Aerogel sorbents

• US 9,302,247 B2
• Filed: 04/26/2013
• Issued: 04/05/2016
• Est. Priority Date: 04/28/2012
• Status: Active Grant

• Current Assignee: Aspen Aerogels, Incorporated
• Original Assignee: Aspen Aerogels, Incorporated
• Inventors: Begag, Redouane, Rhine, Wendell E, Dong, Wenting
• Primary Examiner(s): Dunn, Colleen
• Assistant Examiner(s): Soliman, Haytham
• Application Number:
  US13/871,763
• Publication Number:
  US 20130287661A1
• Time in Patent Office: 1,075 Days
• Field of Search: 423/228, 556/424, 556/413, 502/402
• US Class Current: 1/1
• CPC Class Codes: B01D 2253/20 Organic adsorbents
• CPC Class Codes: B01D 2253/25 Coated, impregnated or composite adsorbents
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• 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 20/103 comprising silica
• CPC Class Codes: B01J 20/22 comprising organic material
• CPC Class Codes: B01J 20/28011 Other properties, e.g. density, crush strength
• CPC Class Codes: B01J 20/28047 Gels
• CPC Class Codes: B01J 20/28059 being less than 100 m2/g
• CPC Class Codes: B01J 20/28061 being in the range 100-500 m2/g
• CPC Class Codes: B01J 20/28071 being less than 0.5 ml/g
• CPC Class Codes: B01J 20/28073 being in the range 0.5-1.0 ml/g
• CPC Class Codes: B01J 20/28076 being more than 1.0 ml/g
• CPC Class Codes: B01J 20/28083 being in the range 2-50 nm, i.e. mesopores
• CPC Class Codes: B01J 20/3085 Chemical treatments not covered by groups B01J20/3007 - B01J20/3078
• CPC Class Codes: B01J 20/3248 the functional group or the linking, spacer or anchoring group as a whole comprising at least one type of heteroatom selected from a nitrogen, oxygen or sulfur, these atoms not being part of the carrier as such
• CPC Class Codes: B01J 20/3272 Polymers obtained by reactions otherwise than involving only carbon to carbon unsaturated bonds
• 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

The current invention describes methods and compositions of various sorbents based on aerogels of various silanes and their use as sorbent for carbon dioxide. Methods further provide for optimizing the compositions to increase the stability of the sorbents for prolonged use as carbon dioxide capture matrices.

Claims

1. A process of preparing a carbon dioxide capture sorbent comprising the steps of hydrolyzing at least an alkylalkoxysilane, reacting the hydrolyzed alkylalkoxysilane with at least a hydrolyzed aminosilane to form a gel and drying the resulting gel to obtain an aerogel, wherein the aerogel comprises at least an open pore accessible to carbon dioxide.

2. The process of claim 1 wherein at least an amino group is accessible to carbon dioxide.

3. The process of claim 1 wherein the aerogel is hydrophobic.

4. The process of claim 1 further comprising the step of reacting a hydrolyzed tetra-alkoxysilane with at least one of the hydrolyzed silanes.

5. The process of claim 1 further comprising the step of reacting a dialkyldialkoxysilane with at least one of the hydrolysed silanes.

6. The process of claim 1 wherein the alkyl group contains between 1 and 6 carbon atoms.

7. The process of claim 1 wherein any of the silanes have additional functional groups.

8. The process of claim 1 wherein the alkylalkoxysilane contains a mono, di or tri alkyl groups and selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, triethylmethoxysilane, triethylethoxysilane, tripropylmethoxysilane, tripropylethoxysilane, (3,3,3-Trifluoropropyl)trimethoxysilane, (3,3,3-Trifluoropropyl)triethoxysilane and a combination thereof.

9. The process of claim 1 wherein the aminosilane comprises mono, di, tri or poly amine groups.

10. The process of claim 1 wherein the aminosilane is selected from the group consisting of 3-aminopropylmethyldiethoxysilane, 3-aminopropyl-triethoxysilane (APTES), 3-aminopropyl-trimethoxysilane (APTMS), N-(2-aminoethyl)-3-aminopropyltriethoxysilane (AE-APTES), N-(2-aminoethyl)-3-aminopropyl-trimethoxysilane (AE-APTMS), p-aminophenyltrimethoxysilane, N-3-([amino(poly-propyleneoxy])-amino-propyl-trimethoxy-silane (aminoether), (3-trimethoxylsilylpropyl)-diethylenetriamine (TMS-DETA), trimethoxy-silane modified polyethyleneimine and a combination thereof.

11. The process of claim 1 wherein at least an aminogroup is located on or adjacent to the pore surfaces.

12. The process of claim 1 further comprising the steps of contacting the sorbent with a gaseous stream comprising at least some carbon dioxide and capturing at least some of the carbon dioxide in the sorbent.

13. The process of claim 12 further comprising a step of regenerating the sorbent.

14. The process of any of claim 13 wherein the sorbent is stable for at least 250 or at least 500 or at least 1000 or at least 2000 capture-regeneration cycles.

15. The process of claim 1 wherein the aminosilanes from 5% to 70% by weight of the total reactants.

16. The process of claim 4 wherein the percentage of tetra-alkoxysilane in the total silanes is between 5 and 90%.

17. The process of claim 1 wherein the density of the aerogel is between 0.01 and 0.6 g/cc and preferably between 0.03 and 0.34 g/cc.

18. The process of claim 12 wherein the carbon dioxide capture rate is between 0.08 gram and 0.5 gram of carbon dioxide per gram of the aerogel in the sorbent.

19. The process of claim 12 wherein any degradation in capture rate is no more than 80% after exposing to temperatures up to 130°

C. and capture-regeneration cycles up to 500.

20. A process of preparing a carbon dioxide capture sorbent comprising the steps of hydrolyzing and condensing at least an alkylalkoxysilane, forming a gel, reacting the gel with at least an amine or amine containing compound, drying the resulting gel to obtain an aerogel, wherein the aerogel comprises at least an open pore accessible to carbon dioxide.

22. The process of claim 20 where the amine is selected from tetraethylenepentamine (TEPA), polyethyleneimine (PEI) or combinations thereof.

21. A process of preparing a carbon dioxide sorbent comprising surface-treating a wet gel or an aerogel prepared from an alkylalkoxysilane with an amine.