Alkylamine functionalized metal-organic frameworks for composite gas separations

• US 10,137,430 B2
• Filed: 11/21/2017
• Issued: 11/27/2018
• Est. Priority Date: 10/18/2011
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Long, Jeffrey R., McDonald, Thomas M., D'Alessandro, Deanna M.
• Primary Examiner(s): Berns, Daniel
• Application Number:
  US15/820,350
• Publication Number:
  US 20180169613A1
• Time in Patent Office: 371 Days
• Field of Search: None
• CPC Class Codes: B01D 2253/204 Metal organic frameworks (MOF's)
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01J 20/226 Coordination polymers, e.g. metal-organic frameworks [MOF], zeolitic imidazolate frameworks [ZIF] preparation of metal complexes containing carboxylic acid moieties C07C51/418; MOF's per se C07F
• CPC Class Codes: B01J 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/3425 of sorbents or filter aids comprising organic materials
• CPC Class Codes: B01J 20/3483 by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
• CPC Class Codes: C07F 1/08 Copper compounds
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02C 20/40 of CO2

Abstract

Functionalized metal-organic framework adsorbents with ligands containing basic nitrogen groups such as alkylamines and alkyldiamines appended to the metal centers and method of isolating carbon dioxide from a stream of combined gases and carbon dioxide partial pressures below approximately 1 and 1000 mbar. The adsorption material has an isosteric heat of carbon dioxide adsorption of greater than −60 kJ/mol at zero coverage using a dual-site Langmuir model.

Claims

1. A method of composite gas separations, the method comprising:

(a) providing a mixture of gases for separation;

(b) adsorbing acid gases from the mixture of gases on a porous metal-organic framework (MOF) adsorbent, the framework comprising;

(i) a framework of M₂(dobpdc) where M is selected from the group of metals consisting of Mg, Ca, Mn, Cr, Fe, Co, Ni, Cu and Zn, the framework having coordinatively unsaturated metal centers; and

(ii) a plurality of ligands disposed within pores of the metal-organic framework to produce a functionalized framework, said ligands having a ligand bridge with at least one first functional group capable of adsorbing a gas and at least one second functional group coupled to at least one metal center of said metal-organic framework;

(iii) wherein contact of the functionalized framework with a volume of gases produces a stepped adsorption isotherm; and

(iv) wherein gas adsorption properties before and after each step cannot be modeled as a continuous Langmuir function;

(c) separating residual gases with reduced acid gas concentrations; and

(d) releasing the adsorbed acid gases from the framework.

2. The method of claim 1, further comprising:

controlling metal-organic framework and gas mixture temperatures during adsorption; and

controlling pressure of the gas mixture during adsorption.

3. The method of claim 1, further comprising:

controlling metal-organic framework temperature during release of adsorbed acid gases from the metal-organic framework; and

controlling pressure of the metal-organic framework during the release of acid gases from the metal-organic framework.

4. The method of claim 1, further comprising:

purging the released acid gases from the metal-organic framework with a purge gas.

5. The method of claim 1, wherein said bridge of said ligand of said metal-organic framework comprises a molecule selected from the group of a linear alkane, a branched alkane, a linear alkene and a branched alkene.

6. The method of claim 1:

wherein said first functional group of said ligand of said metal-organic framework has a reactive atom that contains at least one lone pair of electrons selected from the group consisting of nitrogen, sulfur, and phosphorous; and

wherein said ligand is reversibly bonded through a nitrogen, sulfur, or phosphorous atom to open metal sites of the framework.

7. The method of claim 1, wherein said first functional group of said ligand of said metal-organic framework comprises:

an oxygen containing group selected from the group consisting of alcohols, ethers and alkoxides;

wherein the ligand is reversibly bonded through an oxygen atom to open metal sites of the framework.

8. The method of claim 1, wherein said first functional group of said ligand of said metal-organic framework is selected from the group of carbenes, alkenes, and alkynes.

9. The method of claim 1, wherein said second functional group of said ligand of said metal-organic framework is selected from the group consisting of a primary alkylamine, a secondary alkylamine, and a tertiary alkylamine.

10. The method of claim 1, wherein said second functional group of said ligand of said metal-organic framework is selected from the group consisting of a primary imine and a secondary imine.

11. The method of claim 1, wherein said ligand of said metal-organic framework is selected from the group consisting of a Tetraethylenepentamine and a Diethylenetriamine.

12. The method of claim 1, wherein said ligand of said metal-organic framework is selected from the group consisting of Tris(2-aminoethyl)amine and Tris[2(methylamino)ethyl]amine.

13. The method of claim 1, wherein said ligand of said metal-organic framework comprises N,N′

-dimethylethylenediamine (mmen).

14. The method of claim 1, wherein the metal-organic framework comprises both open metal sites and ligand occupied metal sites.

15. A method of composite gas separations, the method comprising:

(a) providing a mixture of gases for separation;

(b) adsorbing acid gases from the mixture of gases on a porous metal-organic framework (MOF) adsorbent, the framework comprising;

(i) a framework of M₂(dobpdc) where M is selected from the group of metals consisting of Mg, Ca, Mn, Cr, Fe, Co, Ni, Cu and Zn, the framework having coordinatively unsaturated metal centers; and

(ii) a plurality of ligands disposed within pores of the framework, coupled to at least one metal center of said framework, to produce a functionalized framework, said ligands comprising at least two functional groups separated by a ligand bridge, each functional group having at least one reactive atom of nitrogen that contains one or more lone pairs of electrons;

(iii) wherein contact of the functionalized framework with a volume of gases produces a stepped adsorption isotherm; and

(iv) wherein gas adsorption properties before and after each step cannot be modeled as a continuous Langmuir function;

(c) separating residual gases with reduced acid gas concentrations; and

(d) releasing the adsorbed acid gases from the framework.

16. The method of claim 15, wherein said functional group of said ligand of said metal-organic framework is selected from the group consisting of a primary alkylamine, a secondary alkylamine, and a tertiary alkylamine.

17. The method of claim 15, wherein said functional group of said ligand of said metal-organic framework is selected from the group consisting of a primary imine and a secondary imine.

18. The method of claim 15, wherein said ligand of said metal-organic framework is selected from the group consisting of a Tetraethylenepentamine and a Diethylenetriamine.

19. The method of claim 15, wherein said ligand of said metal-organic framework is selected from the group consisting of Tris(2-aminoethyl)amine and Tris[2(methylamino)ethyl]amine.

20. The method of claim 15, wherein said ligand of said metal-organic framework comprises N,N′

-dimethylethylenediamine (mmen).

21. The method of claim 15, wherein the metal-organic framework comprises open metal sites and ligand occupied metal sites.