Simultaneous CO2 Capture, Mineralization, and Lithium and Other Metal Extraction from Brine

Patent metadata

Field	Value
Publication number	US-2023382754-A1
Application number	US-202318199993-A
Country	US
Kind code	A1
Filing date	May 22, 2023
Priority date	May 26, 2022
Publication date	Nov 30, 2023
Grant date	—

Abstract

A method including capturing carbon dioxide (CO 2 ) from air (e.g., atmosphere) in an absorber in which the air contacts a base (e.g., a hydroxide, such as potassium hydroxide KOH and/or sodium hydroxide (NaOH)) to produce a carbonate (e.g., potassium carbonate (K 2 CO 3 ) and/or sodium carbonate (Na 2 CO 3 )); precipitating one or more (e.g., carbonate) salt from an aqueous solution comprising salt (a brine) to provide an aqueous solution comprising a chloride (e.g., potassium chloride (KCl) and/or sodium chloride (NaCl)); using electrochemical regeneration to convert the chloride to electrochemically regenerated product comprising the base (e.g., KOH and/or NaOH); and recycling at least a portion of the electrochemically regenerated product comprising the base to the capturing of the CO 2 from the air. A system for carrying out the method is also provided.

First claim

What is claimed is:

1 . A method comprising:
capturing carbon dioxide (CO 2 ) from air and/or another CO 2 -containing gas in an absorber in which the air and/or the another CO 2 -containing gas contacts a base to produce a carbonate; precipitating one or more salts from a brine to provide an aqueous solution comprising a chloride; using electrochemical regeneration to convert the chloride to electrochemically regenerated product comprising the base; and recycling at least a portion of the electrochemically regenerated product comprising base to the capturing of the CO 2 from the air and/or the another CO 2 -containing gas.

2 . The method of claim 1 , wherein the one or more salts comprise lithium carbonate (Li 2 CO 3 ).

3 . The method of claim 1 , wherein using electrochemical regeneration produces chlorine (Cl 2 ), hydrogen (H 2 ), or both, along with the electrochemically regenerated product comprising the base.

4 . The method of claim 2 , wherein the CO 2 is removed from the air and/or the another CO 2 -containing gas simultaneously with extraction of lithium from the brine via precipitating of lithium carbonate (Li 2 CO 3 ).

5 . The method of claim 1 , wherein a source of energy for the capturing, the using of the electrochemical regeneration, or both comprises renewable energy.

6 . The method of claim 1 , wherein the base contacted with the air and/or the another CO 2 -containing gas in the absorber flows down an absorber column of the absorber, while the air and/or the another CO 2 -containing gas flows in from a bottom of the absorber column, whereby CO 2 in the air and/or the another CO 2 -containing gas reacts with the base to form the carbonate via the equation: 2XOH+CO 2 →X 2 CO 3 +H 2 O, wherein X is sodium (Na) and/or potassium (K).

7 . The method of claim 6 , wherein precipitating comprises mixing the brine with the carbonate, such that carbonate ions (CO 3 2− ) react with cation(s) in the brine to precipitate the one or more salts.

8 . The method of claim 7 , wherein the precipitating comprises:
K 2 CO 3 +2LiCl→Li 2 CO 3 ( s )+2KCl; and/or
K 2 CO 3 +CaCl 2 →CaCO 3 ( s )+2KCl; and/or
K 2 CO 3 +BaCl 2 →BaCO 3 ( s )+2KCl; and/or
K 2 CO 3 +MgCl 2 →MgCO 3 ( s )+2KCl; and/or
Na 2 CO 3 +2LiCl→Li 2 CO 3 ( s )+2NaCl; and/or
Na 2 CO 3 +CaCl 2 →CaCO 3 ( s )+2NaCl; and/or
Na 2 CO 3 +BaCl 2 →BaCO 3 ( s )+2NaCl; and/or
Na 2 CO 3 +MgCl 2 →MgCO 3 ( s )+2NaCl.

9 . The method of claim 1 , wherein the electrochemical regeneration comprises:
2Cl − →Cl 2 +2 e − ;
2H 2 O+2 e − →H 2 +2OH − ; and
2K + +2OH − →2KOH and/or 2Na + +2OH − →2NaOH.

10 . A system comprising:
an absorber for capture of carbon dioxide (CO 2 ) from air or another CO 2 -containing gas via contact of base with the air and/or the another CO 2 -containing gas to produce a carbonate; one or more precipitation vessels configured to precipitate one or more salts from a brine via contact of the brine with the carbonate; and an electrochemical regenerator configured to produce an electrochemical regeneration product comprising base from a chloride solution remaining after precipitating of the one or more salts from the brine.

11 . The system of claim 10 further comprising a recycle line for recycling at least a portion of the electrochemical regeneration product comprising base to the absorber.

12 . The system of claim 10 , wherein the one or more salts comprise lithium carbonate (LiCO 3 ).

13 . The system of claim 10 , wherein the electrochemical regenerator produces chlorine (Cl 2 ), hydrogen (H 2 ), or both, along with the electrochemically regenerated product comprising base.

14 . The system of claim 10 , wherein the one or more precipitation vessels are configured for mixing the brine with the carbonate, such that carbonate ions (CO 3 2− ) react with cation(s) in the brine to precipitate the one or more salts.

15 . The system of claim 10 , wherein the electrochemical regenerator comprises an anode chamber, into which the chloride solution flows, whereby chloride oxidation evolution reaction occurs to generate Cl 2 .

16 . The system of claim 15 further comprising a separator that separates the anode chamber from a cathode chamber.

17 . The system of claim 16 , wherein the cathode chamber is configured for reduction of water in the chloride solution, to generate hydrogen (H 2 ) and hydroxide ions (OH − ), whereby the OH − ions react with alkali ions to form the base of the electrochemically regenerated product that can be recycled to the absorber to form a closed loop.

18 . The system of claim 17 , wherein the electrochemical regenerator is configured for:
2Cl—→Cl 2 +2 e − ;
2H 2 O+2 e − →H 2 +2OH − ; and
2K + +2OH − →2KOH and/or 2Na + +2OH − →2NaOH.

19 . A system for capturing carbon dioxide (CO 2 ) from air and/or another CO 2 -containing gas and extracting lithium and/or other metal(s) from a brine via: CO 2 capture via contact of the air with a first compound to provide a second compound, metal extraction/precipitation of one or more salts from the brine to provide a remaining brine solution comprising a third compound, and electrochemical regeneration of the third compound to regenerate/produce a solution of the first compound for recycle to the CO 2 capture.

20 . The system of claim 19 , wherein the first compound comprises KOH and/or NaOH, the second compound comprises K 2 CO 3 and/or Na 2 CO 3 , and the third compound comprises KCl and/or NaCl.

Assignees

• Univ Houston System

Inventors

• Rahimi Mohammad
• Shan Xiaonan

Classifications

• C01D15/08 Primary

  Carbonates; Bicarbonates · CPC title

• C25B1/26

  Chlorine; Compounds thereof (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34) · CPC title

• C25B1/04

  by electrolysis of water · CPC title

• C25B1/16

  Hydroxides (by simultaneous production of alkali metal hydroxides and chlorine, oxyacids or salts of chlorine C25B1/34) · CPC title

• C01D3/06

  Preparation by working up brines; seawater or spent lyes · CPC title