System and method of carbon capture and sequestration

Abstract

Systems and methods of capturing and sequestering carbon dioxide, comprising mixing a substantially non-aqueous solvent and an alkali such that the solvent and alkali form a solvent suspension, mixing water and a flue gas containing carbon dioxide with the solvent suspension such that a reaction occurs, the reaction resulting in the formation of a carbonate, water and heat.

What is claimed is: 
     
       1. A method of capturing and sequestering carbon dioxide, comprising:
 mixing a substantially non-aqueous solvent and an alkali such that the solvent and alkali form a solvent suspension; 
 mixing water and a flue gas containing carbon dioxide with the solvent suspension in a reaction vessel such that a reaction occurs, the reaction resulting in the rapid formation of a solid dry carbonate, water and heat, the resulting water forming a solution with the solvent, the resulting carbonate being essentially free of organo-metallic products and substantially non-aqueous a metallic salt and being one or more of the carbonates of the group consisting of: ammonium carbonate, lithium carbonate, magnesium carbonate, potassium carbonate, sodium carbonate, or calcium carbonate; 
 the resulting carbonate precipitating out of solution, requiring no further chemical processing steps without carrying water, falling toward the bottom of the reaction vessel, and accumulating at the bottom of the reaction vessel together with some substantially non-aqueous solvent; 
 removing the resulting carbonate from the reaction vessel without any water leaving the reaction vessel at the same location; and 
 evaporating with low-grade heat any remaining non-aqueous solvent. 
 
     
     
       2. The method of  claim 1  further comprising the steps of:
 continuously removing a portion of the solution of water and solvent from the reaction vessel; 
 separating the water from the solvent; 
 introducing additional alkali to the separated solvent; 
 re-mixing the separated solvent with the additional alkali such that the solvent and additional alkali form a solvent suspension; 
 providing additional flue gas containing carbon dioxide; and 
 returning a portion of the separated water to the solvent suspension to continue the reaction. 
 
     
     
       3. The method of  claim 2  wherein the precipitated carbonate is mechanically removed from the reaction vessel. 
     
     
       4. The method of  claim 1  wherein the solvent is an alcohol. 
     
     
       5. The method of  claim 4  wherein the alcohol is methanol. 
     
     
       6. The method of  claim 5  wherein the alkali reacts with the methanol to form methoxide. 
     
     
       7. The method of  claim 6  further comprising introducing ash into the solvent, wherein one or more constituents of the ash are alkalis and the ash contains one or more metal oxides including iron oxide. 
     
     
       8. The method of  claim 2  wherein separating the water from the solvent includes chilling the solution of water and solvent in a cryogenic drying vessel such that the water falls substantially to the bottom of the cryogenic drying vessel and the solvent rises substantially to the top of the cryogenic drying vessel. 
     
     
       9. The method of  claim 2  wherein separating the water from the solvent includes the steps of: applying heat to the solution of water and solvent, using a partial vacuum to draw off vaporous solvent from a hot distillation vessel, and condensing the vaporous solvent. 
     
     
       10. The method of  claim 2  wherein carbon dioxide and water react to form carbonic acid. 
     
     
       11. The method of  claim 10  further comprising introducing ash into the solvent, one or more constituents of the ash being alkalis and the ash containing one or more metal oxides including iron oxide, wherein the carbonic acid reacts with the alkalis to substantially neutralize the alkalis. 
     
     
       12. The method of  claim 11  wherein the reaction of carbonic acid and the alkalis results in a non-alkaline stream comprising one or more carbonates, sand and iron oxide. 
     
     
       13. The method of  claim 2  wherein the reaction temperature is less than about 150 degrees Fahrenheit. 
     
     
       14. A method of separating chemical constituents of flue gas, comprising:
 mixing a substantially non-aqueous solvent and an alkali such that the solvent and alkali form a solvent suspension;   introducing water and a flue gas containing carbon dioxide and nitrogen to the solvent suspension;   contacting the alkali in the solvent suspension with the water and the carbon dioxide in the flue gas in a reaction vessel such that a reaction occurs, the reaction resulting in the rapid formation of a substantially non-aqueous carbonate, water and heat, the carbonate being essentially free of organo-metallic products, and the resulting water forming a solution with the solvent;   removing the solution of water and solvent from the reaction vessel such that the resulting carbonate is substantially non-aqueous; and   substantially liquefying a portion of the nitrogen by compressing and chilling the nitrogen.   
     
     
       15. A method of capturing or sequestering carbon dioxide, comprising:
 mixing methanol and an alkali such that the methanol and alkali form a solvent suspension; 
 mixing water and a flue gas containing carbon dioxide with the solvent suspension such that a reaction occurs, the reaction resulting in the rapid formation of a substantially non-aqueous solid, dry carbonate, water and heat, the carbonate being essentially free of organo-metallic products a metallic salt and being one or more of the carbonates of the group consisting of: ammonium carbonate, lithium carbonate, magnesium carbonate, potassium carbonate, sodium carbonate, or calcium carbonate, the resulting carbonate precipitating out of solution without carrying water; and 
 mechanically removing the resulting carbonate from the reaction vessel without any water leaving the reaction vessel at the same location. 
 
     
     
       16. The method of  claim 15  wherein the alkali reacts with the methanol to form methoxide. 
     
     
       17. The method of  claim 16  further comprising introducing ash into the solvent, wherein one or more constituents of the ash are alkalis and the ash contains one or more metal oxides including iron oxide. 
     
     
       18. The method of  claim 15  wherein the resulting water forms a solution with the methanol and the resulting carbonate precipitates out of solution, requiring no further chemical processing steps, falls toward the bottom of the reaction vessel, and accumulates at the bottom of the reaction vessel together with some methanol. 
     
     
       19. The method of  claim 18  further comprising the steps of:
 continuously removing a portion of the solution of water and methanol from the reaction vessel such that the resulting carbonate is substantially non-aqueous; 
 separating the water from the solvent; 
 introducing additional alkali to the separated solvent; 
 re-mixing the separated solvent with the additional alkali such that the methanol and additional alkali form a solvent suspension; 
 providing additional flue gas containing carbon dioxide; and 
 returning a portion of the separated water to the solvent suspension to continue the reaction. 
 
     
     
       20. The method of  claim 16  wherein the water content of the methanol does not exceed about 10% by volume. 
     
     
       21. A method of capturing and sequestering carbon dioxide, comprising:
 mixing a non-aqueous solvent and an alkali such that the solvent and alkali form a solvent suspension;   mixing water and a gas containing carbon dioxide with the solvent suspension in a reaction vessel such that a reaction occurs, the reaction resulting in the formation of a solid, dry carbonate, water and heat, the resulting water forming a solution with the solvent, the resulting carbonate being a metallic salt;   the resulting carbonate precipitating out of solution without carrying water, falling toward the bottom of the reaction vessel, accumulating at the bottom of the reaction vessel together with some solvent; and   mechanically removing the resulting carbonate from the reaction vessel without any water leaving the reaction vessel at the same location.