SO2 Capture-coal combustion

Claim 2

In a process for the combustion of coal wherein a particulate coal is combusted with an oxygen-containing gas in the presence of a particulate calcium-containing material, the improvement comprising increasing the capture efficiency of the calcium-containing material by carrying out the combustion in the presence of an effective amount of a tin-containing material.

Claim 3

The process of claim 1 wherein the calcium-containing material is limestone.

Claim 4

The process of claim 2 wherein the coal is beneficiated coal.

Claim 5

The process of claim 3 wherein the tin-containing material is present in an amount of from about 0.05 percent by weight to about 10 percent by weight, based on the weight of the coal.

Claim 6

The process of claim 4 wherein the tin-containing material is SnO.

Claim 7

A process for increasing the capture efficiency of a particulate calcium-containing material during the combustion of coal comprising carrying out said combustion in the presence of said calcium-containing material and in the presence of an effective amount of a tin-containing material.

Claim 8

A process for increasing the capture efficiency of a particulate calcium-containing material during the combustion of coal comprising carrying out said combustion in the presence of said calcium-containing material and in the presence of an effective amount of a tin-containing material.

Claim 9

A process comprising burning particulate coal in the presence of a particulate calcium-containing material and an additive mixture comprising a tin-containing material and Cr 2 O 3 , the mol ratio of tin-containing material to Cr 2 O 3 being from 0.2 to 1:1, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 10

A process comprising burning particulate coal in the presence of a particulate calcium-containing material and an additive mixture comprising a tin-containing material and Cr 2 O 3 , the mol ratio of tin-containing material to Cr 2 O 3 being from 0.2 to 1:1, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 11

The process of claim 7 wherein the calcium-containing material is limestone.

Claim 12

The process of claim 8 wherein the coal is beneficiated coal.

Claim 13

The process of claim 9 wherein the additive mixture is present in an amount of from about 0.1 percent by weight to about 5 percent by weight, based on the weight of the coal.

Claim 14

The process of claim 10 wherein the tin-containing material is SnO.

Claim 15

In a process for the combustion of coal wherein a particulate coal is combusted with an oxygen-containing gas in the presence of a particulate calcium-containing material, the improvement comprising carrying out the combustion in the presence of an additive mixture comprising SnO, Cr 2 O 3 , and BaO, the ratio of SnO:Cr 2 O 3 :BaO being from 0.2 to 1:1:0.05 to 0.3, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 16

In a process for the combustion of coal wherein a particulate coal is combusted with an oxygen-containing gas in the presence of a particulate calcium-containing material, the improvement comprising carrying out the combustion in the presence of an additive mixture comprising SnO, Cr 2 O 3 , and BaO, the ratio of SnO:Cr 2 O 3 :BaO being from 0.2 to 1:1:0.05 to 0.3, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 17

A process comprising burning particulate coal in the presence of a particulate calcium-containing material and an additive mixture comprising SnO, Cr 2 O 3 , and BaO, the ratio of SnO:Cr 2 O 3 :BaO being from 0.2 to 1:1:0.5 to 0.3, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 18

A process comprising burning particulate coal in the presence of a particulate calcium-containing material and an additive mixture comprising SnO, Cr 2 O 3 , and BaO, the ratio of SnO:Cr 2 O 3 :BaO being from 0.2 to 1:1:0.5 to 0.3, and the additive mixture being present in an amount sufficient to improve the capture efficiency of the calcium-containing material.

Claim 19

The process of claim 13 wherein the calcium-containing material is limestone.

Claim 20

The method of claim 14 wherein the coal is beneficiated coal.

Claim 21

The method of claim 15 wherein the additive mixture is present in an amount of from about 0.1 percent by weight to about 5 percent by weight, based on the weight of the coal.