Metal organic framework absorbent platforms for removal of CO2 and H2S from natural gas
Provided herein are metal organic frameworks comprising metal nodes and N-donor organic ligands which have high selectivity and stability in the present of gases and vapors including H 2 S, H 2 O, and CO 2 . Methods include capturing one or more of H 2 S, H 2 O, and CO 2 from fluid compositions, such as natural gas.
1. A method of capturing chemical species from a fluid composition, the method comprising
contacting a first metal organic framework characterized by the formula [M a M b F 6-n (O/H 2 O) w (Ligand) x (solvent) y ] z with a fluid composition including at least carbon dioxide and hydrogen sulfide, where M a is Ni 2+ ; M b is Al 3+ , Fe 3+ , V 3+ or Nb 5+ ; Ligand is pyrazine; n is 1; w is 1; x is 2; v is 0 to 4; solvent is a guest molecule; and z is at least equal to 1; and
capturing carbon dioxide and hydrogen sulfide from the fluid composition.
2. The method of claim 1 , wherein the fluid composition further comprises water.
3. The method of claim 1 , further comprising desorbing carbon dioxide and hydrogen sulfide.
4. The method of claim 1 , further comprising desorbing one or more of carbon dioxide and hydrogen sulfide.
5. The method of claim 4 , wherein one or more of capturing and desorbing is effected by multicolumn pressure-temperature swing adsorption.
6. The method of claim 1 , wherein carbon dioxide and hydrogen sulfide are captured from the fluid composition simultaneously.
7. The method of claim 1 , wherein the metal-organic framework has open metal sites.
8. The method of claim 1 , wherein the metal organic framework adsorbent is in the form of a fixed bed, a packed column, or combinations thereof.
9. The method of claim 1 , wherein the fluid composition further comprises methane.
10. The method of claim 1 , further comprising changing the pressure of the capture environment to alter the affinity of one or more of carbon dioxide and hydrogen sulfide for the metal organic framework adsorbent.
11. The method of claim 1 , further comprising changing the temperature of the capture environment to alter the affinity of one or more of carbon dioxide and hydrogen sulfide for the metal organic framework adsorbent.
12. The method of claim 1 , further comprising changing the pressure and temperature of the capture environment to alter the affinity of one or more of carbon dioxide and hydrogen sulfide for the metal organic framework adsorbent.
13. The method of claim 1 , wherein capturing comprises physical adsorption of the one or more captured chemical species by the metal organic framework.
14. The method of claim 1 , wherein capturing comprises chemisorption of the one or more captured chemical species by the metal organic framework.
15. The method of claim 14 , wherein chemisorption occurs by one or more captured chemical species chemically interacting with one or more open metal sites of the metal organic framework.
16. The method of claim 1 , simultaneously or separately contacting the fluid composition with a second metal organic framework, characterized by the formula [M c M d F 6-n (O/H 2 O) w (Ligand) x (solvent) y ] z , wherein n is 1; w is 1; x is 2; y is 0 to 4; and solvent is a guest molecule; wherein M c comprises Ni +2 and M d comprises Al +3 , Fe +2 , or Fe +3 , wherein the second metal organic framework is different from the first metal organic framework.
17. The method of claim 16 , wherein the first metal organic framework is characterized by the formula [NiNbF 6-n (O/H 2 O) w (Ligand) x (solvent) y ] z ; wherein n is 1; w is 1; x is 2; y is 0 to 4; and solvent is a guest molecule.