EP-4735789-A1 - ARCHITECTURE FOR LOADING LIQUID HYDROGEN TRAILERS

Abstract

A method for filling a hydrogen delivery trailer (40) is provided, in which the method can include the steps of: transferring liquid hydrogen from a liquid hydrogen storage vessel (20, 80) to the hydrogen delivery trailer (40) via a liquid transfer line (26); and sending gaseous hydrogen from a gas headspace (15) of the hydrogen delivery trailer (40) to the liquid hydrogen storage vessel (20) via a gaseous transfer line (42), wherein the liquid hydrogen storage vessel (20) is configured to be in fluid communication with a hydrogen liquefier, such that the liquid hydrogen storage vessel (20) is configured to receive liquid hydrogen from the hydrogen liquefier.

Inventors

• LIGHT, JOSHUA

Assignees

• L'Air Liquide, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude

Dates

Publication Date

20260506

Application Date

20240627

Claims (1)

1. CLAIMS I claim: 1. A method for filling a hydrogen delivery’ trailer (40), the method comprising the steps of: a) transferring liquid hydrogen (25) from a liquid hydrogen storage vessel (20, 80) to the hydrogen delivery trailer (40) via a liquid transfer line (26); and b) sending gaseous hydrogen from a gas headspace (15) of the hydrogen delivery trailer (40) to the liquid hydrogen storage vessel (20, 80) via a gaseous transfer line (42), wherein the liquid hydrogen storage vessel (20, 80) is configured to be in fluid communication with a hydrogen liquefier, such that the liquid hydrogen storage vessel (20, 80) is configured to receive liquid hydrogen from the hydrogen liquefier. 2. The method as claimed in Claim 1, further comprising a step of c) treating the gaseous hydrogen of the liquid hydrogen storage vessel (20, 80). 3. The method as claimed in Claim 2, wherein step c) comprises sending the gaseous hydrogen to the hydrogen liquefier for liquefaction therein. 4. The method as claimed in Claim 3, wherein the gaseous hydrogen is liquefied by sending the gaseous hydrogen to the hydrogen liquefier as boil-off gas from the liquid hydrogen storage vessel (20, 80). 5. The method as claimed in Claim 2, wherein step c) further comprises liquefying the gaseous hydrogen within the liquid hydrogen storage vessel (20, 80). 6. The method as claimed in Claim 5. wherein the gaseous hydrogen is liquefied using cooling provided by a refrigeration cycle having a refrigerant. 7. The method as claimed in Claim 6, wherein the cooling takes place within the gas headspace (15) of the liquid hydrogen storage vessel (20, 80) or outside of the liquid hydrogen storage vessel (20, 80) using an indirect heat exchanger (230). 8. The method as claimed in Claim 6, wherein the refrigerant is configured to provide cooling to 20K to 22K. 9. The method as claimed in Claim 6, wherein the refrigerant is selected from the group consisting of helium, hydrogen, neon, and combinations thereof. 10. The method as claimed in Claim 5, wherein the gaseous hydrogen is liquefied by introducing a subcooled liquid hydrogen stream (2) through the gas headspace (15), thereby providing direct contact with the gaseous hydrogen. 1 1. The method as claimed in Claim 10, wherein the subcooled liquid hydrogen stream (2) is introduced using a spray header (10). 12. The method as claimed in Claim 5, wherein the gaseous hydrogen is liquefied by indirect heat exchange via a top condenser (30) that is cooled using a refrigerant. 13. The method as claimed in Claim 12, wherein the refrigerant is configured to provide cooling to 20K to 22K. 14. The method as claimed in Claim 12, wherein the refrigerant is selected from the group consisting of helium, hydrogen, neon, and combinations thereof. 15. The method as claimed in Claim 1, wherein step a) includes the use of a liquid pump (50) disposed on the liquid transfer line (26). 16. The method as claimed in Claim 1, wherein the liquid hydrogen storage vessel (20) comprises a spherical tank (20). 17. The method as claimed in Claim 1, wherein the liquid hydrogen storage vessel (80) comprises a plurality 7 of bullet tanks (80a, 80b, 80c). 18. The method as claimed in Claim 17, wherein step a) further comprises the steps of: selecting a first bullet tank (80A) of the plurality of bullet tanks that has the highest gas phase pressure; equalizing the pressure of the gas phase of the first bullet tank (80A) and the hydrogen delivery trailer (40); and pumping (50) liquid hydrogen from the first bullet tank (80A) to the hydrogen delivery trailer (40) until the hydrogen delivery trailer (40) reaches a predetermined value. 19. The method as claimed in Claim 18, further comprising the steps of: stopping fluid communication between the first bullet tank (80A) and the hydrogen delivery trailer (40); selecting a second bullet tank (80B) of the plurality of bullet tanks that has the second highest gas phase pressure; equalizing the pressure of the gas phase of the second bullet tank (80B) and the hydrogen delivery trailer (40); and pumping (50) liquid hydrogen from the second bullet tank (80B) to the hydrogen delivery trailer (40) until the hydrogen delivery trailer (40) reaches a second predetermined value. 20. The method as claimed in Claim 17, further comprising a step of c) treating the gaseous hydrogen of the liquid hydrogen storage vessel (80a, 80b, 80c), wherein step c) further comprises sending gaseous hydrogen from the plurality of bullet tanks (80a. 80b, 80c) to the hydrogen liquefier for liquefaction therein.

Description

ARCHITECTURE FOR LOADING LIQUID HYDROGEN TRAILERS Cross Reference of Related Applications This patent application claims priority to U.S. Provisional Patent Application Serial No. 63/523.537 filed on June 27, 2023, which is hereby incorporated by reference in its entirety. Background of the Invention Liquid hydrogen trailer loading is a lengthy process that also leads to significant hydrogen venting. Liquid hydrogen trailers arrive at the liquefier with a significant amount of hydrogen gas that must be managed. In order to fill a trailer with hydrogen, the gaseous hydrogen in the trailer is often removed until the trailer is at a low pressure, commonly referred to as depressurization. The trailer then enters the loading phase. While the trailer is “empty, ” there is a small amount of liquid hydrogen within the trailer and a large volume of gaseous hydrogen within the trailer. The gaseous hydrogen should be removed so that liquid can fill the trailer. In addition, the flow coming into the trailer typically contains a fraction of gas hydrogen because 1) some heat is absorbed in the piping that vaporizes liquid hydrogen to gas hydrogen and 2) the incoming flow was saturated at a pressure higher than the trailer pressure which causes the liquid stream to flash to a two phase fluid (liquid and gas). The gas created from cooling down the piping and from flashing should be removed from the trailer to allow the trailer to fill with additional liquid hydrogen. The amount of gas and the rate of gas formation varies, and in order to depressurize and load the trailer as quickly as possible, the gas should be removed as soon as it is available. If the gas is not removed when it is available, the step takes longer than needed. For example, during depressurization, a large amount of hydrogen gas (-200 kg) is immediately available to be removed from the trailer, and a slow flow rate of hydrogen gas being removed from the trailer will increase the duration of this activity. During loading, the hydrogen gas from the vapor space and the hydrogen gas produced from piping cooldown and flashing can fill the trailer gas space and cause the pressure in the trailer to increase. The increased pressure in the trailer slows the flow of liquid hydrogen from the liquid hydrogen storage vessel and increases the duration of the loading step. The current methods for removing the gas from the trailer are 1) by venting the gas from the trailer to atmosphere, or 2) by compressing the gas from the trailer to a higher pressure so that the gas can be used in the liquefier process. Venting the gas to atmosphere allows the gas to be removed from the trailer at a very high flow rate (basically as soon as it the gas is available), and the pressure in the trailer is maintained at near atmospheric pressure. Compressing the gas from the trailer to a higher pressure occurs at a fixed flow rate of the compressor, and the pressure in the trailer is elevated up to -5 psig in order to have sufficient pressure supply the compressor suction. Compressing the gas limits the flow rate of gas that can be removed from the trailer, and this limited flow rate slows the trailer depressurization and loading process. Another factor that impacts the speed of trailer filling is the pressure drop that is available between the liquid hydrogen storage vessel and the trailer. After depressurization and when excess gas from loading has been removed from the trailer, the pressure drop available determines the flow rate of liquid hydrogen from the liquid hydrogen storage vessel to the trailer. Given that the piping system has a fixed resistance and the outlet conditions of the liquid hydrogen storage vessel are constant, the pressure drop correlates to the flow rate of liquid hydrogen from the liquid hydrogen storage vessel to the trailer. In order to load trailers more quickly, the pressure drop from the liquid hydrogen storage vessel to the trailer should be maximized. Liquid hydrogen storage vessels are typically maintained around 10-20 psig. The pressure drop available depends on the method used to remove gas from a trailer. When a compressor is used to remove gas from a trailer, the pressure drop available is 5-15 psi (10-20 psig minus 5 psig). When the trailer gas is removed by a vent, the pressure drop available is 10-20 psi. Trailers ty pically carry7 about 4,000 kg, and the liquid hydrogen flow rate from the liquid hydrogen storage vessel to the trailer is shown below: Table I: Liquid Hydrogen Flow Rates The liquid hydrogen transfer duration can be 2.5 - 4.5 hours, this does not include hose connection, valve manipulations, and purging/cooldown sequences. The total lime required to fill a trailer consists of depressurization and loading, so the total duration is ty pically closer to about 6 hours. A solution is needed to improve the duration to depressurize and to load a trailer while recovering all of the gas into the liquefier. A larger compressor would allow gas