Coal additive for improved furnace operation

Patent metadata

Field	Value
Publication number	US-9464253-B2
Application number	US-201313846963-A
Country	US
Kind code	B2
Filing date	Mar 19, 2013
Priority date	Mar 27, 2012
Publication date	Oct 11, 2016
Grant date	Oct 11, 2016

Abstract

The invention relates to methods of combusting coal containing fuel streams where a coal additive composition is used to improve the combustion of the coal. The invention also relates to the additive composition used in the described methods, and the use of the additive composition as a coal combustion improver.

First claim

What is claimed is:

1. A method for combusting coal, comprising the steps of:
(I) providing a coal containing feed material to a coal combustion chamber, wherein the coal containing feed material comprises:
(a) less than about 15 percent by weight sulfur, taken on a dry basis of the coal containing feed material; and
(b) ash, with the ash containing less than about 25 percent by weight iron and at least about 10 percent by weight alkali metal, taken on a dry basis of the ash;

(II) contacting the feed material with a coal additive comprising a zinc containing compound;
whereby coal in the coal containing feed material is combusted.

2. The method of claim 1 , wherein the coal combustion chamber is part of a cyclone furnace and wherein the coal containing feed material includes coal particles entrained in an oxygen-containing gas and the coal particles have a P 90 size of no more than about 0.25 inches.

3. The method of claim 1 wherein the coal additive further comprises a mineralizer, a flow aid, an abrasive material, or a combination thereof.

4. The method of claim 1 wherein the coal additive is added to the combustion chamber of the furnace in such amounts such that the metal of the zinc containing compound is present in a concentration of from about 5 to about 1000 ppm relative to the total amount of coal containing feed material.

5. The method of claim 1 , wherein the zinc containing compound contains a zinc carboxylate additive comprising the reaction product of a zinc oxide and a fatty carboxylic acid.

6. The method of claim 5 wherein the fatty carboxylic acid comprises acetic acid, propionic acid, oleic acid, napthenic acid, tall oil fatty acid, or any combination thereof.

7. A method of improving the combustion efficiency of a coal fired furnace comprising the steps of:
(I) providing a coal containing feed material to a coal combustion chamber, wherein the coal containing feed material comprises:
(a) less than about 15 percent by weight sulfur, taken on a dry basis of the coal containing feed material; and
(b) ash, with the ash containing less than about 25 percent by weight iron and at least about 10 percent by weight alkali metal, taken on a dry basis of the ash;

(II) contacting the feed material with a coal additive comprising a zinc containing compound;
whereby the efficiency of the combustion of the coal in the coal containing feed material is improved.

8. The method of claim 7 , wherein the coal combustion chamber is part of a cyclone furnace and wherein the coal containing feed material includes coal particles entrained in an oxygen-containing gas and the coal particles have a P 90 size of no more than about 0.25 inches.

9. The method of claim 7 wherein the coal additive further comprises a mineralizer, a flow aid, an abrasive material, or a combination thereof.

10. The method of claim 7 wherein the coal additive is added to the combustion chamber of the furnace in such amounts such that the metal of the zinc containing compound is present in a concentration of from about 5 to about 1000 ppm relative to the total amount of coal containing feed material.

11. The method of claim 7 wherein the zinc containing compound contains a metal carboxylate additive comprising the reaction product of a zinc oxide and a fatty carboxylic acid.

12. The method of claim 7 wherein the fatty carboxylic acid comprises acetic acid, propionic acid, oleic acid, napthenic acid, tall oil fatty acid, or any combination thereof.

Assignees

• Lubrizol Corp

Inventors

• Bush James H

Classifications

• F23J7/00

  Arrangement of devices for supplying chemicals to fire · CPC title

• C09K3/22

  for dust-laying or dust-absorbing · CPC title

• C10L9/10 Primary

  by using additives · CPC title