COMBINED HYDROGEN STORAGE - COMPRESSION SYSTEM FOR THE FILLING OF HIGH PRESSURE HYDROGEN TANKS

Abstract

The present relates to a combined hydrogen storage-compression unit suitable for the filling of high-pressure (350 bar and beyond) hydrogen vessels. It includes a containment vessel filled with a hydrogen storage alloy, a heating system, a cooling system and a thermal management system. The same shall be connected directly to the hydrogen supply (e.g. an electrolyser) on one side and to the end consumer on the other side. Moreover, it offers the possibility for intermediate storage of at least one time the maximal quantity of hydrogen that is to be supplied at high pressure in a single step.

Claims

1-14. (canceled)

15. A combined hydrogen storage-compression module with a variable output pressure comprising a pressurized vessel presenting at least one inlet/outlet port in order to supply/remove hydrogen, a hydrogen storage alloy placed within the vessel, a heating system adapted to increase the temperature of the storage system in order to increase the pressure and a cooling system that can remove the heat of reaction during absorption and/or reduce the pressure of the system on demand, whereby cooling and heating of the vessel decrease and increase, respectively, the pressure inside the vessel because of the thermodynamic characteristics of the hydrogen storage alloy, a thermal management system for the control of said heating and said cooling system, a heat spreader within the pressurized vessel adapted to facilitate heat transfer within the hydrogen storage alloy, and one or more pressure sensors and temperature sensors that measure the temperature and pressure in the pressurized vessel and provide measurement data to the thermal management system, wherein the thermal management system, by controlling the temperature of the vessel and its content, is adapted to permit a progressive ramp up of the pressure in the pressurized vessel to be filled, thereby maintain a pressure differential between the storage-compression unit and the high pressure hydrogen tank to be filled of less than or equal to 100 bar throughout the filling process, where filled means that the pressure inside the vessel has reached its maximal rated pressure.

16. The combined hydrogen storage-compression module according to claim 15, wherein where hydrogen is supplied by an electrolyzer or a reformer or any equivalent hydrogen source, and where hydrogen is removed to fill a high pressure hydrogen tank, such as but not limited to a hydrogen vehicle tank.

17. The combined hydrogen storage-compression module according to claim 15, wherein the hydrogen storage alloy presents an absorption plateau pressure less than or equal to 5 bar at 25° C. and a desorption plateau pressure greater than or equal to 350 bar at a temperature less than or equal to 260° C.

18. The combined hydrogen storage-compression module according to claim 15, wherein the hydrogen storage alloy presents a desorption plateau pressure greater than or equal to 700 bar at a temperature less than or equal to 320° C.

19. The combined hydrogen storage-compression module according to claim 15, wherein the hydrogen storage alloy presents a hydrogen storage capacity greater than or equal to 1 kg hydrogen or, a hydrogen storage capacity greater than or equal to 5 kg hydrogen.

20. The combined hydrogen storage-compression module according to claim 15, wherein the hydrogen storage alloy is comprised in the class of AB2 materials or AB5 materials.

21. The combined hydrogen storage-compression module according to claim 19, wherein the AB2 material A is Titanium which may or may not be partially substituted with Zirconium or any other element and B includes a plurality of components selected from the group consisting of Vanadium, Manganese, Iron, Cobalt and Nickel or any other element and whereby in the AB5 material A is Lanthanum which can be partially substituted with Cerium, Neodymium and/or any other element and B is Nickel which can be partially substituted with at least one component or a plurality of components selected from the group consisting of Cobalt, Aluminium, Manganese and Iron or any other element.

22. The combined hydrogen storage-compression module according to claim 15, wherein the heating system is adapted to enable the desorption of the full hydrogen capacity of the storage system in less than or equal to five minute when the overpressure is greater or equal to 1 bar.

23. The combined hydrogen storage-compression module according to claim 15, wherein the heating system is adapted to enable the desorption of the full hydrogen capacity of the storage system in less than or equal to 20 minutes when the overpressure is greater or equal to 1 bar.

24. The combined hydrogen storage-compression module according to claim 15, wherein the cooling system is adapted to enable the filling of the full hydrogen capacity of the storage system in less than or equal to five minutes with an overpressure of less than or equal to 1 bar.

25. The combined hydrogen storage-compression module according to claim 15, wherein the pressure differential progressive ramp up of the pressure in the vessels to be filled, is maintained under 10 bar.

26. A combined hydrogen storage-compression system, wherein several individual modules according to claim 15, are connected in parallel or in series.

27. The combined hydrogen storage-compression system of 26, where at least two pressure containment vessels are connected and working in a sequence where one containment vessel is absorbing hydrogen while the other is desorbing hydrogen.

28. The combined hydrogen storage-compression system of 27, wherein, heat is transferred from the colder desorbing containment vessel to the hotter absorbing containment vessel using a heat pump.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further particular advantages and features of the invention will become more apparent from the following non-limitative description of at least one embodiment of the invention which will refer to the accompanying drawings, wherein

[0032] FIG. 1 represents a typical pressure-composition isothermal curve (pcI) for the absorption process of hydrogen in metal hydrides

[0033] FIG. 2 represents a typical pressure-composition isothermal curve (pcI) for the desorption process of hydrogen in metal hydrides

[0034] FIG. 3 is a stylistic depiction of the current typical process for the filling of hydrogen vehicles

[0035] FIG. 4 is a Van't Hoff plot of an AB5 alloy suitable for the instant invention

[0036] FIG. 5 is shows two pressure-composition isothermal curves (pcI) together with a typical working cycle of the present invention

[0037] FIG. 6 is a stylistic depiction of a possible technical implementation of the instant invention

[0038] FIG. 7 is a stylistic depiction of a possible technical implementation where heat is transferred from the cold reservoir to the hot reservoir using a heat pump

DETAILED DESCRIPTION OF THE INVENTION

[0039] The present detailed description is intended to illustrate the invention in a non-limitative manner since any feature of an embodiment may be combined with any other feature of a different embodiment in an advantageous manner.

[0040] FIG. 6 shows a schematic embodiment of the present invention which relates to a combined hydrogen storage-compression unit with a variable output pressure for the filling of high-pressure hydrogen vessels, for instance in hydrogen-powered vehicles. The instant invention consists of a pressurized vessel, also called containment vessel, which has at least one inlet/outlet port in order to supply/remove hydrogen, a hydrogen storage alloy placed within the vessel, a heating system that can increase the temperature of the storage system in order to increase the pressure, a cooling system that can remove the heat of reaction during absorption and/or reduce the pressure of the system on demand, a thermal management system for the control of said heating and cooling system, and, a heat spreader within the containment vessel that facilitates heat transfer within the hydrogen storage alloy.

[0041] The containment vessel can be made out of any material withstanding the maximal outlet pressure and withstanding hydrogen corrosion. Such materials can be but are not limited to certain classes of stainless steel and carbon composite materials. The containment vessel has at least one port for the filling/removing of hydrogen. The port is preferably equipped with a filter with a size smaller than the smallest particle in order to prevent particles of the storage alloy to exit the containment vessel. The containment vessel can be made of one single unit, or of several individual units connected in series.

[0042] Advantageously, the containment vessel is either of spherical or cylindrical shape in order to spread the stresses due to high pressures. According to a preferred embodiment of the present invention, the connection to the gaseous hydrogen source is closed using some closing means, e.g. a mechanical or electrical valve or any other closing mean. Advantageously, the output connection of the compressor is opened with some opening/closing means, e.g. a valve or any other electrical, mechanical or electromechanical system.

[0043] The hydrogen storage alloy used in the instant invention has a hydrogen storage capacity higher or equal to 1.2% weight. Advantageously, the hydrogen storage alloy has a storage capacity higher or equal to 1.5% or more. The hydrogen storage alloy absorbs hydrogen at a pressure less or equal to 50 bar at a temperature greater or equal to 5° C. Advantageously, the hydrogen storage alloy absorbs hydrogen at a pressure less or equal to 5 bar at a temperature greater or equal to 25° C. The material can be but is not limited to the classes AB2 and AB5 alloys. Materials with a small hysteresis (<2 bar) between absorption and desorption are preferable.

[0044] The heating system is defined as any aggregate that can provide heat to the hydrogen storage material bed. It can be comprised of but is not limited to an electrical resistance heating, a heat exchanger with through flow of heating fluid or any other mean to elevate or maintain the temperature of the system on demand.

[0045] The cooling system is defined as any aggregate that can remove heat from the hydrogen storage material bed. It can be comprised of but is not limited to a heat spreader subject to free convection outside of the containment vessel, a forced convection circuit inside or outside of the containment vessel or any other mean to reduce or maintain the temperature of the system on demand.

[0046] The thermal management system comprises the hardware and software necessary to the control of the temperature and, thus, the control of the pressure in the hydrogen storage material. Advantageously, the temperature regulation is done with a control approach chosen in the group including PID control, MIMO control or control with any number of inputs and outputs and different sensing devices.

[0047] The heat spreader comprises any hardware that can facilitate the heat transfer from/to the heating and/or cooling system to and within the hydrogen storage alloy. It can consist of but is not limited to extended surfaces made out of high thermal conductivity materials such as aluminium and copper or selected powder with high thermal conductivity.

[0048] The described system allows to fill a high-pressure cylinder starting at a low pressure (e.g. <2 bar) to the maximal pressure of the system (e.g. 700 bar). Throughout the process, the pressure differential between the storage-compression unit and the vessel to be filled is maintained very low (<100 bar, advantageously <10 bar or <1 bar). Thereby, no significant expansion happens during the transfer between the storage-compression unit and the vessel to be filled. Therefore, no pre-cooling of the gas is required.

[0049] In order to improve the overall energetic efficiency of the system, an arrangement is represented in FIG. 7, where two or more pressure containment vessels are connected are working in a sequence is proposed. Thereby, at least one pressure containment vessel is absorbing hydrogen and at least one pressure containment vessel is desorbing hydrogen simultaneously. Thereby, heat is transferred from the vessel absorbing hydrogen to the vessel desorbing hydrogen using a heat pump or any other mean fulfilling the same technical purpose.

[0050] While the embodiments have been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, this disclosure is intended to embrace all such alternatives, modifications, equivalents and variations that are within the scope of this disclosure. This for example is particularly the case regarding the exact temperature used, the material used, the monitoring system, the number of stages, the temperature sensor and all the different apparatuses, which can be used in conjunction with the present invention.