Low mesopore adsorbent contactors for use in swing adsorption processes

• US 7,959,720 B2
• Filed: 04/04/2008
• Issued: 06/14/2011
• Est. Priority Date: 05/18/2007
• Status: Active Grant

• Current Assignee: ExxonMobil Research & Engineering Company (Exxon Mobil Corporation)
• Original Assignee: ExxonMobil Research & Engineering Company (Exxon Mobil Corporation)
• Inventors: Chance, Ronald R., Corcoran, Edward W. Jr., Deckman, Harry W., Stern, David L.
• Primary Examiner(s): Hill, Jr.; Robert J
• Assistant Examiner(s): Jones; Christopher P
• Application Number:
  US12/080,784
• Publication Number:
  US 20080282892A1
• Time in Patent Office: 1,166 Days
• Field of Search: 961/08, 961/30, 961/34, 961/40, 961/41, 95/96
• US Class Current: 96/130
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/106 Silica or silicates
• CPC Class Codes: B01D 2253/31 Pore size distribution
• CPC Class Codes: B01D 2253/342 Monoliths
• CPC Class Codes: B01D 2256/24 Hydrocarbons
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/404 Nitrogen oxides other than dinitrogen oxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 53/0407 Constructional details of adsorbing systems
• CPC Class Codes: B01D 53/047 Pressure swing adsorption
• CPC Class Codes: C07C 7/12 by adsorption, i.e. purification or separation of hydrocarbons with the aid of solids, e.g. with ion-exchangers
• CPC Class Codes: C07C 9/04 Methane production by treatment of sewage C02F11/04; natural gas, synthetic natural gas C10L3/06
• CPC Class Codes: C10L 3/10 Working-up natural gas or synthetic natural gas
• CPC Class Codes: C10L 3/102 of acid contaminants
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

The present invention relates to engineered structured adsorbent contactors for use in pressure swing adsorption and thermal swing adsorption processes. Preferably, the contactors contain engineered and substantially parallel flow channels wherein 20 volume percent or less of the open pore volume of the contactor, excluding the flow channels, is in the mesopore and macropore range.

Claims

1. An adsorbent contactor for use in swing adsorption gas separation process units, comprising:

a) a gas inlet end; and

b) a gas outlet end;

wherein the gas inlet end and the gas outlet end are in fluid connection by a plurality of open flow channels wherein the surface of the open flow channels are comprised of an adsorbent material that has a selectivity for a first gas component over a second gas component of a gas mixture greater than 5, and wherein the contactor has less than about 20% of its open pore volume in pores with diameters greater than about 20 angstroms and less than about 1 micron; and

wherein the open pore volume (in volume percentage) is defined as the volume of the pores in the adsorbent that are between 20 angstroms and 1 micron in diameter divided by the total volume of the adsorbent contactor that is occupied by the adsorbent material including associated mesopores and macropores in the adsorbent structure; and

the adsorbent contactor is comprised of substantially parallel channels wherein the geometry of the adsorbent contactor is selected from monoliths, a plurality of tubular members, stacked layers of adsorbent sheets with or without spacers between each sheet, multi-layered spiral rolls, bundles of hollow fibers, and bundles of substantially parallel solid fibers.

2. The adsorbent contactor of claim 1 wherein the adsorbent material has a selectivity for CO₂ over CH₄ greater than 5.

3. The adsorbent contactor of claim 1 wherein the adsorbent material has a selectivity for N₂ over CH₄ greater than 5.

4. The adsorbent contactor of claim 1 wherein the adsorbent material has a selectivity for H₂S over CH₄ greater than 5.

5. The adsorbent contactor of claim 1 wherein the adsorbent material is comprised of a structured microporous adsorbent selected from the group consisting of zeolites, titanosilicates, ferrosilicates, stannosilicates, aluminophosphates (AlPOs), silicaaluminophosphates (SAPOs) and carbon molecular sieves.

6. The adsorbent contactor of claim 1 wherein the adsorbent material is comprised of a zeolite selected from the group consisting of MFI, faujasite, MCM-41 and Beta.

7. The adsorbent contactor of claim 1 wherein the adsorbent material is comprised of an 8-ring zeolite with a Si to Al ratio of about 1:

1 to about 1000;

1.

8. The adsorbent contactor of claim 7 wherein the 8-ring zeolite is DDR.

9. The adsorbent contactor of claim 7 wherein the 8-ring zeolite is selected from Sigma-1 and ZSM-58.

10. The adsorbent contactor of claim 1 wherein the adsorbent contactor is comprised of a first adsorption zone comprising a first adsorbent material which is in fluid contact with a second adsorption zone comprising a second adsorbent material, wherein the composition of the first adsorbent material is different from the composition of a second adsorbent material.

11. The adsorbent contactor of claim 10 wherein the first adsorbent material has a selectivity for the first gas component of a gas mixture over a second gas component of the gas mixture greater than 5;

the second adsorbent material has a selectivity for a third gas component over the second gas component of the gas mixture greater than 5; and

the second adsorbent material has a greater adsorption uptake for the third gas component than the first adsorbent material.

12. The adsorbent contactor of claim 11 wherein the first gas component is CO₂, the second gas component is CH₄ and the third gas component is H₂S.

13. The adsorbent contactor of claim 11 wherein the first gas component is N₂, the second gas component is CH₄ and the third gas component is H₂S.

14. The adsorbent contactor of claim 11 wherein at least one adsorbent material is comprised of a material selected from the group consisting of zeolites, titanosilicates, ferrosilicates, stannosilicates, aluminophosphates (AlPOs), silicaaluminophosphates (SAPOs) and carbon molecular sieves.

15. The adsorbent contactor of claim 11 wherein the at least one adsorbent material is comprised of an 8-ring zeolite that has a Si to Al ratio of about 1:

1 to about 1000;

1.

16. The adsorbent contactor of claim 15 wherein the 8-ring zeolite is DDR.

17. The adsorbent contactor of claim 15 wherein the 8-ring zeolite is selected from Sigma-1 and ZSM-58.

18. The adsorbent contactor of claim 1 wherein the adsorbent contactor has less than about 15% of its open pore volume in pores with diameters greater than about 20 angstroms and less than about 1 micron.

19. The adsorbent contactor of claim 1 wherein the adsorbent material also contains an effective amount of a thermal mass material having a higher capacity for adsorbing heat than the adsorbent material.

20. The adsorbent contactor of claim 1 wherein the adsorbent material has both mesopores and macropores and wherein at least some of the mesopores and macropores are occupied with a blocking agent of an effective size that is small enough to fit into a mesopore but too large to fit into a micropore of the adsorbent material.

21. The adsorbent contactor of claim 20 wherein the blocking agent is selected from the group consisting of polymers, microporous materials, solid hydrocarbons, and liquids.

22. The adsorbent contactor of claim 1 wherein the parallel flow channels have a channel gap from about 5 to about 1000 microns.

23. The adsorbent contactor of claim 1 wherein the ratio of adsorbent volume to flow channel volume is from about 0.5:

1 to about 100;

1.