System and method for controlling one or more process parameters associated with a combustion process

• US 10,018,356 B2
• Filed: 03/15/2013
• Issued: 07/10/2018
• Est. Priority Date: 07/12/2012
• Status: Active Grant

• Current Assignee: Babcock & Wilcox Company (Babcock International Group PLC)
• Original Assignee: Babcock & Wilcox Company (Babcock International Group PLC)
• Inventors: Johnson, Daniel B., Brown, Shannon R.
• Primary Examiner(s): Menon, Krishnan S
• Assistant Examiner(s): Gerido, Dwan A
• Application Number:
  US13/837,221
• Publication Number:
  US 20140196639A1
• Time in Patent Office: 1,943 Days
• CPC Class Codes: B01D 2251/2062 Ammonia
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/346 Controlling the process
• CPC Class Codes: B01D 53/504 characterised by a specific device
• CPC Class Codes: B01D 53/8631 Processes characterised by a specific device
• CPC Class Codes: B03C 2201/24 for measuring or calculating of parameters, e.g. efficiency
• CPC Class Codes: B03C 3/013 Conditioning by chemical additives, e.g. with SO3
• CPC Class Codes: B03C 3/017 Combinations of electrostatic separation with other processes, not otherwise provided for
• CPC Class Codes: B03C 3/68 Control systems therefor electricity supply or control systems for cleaning the electrodes B03C3/746, B03C3/763
• CPC Class Codes: F23J 15/02 of purifiers, e.g. for removing noxious material traps for solid residues F23J3/04
• CPC Class Codes: F23J 2215/20 Sulfur; Compounds thereof
• CPC Class Codes: F23J 2219/40 Sorption with wet devices, e.g. scrubbers
• CPC Class Codes: G01N 1/22 in the gaseous state specially adapted for biological material G01N33/497; measuring breath flow A61B5/087
• CPC Class Codes: G01N 31/005 investigating the presence of an element by oxidation G01N31/12 takes precedence
• CPC Class Codes: G01N 31/12 using combustion G01N25/20 takes precedence
• CPC Class Codes: G01N 33/1846 Total carbon analysis

Abstract

The present invention relates generally to the generation of steam via the use of a combustion process to produce heat and, in one embodiment, to a device, system and/or method that enables one to control one or more process parameters of a combustion process so as to yield at least one desirable change in at least one downstream parameter. In one embodiment, the present invention is directed to a system and/or method for controlling at least one process parameter of a combustion process so as to yield at least one desirable change in at least one downstream process parameter associated with one or more of a wet flue gas desulfurization (WFGD) unit, a particulate collection device and/or control of additives thereto and/or a nitrogen oxide control device and/or control of additives thereto and/or additives to the system.

Claims

1. A method for optimizing a wet flue gas desulfurization unit, the method comprising the steps of:

(I) measuring, analyzing and/or controlling at least one parameter selected from the chemistry in the flue gas and/or absorber tank of the WFGD;

(II) generating data from the at least one parameter of Step (I); and

(III) using the data generated in Step (II) to adjust at least one operational parameter selected from at least one reagent feed flow to the wet flue gas desulfurization unit,

wherein Step (III) comprises a method for controlling the oxidation-reduction potential in a recirculation tank, or an absorber recirculation tank, of a wet flue gas desulfurization unit, the method comprising the steps of;

(A) supplying an aqueous solution of at least one reducing agent to a slurry, or a solution, portion of the recirculation tank, or the absorber recirculation tank, or at least one recirculation pump so that the at least one reducing agent is supplied to the wet flue gas desulfurization unit recirculation tank or absorber recirculation tank; and

(B) permitting the at least one reducing agent to react with one or more oxidizing compounds and/or ions present in the slurry, or the solution, portion of the recirculation tank, or the absorber recirculation tank or the at least one recirculation pump, so as to achieve a reduction in the oxidation-reduction potential of the slurry, or the solution, in the recirculation tank, or the absorber recirculation tank, or in the at least one recirculation pump, or in a combination of the recirculation tank, or the absorber recirculation tank, and the at least one recirculation pump so that an amount of at least one insoluble precipitate compound in the recirculation tank, or the absorber recirculation tank, is controlled, prevented, or eliminated by the addition of the at least one reducing agent,

wherein the at least one reducing agent is selected from phosphorous acid (H₃PO₃), iron (II) ammonium sulfate ((NH₄)₂Fe(SO₄)₂), hydroxylamine hydrochloride (HONH₂.HCl), hypophosphorous acid (H₃PO₂), or a combination of any two or more thereof.

2. A method for optimizing a wet flue gas desulfurization unit, the method comprising the steps of:

(i) measuring, analyzing and/or controlling at least one parameter in real time selected from the chemistry in the flue gas and/or absorber tank of the WFGD;

(ii) generating real-time data from the at least one parameter of Step (i); and

(iii) using the real-time data generated in Step (ii) to adjust at least one operational parameter selected from at least one reagent feed flow to the wet flue gas desulfurization unit,

wherein Step (iii) comprises a method for controlling the oxidation-reduction potential in a recirculation tank, or an absorber recirculation tank, of a wet flue gas desulfurization unit, the method comprising the steps of;

(a) supplying an aqueous solution of at least one reducing agent to a slurry, or a solution, portion of the recirculation tank, or the absorber recirculation tank, or at least one recirculation pump so that the at least one reducing agent is supplied to the wet flue gas desulfurization unit recirculation tank or absorber recirculation tank; and

(b) permitting the at least one reducing agent to react with one or more oxidizing compounds and/or ions present in the slurry, or the solution, portion of the recirculation tank, or the absorber recirculation tank or the at least one recirculation pump, so as to achieve a reduction in the oxidation-reduction potential of the slurry, or the solution, in the recirculation tank, or the absorber recirculation tank, or in the at least one recirculation pump, or in a combination of the recirculation tank, or the absorber recirculation tank, and the at least one recirculation pump so that an amount of at least one insoluble precipitate compound in the recirculation tank, or the absorber recirculation tank, is controlled, prevented, or eliminated by the addition of the at least one reducing agent,

wherein the at least one reducing agent is selected from phosphorous acid (H₃PO₃), iron (II) ammonium sulfate ((NH₄)₂Fe(SO₄)₂), hydroxylamine hydrochloride (HONH₂.HCl), hypophosphorous acid (H₃PO₂), or a combination of any two or more thereof.

3. A method for optimizing a wet flue gas desulfurization unit, the method comprising the steps of:

controlling, measuring and/or analyzing at least one process parameter of a combustion process and/or at least one combustion process air quality control system in order to yield at least one data set; and

using the at least one data set to effect a desirable change in at least one downstream process parameter associated with one or more of a wet flue gas desulfurization unit, a particulate collection device and/or a nitrogen oxide control device,

wherein the desirable change effected is accomplished by at least the measurement of an oxidation-reduction potential and using the at least one data set generated thereby to control the oxidation-reduction potential in a recirculation tank, or an absorber recirculation tank, of a wet flue gas desulfurization unit, the control method comprising the steps of;

supplying an aqueous solution of at least one reducing agent to a slurry, or a solution, portion of the recirculation tank, or the absorber recirculation tank, or at least one recirculation pump so that the at least one reducing agent is supplied to the wet flue gas desulfurization unit recirculation tank or absorber recirculation tank; and

permitting the at least one reducing agent to react with one or more oxidizing compounds and/or ions present in the slurry, or the solution, portion of the recirculation tank, or the absorber recirculation tank or the at least one recirculation pump, so as to achieve a reduction in the oxidation-reduction potential of the slurry, or the solution, in the recirculation tank, or the absorber recirculation tank, or in the at least one recirculation pump, or in a combination of the recirculation tank, or the absorber recirculation tank, and the at least one recirculation pump so that an amount of at least one insoluble precipitate compound in the recirculation tank, or the absorber recirculation tank, is controlled, prevented, or eliminated by the addition of the at least one reducing agent,

wherein the at least one reducing agent is selected from phosphorous acid (H₃PO₃), iron (II) ammonium sulfate ((NH₄)₂Fe(SO₄)₂), hydroxylamine hydrochloride (HONH₂.HCl), hypophosphorous acid (H₃PO₂), or a combination of any two or more thereof.

4. A method for optimizing a wet flue gas desulfurization unit, the method comprising the steps of:

controlling, measuring and/or analyzing at least two process parameters of a combustion process and/or at least one combustion process air quality control system in order to yield at least two data sets;

using the at least two data sets to effect a desirable change in at least one downstream process parameter associated with one or more of a wet flue gas desulfurization unit, a particulate collection device and/or a nitrogen oxide control device,

wherein the desirable change effected is accomplished by at least the measurement of an oxidation-reduction potential and at least the concentration of at least one concentration of one or more oxidizer compounds and/or species using the at least two data sets generated thereby to control the oxidation-reduction potential in a recirculation tank, or an absorber recirculation tank, of a wet flue gas desulfurization unit, the control method comprising the steps of;

supplying an aqueous solution of at least one reducing agent to a slurry, or a solution, portion of the recirculation tank, or the absorber recirculation tank, or at least one recirculation pump so that the at least one reducing agent is supplied to the wet flue gas desulfurization unit recirculation tank or absorber recirculation tank; and

permitting the at least one reducing agent to react with one or more oxidizing compounds and/or ions present in the slurry, or the solution, portion of the recirculation tank, or the absorber recirculation tank or the at least one recirculation pump, so as to achieve a reduction in the oxidation-reduction potential of the slurry, or the solution, in the recirculation tank, or the absorber recirculation tank, or in the at least one recirculation pump, or in a combination of the recirculation tank, or the absorber recirculation tank, and the at least one recirculation pump so that an amount of at least one insoluble precipitate compound in the recirculation tank, or the absorber recirculation tank, is controlled, prevented, or eliminated by the addition of the at least one reducing agent,

wherein the at least one reducing agent is selected from phosphorous acid (H₃PO₃), iron (II) ammonium sulfate ((NH₄)₂Fe(SO₄)₂), hydroxylamine hydrochloride (HONH₂.HCl), hypophosphorous acid (H₃PO₂), or a combination of any two or more thereof.

5. A method for optimizing a wet flue gas desulfurization unit, the method comprising the steps of:

measuring, analyzing and/or controlling at least one parameter selected from desulfurization tower load;

generating data from the at least one parameter of the previous Step; and

using the data generated in the previous Step to adjust at least one operational parameter selected from the concentration, type and/or speciation of one or more compounds and/or ions in an absorber recirculation tank solution of a desulfurization tower,

wherein the method to adjust at least one operational parameter comprises at least the steps of;

supplying an aqueous solution of at least one reducing agent to a slurry, or a solution, portion of the recirculation tank, or the absorber recirculation tank, or at least one recirculation pump so that the at least one reducing agent is supplied to the wet flue gas desulfurization unit recirculation tank or absorber recirculation tank; and

permitting the at least one reducing agent to react with one or more oxidizing compounds and/or ions present in the slurry, or the solution, portion of the recirculation tank, or the absorber recirculation tank or the at least one recirculation pump, so as to achieve a reduction in the oxidation-reduction potential of the slurry, or the solution, in the recirculation tank, or the absorber recirculation tank, or in the at least one recirculation pump, or in a combination of the recirculation tank, or the absorber recirculation tank, and the at least one recirculation pump so that an amount of at least one insoluble precipitate compound in the recirculation tank, or the absorber recirculation tank, is controlled, prevented, or eliminated by the addition of the at least one reducing agent,

wherein the at least one reducing agent is selected from phosphorous acid (H₃PO₃), iron (II) ammonium sulfate ((NH₄)₂Fe(SO₄)₂), hydroxylamine hydrochloride (HONH₂.HCl), hypophosphorous acid (H₃PO₂), or a combination of any two or more thereof.

6. The method of claim 5, wherein the method includes a step of adding at least one of SO₃ or trona to an electrostatic precipitator and controlling the amount of such one or more compounds to the electrostatic precipitator so as to reduce the amount of sparking that occurs in an electrostatic precipitator while injecting one or more of SO₃ or trona versus the amount of sparking that occurs without such injection.

7. The method of claim 5, wherein the method includes a step of controlling the amount of sparking that occurs in an electrostatic precipitator so as to reduce the concentration and/or type of one or more oxidizers that are formed as a result of the sparking.

8. The method of claim 5, wherein the method includes a step of controlling the amount of sparking that occurs in an electrostatic precipitator so as to reduce the concentration and/or type of one or more oxidizers that are formed in the electrostatic precipitator.

9. The method of claim 8, wherein the concentration, type and/or speciation of one or more compounds and/or ions that are controlled in the absorber recirculation tank solution of the desulfurization tower include one or more oxidizers are selected from persulfate, permanganate, manganate, ozone, hypochlorite, chlorate, nitric acid, iodine, bromine, chlorine, fluorine, or combinations of any two or more thereof.

10. The method of claim 5, wherein the method permits control of both an oxidation-reduction potential and a pH in the solution of the absorber recirculation tank.

11. The method of claim 10, wherein the oxidation-reduction potential in the solution of the absorber recirculation tank is less than about 500 mV and the pH is less than about 7.

12. The method of claim 10, wherein the oxidation-reduction potential in the solution of the absorber recirculation tank is less than about 450 mV and the pH is less than about 6.5.

13. The method of claim 10, wherein the oxidation-reduction potential in the solution of the absorber recirculation tank is less than about 400 mV and the pH is less than about 6.

14. The method of claim 10, wherein the oxidation-reduction potential in the solution of the absorber recirculation tank is less than about 350 mV and the pH is less than about 6.

15. The method of claim 10, wherein the oxidation-reduction potential in the solution of the absorber recirculation tank is less than about 300 mV and the pH is less than about 6.

16. The method of claim 5, wherein the method permits control of an oxidation-reduction potential in the solution of the absorber recirculation tank so that the oxidation-reduction potential is less than about 500 mV.

17. The method of claim 5, wherein the method permits control of an oxidation-reduction potential in the solution of the absorber recirculation tank so that the oxidation-reduction potential is less than about 450 mV.

18. The method of claim 5, wherein the method permits control of an oxidation-reduction potential in the solution of the absorber recirculation tank so that the oxidation-reduction potential is less than about 400 mV.

19. The method of claim 5, wherein the method permits control of an oxidation-reduction potential in the solution of the absorber recirculation tank so that the oxidation-reduction potential is less than about 350 mV.

20. The method of claim 5, wherein the method permits control of an oxidation-reduction potential in the solution of the absorber recirculation tank so that the oxidation-reduction potential is less than about 300 mV.

21. The method of claim 5, wherein the method permits control of at least selenium speciation in the absorber recirculation tank solution while simultaneously permitting control of mercury reemission from the desulfurization unit.

22. The method of claim 5, wherein the method permits control of at least selenium speciation in the absorber recirculation tank solution.

23. The method of claim 5, wherein the method permits control of one or more of selenium speciation, manganese speciation, cobalt speciation, mercury speciation, or any two or more thereof in the absorber recirculation tank solution.