Sorbents for coal combustion

• US 9,702,554 B2
• Filed: 10/07/2015
• Issued: 07/11/2017
• Est. Priority Date: 03/17/2005
• Status: Active Grant

• Current Assignee: Nox Ii Ltd. (Arthur J Gallagher & Company)
• Original Assignee: Nox Ii Ltd. (Arthur J Gallagher & Company)
• Inventors: Comrie, Douglas C.
• Primary Examiner(s): Vanoy, Timothy
• Application Number:
  US14/877,145
• Publication Number:
  US 20160025337A1
• Time in Patent Office: 643 Days
• CPC Class Codes: B01D 2253/104 Alumina
• CPC Class Codes: B01D 2253/11 Clays
• CPC Class Codes: B01D 2257/30 Sulfur compounds
• CPC Class Codes: B01D 2257/602 Mercury or mercury compounds
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01D 53/30 Controlling by gas-analysis apparatus regulating non electrical variables in general G05D
• CPC Class Codes: B01D 53/485 containing only one sulfur compound other than sulfur oxides or hydrogen sulfide
• CPC Class Codes: B01D 53/64 Heavy metals or compounds thereof, e.g. mercury
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B01J 20/041 Oxides or hydroxides
• CPC Class Codes: B01J 20/043 Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite
• CPC Class Codes: B01J 20/046 containing halogens, e.g. halides
• CPC Class Codes: B01J 20/06 comprising oxides or hydroxides of metals not provided for in group B01J20/04
• CPC Class Codes: B01J 20/12 Naturally occurring clays or bleaching earth
• CPC Class Codes: B01J 20/16 Alumino-silicates B01J20/12 takes precedence
• CPC Class Codes: B01J 2220/42 Materials comprising a mixture of inorganic materials materials coated or impregnated on a carrier B01J20/32
• CPC Class Codes: C10L 10/00 Use of additives to fuels or fires for particular purposes additives for liquid carbonaceous fuels characterised by their chemical nature C10L1/10; using binders for briquetting solid fuels C10L5/10; using additives to improve the combustion of solid fuels C10L9/10
• CPC Class Codes: C10L 10/02 for reducing smoke development
• CPC Class Codes: C10L 9/10 by using additives
• CPC Class Codes: F23J 15/00 Arrangements of devices for treating smoke or fumes
• CPC Class Codes: F23J 15/025 : using filters
• CPC Class Codes: F23J 15/04 : using washing fluids scrubbers for removing solids only F23J15/022
• CPC Class Codes: F23J 7/00 : Arrangement of devices for supplying chemicals to fire
• CPC Class Codes: F23K 1/00 : Preparation of lump or pulverulent fuel in readiness for delivery to combustion apparatus
• CPC Class Codes: F23K 2201/505 : with additives
• CPC Class Codes: Y02P 40/10 : Production of cement, e.g. improving or optimising the production methods; Cement grinding
• CPC Class Codes: Y10S 423/05 : Automatic, including computer, control

Abstract

Sorbent compositions containing iodine are added to coal to mitigate the release of mercury and/or other harmful elements into the environment during combustion of coal containing natural levels of mercury.

Claims

1. A method for reducing environmental emissions of mercury arising from combusting a mercury containing fuel in a furnace of a facility, wherein the facility comprises a convective pathway for combustion gases from the furnace, the method comprising:

applying a sorbent composition comprising iodine and calcium onto the fuel;

delivering the fuel into the furnace;

combusting the fuel together with the applied sorbent composition to produce heat energy and combustion gases; and

measuring the level of mercury in the combustion gases.

2. The method of claim 1, wherein the sorbent composition comprises calcium iodide.

3. The method of claim 1, wherein the sorbent composition comprises an iodide, an iodate, or a hypoiodite.

4. The method of claim 1, comprising applying 0.01-10% by weight of the sorbent composition, based on the weight of the fuel being burned.

5. The method of claim 1, wherein the sorbent composition further comprises silica and alumina.

6. The method of claim 5, wherein the sorbent composition comprises an aluminosilicate clay.

7. The method of claim 6, wherein the clay comprises kaolin.

8. The method of claim 6, wherein the clay comprises montmorillonite.

9. The method of claim 1, wherein the facility comprises a chemical scrubber disposed in the convective pathway.

10. The method of claim 9, wherein the chemical scrubber is a wet scrubber or an SCR control system.

11. The method of claim 1, wherein the facility comprises a particulate removal system disposed in the convective pathway.

12. The method according to claim 11, wherein the particulate removal system is an electrostatic precipitator.

13. The method according to claim 11, wherein the particulate removal system is a bag house.

14. The method of claim 1, further comprising applying a mercury sorbent composition comprising a halogen into the combustion gases where the temperature is between 1500°

F. and 2700°

F.

15. The method of claim 14, wherein the mercury sorbent composition comprises an organic bromine compound.

16. The method of claim 14, wherein the mercury sorbent composition comprises a bromide salt, a bromate salt, or a hypobromite salt.

17. The method of claim 14, wherein the mercury sorbent composition comprises an iodide salt, and iodate salt, or a hypoiodite salt.

18. The method of claim 1, wherein the fuel is coal.

19. A method of reducing emissions of mercury to a desired level, the emissions arising from combustion of mercury containing coal in the furnace of a facility comprising a convective pathway for combustion gases, the method comprising:

adding a sorbent composition onto the coal at an initial treat level;

combusting the coal in the furnace to create heat energy and combustion gases;

measuring the level of mercury in the combustion gases; and

adjusting the treat level up or down as required to meet the desired emissions level;

wherein the sorbent composition comprises calcium iodide.

20. The method of claim 19, wherein the initial treat level is in the range of 0.01-10% by weight of the coal being combusted.