Process for capturing CO;from a gas using carbonic anhydrase and potassium carbonate

• US 9,533,258 B2
• Filed: 04/28/2015
• Issued: 01/03/2017
• Est. Priority Date: 08/04/2009
• Status: Active Grant

• Current Assignee: Saipem SPA (Saipem)
• Original Assignee: C02 Solutions Inc.
• Inventors: Carley, Jonathan, Fradette, Sylvie, Gingras, Julie, Kelly, Glenn R., Ceperkovic, Olivera
• Primary Examiner(s): GITOMER, RALPH J
• Application Number:
  US14/698,159
• Publication Number:
  US 20150231562A1
• Time in Patent Office: 616 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B01D 2251/206 Ammonium compounds
• CPC Class Codes: B01D 2251/304 of sodium
• CPC Class Codes: B01D 2251/306 of potassium
• CPC Class Codes: B01D 2251/606 Carbonates
• CPC Class Codes: B01D 2252/20494 Amino acids, their salts or derivatives
• CPC Class Codes: B01D 2252/205 Other organic compounds not covered by B01D2252/00 - B01D2252/20494
• CPC Class Codes: B01D 2252/602 Activators, promoting agents, catalytic agents or enzymes
• CPC Class Codes: B01D 2255/804 Enzymatic
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/1425 Regeneration of liquid absorbents
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1493 Selection of liquid materials for use as absorbents
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/84 Biological processes
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: C12N 9/88 Lyases (4.)
• CPC Class Codes: C12Y 402/01001 Carbonate dehydratase (4.2.1.1), i.e. carbonic anhydrase
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/59 Biological synthesis; Biological purification

Abstract

A formulation and process for capturing CO₂ use an absorption mixture containing water, biocatalysts and a carbonate compound. The process includes contacting a CO₂-containing gas with the absorption mixture to enable dissolution and transformation of CO₂ into bicarbonate and hydrogen ions, thereby producing a CO₂-depleted gas and an ion-rich solution, followed by subjecting the ion-rich solution to desorption. The biocatalyst improves absorption of the mixture comprising carbonate compounds and the carbonate compound promotes release of the bicarbonate ions from the ion-rich solution during desorption, producing a CO₂ gas stream and an ion-depleted solution.

Claims

1. A process for capturing CO₂ from a CO₂-containing gas comprising:

contacting the CO₂-containing gas with an absorption mixture comprising water, biocatalyst and a carbonate compound to enable dissolution and transformation of CO₂ into bicarbonate and hydrogen ions, thereby producing a CO₂-depleted gas and an ion-rich solution comprising water, the biocatalyst, carbonate compound and absorbed CO₂; and

subjecting the ion-rich solution to desorption wherein the carbonate compound promotes release of the bicarbonate ions from the ion-rich solution and the biocatalyst catalyses dehydration of the bicarbonate ions, thereby producing a CO₂ gas stream and an ion-depleted solution comprising the biocatalyst;

wherein the carbonate compound comprises potassium carbonate;

wherein the biocatalyst is carbonic anhydrase;

wherein the biocatalyst is provided free in the water, dissolved in the water, immobilized on the surface of supports that are mixed in the water and are flowable therewith, entrapped or immobilized by or in porous supports that are mixed in the water and are flowable therewith, as cross-linked aggregates or crystals, or a combination thereof; and

wherein the biocatalyst is present in the absorption mixture in a biocatalyst concentration of at most 1 g/L.

2. The process of claim 1, comprising removing the biocatalyst from the ion-rich solution after subjecting the ion-rich solution to the desorption.

3. The process of claim 1, comprising recycling the ion-depleted solution to form at least a part of the absorption mixture for re-contacting the CO₂-containing gas.

4. The process of claim 1, comprising adding an amount of biocatalyst into the ion-depleted solution to convert the ion-depleted solution into at least part of the absorption mixture for recycling to contact the CO₂-containing gas.

5. The process of claim 1, wherein the absorption mixture comprises an additional absorption compound comprising piperidine, piperazine and derivatives thereof which are substituted by at least one alkanol group, alkanolamines, monoethanolamine (MEA), 2-amino-2-methyl-1-propanol (AMP), 2-(2-aminoethylamino)ethanol (AEE), 2-amino-2-hydroxymethyl-1,3-propanediol (Tris), amino acids, potassium or sodium salts of amino acids, glycine, proline, arginine, histidine, lysine, aspartic acid, glutamic acid, methionine, serine, threonine, glutamine, cysteine, asparagine, leucine, isoleucine, alanine, valine, tyrosine, tryptophan, phenylalanine, and derivatives such as taurine, N,cyclohexyl 1,3-propanediamine, N-secondary butyl glycine, N-methyl N-secondary butyl glycine, diethylglycine, dimethylglycine, sarcosine, methyl taurine, methyl-α

-aminopropionic acid, N-(β

-ethoxy)taurine, N-(β

-aminoethyl)taurine, N-methyl alanine, 6-aminohexanoic acid, sodium carbonate, ammonium carbonate or a combination thereof.

6. The process of claim 1, wherein contacting the absorption mixture with the CO₂-containing gas is performed in an absorption stage comprising at least one reactor selected from a packed tower, a vertical or horizontal spray scrubber, a fluidized bed reactor or a series of reactors comprising the same.

7. The process of claim 1, wherein the carbonate compound and biocatalyst is provided in concentrations to achieve more than a five-fold increase in CO₂ transfer rate, with respect to a CO2 transfer rate without biocatalyst.

8. The process of claims 1, wherein the carbonate compound is provided in the absorption mixture in a concentration at or below saturation thereof.

9. The process of claim 1, the carbonate compound comprises potassium carbonate and is provided in the absorption mixture in a concentration up to the solubility limit at a temperature range between about 40°

C. and about 70°

C.

10. The process of claim 1, wherein the carbonate compound comprises ammonium carbonate and is provided in the absorption mixture in a concentration up to the solubility limit at a temperature range between about 10°

C. and about 70°

C.

11. The process of claim 1, the carbonate compound comprises sodium carbonate and is provided in the absorption mixture in a concentration up to the solubility limit at a temperature range between about 40°

C. and about 70°

C.

12. The process of claim 1, wherein the biocatalyst is supported by micro-particles that are carried with the water.

13. The process of claim 1, wherein the carbonate compound is provided in the absorption mixture in a concentration below saturation thereof.

14. The process of claim 13, wherein the carbonate compound is potassium carbonate and is provided in the absorption mixture in a carbonate concentration of 0.1 M to 1.45 M.

15. The process of claim 1, wherein the desorption of the ion-rich solution is performed in a desorption unit that comprises a reboiler that receives part of the ion-depleted solution for heating the same.

16. The process of claim 15, wherein the desorption unit comprises a filter mounted in relation to the reboiler to prevent flow of the biocatalyst through the reboiler.

17. The process of claim 1, wherein the desorption of the ion-rich solution is performed in a desorption unit that comprises:

a heater that receives part of the ion-depleted solution for heating the same; and

a mechanism provided in relation to the heater to prevent flow of biocatalyst into the heater.

18. The process of claim 1, wherein the absorption mixture further comprises dimethylglycine.

19. The process of claim 18, wherein the dimethylglycine comprises potassium or sodium salts of dimethylglycine.

20. The process of claim 1, wherein the ion-rich solution containing the biocatalyst, water, carbonate compound and absorbed CO₂ is heated prior to the desorption.