Method of removing sulfur dioxide from a flue gas stream

• US 7,854,911 B2
• Filed: 03/27/2009
• Issued: 12/21/2010
• Est. Priority Date: 08/18/2005
• Status: Active Grant

• Current Assignee: Solvay Chemicals Incorporated (Solvac SA)
• Original Assignee: Solvay Chemicals Incorporated (Solvac SA)
• Inventors: Maziuk, John Jr.
• Primary Examiner(s): Vanoy; Timothy C
• Application Number:
  US12/413,057
• Publication Number:
  US 20090241774A1
• Time in Patent Office: 634 Days
• Field of Search: 423/243.01, 423/243.08, 423/244.01, 423/244.07, 423/244.08
• US Class Current: 423/243.01
• CPC Class Codes: B01D 53/508 by treating the gases with solids

Abstract

A method of removing SO_x from a flue gas stream including SO_x includes providing a source of trona and injecting the trona as a dry sorbent into the flue gas stream. The temperature of the flue gas is at an elevated temperature greater than 400° F., preferably between about 600° F. and about 900° F. The trona is maintained in contact with the flue gas for a time sufficient to react a portion of the trona with a portion of the SO_x to reduce the concentration of the SO₂ and/or SO₃ in the flue gas stream.

Claims

1. A method of removing SO₂ from a flue gas stream comprising SO₂ and SO₃, the method comprising:

providing a source of trona;

injecting the trona into the flue gas stream, wherein the temperature of the flue gas is between about 600°

F. and about 900°

F.; and

maintaining the trona in contact with the flue gas for a time sufficient to react a portion of the trona with a portion of the SO₂ and to react a portion of the trona with a portion of the SO₃ to reduce the concentration of the SO₂ and the SO₃ in the flue gas stream.

2. The method of claim 1 wherein the mean particle size of the trona is less than about 40 micron.

3. The method of claim 1 wherein the mean particle size of the trona is between about 10 micron and about 40 micron.

4. The method of claim 1 wherein the mean particle size of the trona is between about 24 micron and about 28 micron.

5. The method of claim 1 wherein the temperature of the flue gas is greater than about 630°

F.

6. The method of claim 1 wherein the temperature of the flue gas is greater than about 700°

F.

7. The method of claim 1 wherein the temperature of the flue gas is less than about 800°

F.

8. The method of claim 1 wherein the temperature of the flue gas is less than about 750°

F.

9. The method of claim 1 wherein the temperature of the flue gas is between about 700°

F. and about 750°

F.

10. The method of claim 1 wherein the trona is injected at a rate with respect to the flow rate of the SO₂ to provide a normalized stoichiometric ratio of sodium to sulfur of between about 1.0 and 1.5.

11. The method of claim 1 wherein the trona is injected as a dry material.

12. The method of claim 1 further comprising milling the trona to a desired mean particle size at a location proximate the flue gas stream.

13. The method of claim 1 further comprising collecting a reaction product of the trona and the SO₂ in an electrostatic precipitator.