Methods for operating a furnace

Patent metadata

Field	Value
Publication number	US-10641482-B2
Application number	US-201514833294-A
Country	US
Kind code	B2
Filing date	Aug 24, 2015
Priority date	Oct 27, 2008
Publication date	May 5, 2020
Grant date	May 5, 2020

Abstract

A method for combusting fuel in the presence of an alkali-containing material may include introducing fuel into a furnace configured to combust the fuel. The method may also include introducing ball clay having a moisture content of at least about 5% by weight into the furnace, and heating at least a portion of the fuel and ball clay, such that at least a portion of the ball clay is at least partially calcined, and the at least partially calcined ball clay adsorbs at least a portion of alkali present in the furnace.

First claim

What is claimed is:

1. A method for combusting fuel in the presence of an alkali-containing material, the method comprising:
introducing fuel into a furnace configured to combust the fuel;
introducing ball clay comprising 20-80% kaolinite, 10-25% mica, and 6-65% quartz and having a moisture content of at least about 5% by weight into the furnace; and
heating at least a portion of the fuel and ball clay, such that at least a portion of the ball clay is at least partially calcined and the at least partially calcined ball clay adsorbs at least a portion of alkali present in the furnace.

2. The method of claim 1 , wherein the ball clay has a moisture content ranging from about 5% by weight to about 15% by weight.

3. The method of claim 1 , wherein the ball clay has a moisture content ranging from about 8% by weight to about 12% by weight.

4. The method of claim 1 , wherein the ball clay comprises lump clay.

5. The method of claim 1 , wherein the ball clay comprises clay that has been at least one of shredded and crushed.

6. The method of claim 1 , wherein the ball clay comprises non-beneficiated ball clay.

7. The method of claim 1 , wherein the ball clay has a BET surface area of at least about 9 m 2 /g.

8. The method of claim 1 , wherein the ball clay has a BET surface area of at least about 15 m 2 /g.

9. The method of claim 1 , wherein ball clay comprises clay derived from crude clay having a moisture content of at least about 15%.

10. The method of claim 1 , further including introducing calcium carbonate into the furnace.

11. The method of claim 1 , further comprising incorporating the furnace into a fluidized-bed reactor system.

12. The method of claim 11 , wherein the fluidized-bed reactor system is a circulating fluidized-bed reactor system.

13. The method of claim 1 , wherein the step of heating results in calcining at least a portion of the ball clay, and the method further comprises:
adsorbing at least a portion of alkali in the furnace via the calcined clay; and
removing at least a portion of the calcined clay and adsorbed alkali from the furnace.

14. The method of claim 1 , wherein the fuel is coal, petroleum coke, or biofuel, or a combination of any of the foregoing.

15. The method of claim 1 , wherein the ball clay comprises ball clay agglomerates having a size of no more than about 3 inches.

16. The method of claim 15 , wherein the ball clay agglomerates have a size of no more than about 2 inches.

17. The method of claim 16 , wherein the ball clay agglomerates have a size of no more than about 1 inch.

18. A method for combusting fuel in the presence of an alkali-containing material, the method comprising:
introducing fuel and calcium carbonate into a furnace configured to combust the fuel;
introducing ball clay into the furnace, the ball clay comprising 20-80% kaolinite, 10-25% mica, and 6-65% quartz and having a moisture content of at least about 5% by weight; and
heating at least a portion of the fuel, calcium carbonate, and ball clay, such that at least a portion of the ball clay is at least partially calcined and the at least partially calcined clay adsorbs at least a portion of alkali present in the furnace.

19. A method for operating a fluidized-bed reactor, the method comprising:
introducing an alkali-containing material into a fluidized-bed reactor;
introducing ball clay into the fluidized-bed reactor, the ball clay comprising 20-80% kaolinite, 10-25% mica, and 6-65% quartz and having a moisture content of at least about 5% by weight;
heating at least a portion of the alkali-containing material and ball clay, such that at least a portion of the ball clay is at least partially calcined and the at least partially calcined clay adsorbs at least a portion of alkali present in the fluidized-bed reactor; and
removing at least a portion of the at least partially calcined clay and adsorbed alkali from the fluidized-bed reactor.

20. The method of claim 1 , wherein the ball clay is added in an amount sufficient to maintain a boiler temperature in the range of about 930° C. to about 1010° C.

Assignees

• Imerys Usa Inc

Inventors

• Leach Billie
• Landon Thomas

Classifications

• F23G5/30

  having a fluidised bed · CPC title

• F23G2200/00

  Waste incineration · CPC title

• F23J7/00 Primary

  Arrangement of devices for supplying chemicals to fire · CPC title

• F23J9/00

  Preventing premature solidification of molten combustion residues · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title