Method of simultaneously reducing CO2 and SO2 emissions in a combustion installation

• US 6,737,031 B2
• Filed: 09/14/2001
• Issued: 05/18/2004
• Est. Priority Date: 09/27/2000
• Status: Expired due to Term

• Current Assignee: General Electric Technology GmbH (GE Vernova, Inc.)
• Original Assignee: Alstom Power NV (Alstom SA)
• Inventors: Beal, Corinne, Vandycke, Michel, Morin, Jean-Xavier
• Primary Examiner(s): Bos, Steven
• Assistant Examiner(s): WRIGHT, WILLIAM G
• Application Number:
  US09/951,389
• Publication Number:
  US 20020037246A1
• Time in Patent Office: 977 Days
• Field of Search: 423/230, 423/243.08, 423/244.01, 423/244.07, 423/244.08, 423/244.09
• US Class Current: 423/230
• CPC Class Codes: B01D 2251/404 of calcium
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/501 by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: F23C 2206/10 Circulating fluidised bed
• CPC Class Codes: F23J 15/003 for supplying chemicals to fumes, e.g. using injection devices
• CPC Class Codes: F23J 15/006 Layout of treatment plant
• CPC Class Codes: F23J 2215/20 Sulfur; Compounds thereof
• CPC Class Codes: F23J 2215/50 Carbon dioxide
• CPC Class Codes: F23J 2900/01007 Thermal treatments of ash, e.g. temper or shock-cooling for granulation
• CPC Class Codes: F23J 7/00 Arrangement of devices for supplying chemicals to fire
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02E 20/32 Direct CO2 mitigation

Abstract

The method of simultaneously reducing carbon dioxide (CO₂) emissions and sulfur dioxide (SO₂) emissions produced by the combustion of carbon-containing matter in a hearth consists in injecting into the hearth a calcium-based agent, a fraction of which absorbs SO₂ after decarbonization, and then, after the flue gases have been subjected to intermediate cooling, in causing them to transit via a first reactor and in putting them in contact therein with the other fraction of the absorbant that has not reacted with SO₂ so as to capture CO₂ from the flue gases by carbonization, then, in a separator, in extracting the solids contained in the flue gases output from the first reactor so as to subject them to heat treatment in a second reactor in order to extract CO₂ therefrom by decarbonization and in order to recycle the resulting regenerated CO₂ absorbant to the first reactor.

Claims

1. A method of simultaneously reducing carbon dioxide (CO₂) emissions and sulfur dioxide (SO₂) emissions from flue gases produced by the combustion of carbon-containing matter in a hearth, said method comprising the steps of:

injecting into the hearth a calcium-based agent, a fraction of which absorbs SO₂ after decarbonization;

causing the flue gases, after the flue gases have been subjected to intermediate cooling, to transit via a first reactor and putting the flue gases in contact therein with the other fraction of the absorbant that has not reacted with SO₂ so as to capture CO₂ from the flue gases by carbonization; and

extracting, in a separator, the solids contained in the flue gases output from the first reactor so as to subject the solids to heat treatment in a second reactor in order to extract CO₂ therefrom by decarbonization and in order to recycle the resulting regenerated CO₂ absorbant to the first reactor.

2. The method of claim 1, in which the flue gases output from the separator are sent to a dust filter, and part of the solids extracted from the dust filter are mixed with the solids extracted from the separator before being subjected to heat treatment in the second reactor.

3. The method of claim 2, in which the flue gases output from the separator are cooled in a recuperator boiler before being sent into the dust filter.

4. The method of claim 1, in which, before the solids are sent to the second reactor, their temperature is reduced in a first enclosure by treatment with water.

5. The method of claim 1, in which a fraction of the solids output from the second reactor is re-injected into the hearth.

6. The method of claim 1, in which a fragment of the ash taken from the hearth is sent to the second reactor.

7. The method of claim 1, in which the solids output from the second reactor are treated in a second enclosure so as to improve their reactivity before being re-injected into the hearth or into the first reactor.

8. The method of claim 7, in which the solids are reactivated in the second enclosure by adding alkaline salts.

9. The method of claim 1, in which a fraction of the solids output from the separator is re-injected into the first reactor via a valve having an adjustable flow rate.

10. The method of claim 1, in which a fraction of the solids output from the separator is cooled in a solid particles heat exchanger and is then re-injected into the first reactor.

11. The method of claim 1, in which the first reactor is a fluidized bed reactor.

12. The method of claim 1, in which the hearth is a circulating fluidized bed hearth.

13. The method of claim 1, in which the absorbant is calcium carbonate.

14. A method of simultaneously reducing carbon dioxide (CO₂) emissions and sulfur dioxide (SO₂) emissions from flue gases produced by the combustion of carbon containing matter in a hearth, said method comprising the steps of:

Injecting into the hearth an alkaline earth based agent, a fraction of which absorbs SO₂ after decarbonization;

causing the flue gases, after the flue gases have been subjected to intermediate cooling, to transit via a first reactor and putting the flue gases in contact therein with the other fraction of the absorbent that has not reacted with SO₂ so as to capture CO₂ from the flue gases by the carbonization; and

extracting in a separator, the solids contained in the flue gases output from the first reactor so as to subject the solids to heat treatment in a second reactor in order to extract CO₂ therefrom by decarbonization and in order to recycle the resulting regenerated CO₂ absorbent to the first reactor.

15. The method of claim 14, in which the absorbant is dolomite.