxide stream prior to injecting the lean carbon dioxide stream into the subterranean reservoir.

27. The method of claim 24 , further compressing the at least a portion of the rich carbon dioxide stream to at least one rich product compressor prior to delivering the rich carbon dioxide stream to a subterranean reservoir for enhanced hydrocarbon recovery.

28. The method of claim 25 , comprising compressing at least a portion of the rich carbon dioxide stream prior to providing the rich carbon dioxide stream to a carbon sequestration unit.

29. The method of claim 22 , comprising processing at least a portion of the lean carbon dioxide stream in a gas dehydration unit.

30. The method of claim 22 , comprising processing at least a portion of the rich carbon dioxide stream in a gas dehydration unit.

31. The method of claim 1 , comprising cooling the exhaust gas in a heat recovery steam generator to produce steam.

32. The method of claim 31 , comprising:
driving a steam turbine with the steam; and
generating mechanical power.

33. The method of claim 31 , comprising heating process fluids with the steam.

34. The method of claim 1 , comprising:
cooling the exhaust gas in a heat recovery unit; and
heating process fluids.

35. The method of claim 3 , comprising measuring a parameter comprising oxygen concentration, carbon monoxide concentration, hydrogen concentration, unburned hydrocarbon concentration, nitrogen oxides or any combinations thereof in the low oxygen content product gas.

36. The method of claim 35 , comprising adjusting the flow rate of the deoxidation fuel to cause the parameter to reach a target range.

Assignees

• Huntington Richard A
• Exxonmobil Upstream Res Co

Inventors

• Huntington Richard A

Classifications

• F02C3/34

  with recycling of part of the working fluid, i.e. semi-closed cycles with combustion products in the closed part of the cycle · CPC title

• F02D41/1444

  characterised by the characteristics of the combustion gases · CPC title

• Y02E20/16

  Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT] · CPC title

• Y02T50/677

  Cross-Sectional Technologies · mapped topic

• F02D41/1454

  the characteristics being an oxygen content or concentration or the air-fuel ratio · CPC title