Method for loading and storing gas in nano-valved sorbents

Patent metadata

Field	Value
Publication number	US-9249934-B2
Application number	US-201414262161-A
Country	US
Kind code	B2
Filing date	Apr 25, 2014
Priority date	Apr 25, 2014
Publication date	Feb 2, 2016
Grant date	Feb 2, 2016

Abstract

Adsorbent pellets coated with an outer nano-porous layer can be loaded with gas at loading pressures of 250 bar or greater, enabling a much higher loading than can be achieved at low pressures. The nano-porous layer provides nano-valves which can be sealed with an adsorbate such as ethanol or a hydrocarbon to close the nano-valves. The closed nano-valves maintain the high loading pressure inside the adsorbent pellets, and thus maintain the gas loading, during storage of the loaded nano-valved adsorbent pellets at much lower pressure. To release the gas, the nano-porous layer can be heated to a temperature sufficient to vaporize the adsorbate and open the nano-valves.

First claim

We claim:

1. A method for loading and storing gas, comprising the steps of:
providing adsorbent pellets coated with a nano-porous outer layer, the nano-porous outer layer including nano-valves capable of being opened and closed on demand;
loading the adsorbent pellets with gas at a loading pressure when the nano-valves are opened, forming loaded nano-valved adsorbent pellets;
closing the nano-valves in the loaded nano-valved adsorbent pellets; and
storing the loaded nano-valved adsorbent pellets at a storage pressure that is lower than the loading pressure.

2. The method of claim 1 , wherein the step of closing the nano-valves comprises the step of sealing the nano-porous outer layer with an adsorbate.

3. The method of claim 2 , wherein the adsorbate comprises ethanol or a hydrocarbon.

4. The method of claim 1 , wherein the loaded nano-valved adsorbent pellets have an internal pressure that is higher than the storage pressure, and the closed nano-valves maintain a pressure differential between the internal pressure and the storage pressure.

5. The method of claim 1 , further comprising the step of opening the closed nano-valves to release the gas from the loaded nano-valved adsorbent pellets.

6. The method of claim 1 , wherein the adsorbent pellets comprise a zeolite.

7. The method of claim 1 , wherein the adsorbent pellets comprise a carbon-based material.

8. The method of claim 1 , wherein the adsorbent pellets comprise a metal-organic framework.

9. The method of claim 1 , wherein the adsorbent pellets comprise a covalent-organic framework.

10. The method of claim 1 , wherein the nano-porous outer layer has an average pore size of about 0.3 nanometers to about 1 nanometer.

11. The method of claim 4 , wherein the pressure differential is at least about 50 bar.

12. The method of claim 1 , wherein the loading pressure is at least about 250 bar.

13. The method of claim 12 , wherein the storage pressure is about 35 bar or less.

14. The method of claim 1 , wherein the loaded nano-valved adsorbent pellets are stored in one or more conformable cartridge-type tanks.

15. A method for storing and releasing gas, comprising the steps of:
providing loaded nano-valved adsorbent pellets including a nano-porous outer layer and loaded with gas, the nano-porous outer layer including nano-valves capable of being opened and closed on demand;
storing the loaded nano-valved adsorbent pellets with the nano-valves being closed; and
opening the nano-valves to release the gas.

16. The method of claim 15 , wherein the nano-valves are maintained in a closed position by sealing the nano-porous outer layer with an adsorbate.

17. The method of claim 16 , wherein the nano-porous outer layer comprises pores having an average diameter of about 0.3 nanometers to about 1 nanometer.

18. The method of claim 17 , wherein the adsorbate comprises liquid molecules having a kinetic diameter of about 0.3 nanometers to about 1 nanometer.

19. The method of claim 15 , wherein the step of opening the nano-valves comprises heating the nano-porous outer layer to a temperature of about 55° C. to about 85° C.

20. The method of claim 15 , wherein the adsorbent pellets comprise a zeolite, a carbon-based material, a metal-organic framework, a covalent-organic framework, or a combination thereof.

21. The method of claim 15 , wherein the nano-valves are maintained in a closed position by sealing with a liquid, and the step of opening the nano-valves comprises the step of vaporizing the liquid.

22. A system for on-board storage of gas, comprising:
a storage tank including a plurality of zones;
loaded nano-valved adsorbent pellets including a nano-porous outer layer in the zones, the nano-porous outer layer including nano-valves capable of being opened and closed on demand;
gas stored in the loaded the nano-valved adsorbent pellets in one or more of the plurality of zones, the nano-valves on the loaded nano-valved adsorbent pellets being maintained in a closed position; and
a thermal management system capable of independently heating each of the plurality of zones to open the nano-valves and release gas from the loaded nano-valved adsorbent pellets in the zone.

23. The system of claim 22 , further comprising a gas transfer unit for loading gas under pressure into each of the plurality of zones.

24. The system of claim 23 , wherein the gas transfer unit comprises apparatus for transferring loaded nano-valved adsorbent pellets into one or more of the plurality of zones.

25. The system of claim 24 , wherein the gas transfer unit comprises one or more cartridges, each one including a plurality of nano-valved adsorbent pellets, which can be manually transferred back and forth between a vehicle and a charging tank.

26. A method for loading and storing gas, comprising the steps of:
providing adsorbent pellets coated with a nano-porous outer layer, the nano-porous outer layer including nano-valves capable of being opened and closed on demand;
storing the adsorbent pellets in one or more cartridge-type tanks, each tank containing a plurality of the adsorbent pellets;
loading the adsorbent pellets in the cartridges with gas at a loading pressure when the nano-valves are opened, forming loaded nano-valved adsorbent pellets in the cartridges;
closing the nano-valves in the loaded nano-valved adsorbent pellets; and
storing the cartridges containing the loaded nano-valved adsorbent pellets at a storage pressure that is lower than the loading pressure.

Assignees

• Li Shiguang
• Zhou Shaojun
• Meyer Howard S
• Yu Miao
• Carreon Moises A
• Gas Technology Inst
• Univ Louisville Res Found
• Univ South Carolina

Inventors

• Li Shiguang
• Zhou Shaojun
• Meyer Howard S
• Yu Miao
• Carreon Moises A

Classifications

• B01J20/20

  comprising free carbon; comprising carbon obtained by carbonising processes · CPC title

• B01J20/2808

  being less than 2 nm, i.e. micropores or nanopores · CPC title

• B01J20/28016

  Particle form · CPC title

• B01J20/28052

  Several layers of identical or different sorbents stacked in a housing, e.g. in a column · CPC title

• B01J20/28097

  being coated, filled or plugged with specific compounds · CPC title