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-10213738-B2
Application number	US-201313769686-A
Country	US
Kind code	B2
Filing date	Feb 18, 2013
Priority date	Apr 22, 2009
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

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 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. In yet another embodiment, the present invention relates to a method and apparatus for controlling, mitigating and/or reducing the amount of selenium contained in and/or emitted by one or more pieces 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.).

First claim

What is claimed is:

1. A method for controlling the selenium speciation in a flue gas generated from the combustion of at least one biomass-based fuel and/or in a gas phase of at least one piece of emission control equipment where a flue gas stream in the at least one piece of emission control equipment is generated from the combustion of at least one biomass-based fuel, the method comprising the steps of:
(a) providing at least one biomass-based fuel to a furnace, or boiler;
(b) subjecting the at least one biomass-based fuel to a staged combustion process, wherein the staged combustion process produces gaseous selenium and/or gaseous selenium compounds;
(c) providing at least one metal-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 at a point that is both prior to entry of the flue gas into an SCR as well as after a point that where the majority of one or more selenium and/or selenium compounds are converted and/or oxidized into selenium (VI) ions; and
(d) permitting the at least one metal-bearing compound to react with any selenium and/or selenium compounds present in the combustion zone, flue gas, and/or the gas phase of at least one piece of emission control equipment,
wherein the at least one metal-bearing compound is provided in an amount that permits the control of the selenium speciation in one or more of the combustion zone, flue gas, and/or one or more gas phases present in the at least one piece of emission control equipment thereby resulting in a reduction in the amount, or concentration, of selenium (VI) ions emitted from, or contained in the combustion zone, the flue gas and/or from any one or more gas phases present in the at least one piece of emission control equipment.

2. The method of claim 1 , wherein the metal-bearing compound is selected from at least one inorganic iron-bearing compound.

3. The method of claim 1 , wherein the metal-bearing compound is selected from metallic iron, one or more iron oxides, iron carbonate, iron (II) acetate, iron (II) nitrate, iron (III) nitrate, iron (II) sulfate, iron (III) sulfate, or mixtures of two or more thereof.

4. The method of claim 1 , wherein the metal-bearing compound is selected from iron (III) oxide, iron (II) carbonate, iron (II) oxide, iron (II) acetate, or mixtures of two or more thereof.

5. The method of claim 1 , wherein the metal-bearing compound is selected from an organic iron-bearing compound.

6. The method of claim 1 , wherein the metal-bearing compound is selected from metallic aluminum, aluminum acetate, aluminum bromate, aluminum bromide, aluminum chloride, aluminum fluoride, aluminum hydroxide, aluminum iodide, aluminum nitrate, aluminum oxide, aluminum sulfate, or mixtures of two or more thereof.

7. The method of claim 1 , wherein the metal-bearing compound is selected from an organic aluminum-bearing compound.

8. The method of claim 1 , wherein the metal-bearing compound is selected from metallic nickel, nickel acetate, nickel bromate, nickel bromide, nickel carbonate, basic nickel carbonate, nickel chloride, nickel fluoride, nickel hydroxide, nickel iodate, nickel iodide, nickel nitrate, nickel oxide, nickel sulfate, or mixtures of two or more thereof.

9. The method of claim 1 , wherein the metal-bearing compound is selected from an organic nickel-bearing compound.

10. The method of claim 1 , wherein the metal-bearing compound is selected from metallic copper, copper acetate, copper bromate, copper bromide, copper trioxybromide, copper carbonate, basic copper carbonate, copper chloride, copper fluoride, copper hydroxide, copper iodate, copper iodide, copper nitrate, copper oxide, copper sulfate, or mixtures of two or more thereof.

11. The method of claim 1 , wherein the metal-bearing compound is selected from an organic copper-bearing compound.

12. The method of claim 1 , wherein the metal-bearing compound is selected from metallic zinc, zinc acetate, zinc bromate, zinc bromide, zinc carbonate, zinc chloride, zinc ferrate, zinc fluoride, zinc hydroxide, zinc iodate, zinc iodide, zinc nitrate, zinc oxide, zinc sulfate, or mixtures of two or more thereof.

13. The method of claim 1 , wherein the metal-bearing compound is selected from an organic zinc-bearing compound.

14. The method of claim 1 , wherein the metal-bearing compound is selected from one or more iron-bearing compounds, one or more aluminum-bearing compounds, one or more nickel-bearing compounds, one or more copper-bearing compounds, one or more zinc-bearing compounds, or mixtures of any two or more thereof.

15. The method of claim 1 , wherein the at least one metal-bearing compound is provided to the combustion zone via addition to the at least one biomass-based fuel.

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

17. The method of claim 1 , wherein the at least one piece of emission control equipment is a WFGD unit.

18. The method of claim 1 , wherein the at least one piece of emission control equipment is a DFGD unit.

19. A method for controlling the selenium speciation in a flue gas generated from the combustion of at least one biomass-based fuel and/or in a gas phase of at least one piece of emission control equipment where a flue gas stream in the at least one piece of emission control equipment is generated from the combustion of at least one biomass-based fuel in conjunction with a post combustion CO 2 capture process, the method comprising the steps of:
(I) providing at least one biomass-based fuel to a furnace, or boiler;
(II) subjecting the at least one biomass-based fuel to a staged combustion process, wherein the staged combustion process produces gaseous selenium and/or gaseous selenium compounds;
(III) providing at least one metal-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 at a point that is both prior to entry of the flue gas into an SCR as well as after a point that where the majority of one or more selenium and/or selenium compounds are converted and/or oxidized into selenium (VI) ions; and
(IV) permitting the at least one metal-bearing compound to react with any selenium and/or selenium compounds present in the combustion zone, flue gas, and/or the gas phase of at least one piece of emission control equipment,
wherein the at least one metal-bearing compound is provided in an amount that permits the control of the selenium speciation in one or more of the combustion zone, flue gas, and/or one or more gas phases present in the at least one piece of emission control equipment thereby resulting in a reduction in the amount, or concentration, of selenium (VI) ions emitted from, or contained in the combustion zone, the flue gas and/or from any one or more gas phases present in the at least one piece of emission control equipment and/or in at least one amine compound that is utilized in conjunction with the post combustion CO 2 capture process.

20. The method of claim 19 , wherein the metal-bearing compound is selected from at least one inorganic iron-bearing compound.

21. The method of claim 19 , wherein the metal-bearing compound is selected from metallic iron, one or more iron oxides, iron carbonate, iron (II) acetate, iron (II) nitrate, iron (III) nitrate, iron (II) sulfate, iron (III) sulfate, or mixtures of two or more thereof.

22. The method of claim 19 , wherein the

Assignees

• Babcock & Wilcox Power Generat
• Babcock & Wilcox Co

Inventors

• Gadgil Mandar R
• Jankura Bryan J
• Gayheart Jeb W

Classifications

• B01D2255/20738

  Iron · CPC title

• F23J2217/102

  electrostatic · CPC title

• F23N5/003

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

• B01D2257/10

  Single element gases other than halogens · CPC title

• B01D53/869

  Multiple step processes · CPC title