System and method for increasing the service life and/or catalytic activity of an SCR catalyst and control of multiple emissions

Patent metadata

Field	Value
Publication number	US-9874350-B2
Application number	US-201414246380-A
Country	US
Kind code	B2
Filing date	Apr 7, 2014
Priority date	Apr 22, 2009
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.) and, in particular to a new and useful method and apparatus for reducing or preventing the poisoning and/or contamination of an SCR catalyst. In another embodiment, the method and apparatus of the present invention is designed to protect the SCR catalyst. In still another embodiment, the present invention relates to a method and apparatus for increasing the service life and/or catalytic activity of an SCR catalyst while simultaneously controlling various emissions.

First claim

What is claimed is:

1. A method for increasing the active life of an SCR catalyst, the method comprising the steps of:
(a) providing a fuel to a furnace, or boiler, wherein the fuel is selected from a form of biomass;
(b) subjecting the fuel to a combustion process, wherein the combustion process produces at least one gaseous phosphorus compound and/or at least one gaseous phosphorus-containing compound;
(c) providing at least one iron-bearing compound to a combustion zone or flue gas stream of the furnace, or boiler, prior to entry of the flue gas into an SCR, wherein the SCR is located upstream of at least one air heater; and
(d) permitting the at least one iron-bearing compound to react with the at least one gaseous phosphorus compound and/or the at least one gaseous phosphorus-containing compound present in the combustion zone or flue gas prior to the entry of the flue gas into the SCR to form an iron phosphorus-containing compound.

2. The method of claim 1 , wherein the at least one iron-bearing compound is selected from metallic iron, one or more iron oxides, iron carbonate, or mixtures of two or more thereof.

3. The method of claim 1 , wherein the at least one iron-bearing compound is selected from iron (III) oxide, iron (II) carbonate, iron (II) oxide, or mixtures of two or more thereof.

4. The method of claim 1 , wherein the at least one iron-bearing compound is selected from iron (III) oxide, iron (II) carbonate, or a mixture thereof.

5. The method of claim 1 , wherein the at least one iron-bearing compound is provided to the combustion zone via addition to the biomass.

6. The method of claim 1 , wherein the at least one iron-bearing compound is provided to the combustion zone via a dedicated supply line.

7. The method of claim 1 , wherein the at least one iron-bearing compound is a water soluble iron-bearing compound.

8. The method of claim 1 , wherein the at least one iron-bearing compound is a water soluble iron-bearing compound that is supplied in the form of an aqueous solution.

9. The method of claim 1 , wherein the at least one iron-bearing compound is a water insoluble iron-bearing compound that is supplied in the form of an aqueous suspension or emulsion.

10. The method of claim 1 , wherein the at least one iron-bearing compound is at least one iron-bearing halide, and wherein Step (d) involves:
permitting the iron portion of the at least one iron-bearing halide compound to react with the at least one gaseous phosphorus compound and/or the at least one gaseous phosphorus-containing compound present in the combustion zone or flue gas prior to the entry of the flue gas into the SCR to form an iron phosphorus-containing compound; and
wherein the method further includes the step of:
(e) permitting the halide portion of the at least one iron-bearing halide compound to react with any gaseous mercury compounds, or mercury-containing compounds, present in the combustion zone or flue gas.

11. The method of claim 10 , wherein the at least one iron-bearing halide compound is selected from iron (II) bromide, iron (III) bromide, iron (II) chloride, iron (III) chloride, iron (II) iodide, iron (III) iodate, or mixtures of two or more thereof.

12. The method of claim 10 , wherein the at least one iron-bearing halide compound is iron (II) bromide.

13. The method of claim 10 , wherein the at least one iron-bearing halide compound is provided at an amount sufficient to yield a halide concentration of between about 10 ppm to about 200 ppm.

14. A method for sequestering one or more gaseous phosphorus compounds, or gaseous phosphorus-containing compounds, in the form of one or more less reactive iron-phosphorus-containing compounds, the method comprising the steps of:
(i) providing a fuel to a furnace, or boiler, wherein the fuel is selected from a form of biomass;
(ii) subjecting the fuel to a combustion process, wherein the combustion process produces at least one gaseous phosphorus compound and/or at least one gaseous phosphorus-containing compound;
(iii) providing at least one iron-bearing compound to a combustion zone or flue gas stream of the furnace, or boiler; and
(iv) permitting the at least one iron-bearing compound to react with the at least one gaseous phosphorus compound and/or the at least one gaseous phosphorus-containing compound present in the combustion zone or flue gas to form one or more less reactive iron-phosphorus-containing compounds.

15. The method of claim 14 , wherein the at least one iron-bearing compound is selected from metallic iron, one or more iron oxides, iron carbonate, or mixtures of two or more thereof.

16. The method of claim 14 , wherein the at least one iron-bearing compound is selected from iron (III) oxide, iron (II) carbonate, iron (II) oxide, or mixtures of two or more thereof.

17. The method of claim 14 , wherein the at least one iron-bearing compound is selected from iron (III) oxide, iron (II) carbonate, or a mixture thereof.

18. The method of claim 14 , wherein the at least one iron-bearing compound is provided to the combustion zone via addition to the biomass.

19. The method of claim 14 , wherein the at least one iron-bearing compound is provided to the combustion zone via a dedicated supply line.

20. The method of claim 14 , wherein the at least one iron-bearing compound is a water soluble iron-bearing compound.

21. The method of claim 14 , wherein the at least one iron-bearing compound is a water soluble iron-bearing compound that is supplied in the form of an aqueous solution.

22. The method of claim 14 , wherein the at least one iron-bearing compound is a water insoluble iron-bearing compound that is supplied in the form of an aqueous suspension or emulsion.

23. The method of claim 14 , wherein the at least one iron-bearing compound is at least one iron-bearing halide, and wherein Step (iv) involves:
permitting the iron portion of the at least one iron-bearing halide compound to react with the at least one gaseous phosphorus compound and/or the at least one gaseous phosphorus-containing compound present in the combustion zone or flue gas to form an iron phosphorus-containing compound; and
wherein the method further includes the step of:
(v) permitting the halide portion of the at least one iron-bearing halide compound to react with any gaseous mercury compounds, or mercury-containing compounds, present in the combustion zone or flue gas.

24. The method of claim 23 , wherein the at least one iron-bearing halide compound is selected from iron (II) bromide, iron (III) bromide, iron (II) chloride, iron (III) chloride, iron (II) iodide, iron (III) iodate, or mixtures of two or more thereof.

25. The method of claim 23 , wherein the at least one iron-bearing halide compound is iron (II) bromide.

26. The method of claim 23 , wherein the at least one iron-bearing halide-bearing compound is provided at an amount sufficient to yield a halide concentration of between about 10 ppm to about 200 ppm.

27. A method for increasing the active life of an SCR catalyst, the method comprising the steps of:
(A) providing a fuel to a furnace, or boiler, wherein the fuel is selected from a form of biomass;
(B) subjecting the fuel to a combustion process, wherein the combustion process produces at least one gaseous phosphorus compound and/or at least one gaseous phosphorus-containing compound;
(C) providing at least one iron-bearing compound

Assignees

• Babcock & Wilcox Power Generat
• Babcock & Wilcox Co

Inventors

• Gadgil Mandar R
• Ghorishi S Behrooz
• Tonn Donald P

Classifications

• B01D53/64

  Heavy metals or compounds thereof, e.g. mercury · CPC title

• B01D2257/55

  Compounds of silicon, phosphorus, germanium or arsenic · CPC title

• F23J2219/40

  Sorption with wet devices, e.g. scrubbers · CPC title

• F23K2201/505

  with additives · CPC title

• F23N5/003

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