Reducing oxygen in a gas turbine exhaust

Patent metadata

Field	Value
Publication number	US-10082063-B2
Application number	US-201815903376-A
Country	US
Kind code	B2
Filing date	Feb 23, 2018
Priority date	Feb 21, 2013
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

The present techniques are directed to a system and methods for operating a gas turbine system. An exemplary gas turbine system includes an oxidant system, a fuel system, and a control system. A combustor is adapted to receive and combust an oxidant from the oxidant system and a fuel from the fuel system to produce an exhaust gas. A catalyst unit including an oxidation catalyst that includes an oxygen storage component is configured to reduce the concentration of oxygen in the exhaust gas to form a low oxygen 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 of the gas turbine;
providing an oxidant to the combustor;
combusting the fuel and the oxidant in the combustor to produce an exhaust gas; and
passing at least a portion of the exhaust gas through a catalyst bed comprising a catalyst having an oxygen storage component (OSC) catalyst to form a low oxygen content product gas;
wherein the catalyst comprises:
a mixture of platinum and palladium in a ratio between about 0.1 and about 100,000;
zirconia;
ceria, wherein the ceria is in a ratio of between about 0.1 to about 5.0 to the zirconia; and
rhodium.

2. The method of claim 1 , wherein the catalyst further comprises:
an element from groups 8-10 other than platinum or palladium; and
a refractory oxide other than zirconia.

3. The method of claim 2 , wherein the element from groups 8-10 comprises iron, cobalt, or nickel, or any combinations thereof.

4. The method of claim 2 , wherein the refractory oxide comprises alumina, silica, or titania, or any combinations thereof.

5. The method of claim 1 , wherein the alkaline earth metal oxide comprises magnesium oxide, calcium oxide, strontium oxide, or barium oxide, or any combinations thereof.

6. The method of claim 1 , comprising operating the gas turbine in a fuel rich condition to decrease an amount of oxygen in the exhaust gas.

7. The method of claim 1 , comprising:
operating the gas turbine in a substantially stoichiometric condition for a majority of time;
interspersing short periods of rich operating conditions to use up oxygen; and
interspersing periods of lean operating conditions to recharge the OSC.

8. The method of claim 1 , comprising:
cooling the low oxygen content product gas in a heat recovery unit;
chilling the low oxygen content product gas to condense water, and form a dry exhaust gas;
compressing the dry exhaust gas to form a diluent; and
using the diluent to cool the combustor, the exhaust gas, or both.

9. The method of claim 8 , comprising:
mixing the diluent with a first portion of one of the fuel and the oxidant prior to using the diluent to cool the combustor, the exhaust gas, or both.

10. The method of claim 1 , comprising:
extracting a portion of exhaust gas from the gas turbine as a side stream; and
delivering the side stream to an oxidation catalyst configured to oxidize carbon monoxide, hydrogen, and unburned hydrocarbons to carbon dioxide and water vapor.

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

12. The method of claim 1 , comprising cooling the low oxygen content product gas in a heat recovery steam generator to produce steam.

13. 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 low oxygen content product gas.

14. The method of claim 13 , comprising adjusting a fuel flow rate, an oxidant flow rate, or both to maintain the parameter within a target set-point range.

15. The method of claim 1 , comprising:
compressing the oxidant prior to introduction into the combustor.

16. The method of claim 1 , comprising:
compressing the fuel prior to introduction into the combustor.

17. The method of claim 8 , comprising:
compressing the diluent prior to using it to cool the combustor, the exhaust gas, or both.

Assignees

• Beutel Tilman W
• Dhanuka Sulabh K
• Exxonmobil Upstream Res Co

Inventors

• Beutel Tilman W
• Dhanuka Sulabh K

Classifications

• F23N2241/20

  Gas turbines · CPC title

• F23N2237/12

  catalytic burners · CPC title

• Y02E20/12

  Heat utilisation in combustion or incineration of waste · CPC title

• F23N5/003

  using detectors sensitive to combustion gas properties (F23N5/02, F23N5/18 - F23N5/26 take precedence) · CPC title

• F01N3/2889 Primary

  with heat exchangers in a single housing · CPC title