Removing Carbon Dioxide From Waste Streams Through Co-Generation of Carbonate and/or Bicarbonate Minerals

• US 20090127127A1
• Filed: 09/22/2008
• Published: 05/21/2009
• Est. Priority Date: 09/20/2007
• Status: Active Grant

• Current Assignee: Carbonfree Chemicals Holdings, LLC
• Original Assignee: Skyonic Corp.
• Inventors: Jones, Joe David
• Granted Patent: US 9,205,375 B2
• Time in Patent Office: Days
• US Class Current: 205/464
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/502 Hydrochloric acid
• CPC Class Codes: B01D 2251/604 Hydroxides
• CPC Class Codes: B01D 2257/302 Sulfur oxides
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/602 Mercury or mercury compounds
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/73 After-treatment of removed components
• CPC Class Codes: B01D 53/75 Multi-step processes
• CPC Class Codes: B01D 53/965 including an electrochemical process step
• CPC Class Codes: C01B 11/062 Hypochlorites of alkali metals
• CPC Class Codes: C01B 7/01 Chlorine; Hydrogen chloride
• CPC Class Codes: C01B 7/03 Preparation from chlorides
• CPC Class Codes: C01B 7/035 Preparation of hydrogen chloride from chlorides
• CPC Class Codes: C01B 7/04 Preparation of chlorine from hydrogen chloride
• CPC Class Codes: C01B 9/02 Chlorides
• CPC Class Codes: C01F 11/24 Chlorides
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/129 Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2
• CPC Class Codes: Y02W 10/37 : using solar energy

Abstract

Apparatuses and methods for removing carbon dioxide and other pollutants from a gas stream are provided. The methods include obtaining hydroxide in an aqueous mixture, and mixing the hydroxide with the gas stream to produce carbonate and/or bicarbonate. Some of the apparatuses of the present invention comprise an electrolysis chamber for providing hydroxide and mixing equipment for mixing the hydroxide with a gas stream including carbon dioxide to form an admixture including carbonate and/or bicarbonate.

Claims

1. A method of removing an initial amount of carbon dioxide from a gas stream comprising:

obtaining a hydroxide in an aqueous mixture;

obtaining chlorine;

admixing the hydroxide with the gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture;

separating said carbonate and/or bicarbonate products from the admixture, thereby removing a portion of the initial amount of carbon dioxide from the gas stream;

combining chlorine with water to form hypochlorous acid;

decaying the hypochlorous acid to form hydrochloric acid and oxygen; and

combining the hydrochloric acid with calcium carbonate to form calcium chloride and a reduced amount of carbon dioxide.

2. The method of claim 1 further comprising:

obtaining hydrogen; and

combusting the hydrogen in a power plant.

3. The method of claim 1 wherein the reduced amount of carbon dioxide is one-half of the initial amount of carbon dioxide.

4. The method of claim 1 wherein the hydroxide is sodium hydroxide.

5. A method of removing an initial amount of carbon dioxide from a gas stream comprising:

obtaining a hydroxide in an aqueous mixture;

obtaining hydrochloric acid;

admixing the hydroxide with the gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture;

separating said carbonate and/or bicarbonate products from the admixture, thereby removing a portion of the initial amount of carbon dioxide from the gas stream; and

combining the hydrochloric acid with calcium carbonate to form calcium chloride and a reduced amount of carbon dioxide.

6. The method of claim 5 further comprising:

obtaining hydrogen; and

combusting the hydrogen in a power plant.

7. The method of claim 5 wherein the reduced amount of carbon dioxide is one-half of the initial amount of carbon dioxide.

8. The method of claim 5 wherein the hydroxide is sodium hydroxide.

9. An apparatus comprising:

a electrolysis chamber comprising at least one cathode and at least one anode, the electrolysis chamber adapted to produce hydroxide, hydrogen, and chlorine during use;

a first set of mixing equipment operably connected to the electrolysis chamber and to a conduit adapted to contain a gas stream during use, the mixing equipment adapted to admix hydroxide from the electrolysis chamber with the gas stream during use to create an admixture in which carbon, sulfur, and/or nitrogen compounds in the gas stream can react with the hydroxide;

a second set of mixing equipment operably connected to the electrolysis chamber and adapted to admix the chlorine with water during use to create hypochlorous acid;

process equipment adapted to decay the hypochlorous acid to create hydrochloric acid and oxygen;

a third set of mixing equipment adapted to combine the hydrochloric acid and calcium carbonate to create calcium chloride and carbon dioxide during use; and

a separation chamber operably connected to the mixing equipment and adapted to separate the admixture into a separate gas phase and solid and/or liquid phase.

10. An apparatus comprising:

a electrolysis chamber comprising at least one cathode and at least one anode, the electrolysis chamber adapted to produce hydroxide, hydrogen, and oxygen during use;

a first set of mixing equipment operably connected to the electrolysis chamber and to a conduit adapted to contain a gas stream during use, the mixing equipment adapted to admix hydroxide from the electrolysis chamber with the gas stream during use to create an admixture in which carbon, sulfur, and/or nitrogen compounds in the gas stream can react with the hydroxide;

a chamber operably connected to the anode side of the cell and adapted to separate the admixture into a separate gas phase and liquid phase; and

a chamber operably connected to the cathode side of the cell and adapted to separate the admixture into a separate gas phase and liquid phase.

11. An apparatus comprising:

a electrolysis chamber comprising at least one cathode and at least one anode, the electrolysis chamber adapted to produce hydroxide, while suppressing hydrogen, by consuming oxygen during use;

a first set of mixing equipment operably connected to the electrolysis chamber and to a conduit adapted to contain a gas stream during use, the mixing equipment adapted to admix hydroxide from the electrolysis chamber with the gas stream during use to create an admixture in which carbon, sulfur, and/or nitrogen compounds in the gas stream can react with the hydroxide;

a chamber operably connected to the anode side of the cell and adapted to separate the admixture into a separate gas phase and liquid phase; and

a chamber operably connected to the cathode side of the cell and adapted to separate the admixture into a separate gas phase and liquid phase.

12. A method of separating heavy metals from water in a flue-gas condensate from a process in which carbon dioxide is removed from a gas stream at a power plant, comprising:

obtaining a chloride salt;

admixing the salt with water, steam, or both to produce a solution;

electrolyzing the solution to produce a hydroxide and chlorine gas;

admixing a portion of the hydroxide with a flue-gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture;

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream;

adding a portion of the hydroxide to the flue-gas condensate to change its pH from acidic to basic, resulting in precipitation of the heavy metals; and

passing the condensate through a filtering medium.

13. The method of claim 12, wherein the filtering medium comprises activated charcoal.

14. The method of claim 12, wherein the condensate is gravity-fed through the filtering medium.

15. The method of claim 12, wherein the condensate is actively pumped through the filtering medium.

16. A method of recycling chlorine gas from a process in which carbon dioxide is removed from a gas stream at a power plant, comprising:

obtaining a chloride salt;

admixing the salt with water, steam, or both to produce a solution;

electrolyzing the solution to produce a hydroxide and chlorine gas;

admixing the hydroxide with a flue-gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture;

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream;

reacting the chlorine gas with water and light to produce muriatic acid and oxygen; and

returning the oxygen to the air-inlet of the power plant.

17. The method of claim 16, wherein the muriatic acid is neutralized by reacting it with Group-I bicarbonate products separated from the admixture to produce a Group-I-chloride salt, water, and carbon dioxide gas.

18. The method of claim 16, wherein the muriatic acid is neutralized by reacting it with Group-II-carbonate products separated from the admixture to produce a Group-II-chloride salt and carbon dioxide gas.

19. The method of claim 16, wherein the muriatic acid is neutralized by reacting it with Group-I-carbonate products separated from the admixture to produce a Group-I-chloride salt and a Group-I-bicarbonate.

20. The method of claim 16, wherein the reaction is accomplished by simple mixing.

21. The method of claim 16, wherein the reaction is accomplished across a membrane, and DC-power from the acid-base battery so formed is extracted.

22. A method of removing carbon dioxide from a gas stream at a power plant, comprising:

obtaining a chloride salt;

admixing the salt with water, steam, or both to produce a solution;

electrolyzing the solution to produce a hydroxide and chlorine gas;

admixing the hydroxide with a flue-gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture; and

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream;

wherein the admixing occurs in a pair of bubble-columns that comprise a carbonator column, in which carbonate is formed from the hydroxide and the carbon dioxide, and a bicarbonator column, in which bicarbonate is formed from the carbonate.

23. The method of claim 22, wherein the bicarbonator column is wetted and packed, but contains essentially zero-liquid-level, and is paired with a liquid carbonator column.

24. The method of claim 22, wherein the bicarbonator and carbonator columns are both wetted and packed, but contain essentially zero-liquid-level.

25. A method of removing carbon dioxide from a gas stream at a power plant, comprising:

obtaining a chloride salt;

admixing the salt with water, steam, or both to produce a solution;

electrolyzing the solution to produce a hydroxide and chlorine gas;

admixing the hydroxide with a flue-gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture; and

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream;

wherein the admixing occurs in a single bubble-column in which the hydroxide is converted to carbonate in the upper section of the column, which is then converted to bicarbonate in the lower section of the column.

26. A method of removing carbon dioxide from a gas stream at a power plant, comprising:

obtaining a chloride salt;

admixing the salt with water, steam, or both to produce a solution;

electrolyzing the solution to produce a hydroxide and hydrogen gas;

admixing the hydroxide with a flue-gas stream to produce carbonate products, bicarbonate products, or a mixture of carbonate and bicarbonate products in an admixture; and

separating said carbonate and/or bicarbonate products from the admixture, thereby removing carbon dioxide from the gas stream;

wherein waste-heat from the power plant is used to elevate the temperature at which the electrolysis occurs to a temperature at which the energy required for the electrolysis is equal to the theoretical maximum energy returnable from the hydrogen gas produced by the electrolysis.