EP3830468A1

EP3830468A1 - Sorptive gas storage device

Info

Publication number: EP3830468A1
Application number: EP19745158.6A
Authority: EP
Inventors: Michael Francis Levy; Jorn OUBRAHAM; Carsten Pohlmann; Jean-Baptiste Dementhon
Original assignee: Aaqius and Aaqius SA
Current assignee: Aaqius and Aaqius SA
Priority date: 2018-07-31
Filing date: 2019-07-31
Publication date: 2021-06-09
Also published as: FR3084719A1; CN112789445A; WO2020025662A1; JP2021533313A; MA53318A; US20210293383A1

Abstract

The invention relates to a sorptive gas storage device (1) comprising: a sorptive gas storage structure (10) comprising a sorptive gas storage material, said storage structure (10) having a circumferential edge (B), - heating means (3) configured to heat the storage material, and facilitate the desorption of the gas, said heating means (3) comprising: • a first heating part (30) arranged in the storage structure (10), at a distance from the circumferential edge (B), • a second heating part (32) arranged in the storage structure (10), at a distance from the circumferential edge (B) on the one hand and from the first heating part (30) on the other hand, the first heating part (30) and the second heating part (32) defining between them a space whereinto a first portion (11) of the storage structure (10) extends.

Description

SORPTION GAS STORAGE DEVICE

FIELD OF THE INVENTION The invention relates to the storage of gas by sorption.

The invention relates more specifically to a device for storing gas by sorption, a system for storing and / or supplying gas, and a method for manufacturing a device for storing gas by sorption.

STATE OF THE ART

The use of gas in industry, whether in the mobility, energy, chemical or production sector, is subject to multiple constraints. In this regard, numerous gas storage devices have already been proposed. Some of these devices may include a solid material for storing a gas.

Such solid storage devices must have particular properties, in order to respond to the constraints induced by the gas and linked to the conditions of its use. Gas stored in solid form can, for example, when used as an energy carrier, power a fuel cell. In the mobility sector, it can also be used in a motor vehicle.

Depending on the intended use, the storage structures are sized in different ways depending on the choice of storage material and its size. Some of these materials allow both to store and destock gas, depending on the temperature and pressure conditions to which these materials are subjected. Generally, such materials store gas during an exothermic reaction, and destock it during an endothermic reaction. These reactions take place, for example, by sorption of the gas on the material.

In any case, managing the distribution of heat within the storage material is an essential issue to guarantee the performance of such devices. In this respect, it is for example known to have the storage material inside a confined enclosure comprising heating walls. In other examples of a device the storage material is arranged around a cylindrical heating tube. In all cases, the heating can be adjustable according to storage needs.

The known systems are however exposed to efficiency problems, in particular with regard to the homogenization of the transfer of heat from the heating means to all of the storage material. For example, the portion of the material furthest from said heating means is less well heated than the closest portion. The known systems are also exposed to problems of robustness and longevity of operation of the storage structures, but also of safety of use, of manufacturing complexity, and of economic and energy efficiency in the implementation of said systems.

DESCRIPTION OF THE INVENTION

An object of the invention is to overcome at least one of the aforementioned drawbacks. Another object of the invention is to improve heat transfers within a structure for storing a gas by sorption.

Another object of the invention is to promote the modularity of a gas storage structure.

The invention notably proposes a device for storing gas by sorption comprising:

a sorption gas storage structure comprising a sorption gas storage material, said storage structure having a circumferential edge,

heating means configured to heat the storage material, and facilitate the desorption of the gas, said heating means comprising:

o a first heating part arranged in the storage structure, at a distance from the circumferential edge, o a second heating part arranged in the storage structure, at a distance from the circumferential edge on the one hand, and from the first heating part on the other hand , the first heating part and the second heating part defining between them a space in which a first portion of the storage structure extends.

Such a device makes it possible to reduce the losses associated with heating, while ensuring homogenization of the heat transfers within the storage structure.

The device according to the invention may also include one or other of the following characteristics, taken alone or in combination:

- the first heating part and the second heating part are connected to each other by a third heating part,

the storage structure has a preferred direction defining a longitudinal axis, the heating means having a substantially annular structure along the longitudinal axis,

the compositions and / or distributions of the storage material in the first portion of the storage structure are different from the compositions and / or distributions of the storage material in the rest of the storage structure, with a view to optimizing the distribution of the heat from the heating means within the storage structure,

- it also includes:

o an enclosure comprising an outer wall, the storage structure being disposed inside the enclosure, and

a thermally insulating layer disposed between the storage structure and the outer wall of the enclosure, said layer being further configured to diffuse gas,

the insulating layer comprises a porous structure,

the insulating layer comprises a grooved structure,

- the insulating layer is a film,

the insulating layer is formed at the level of an internal wall of the enclosure, for example by treating said wall, or by depositing an additional coating,

- the storage structure includes: a first layer comprising a sorption storage material,

o a second layer comprising:

^■ a first portion of the second layer, in contact with the first layer, and comprising a thermally conductive material, thermal conductivity greater than that of the storage material, in order to increase heat transfer within the storage structure, and

^■ a second part of second layer comprising a material:

• compressible in order to deform under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and desorption phases of the gas,

• greater compressibility than that of the first part material, and

• thermally conductive, with a higher thermal conductivity than that of the storage material, with a view to increasing the heat transfers within the storage structure, and the storage structure comprises:

a plurality of first layers, each first layer comprising the gas storage material by sorption in pre-compressed powder form, and

a plurality of second layers, each second layer comprising a material:

^■ compressible to be deformed under the action of forces exerted by the storage material during variations in volume of the storage material during phases of sorption and desorption of gas, and

^■ thermally conductive, with a higher thermal conductivity than that of the storage material, with a view to to increase heat transfers within the repository structure,

the first and second layers being arranged in an alternating pattern. The invention further relates to a method of manufacturing a device as described above comprising the steps of:

- compression of a powder of gas storage material by sorption so as to form a first layer of gas storage material by sorption in pre-compressed powder form,

- provision of a second layer adjacent to the first layer, said second layer comprising a thermally conductive material, of thermal conductivity greater than that of the storage material.

The invention also relates to a gas storage and / or supply system comprising a device as described above, and a gas use unit.

DESCRIPTION OF THE FIGURES

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows and with reference to the appended drawings given by way of non-limiting example and in which:

FIG. 1 represents a sectional view of a first example of a gas storage device according to the invention,

FIG. 2 represents a sectional view of an example of a gas storage structure,

- Figure 3 shows a schematic view of a gas storage structure in different operating states,

FIG. 4 is a top view of a second example of a gas storage device according to the invention,

FIG. 5 is a top view of a third example of a gas storage device according to the invention,

- Figure 6 shows a sectional view of a fourth example of a gas storage device according to the invention,

FIG. 7 is an enlarged sectional view of a fifth example of a gas storage device according to the invention,

FIG. 8 is an enlarged sectional view of a sixth example of a gas storage device according to the invention,

FIG. 9 schematically illustrates a gas storage and / or supply system according to the invention, and

- Figure 10 is a flowchart illustrating an example of implementation of a method of manufacturing a gas storage device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION With reference to the figures, a description will now be given of a sorption gas storage device 1, a gas storage and / or supply system 5, as well as a method E of manufacturing a device sorption gas storage.

The gas stored can be of any kind and of any type. For example, the storage device 1 can store alone, or in combination, hydrogen, ammonia, water vapor, oxygen, and / or carbon dioxide.

Gas storage structure

Referring to Figure 1, a sorption gas storage device 1 comprises a sorption gas storage structure 10 comprising a sorption storage material.

The sorption storage structure further comprises a circumferential edge B which surrounds said storage structure 10.

Furthermore, with reference to FIGS. 1 and 2, the sorption gas storage structure 10 can comprise a first layer 100 and a second layer 200.

The first layer 100 is then configured to store gas by sorption. To do this, it can include the sorption storage material.

Advantageously, the storage material can be in pre-compressed powder form. Indeed, this shape facilitates the transport of the storage material because it is then easier to handle and has a lower volume. In addition, this form is more suitable for the sorption storage operation, because it is more stable, facilitates heat transfer, makes the expansion of the storage material more homogeneous.

In addition, the material can have an optimized porosity in order to increase the volumetric storage capacity of the storage structure, but also to accommodate variations in volume of the second layer 200. For example the porosity of the storage material is between 10 vol.% and 50 vol.%, and is preferably between 25 vol.% and 35 vol.%. By porosity is meant the ratio of the volume of air not occupied by the storage material within a given volume of the storage material, over said given volume. In other words, the porosity corresponds to the ratio of the volume not occupied by the storage material, over its apparent volume, that is to say that the porosity is equal to the ratio between the theoretical density at which the apparent density is subtracted from the theoretical density. In any event, the pre-compressed powder form makes it possible to control the porosity of the storage material.

In addition, the storage material can include:

a material suitable for forming a metal hydride, preferably of the Mghh, NaAlhU, UNH2, and / or UBH4 type, and / or

a material suitable for forming an intermediate alloy, preferably of the TiMn2, T 2, LaNi ₅ , FeTi, TiV, and / or TiZr type, and / or

- a material suitable for forming an ammonia salt, preferably of the BaCh, and / or CaCh type, or

a material suitable for forming a hydroxide, preferably of the CaO, and / or Ca (OH) 2 type, or

- a material suitable for forming an oxide, preferably of the PbO, and / or CaO type.

The applicant has in fact noticed that the above materials are particularly suitable for storing and / or supplying gas such as hydrogen, ammonia, water vapor, oxygen, and / or carbon dioxide. This is not, however, limiting, since such materials can also be particularly suitable for other types of gas.

The second layer 200 can, for its part, comprise a material:

thermally conductive, with higher thermal conductivity than storage material, with a view to increasing the heat transfers within the storage structure 10, and

compressible in order to deform under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and desorption phase of gas.

Thanks to the second layer 200, the phenomena of sorption and desorption of gas by the storage material, which involve significant flows of heat, are facilitated. In fact, the heat transfers are thus distributed homogeneously across the entire storage structure 10, which reinforces its efficiency and durability. In fact, the heat can be transported and easily extracted from the first layer 100, which ensures the rapid storage and / or destocking of the gas within the storage structure 10. The energy stored by a given mass of material of storage is therefore increased. Advantageously, the dimensions, the shape, and the relative positioning of the first layer 100 and of the second layer 200 make it possible in particular to optimize the heat transfers within the storage structure 10. For example, when the first layer 100 and the second layer 200 extend in a preferred longitudinal direction, as can be seen in FIG. 1, the layer thickness in the longitudinal direction is a lever for possible optimization of the heat flows within the storage structure 10. Alternatively, or by combination, providing a porosity gradient of storage material within the first layer 100, in a radial direction relative to the longitudinal direction, also constitutes a possible optimization path for the heat exchanges within the storage structure 10. Indeed, it is observed that, when the first layer 100 and the second layer 200 extend in a long direction itudinal, the radial direction constitutes a preferred direction of heat exchange within the storage structure 10. In any event, most of the heat emitted or received by the first layer 100 is transferred by the second layer 200.

In addition, the second layer 200 acts as a buffer during the operation of the storage structure 10. In fact, the second layer 200 compensates for the variations in volume of the storage material during the sorption and desorption phases of gas, and thus preserves the mechanical coherence of the storage structure 10. In this way, the volumetric capacity of the storage material is advantageously increased, since it is no longer necessary to spare empty spaces within the storage structure 10. Finally, the second layer 200 makes it possible to distribute the mechanical forces arising from variations in the volume of the storage material in operation.

Furthermore, the second layer 200 may comprise a matrix comprising graphite, for example natural graphite, for example expanded natural graphite. Alternatively, or in addition, the second layer 200 can comprise a metal, for example aluminum or copper. The applicant has in fact noticed that these materials have adequate compressibility and / or heat transfer properties to fulfill the functions of the second layer 200.

Alternating structure

As shown in Figures 1 and 2, but also in Figures 6 to 8, the storage structure 10 may comprise the first layer 100 and the second layer 200, alternately. Preferably, the storage structure 10 then comprises an alternation of first layers 100 and second layers 200, the first layers 100 preferably being separated in pairs by one of the second layers 200. In other words, the plurality of first layers 100 and the plurality of second layers 200 are arranged in an alternating pattern. The alternating distribution in particular facilitates the distribution of thermal and mechanical stresses within the storage structure 10. In addition, an alternating structure is easily reproducible on an industrial scale, both at the manufacturing and maintenance stage of the storage structure. storage 10. In addition, such a structure can easily be adapted according to the needs in terms of storage performance and / or gas supply. Finally, such a distribution allows a compactness of the storage structure 10 which can prove to be particularly advantageous for applications such as transport, for example automobile.

Advantageously, the storage structure 10 comprises alternating wafers, each first layer 100 and / or each second layer 200 preferably forming a wafer. Privileged, but however optional, the wafers are mechanically independent of each other. Such a configuration can in particular facilitate the handling of the different elements of the storage structure during the various operations associated with the manufacture, maintenance and / or recycling of the storage structure 10. In addition, the configuration in wafer promotes geometric optimization distribution and the distribution of materials within the storage structure 10. In addition, this configuration is more suitable for the sorption storage operation, because it is more stable, facilitates heat transfer, makes the expansion of the storage material more homogeneous. Thus, the gas can be better distributed throughout the entire storage structure 10 when loading the storage material.

Second layer parts

With reference to FIGS. 2 and 3, the second layer 200 may comprise a first part of the second layer 201, 203 in contact with the first layer 100, and a second part of the second layer 202.

In this configuration, the first part 201, 203 can then comprise a thermally conductive material, with thermal conductivity greater than that of the storage material, in order to increase the heat transfers within the storage structure. The second part 202 may, for its part, comprise a compressible material in order to deform under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and desorption phase. gas. In addition, the second part material 202 is, in this case, advantageously of greater compressibility than the first part material. By compressibility, we understand the capacity of a material to decrease its volume when it is subjected to a given compression force. Thus, for the same compression force, the reduction in volume of the second part material 202 is greater than the reduction in volume of the first part material 201, 203. In other words, to obtain a given reduction rate of the volume of the first part material 201, 203 and of the second part material 202, greater compressive forces are required for the first part material 201, 203 than for the second part material 202. In any event, the second part material 202 can also be thermally conductive, with a thermal conductivity greater than that of the storage material, with a view to increasing the heat transfers within the storage structure 10.

The functions of the second layer 200 are then partially distributed between the first part 201, 203 and the second part 202. In this way, each of these functions can be optimized independently of each other, which improves the efficiency of the storage structure 10, and makes it possible more to adapt the storage structure 10 as a function of gas supply and / or storage needs. In addition, the presence of a thermally conductive material in each of the two parts 201, 202, 203 guarantees that the heat exchanges within the storage structure 10 are facilitated in order to distribute the heat evenly throughout the storage structure. 10.

The first part material 201, 203 can be identical to the second part material 202. This allows an advantageous cost reduction and a simplification of the manufacture of the storage structure 10. Alternatively, the first part material 201, 203 can be different from the second part material 202. This promotes the adaptation of the storage structure 10 in order to optimize its storage and / or supply capacities for a given gas.

Furthermore, the first part material 201, 203, and / or the second part material 202, can comprise a matrix comprising graphite, for example natural graphite, for example expanded natural graphite. Alternatively, or in addition, the first part material 201, 203 can comprise a metal, for example aluminum or copper. Alternatively, or in addition, the second part material 202 may comprise a foam. The applicant has in fact noticed that these materials exhibited compressibility and / or thermal transfer properties adequate to fulfill the functions of first part 201, 203 and / or second part 202 of a storage structure 10.

The first part material 201, 203 may furthermore have a lower porosity than the second part material 202. The porosity indeed constitutes a parameter influencing both the compressibility and the thermal properties of a material. Consequently, this difference in porosity favors the deformation of the second part 202 under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and gas desorption phase, and allows the first part 201, 203 to increase the heat transfers within the storage structure 10. More specifically, the first part material 201, 203 can have a porosity of less than 50%, preferably less than 15%, and preferably less than 5%.

With reference to FIG. 3, the mechanical properties of the second layer 200 change during the different operating cycles of the storage structure 10. In fact, the first operating cycles of the storage structure 10 make it possible to activate the first layer 100. More precisely, during the first loading and / or unloading cycles of the storage structure 10, the storage material included in the first layer 100 acquires its full storage capacity by sorption. This initial conditioning can be implemented during loading and / or unloading cycles which may be of long duration and / or carried out at high temperature and / or carried out at high pressure. In this regard, it should be noted that, when the storage material is in pre-compressed powder form, activation is facilitated since the number and duration of the first loading and / or unloading cycles decrease. Gradually, the quantity of gas stored, then supplied, by the first layer 100 increases, as and when successive loading and / or unloading, until reaching an expected level of storage under given temperature and pressure conditions. This expected level corresponds to the maximum quantity of gas that it is possible to store in the first layer 100 at a given temperature and pressure. Once this level is reached, the storage material is activated. However, this or these first operating cycles result in significant changes in the volume of the first layer 100. This leads to plastic compression of the second layer 200, essentially by plastic compression of the second part of the second layer 202, as shown in FIG. 2 .

Thereafter, the volume variations of the first layer 100, during storage and / or supply of gas, are less significant than during the activation of the storage material. This is called breathing of the first layer 100. These small variations in volume are compensated for by an elastic deformation of the second layer 200 as visible in FIG. 3.

Thus, the first part 201, 203 may have, before activation of the storage material, a thickness of less than 5 millimeters, preferably of approximately 2 millimeters, and in a preferred manner of approximately 1 millimeters. The second part 202 can, for its part, present, before activation of the storage material, a thickness of between 2 and 10 millimeters, preferably between 2 and 8 millimeters, and preferably between 2 and 4 millimeters. The applicant has in fact noticed that these thicknesses guarantee the best thermal conductivity within the storage structure 10, but also good compensation for the forces exerted by the storage material during variations in the volume of storage material during gas sorption and desorption phases. In any event, the plastic compression of the second layer 200 leads to a reduction in height of the second layer 200 of the order of 20 to 60% relative to its initial height, before activation, and the elastic compression leads to a reduction in height of the second layer 200 of the order of 80 to 99% relative to its initial height, before activation.

In addition, the second part material 202 may have, before activation of the storage material, a porosity greater than 70%, preferably more than 80%, and more preferably more than 95% and, after activation of the storage material, a porosity greater than 20%, preferably more than 30%, and preferably between 45% and 60%. The applicant has in fact noticed that these porosities guarantee the best thermal conductivity within the storage structure, but also good compensation for the forces exerted by the storage material during variations in the volume of the storage material during gas sorption and desorption phases.

As can be seen in FIGS. 1 to 3, the first part 201, 203 can be a first sublayer and / or the second part 202 can be a second sublayer. This guarantees a structural homogeneity which facilitates the manufacturing, maintenance and / or recycling operations of the storage structure 10. In addition, the functions of the second layer 200 can be ensured while retaining good compactness of the storage structure 10. This is however not limiting, since other forms of first part 201, 203 and second part 202 are conceivable. For example, the second layer 202 can also be structured in angular sectors, each sector corresponding to one or the other of the first part 201, 203 and of the second part 202.

Advantageously, with reference to FIGS. 1 to 3, for at least a second layer 200, the second sublayer 202 may be disposed between the first sublayer 201 and a third sublayer of second layer 203, in contact with another of the at least one first layer 100, and comprising a thermally conductive material, of thermal conductivity greater than that of the storage material, with a view to increasing the heat transfers within the storage structure. In this second sandwich 200 layer configuration, the second sublayer 202 is not in contact with the first layer 100. This configuration allows optimization of heat transfers through the storage structure 10.

Heating means

With reference to FIGS. 1, 4 and 5, a device for storing gas by sorption 1 can also comprise heating means 3 configured to heat the storage material and facilitate the desorption of the gas.

The heating means 3 may comprise a device suitable for routing a heat fluid, such as water. For example, such a device can take the form of a radiator, or a cylindrical shell of revolution, with a double wall, surrounding the storage structure 1. When the storage device 1 is connected to a gas utilization unit 6 which releases energy in the form of heat (eg fuel cell, combustion engine, exhaust line, etc.), such a heating device may include a closed circuit of heat fluid connecting the storage structure 1 to the gas use unit 6. In operation, the heat emitted by the gas use unit 6 is captured by the heat fluid in circulation, then radiated within the storage structure 1, by means of the same circulating heat fluid. This makes it possible both to cool the gas utilization unit 6, but also to facilitate the desorption of the gas by heating. This type of heating means 3 thus offers the advantage of being optimized in terms of energy, that is to say it makes it possible not to expend excess energy during the operation of the storage device 1. In addition, this makes it possible to reduce the dimensions of a possible cooling system for the gas use unit 6.

Alternatively, or in addition, the heating means 3 comprise means of ventilation by the air surrounding the storage device 1. The ventilation means indeed offer the advantage of being simple and inexpensive.

Alternatively, or in addition, the heating means 3 may comprise a resistor, for example of the electrical type, connected to an electric power generator. This type of heating means 3 is simple and quick to implement. A resistance also offers the advantage of being easily modular according to the desired applications.

Alternatively, or in addition, when the stored gas is a fuel, and the storage device 1 is connected, in addition to the gas utilization unit 6, to a gas combustion unit (not shown), it is possible to connect the heating means 3 to said gas combustion unit, so as to recover the heat released by combustion of gas. This type of heating means 3, dedicated to the storage device 1, makes it possible to very quickly increase the temperature within the storage structure 10.

As shown in FIGS. 4 and 5, the heating means 3 can include:

a first heating part 30 arranged in the storage structure 10, at a distance from the circumferential edge B, and

a second heating part 32, also arranged in the storage structure, at a distance from the circumferential edge on the one hand, and from the first heating part 30 on the other hand.

By "remote", it is understood that the first heating part 30 and the second heating part 32 are not directly in contact with the circumferential edge B, nor with each other. Thus, the first heating part 30 and the second heating part 32 define between them a space, in which a first portion 1 1 of the storage structure 10 extends.

This arrangement of the heating means 3 within the storage structure 10 makes it possible to release a central volume V _c and a peripheral volume V _p of the storage structure 10. As the heating means 3 are neither arranged at a wall of the storage structure 10, nor in the center of said storage structure 10, it is possible to heat the storage structure 10 more homogeneously. Thus, the heat flows emitted by the heating means 3 benefit the entire storage structure 10. The gas stored and / or supplied is therefore better distributed throughout the entire storage structure 10, so that it is possible to extend the life of the storage device 10.

The first heating part 30 and the second heating part 32 can also be connected to each other by a third heating part 34. Thus, the heating means 3 can have a substantially annular section, as in FIG. 1, or in the form of an S, as in FIG. 4. In this way, it is possible to optimize the segmentation of the storage structure 10 between the first portion 11 and the rest of the storage structure 10. For example, with reference to FIG. 1, it is possible to completely isolate the first portion 11 from the rest of the storage structure 10.

Furthermore, as visible in FIGS. 4 and 5, the storage structure 10 can comprise a second portion 12 extending to the circumferential edge B of the storage structure 10, and connected to the first portion 11. In this case, the first portion 11 is not isolated from the rest of the storage structure 10. This configuration advantageously makes it possible to facilitate the diffusion of gas after desorption.

As also visible in FIG. 1, the compositions and / or distributions of the storage material in the first portion 11 of the storage structure 10 may be different from the compositions and / or distributions of the storage material in the rest of the storage structure storage 10. More specifically, the storage material in the first portion 11 may be different from the storage material in the rest of the storage structure 10. Alternatively, or in addition, a thickness of at least one among the first layers 100 configured to store gas by sorption in the first portion 1 1 may be different in thickness by at least one of the first layers 100 configured to store gas by sorption in the rest of the storage structure 10, l ' thickness means the dimension along the longitudinal axis XX as defined below. Alternatively, or in addition, the number of first layers 100 and / or second layers 200, comprising the thermally conductive material, of thermal conductivity greater than that of the storage material, with a view to increasing the heat transfers within the structure storage device 10, and compressible in order to deform under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and desorption phase of gas, in the first portion 1 1 may be different from the number of first layers 100 and / or second layers 200 in the rest of the storage structure 10. Alternatively, or in addition, the material and / or a thickness of at least one of the second layers 200 of the first portion 1 1 may be different from the material and / or a thickness of at least one of the second layers 200 in the rest of the storage structure 10. Alternative ment, or in addition, at least one of the second layers 200 of the first portion 1 1 may not include two and / or three parts 201, 202, 203, while at least one of the second layers 200 in the rest of the storage structure 10 comprises two and / or three separate parts 201, 202, 203, the first part 201 and / or the third part 203 comprising a thermally conductive material, of thermal conductivity greater than that of the storage material , in order to increase the heat transfers within the storage structure 10, the second part 202 comprising, for its part, a compressible material with a view to deforming under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and gas desorption phase .

Thus, it is possible to optimize the distribution of the heat from the heating means 3 within the storage structure 10, between the first portion 11 and the rest of the storage structure 10. In fact, in operation, the first portion 1 1 will tend to heat more quickly than the rest of the storage structure 10. Consequently, it is possible to have storage and / or second layer materials 200 whose mechanical and / or thermal properties are more suitable for rapid heating within the first portion 1 1, and vice versa in the rest of the storage structure 10.

Referring to Figure 1, the storage structure 10 may have a preferred direction defining a longitudinal axis X-X. Such a configuration makes the storage device 10 particularly easy to store and / or transport. In this configuration, as visible in FIG. 1, the heating means 3 may have a substantially annular structure along the longitudinal axis X-X. In this way the distribution of heat within the first portion 1 1 and within the rest of the storage structure 10 is optimized. In fact, heat tends to propagate radially with respect to the longitudinal axis X-X. Also, an annular structure of the heating means 3 guarantees the best possible distribution of the heat transfers within the storage structure 10. Advantageously, in this case, the heating means 3 are centered around the longitudinal axis XX, in order to guarantee symmetrical homogeneity of the heat distribution.

Gas enclosure and evacuation

Referring to Figure 1, a gas discharge conduit 400 may be provided within the first portion 1 1. This is not, however, limiting since, as an alternative or in addition, a gas evacuation conduit 400 can also be provided in the rest of the storage structure 10. In any event, such conduits 400 facilitate the transport of the gas during its desorption from the storage material.

With reference to Figures 1, and 6 to 8, the storage device 10 can also include an enclosure 4 comprising an outer wall 40, the storage structure 10 being disposed inside the enclosure 4. The presence of such an enclosure 4 facilitates the transport and the use of the storage device 1. In addition, the enclosure 4 enhances the safety of use of the storage device 1, by protecting a user from possible gas leaks and / or high intensity thermal transfers.

In order to strengthen the protection of the user, but also to facilitate the diffusion of the gas during its desorption of the storage material, the storage device 1 can advantageously comprise a thermally insulating layer 42, disposed between the storage structure 10 and the outer wall 40 of the enclosure 4. This thermally insulating layer 42 is, moreover, configured to diffuse gas. In addition, the insulating layer 42 can be in contact with the storage structure 10, in order to further facilitate the diffusion of the gas, but also to improve the compactness of the storage device 1. This is not, however, limiting, since the insulating layer 42 can also be separated from the storage structure 10, for example by a free space, comprising neither storage material 10 nor second layer material 200, and which can be initially occupied by gas. This latter configuration can be encountered when the storage structure materials 10 are not compatible with the insulating layer material 42, or when it is preferable to increase the thermal insulation thanks to the free space.

The insulating layer 42 may, in one embodiment, comprise a porous structure, for example with a decreasing porosity gradient from the storage structure 10 towards the external wall 40 of the enclosure 4. This embodiment is illustrated in particular in FIG. 7. In this way, the portion of insulating layer 42 closest to the storage material can efficiently evacuate the gas after desorption, while the portion of insulating layer 42 closest to the enclosure 4 can effectively isolate heat. released by the storage structure 10.

Alternatively, or in combination, the insulating layer 42 may comprise a grooved structure. With reference to FIG. 8, grooves 420 are for example formed at the wall of the insulating layer 42 which opens onto the storage structure 10. Thus, the portion of insulating layer 42 closest to the storage material can also effectively evacuate the gas after desorption, while the portion of insulating layer 42 closest to the enclosure can isolate efficiently of the heat given off by the storage structure 10.

In addition, the insulating layer 42 can be formed at the level of an internal wall 44 of the enclosure 4, for example by treating said wall 44, or by depositing an additional coating. Such a configuration simplifies the assembly process of the storage device 1. In addition, this embodiment can advantageously lead to a reduction in the maintenance costs of the storage device.

Furthermore, the insulating layer 42 can be a film. In this case, the insulating layer 42 has a very thin thickness relative to the thickness of the enclosure 4, for example less than 25% of the thickness of the enclosure, or of the order of 10% of the 'thickness of the enclosure, preferably 5% of this thickness. This configuration makes it possible on the one hand to improve the compactness and lightness of the storage device 1, and on the other hand to facilitate its manufacture and maintenance.

One or more gas evacuation conduits 400 may also be provided within the insulating layer 42, as visible in FIG. 1, in order to facilitate the transport of the gas outside the storage device 1, after desorption.

Gas storage and / or supply system

With reference to FIG. 9, a gas storage and / or supply system 5 comprises a sorption gas storage device 1 according to any of the embodiments previously described, and a gas utilization unit 6 .

The gas utilization unit 6 can, for example, be a motor vehicle fuel cell when the stored gas is hydrogen.

Method of manufacturing a storage device

Referring to FIG. 10, a method of manufacturing a sorption gas storage device 1 according to any one of the previously described embodiments comprises a step E1 of compressing a powder of gas storage material by sorption so as to form a first layer of gas storage material 100 by sorption in pre-compressed powder form. In addition, such a method E may include a step E2 of disposing a second layer 200 adjacent to the first layer 100, said second layer 200 comprising a thermally conductive material, with thermal conductivity greater than that of the storage material.

Claims

1. Gas storage device by sorption (1) comprising:

a sorption gas storage structure (10) comprising a sorption gas storage material, said storage structure (10) having a circumferential edge (B),

- heating means (3) configured to heat the storage material, and facilitate the desorption of the gas, said heating means (3) comprising:

o a first heating part (30) arranged in the storage structure (10), at a distance from the circumferential edge (o), a second heating part (32) arranged in the storage structure (10), at a distance from the circumferential edge (B) on the one hand, and the first heating part (30) on the other hand, the first heating part (30) and the second heating part (32) defining between them a space in which a first portion (1 1 ) of the storage structure (10) extends.

2. Storage device (1) according to claim 1, wherein the first heating part (30) and the second heating part (32) are connected to each other by a third heating part (34).

3. Storage device (1) according to one of claims 1 and 2, wherein the storage structure (10) has a preferred direction defining a longitudinal axis (XX), the heating means (3) having a substantially structure annular along the longitudinal axis (XX).

4. Storage device (1) according to one of claims 1 to 3, in which the compositions and / or distributions of the storage material in the first portion (11) of the storage structure (10) are different from the compositions and / or distributions of the storage material in the rest of the storage structure (10), in order to optimize the distribution of the heat from the heating means (3) within the storage structure (10).

5. Storage device (1) according to one of claims 1 to 4, further comprising:

- an enclosure (4) comprising an outer wall (40), the storage structure (2) being arranged inside the enclosure (4), and

- a thermally insulating layer (42) disposed between the storage structure (10) and the outer wall (40) of the enclosure (4), said layer (42) being further configured to diffuse gas.

6. Storage device (1) according to claim 5, wherein the insulating layer (42) comprises a porous structure.

7. Storage device (1) according to one of claims 5 and 6, wherein the insulating layer (42) comprises a grooved structure.

8. Storage device (1) according to one of claims 5 to 7, in which the insulating layer (42) is a film.

9. Storage device (1) according to one of claims 5 to 8, in which the insulating layer (42) is formed at the level of an internal wall (44) of the enclosure (4), for example by treatment of said wall (44), or by depositing an additional coating.

10. Storage device (1) according to one of claims 1 to 9, in which the storage structure (10) comprises:

- a first layer (100) comprising a sorption storage material,

- a second layer (200) comprising:

a first part of the second layer (201, 203), in contact with the first layer (100), and comprising a thermally conductive material, of thermal conductivity greater than that of the storage material, with a view to increasing the heat transfers to the within the storage structure (10), and o a second part of the second layer (202), comprising a material: ^■ compressible in order to deform under the action of forces exerted by the storage material during variations in the volume of the storage material during the sorption and desorption phases of the gas,

^■ greater compressibility than that of the first part material (201, 203), and

^■ thermally conductive, with a higher thermal conductivity than that of the storage material, in order to increase the heat transfers within the storage structure (10).

11. Storage device (1) according to one of claims 1 to 10, in which the storage structure (10) comprises:

a plurality of first layers (100), each first layer (100) comprising the material for storing gas by sorption in pre-compressed powder form, and

- a plurality of second layers (200), each second layer (200) comprising a material:

o compressible in order to deform under the action of forces exerted by the storage material during variations in volume of the storage material during sorption and desorption phases of gas, and

o thermally conductive, with a higher thermal conductivity than that of the storage material, in order to increase the heat transfers within the storage structure (10), the first (100) and the second (200) layers being arranged in a alternate pattern.

12. Manufacturing process (E) of a device (1) according to one of claims 1 to 11 comprising the steps of:

- compression (E1) of a powder of gas storage material by sorption so as to form a first layer (100) of gas storage material by sorption in pre-compressed powder form, - Provision (E2) of a second layer (200) adjacent to the first layer (100), said second layer (200) comprising a thermally conductive material, of thermal conductivity greater than that of the storage material.

13. A gas storage and / or supply system (5) comprising a device (1) according to one of claims 1 to 1 1, and a gas utilization unit (6).