Functionalized adsorbent for removal of acid gases and use thereof

• US 7,767,004 B2
• Filed: 03/13/2006
• Issued: 08/03/2010
• Est. Priority Date: 03/11/2005
• Status: Active Grant

• Current Assignee: University of Ottawa
• Original Assignee: University of Ottawa
• Inventors: Harlick, Peter J. E., Sayari, Abdelhamid
• Primary Examiner(s): Hill, Jr.; Robert J
• Assistant Examiner(s): Jones; Christopher P
• Application Number:
  US11/908,248
• Publication Number:
  US 20080276804A1
• Time in Patent Office: 1,604 Days
• Field of Search: 961/08, 951/36, 952/85, 555/24, 264/48, 428/305.5, 428/310.5
• US Class Current: 95/285
• CPC Class Codes: B01D 2253/306 Surface area, e.g. BET-specific surface
• CPC Class Codes: B01D 2253/308 Pore size
• CPC Class Codes: B01D 2253/311 Porosity, e.g. pore volume
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/40 Nitrogen compounds
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/05 Biogas
• CPC Class Codes: B01D 2258/06 Polluted air
• CPC Class Codes: B01D 2259/4009 using hot gas
• 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 20/28057 Surface area, e.g. B.E.T specific surface area
• CPC Class Codes: B01J 20/28069 Pore volume, e.g. total pore volume, mesopore volume, micropore volume
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/28097 being coated, filled or plugged with specific compounds
• CPC Class Codes: B01J 20/3204 Inorganic carriers, supports or substrates
• CPC Class Codes: B01J 20/3246 having a well defined chemical structure
• CPC Class Codes: B01J 20/3257 the functional group or the linking, spacer or anchoring group as a whole comprising at least one of the heteroatoms nitrogen, oxygen or sulfur together with at least one silicon atom, these atoms not being part of the carrier as such
• 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: B01J 2229/32 : Reaction with silicon compounds, e.g. TEOS, siliconfluoride
• CPC Class Codes: B01J 29/0308 : Mesoporous materials not having base exchange properties, e.g. Si-MCM-41
• CPC Class Codes: B01J 31/0254 : on mineral substrates
• CPC Class Codes: B01J 31/0274 : containing silicon ligands in coordination complexes B01J31/1608
• CPC Class Codes: Y02C 20/20 : of methane
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y10T 428/249954 : With chemically effective material or specified gas other than air, N, or carbon dioxide in void-containing component
• CPC Class Codes: Y10T 428/249961 : With gradual property change within a component

Abstract

The present invention provides a functionalized adsorbent for removal of acid gases, which comprises a pore-expanded mesoporous support having a pore volume of between 0.7 and 3.6 cc/g, a median pore diameter of between 1 and 25 nm, and a BET surface area of between 500 and 1600 m²/g. The support is functionalized by addition of acid-gas reactive functional groups within the pores and external surface of said support material. Also provided are methods of manufacturing the adsorbent and methods of use.

Claims

1. A mesoporous support having a pore volume of between 0.7 and 3.6 cc/g, a median pore diameter of between 1 and 25 nm, and a BET surface area of between 500 and 1600 m²/g, wherein said support is a pore-expanded mesoporous silica or organosilica, which is functionalized by covalent attachment of compounds containing acid-gas reactive functional groups within the pores of said support.

2. A regenerable acid-gas adsorbent comprising the mesoporous support of claim 1.

3. The acid-gas adsorbent of claim 2, wherein said acid-gas reactive functional groups are amino groups.

4. The acid-gas adsorbent of claim 3, wherein said functional groups are added by grafting of silane compounds containing said functional groups to said mesoporous support.

5. The acid-gas adsorbent of claim 4, wherein said silane compounds are alkoxy-silane compounds, chloro-silane compounds, silanol compounds, or any combination thereof.

6. The acid-gas adsorbent of claim 5, wherein said alkoxy-silane compounds are selected from the group consisting of aminopropyl-methyl-dimethoxysilane, amino-propyl-trimethoxysilane, aminoethylaminopropyl-methyl-dimethoxysilane, aminoethylaminopropyl-trimethoxysilane, aminoethylaminoethylaminopropyl-methyl-dimethoxysilane, aminoethylaminoethylaminopropyl-trimethoxysilane and combinations thereof.

7. The acid-gas adsorbent of claim 4, wherein said grafting is performed in the presence of water.

8. The acid-gas adsorbent of claim 3, wherein said functional groups are added by grafting of 3-[2-(2-aminoethylamino)ethylamino]propyl-trimethoxysilane.

9. The acid-gas adsorbent of claim 3, wherein said functional groups are added by grafting of [3-(2-aminoethylamino)propyl]trimethoxysilane.

10. The acid-gas adsorbent of claim 3, wherein said functional groups are added by grafting of 3-(aminopropyl)trimethoxysilane.

11. The acid-gas adsorbent of claim 3, wherein said adsorbent has a CO₂ equilibrium adsorption capacity of at least 1.4 mmol/g under dry conditions.

12. A method for removing or recovering acid gas from an gaseous stream or atmosphere containing said acid gas, comprising the step of contacting the gaseous stream or atmosphere with an adsorbent according to claim 2.

13. The method according to claim 12, for use in a confined space closed loop system, a fossil fuel combustion process, a biogas combustion process, a biogas derived process, a natural gas treatment process, an industrial process or a chemical production process.

14. A process for manufacturing an adsorbent according to claim 2, comprising:

(a) providing the mesoporous support material; and

(b) grafting a functionalization compound, which contains one or more acid-gas reactive groups, to the surface of the pores of said support material;

or

(c) directly loading a functionalization compound, which contains one or more acid-gas reactive groups, into the pores of said support material.

15. The process according to claim 14, wherein the grafting step (b) comprises:

(i) suspending said support material in a solvent;

(ii) adding an amount of said functionalization compound to the suspension formed in step (i); and

(iii) maintaining the mixture formed in step (ii) at a functionalization temperature for a set time period to produce said adsorbent.

16. The process according to claim 15, wherein said functionalization compound is an alkoxy-silane compound, a chloro-silane compound, a silanol compound, or any combination thereof.

17. The process according to claim 16, wherein said alkoxy-silane compound is selected from the group consisting of aminopropyl-methyl-dimethoxysilane, aminopropyl-trimethoxysilane, aminoethylaminopropyl-methyl-dimethoxysilane, aminoethylaminopropyl-trimethoxysilane, aminoethylaminoethylaminopropyl-methyl-dimethoxysilane, aminoethylaminoethylaminopropyl-trimethoxysilane and combinations thereof.

18. The process according to claim 16, wherein the ratio of silane compound to said support material is in the range of 0.0001 to 10 (volume/weight).

19. The process according to claim 15, wherein a temperature ratio is in the range of 0.1 to 1.0, said temperature ratio being the ratio of the functionalization temperature to the boiling point of said solvent.

20. The process according to claim 19, wherein said solvent is toluene and said temperature ratio is in the range of 0.68 to 0.82.

21. The process according to claim 15, wherein water is added to the suspension formed in step (i) prior to the addition of said functionalization compound in step (ii).

22. The process according to claim 21, wherein said functionalization compound is an alkoxy-silane compound, said solvent is toluene and the ratio of the molar amount of water added to the molar amount of alkoxy groups present in said alkoxy-silane compound is in the range of 0.0 to 1.0.