System and method for treating hydrogen to be stored in a salt cavern and supplying therefrom

Patent metadata

Field	Value
Publication number	US-9718618-B2
Application number	US-201414475120-A
Country	US
Kind code	B2
Filing date	Sep 2, 2014
Priority date	Sep 2, 2014
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A novel system and method for storing hydrogen in a salt cavern and supplying therefrom is provided. Hydrogen product withdrawn from a hydrogen pipeline may be chilled prior to being introduced into a cavern in order to cool at least a portion of the walls of the salt cavern so that one or more layers of the localized portion of the walls attains a stabilized state whereby contaminant release from the walls is suppressed. The present invention anticipates and strategically plans for contaminant intrusion form a salt cavern in order to reduce the degree of contaminant intrusion from a salt cavern while also allowing the stored hydrogen to have more absorption capacity for water vapor by virtue of entering the salt cavern in a sufficiently drier state. Alternatively, or in addition thereto, a crude hydrogen stream may be withdrawn from the cavern and chilled prior to introducing to the hydrogen pipeline.

First claim

The invention claimed is:

1. A method for treating a moisture-containing hydrogen product to be stored in a salt cavern, comprising:
removing hydrogen product from a hydrogen pipeline;
compressing the hydrogen product to produce a compressed hydrogen product;
cooling the compressed hydrogen product to condense at least a portion of water vapor prior to the compressed hydrogen product entering the salt cavern;
removing the water vapor condensate to produce a compressed and chilled hydrogen product; and
introducing the compressed and chilled hydrogen product into the salt cavern to produce chilled and stored hydrogen within the salt cavern.

2. The method of claim 1 , further comprising the steps of:
reducing a temperature of at least a localized portion of walls of the salt cavern by contacting at least a portion of the chilled and stored hydrogen with the localized portion of the walls so that one or more layers of the localized portion of the walls attains a stabilized state whereby contaminant release from said walls is suppressed.

3. The method of claim 1 , wherein the chilled and stored hydrogen is—dry to have capacity to absorb water vapor contained in the cavern to a level at or below a product purity specification.

4. The method of claim 3 , further comprising:
withdrawing said chilled and stored hydrogen from the salt cavern to produce a supply of hydrogen; and
introducing the supply of hydrogen into the pipeline.

5. The method of claim 4 , wherein the introducing of the supply of hydrogen into the pipeline is characterized by an absence of drying of the supply of hydrogen.

6. The method of claim 5 , further comprising sampling concentration levels of one or more contaminants in the supply of hydrogen, said contaminants selected group from the group consisting of hydrocarbons, water vapor, sulfur compounds and carbon dioxide.

7. The method of claim 3 , further comprising:
withdrawing said stored hydrogen from the salt cavern to produce a supply of hydrogen product;
chilling the supply of hydrogen to remove a sufficient amount of water vapor having an impurity level of water vapor at or below a product purity specification; and
introducing the hydrogen product into the hydrogen pipeline.

8. The method of claim 1 , wherein the compressed and chilled hydrogen to be introduced into the salt cavern is characterized by an impurity level of water vapor at or below a product purity specification.

9. The method of claim 1 , further comprising:
contacting at least a portion of the chilled and stored hydrogen with walls of the salt cavern; and
reducing a temperature of the walls to a temperature sufficient to lower the rate of infiltration of a substantial portion of contaminants contained therein, wherein said contaminants is selected from the group consisting of water vapor, carbon dioxide, hydrocarbons, sulfur-containing compounds and any combination thereof.

10. A system for storing hydrogen product in a salt cavern, comprising:
a compressor configured to pressurize hydrogen product within the salt cavern to form stored hydrogen;
an aftercooler situated downstream of the compressor, said aftercooler configured to remove a heat of compression from the pressurized hydrogen product;
a chiller configured to impart additional cooling beyond the heat of compression to condense at least water vapor from the hydrogen product, said chiller in fluid communication with the compressor;
a liquid-vapor separator vessel configured collect and accumulate at least the removed water vapor condensate, said collection vessel located downstream and in fluid communication with the chiller;
a flow network positioned between the salt cavern and the compressor, the chiller and the collection vessel, said flow network comprising a first leg and a second leg;
the first leg in flow communication with the salt cavern to introduce product hydrogen into the salt cavern to form stored hydrogen that is chilled to a temperature sufficient to remove a portion of water vapor to produce a chilled and stored hydrogen product; and
the second leg in flow communication with a hydrogen pipeline and the first leg to withdraw the stored and chilled hydrogen from the salt cavern.

11. The system of claim 10 , further comprising:
a third leg in flow communication with the salt cavern and the chiller to re-chill and/or separate condensate from the stored and chilled hydrogen to produce a supply of hydrogen; and
a fourth leg in flow communication with the first leg and the second leg to return the supply of hydrogen to the hydrogen pipeline.

12. The system of claim 10 , further comprising a temperature detection means for monitoring a temperature of the cavern.

13. The system of claim 10 , further comprising an analyzer bank for measuring at least water vapor, said analyzer positioned along the second leg.

14. The system of claim 10 , wherein said system is characterized by the absence of purification equipment.

15. A method for supplying hydrogen to a hydrogen pipeline from an underground hydrogen storage cavern, comprising:
removing hydrogen product from a hydrogen pipeline;
compressing the hydrogen product to produce a compressed hydrogen product;
cooling the compressed hydrogen product to remove heat of compression from the compressed hydrogen product;
imparting additional cooling of the compressed hydrogen product to condense at least a portion of water vapor to create water vapor condensate prior to the compressed hydrogen product entering the salt cavern;
removing the water vapor condensate to produce a compressed and chilled hydrogen product; followed by
introducing the compressed and chilled hydrogen product into the salt cavern to produce chilled and stored hydrogen within the salt cavern;
withdrawing a crude hydrogen stream from a salt cavern, the crude hydrogen stream comprising one or more contaminants imparted by the salt cavern;
separating at least a portion of the one or more contaminants to form a condensate from the crude hydrogen stream to produce a hydrogen product; and
introducing the hydrogen product into the hydrogen pipeline to supply additional hydrogen to the pipeline.

16. The method of claim 15 , further comprising cooling the crude hydrogen stream to a temperature less than about 200 deg F. but above the liquefaction temperature of the crude hydrogen stream.

17. The method of claim 15 , wherein said crude hydrogen stream is derived from a compressed hydrogen product stream that is cooled prior to introduction in the underground hydrogen storage cavern.

18. The method of claim 15 , wherein said contaminants is selected from the group consisting of water vapor, carbon dioxide, hydrocarbons, sulfur compounds and any combination thereof.

19. The method of claim 15 , further comprising introducing the hydrogen product into the hydrogen pipeline, wherein said hydrogen product comprises contaminants each of which has an impurity level at or below a product purity specification.

20. A method for operating an underground salt cavern, comprising the steps of:
detecting one or more contaminants in a crude hydrogen stream withdrawn from the cavern to exceed a product purity specification; and in response thereto
increasing cooling of a compressed hydrogen stream that is removed as hydrogen product from a hydrogen pipeline; and
increasing cooling of the crude hydrogen stream that is withdrawn from the cavern;
wherein the cooling of the compressed hydrogen stream and the cooling of the crude hydrogen stre

Assignees

• Oates Rommel M
• Praxair Technology Inc

Inventors

• Oates Rommel M

Classifications

• C01B3/506

  at low temperatures · CPC title

• B65G5/00 Primary

  Storing fluids in natural or artificial cavities or chambers in the earth · CPC title

• B01D53/265

  by refrigeration (condensation) · CPC title

• C01B3/00

  Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen; Reversible storage of hydrogen (production of water-gas or synthesis gas from solid carbonaceous material C10J) · CPC title

• C01B2203/0465

  Composition of the impurity · CPC title