Facility for storing and / or producing cooled / liquefied hydrogen and activation and / or regeneration method

Abstract

The invention relates to a facility for storing and / or producing cryogenic hydrogen, comprising at least one catalysis section (6) comprising a catalyst, for example based on ferrous oxide, the catalysis section (6) being configured to promote ortho-para conversion of hydrogen, the facility (1) comprising a device for activating and / or regenerating the catalyst of the catalysis section (6), the activation and / or regeneration device comprising a pipe for injecting a flow of flushing gas having a temperature of greater than 20°C, the injection pipe being configured to allow a gas flush of the catalyst of the catalysis section (6).

Description

[0001] Installation for storing and / or producing cooled / liquefied hydrogen and activation and / or regeneration process

[0002] Description

[0003] The invention relates to a cooled / liquefied hydrogen production plant and an activation and / or regeneration method.

[0004] The invention relates more particularly to an installation for storing and / or producing cryogenic hydrogen comprising at least one catalysis section, comprising a catalyst, for example based on ferrous oxide, the catalysis section being configured to promote the ortho-para conversion of hydrogen, the installation comprising a device for activating and / or regenerating the catalyst of the catalysis section.

[0005] The invention relates in particular to an activation and / or regeneration of a catalyst which promotes the ortho-para conversion of hydrogen in a hydrogen plant, in particular liquefied hydrogen.

[0006] The ortho / para conversion catalyst, which typically comprises a ferric oxide, is integrated into a cryogenic hydrogen storage and / or production facility such as a hydrogen liquefaction facility.

[0007] The invention aims to activate and / or regenerate this catalyst to guarantee the performance of the installation and / or the specifications of the hydrogen concerned.

[0008] This equipment equipped with an ortho / para conversion catalyst can be installed inside a storage facility, a vehicle (ship) within the exchanger(s) or pot(s) of the installation. For example, in the case of a hydrogen liquefaction installation, exchanger passages and / or pots of the hydrogen supply circuit to be cooled are filled with catalyst to ensure the conversion of the hydrogen concomitantly with the cooling and liquefaction of the hydrogen.

[0009] The conversion performance of the catalyst may degrade and degrade the specifications of the hydrogen stored or produced by the facility.

[0010] An aim of the present invention is to overcome all or part of the drawbacks of the prior art noted above.

[0011] To this end, the installation according to the invention, moreover in accordance with the generic definition given in the preamble above, is essentially characterized in that the activation and / or regeneration device comprises a pipe for injecting a flow of scavenging gas having a temperature greater than 20°C, the injection pipe being configured to allow gas scavenging of the catalyst of the catalysis section.

[0012] This activation or regeneration of the catalyst makes it possible to eliminate all or part of the moisture or other adsorbed impurities present in / on the catalyst.

[0013] Furthermore, embodiments of the invention may include one or more of the following features:

[0014] - the installation comprises a supply circuit having an upstream end intended to be connected to a source of gaseous hydrogen and a downstream end intended to be connected to a receiver of cooled / liquefied hydrogen, at least one cryogenic refrigerator configured to provide cold power, and a set of heat exchanger(s) configured to ensure a heat exchange between the cryogenic refrigerator and the hydrogen circulating in the supply circuit for the purpose of cooling it, the at least one catalysis section comprising a catalysis section arranged in the supply circuit,

[0015] - the sweeping gas comprises at least one of: hydrogen, nitrogen, argon, neon, helium, and for example a mixture containing hydrogen and with at least one inert gas,

[0016] - the sweep gas comprises 5% to 98% by mole of hydrogen, the activation and / or regeneration device comprising a pipe for recovering the flow of sweep gas having swept the catalyst of the catalysis section,

[0017] - the injection line includes or consists of a supply circuit line,

[0018] - the injection line comprises a line separate from the supply circuit and connected to the latter,

[0019] - the activation and / or regeneration device comprises a source of scavenging gas connected to the injection line, for example a PSA, an electrolyser, a gas network, the activation and / or regeneration device possibly comprising a member for reheating the scavenging gas,

[0020] - the sweep gas source is configured to provide a sweep gas flow having a pressure between atmospheric pressure and 30 bara, preferably between atmospheric pressure and 12 bara, for example between atmospheric pressure and 3 bara,

[0021] - the installation comprises several catalysis sections, the activation and / or regeneration device comprising several separate injection lines connected respectively to different catalysis sections or sets of separate catalysis sections and / or the activation and / or regeneration device comprises at least one injection line configured to ensure hot gas sweeping of the catalyst in series with several catalysis sections,

[0022] - the activation and / or regeneration device comprising one or more recovery pipes respectively for the sweep gas flows having swept separate catalysis sections,

[0023] - the activation and / or regeneration device comprises a bypass line configured to allow the transfer of sweeping gas to the refrigerator for the purpose of reheating the installation,

[0024] - the activation and / or regeneration device comprises a device for creating a vacuum in the catalysis section and configured to allow cycles of creating a vacuum in the catalyst alternating with pressure increases in the catalysis section,

[0025] - the activation and / or regeneration device comprises at least one member for determining the dew point, the temperature and / or the humidity level of the flow of sweeping gas having swept the catalysis section, the installation being configured to carry out or interrupt the gas sweeping of the catalyst of the catalysis section as a function of a signal from the at least one determination member.

[0026] The invention also relates to a method for activating and / or regenerating the catalyst of a catalysis section of a plant according to any one of the preceding claims, the method comprising a step of hot gas sweeping of the catalyst of the catalysis section with a sweep gas flow having a temperature greater than 20°C, for example greater than 50°C, for example 65°C or 80°C or 100°C or more.

[0027] According to other possible particularities: the scanning step is carried out before starting the installation and / or during at least partial shutdown of the installation,

[0028] - the sweeping step is interrupted as a function of a measurement or calculation of a temperature or of the humidity level or of the dew point of the sweep gas flow having swept the catalysis section, the sweep gas is supplied by at least one source from among: an electrolyser, a gas network, a PSA, the sweep gas being supplied at a determined hot temperature above 20°C by the source and / or heated downstream of the source, the outlet of a stage of a compression stage at a temperature above 20°C of a refrigeration cycle of a cycle gas of the installation - the sweeping step is preceded by at least one cycle comprising a vacuuming of the catalysis section followed by a pressure increase of the catalysis section,

[0029] - the sweeping step is preceded by at least one cycle comprising a vacuuming of the catalysis section followed by a pressure increase of the catalysis section, the vacuuming and / or the pressure increase is carried out at a determined temperature above 20°C.

[0030] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0031] Other features and advantages will appear on reading the description below, made with reference to the figures in which:

[0032] Brief description of the figures

[0033] The invention will be better understood on reading the following description, given solely by way of example and with reference to the appended drawings in which:

[0034] Fig. 1 is a schematic and partial view illustrating a first example of structure and operation of an installation according to the invention,

[0035] Fig. 2 is a schematic and partial view illustrating a second example of structure and operation of an installation according to the invention,

[0036] Fig. 3 is a schematic and partial view illustrating a third example of structure and operation of an installation according to the invention,

[0037] Fig. 4 is a schematic and partial view illustrating a fourth example of structure and operation of an installation according to the invention,

[0038] Fig. 5 is a schematic and partial view illustrating a fifth example of structure and operation of an installation according to the invention,

[0039] Fig. 6 is a schematic and partial view illustrating a sixth example of structure and operation of an installation according to the invention,

[0040] Fig. 7 is a schematic and partial view illustrating a seventh example of structure and operation of an installation according to the invention,

[0041] Fig. 8 is a schematic and partial view illustrating an eighth example of structure and operation of an installation according to the invention.

[0042] Detailed description

[0043] In all figures, the same references refer to the same elements.

[0044] In this detailed description, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Single features of different embodiments may also be combined and / or interchanged to provide other embodiments.

[0045] Fig. 1 illustrates the general principle of the invention applied to a hydrogen storage and / or production facility 1. The facility 1 comprises, for example, hydrogen storage, for example a liquefied hydrogen tank of a vehicle or ship. The facility 1 comprises at least one catalysis section 6, comprising a catalyst, for example based on ferrous oxide. The catalysis section 6 is configured to ensure conversion of ortho hydrogen into para hydrogen.

[0046] The installation 1 comprises a device for activating and / or regenerating the catalyst of the catalysis section 6. This activation and / or regeneration device comprises a pipe 9 for injecting a flow of sweeping gas having a temperature greater than 20°C. The injection pipe 9 is configured to allow hot gas sweeping of the catalyst of the catalysis section 6 for the purpose of its regeneration or activation.

[0047] Thus, according to a first embodiment, a flow of dry and relatively hot gas is injected through one or more pieces of equipment containing an ortho-para conversion catalyst.

[0048] The sweep gas comprises at least one of: hydrogen, nitrogen, argon, neon, helium, and for example a mixture containing hydrogen and with at least one inert gas.

[0049] The sweep gas is preferably a dry gas, i.e. containing less than 10 ppm of water or less than 0.1 ppm of water.

[0050] Dry hydrogen, nitrogen, argon, neon, helium or any other inert gas can be used for this activation / regeneration. The sweep gas can contain trace impurities (preferably oil-free). Thus, different mixtures with hydrogen can be considered (such as H2 and Ar or H2 and N2 or any mixture of hydrogen with one or more inert gases). The sweep gas can have, for example, a hydrogen content of 5 mol% to 98 mol%. The oxygen content of the sweep gas is low and preferably less than 30 ppb.

[0051] If the sweep gas is mainly nitrogen-based, it may possibly contain a greater amount of oxygen. In this case, the swept equipment is preferably purged with pure nitrogen before being subsequently exposed to hydrogen when the plant is restarted 1.

[0052] The sweep gas flow rates used may depend on the operating pressure and operating temperature. These flow rates are limited to avoid catalyst damage, in particular to avoid catalyst attrition and / or significant catalyst movement in the exchangers or other equipment that houses it. The flow rate is therefore chosen to avoid erosion or the creation of privileged paths in the catalyst.

[0053] Preferably, the sweep gas stream has a pressure between atmospheric pressure and 30 bara, preferably between atmospheric pressure and 12 bara and more preferably between atmospheric pressure and 3 bara. Desorption at a relatively low pressure improves the final state of the catalyst.

[0054] The temperature of the catalyst during the activation / regeneration step is above 20°C, for example 50°C or more, for example 65°C or more, for example 80°C.

[0055] Activation can be performed at higher temperatures (e.g. 100°C or above 100°C).

[0056] As illustrated, the activation and / or regeneration device preferably comprises a line 10 for recovering the flow of sweeping gas having swept the catalyst of the catalysis section 6.

[0057] Fig. 2 illustrates this principle applied to a plant 1 for producing cryogenic hydrogen, for example liquefied. The plant 1 comprises a supply circuit 2 having an upstream end intended to be connected to a source of gaseous hydrogen to be cooled and a downstream end intended to be connected to a receiver of cooled / liquefied hydrogen (for example a cryogenic storage not shown for the sake of simplification). The plant 1 comprises at least one cryogenic refrigerator 3 configured to provide cold power and a set of heat exchanger(s) 4, 5 configured to ensure a heat exchange between the cryogenic refrigerator 3 and the hydrogen circulating in the supply circuit 2 for the purpose of cooling it.

[0058] The installation 1 comprises in this example several catalysis sections 6 arranged in the supply circuit 2, for example in one or more passages of the heat exchangers 4, 5 and / or in dedicated catalytic converters (outside the exchangers).

[0059] In the example illustrated schematically and partially, the refrigerator 3 is of the cycle circuit type producing a cold power by subjecting a cycle gas (comprising for example hydrogen and / or helium and / or other gases) to a thermodynamic cycle. The cycle gas is in particular compressed, cooled and then expanded. For the sake of simplification, only one compression stage is shown schematically. Similarly, the refrigerator 3 may comprise other refrigeration and pre-refrigeration systems. For example, several (pre)refrigeration systems may be provided to stage the cooling of the hydrogen flow of the supply circuit 2 between its upstream and downstream ends. In the example illustrated, the installation 1 comprises several heat exchangers 4, 5 for cooling the cycle circuit 2.Furthermore, as illustrated, the heat exchangers 4, 5 can be distributed in two separate cold boxes 12, 13 thermally insulated and containing the cold equipment of the installation 1. For example, a first pre-cooling cold box 12 contains the pre-cooling equipment up to a first temperature (for example 80K), while the second cold box contains the cooling equipment from the first temperature up to a second temperature: for example 20K.

[0060] Fig. 2 illustrates several catalysis sections 6 arranged in series along the supply circuit 2, in the cold boxes 12, 13.

[0061] Installation 1 includes an activation and / or regeneration device enabling the catalyst to be activated before starting the liquefier and / or enabling the catalyst to be regenerated if the catalyst's performance is degraded (observation or suspicion of low ortho-para conversion of Hydrogen, for example).

[0062] In the example of Fig. 2, the injection line comprises or consists of a line of the supply circuit 2. That is to say that the supply circuit is itself used to ensure the activation and / or regeneration of the catalyst of the catalysis section(s) 6. Thus, before starting up the installation or after at least partial shutdown of the installation 1, the sweep gas is circulated in the supply circuit so as to “rinse” the catalyst. That is to say that a relatively hot and dry sweep gas feeds the supply circuit 2 with a determined flow rate.

[0063] This sweep gas may be supplied by a source including, for example, a pressure vessel, a PSA (pressure swing adsorption system), an electrolyzer, a gas network. The sweep gas may be supplied at a relatively warm temperature by the source and / or may be reheated downstream of the source if required.

[0064] In the case of a PSA, the gas temperature at the PSA inlet is, for example, adjusted to produce sweep gas (e.g., hydrogen) at the desired temperature. This method may require the PSA to be relatively close to the facility and the liquefaction unit, or the pipe between the PSA and the liquefier to be thermally insulated.

[0065] A downstream end of the supply circuit 2 may form all or part of a recovery pipe collecting the sweep gas having swept the catalysis section(s) 6.

[0066] In the example of Fig. 3, a dedicated purge gas injection line 9 and a recovery line 10 are provided respectively for several (and for example each) of the catalysis sections 6. That is to say, an injection line 9 and a recovery line 10 can be provided exclusively for each of the catalysis sections 6.

[0067] As illustrated, the injection pipe(s) 9 may be taps connected to the supply circuit 2, at a first end of a catalysis section 6. Similarly, the recovery pipe(s) 10 may comprise taps connected to the supply circuit 2, at a second end of a catalysis section 6. Thus, each catalysis section 6 may be swept by a separate respective sweep gas flow. That is to say, the sweeping (activation or regeneration) may be carried out independently (equipment by equipment simultaneously or not or in a manner for certain equipment only).

[0068] This embodiment is different from the embodiment of Fig. 1 in which the same flow of sweeping gas ensures the series sweeping of a plurality of catalysis sections.

[0069] As schematically illustrated, a heater 7 may be provided on the injection line 9. A temperature sensor 14 may also be provided on the injection line 9 to monitor the temperature of the injection gas. Similarly, a temperature sensor 15 may also be provided on the purge gas recovery line 10.

[0070] The example of Fig. 4 differs from that of Fig. 3 only in that the ends of the injection and recovery 10 lines 9 are tappings connected to the supply circuit 2. That is to say, the scavenging of the catalysis sections uses dedicated inlets and outlets to pass through the supply circuit to scavenge several devices in series with gas. In addition, as illustrated, a heater 7 may be provided on the injection line 9 (for example a reheating heat exchanger 7).

[0071] In the example of Fig. 5, a dedicated sweep gas injection line 9 and recovery line 10 are provided respectively for two separate sets of catalysis sections 6.

[0072] That is to say, a first injection line 9 and a first recovery line 10 may be provided exclusively for a first set of catalysis sections 6 in series and a second injection line 9 and a second recovery line 10 may be provided exclusively for a second set of catalysis sections 6 in series. As illustrated, these two sets of catalysis sections 6 may correspond respectively to the two cold boxes 12, 13 of the installation. That is to say, the catalysis sections 6 of the two cold boxes are activated or regenerated via separate and independent dedicated sweep gas circuits. As before, at least one injection line 9 may be provided with a heater 7. Fig. 5 also schematically illustrates via a dotted line the possibility that at least one of the injection lines 9 is supplied with sweep gas from cycle gas of a cycle of the refrigerator 3.Indeed, when the cycle gas is suitable (for example hydrogen and / or helium and / or other gas), the cycle gas can be used for this scavenging. In particular, the cycle gas can be taken from the cycle at the outlet of a compression stage at a suitable temperature and pressure.

[0073] The embodiment of Fig. 6 differs from that of Fig. 4 only in that the two injection lines 9 are supplied in parallel via the same source. In addition, the same recovery line 10 recovers the two gas flows after scavenging. The two scavenging gas flows can be in opposite directions in the supply circuit 2 (for example opposite circulation in the two cold boxes 12, 13 and common outlet between the two assemblies).

[0074] The embodiment of Fig. 7 differs from that of Fig. 5 essentially in that the injection line 9 comprises an extension also making it possible to supply the cycle circuit of the refrigerator 3 with purging gas. This makes it possible to heat the catalysis section 6 indirectly by circulating a flow of relatively hot gas in a circuit which exchanges heat indirectly with the catalysis section 6 (via at least one common heat exchanger for example).

[0075] This saves heating and catalyst activation / regeneration time. In fact, this improves the heating of the metal mass of all equipment involved or connected to the catalysis sections 6).

[0076] Thus, for plate and fin heat exchangers, it is possible to accelerate the activation or regeneration of the catalyst they contain by minimizing the heating time of the metal mass of the plate and fin exchanger. This can be achieved by ensuring circulation of hot sweep gas over all or part of the circuits of the exchangers which exchange heat with the activation catalyst fluid.

[0077] As illustrated, an outlet conduit 101 may be provided to recover and evacuate this flow of scavenging gas from the cycle circuit.

[0078] Fig. 8 illustrates another variant in which the installation 1 comprises a device for placing the catalyst section(s) 6 under vacuum to allow cycles of placing the catalyst under vacuum alternating with pressure increases in the catalyst section 6. Vacuum / pressurization cycles can be carried out on circuits and equipment containing ortho-para catalyst material. For this purpose, the installation 1 comprises a sealed shutter 10 at one end of the supply circuit 2 (for example a valve) and a suction pipe which can be provided for example with a vacuum pump 11. As illustrated, the suction pipe 11 can be a tapping made on the supply circuit 2. This configuration makes it possible to carry out a succession of vacuum cycles and pressure increases (or pressurization) of the catalyst sections.

[0079] This helps to complete or prepare the flushing step described above to improve the efficiency of the catalyst regeneration / activation procedure.

[0080] Vacuuming and / or pressure build-up can also be carried out at relatively high temperatures (like flushing).

[0081] After these vacuum / pressurization cycles the catalyst sections can be swept / rinsed as described above (relatively hot and dry sweep gas).

[0082] In the example illustrated in Fig. 8, the evacuation and subsequent re-pressurization apply to a series of catalysis sections of the feed circuit 2. Of course, it is possible to provide independent evacuation and pressurization circuits for equipment or groups of equipment as described above for the sweep.

[0083] Thus, this sweeping or vacuuming can be carried out

[0084] - for the entire portion of supply circuit 2 (online)

[0085] - by groups of equipment (for example by cold box) simultaneously or successively (for example first the first pre-cooling cold box), in series or independently, or independently for each equipment equipped with a catalysis section 6.

[0086] It should be noted that in the examples described above, the circulation of the scavenging gas in the supply circuit 2 is essentially in the direction of circulation of the cycle gas (from the first upper end to the second lower end). Of course, this direction of circulation of the scavenging gas is in no way limiting and can be reversed (direction opposite to the direction of circulation of the supply gas).

[0087] The scanning operation can be performed for a fixed duration and / or stopped in response to a fixed parameter.

[0088] For example, the humidity and / or dew point of the recovered sweep gas stream can be calculated or measured and when it reaches a determined value, the sweep is stopped.

[0089] For example, this dew point value may be -40°C. This may characterize sufficient activation or regeneration. Alternatively or in combination, this activation / regeneration may be interrupted based on a measurement 15 of the temperature of the sweep gas at the outlet of the circuit.

[0090] When the activation or regeneration of the catalysts is complete, a positive pressure is preferably maintained in the installation circuitry (tanks and / or pipes of supply circuit 2).

[0091] Installation 1 can then be started or restarted (starting the refrigerator and gradually cooling the various cold parts, etc.).

Claims

Claims

1. Installation for storing and / or producing cryogenic hydrogen comprising at least one catalysis section (6), comprising a catalyst, for example based on ferrous oxide, the catalysis section (6) being configured to promote the ortho-para conversion of hydrogen, the installation (1) comprising a device for activating and / or regenerating the catalyst of the catalysis section (6), the activation and / or regeneration device comprising a conduit for injecting a flow of sweeping gas having a temperature greater than 20°C, the injection conduit being configured to allow gas sweeping of the catalyst of the catalysis section (6), the installation (1) further comprising a supply circuit (2) having an upstream end intended to be connected to a source of gaseous hydrogen and a downstream end intended to be connected to a receiver of cooled / liquefied hydrogen,at least one cryogenic refrigerator (3) configured to provide cooling power, and a set of heat exchanger(s) (4, 5) configured to ensure a heat exchange between the cryogenic refrigerator (3) and the hydrogen circulating in the supply circuit (2) for the purpose of cooling it, the at least one catalysis section (6) comprising a catalysis section arranged in the supply circuit (2), the activation and / or regeneration device comprising a bypass pipe (8) configured to allow the transfer of sweeping gas to the refrigerator (3) for the purpose of heating the installation.,

2. Installation according to claim 1, characterized in that the sweeping gas comprises at least one of: hydrogen, nitrogen, argon, neon, helium, and for example a mixture containing hydrogen and with at least one inert gas.

3. Installation according to any one of the preceding claims, characterized in that the sweeping gas comprises 5% to 98% by mole of hydrogen.

4. Installation according to any one of the preceding claims, characterized in that the activation and / or regeneration device comprising a pipe (10) for recovering the flow of sweeping gas having swept the catalyst of the catalysis section (6).

5. Installation according to any one of the preceding claims, characterized in that the injection pipe comprises or consists of a pipe of the supply circuit (2).

6. Installation according to any one of the preceding claims, characterized in that the injection pipe comprises a pipe (9) separate from the supply circuit (2) and connected to the latter.

7. Installation according to any one of the preceding claims, characterized in that the activation and / or regeneration device comprises a source of sweeping gas connected to the injection pipe, for example a PSA, an electrolyser, a gas network, the activation and / or regeneration device possibly comprising a member (7) for heating the sweeping gas.

8. Installation according to claim 7, characterized in that the source of sweeping gas is configured to provide a flow of sweeping gas having a pressure between atmospheric pressure and 30 bara, preferably between atmospheric pressure and 12 bara, for example between atmospheric pressure and 3 bara.

9. Installation according to any one of the preceding claims, characterized in that it comprises several catalysis sections (6), the activation and / or regeneration device comprising several distinct injection pipes (9) connected respectively to different catalysis sections (6) or sets of distinct catalysis sections (6) and / or the activation and / or regeneration device comprises at least one injection pipe configured to ensure hot gas sweeping of the catalyst in series with several catalysis sections (6).

10. Installation according to the preceding claim characterized in that the activation and / or regeneration device comprising one or more pipes (10) for recovering respectively the sweep gas flows having swept separate catalysis sections (6).

11. Installation according to any one of the preceding claims, characterized in that the activation and / or regeneration device comprises a device (10, 11) for placing the catalysis section (6) under vacuum and configured to allow cycles of placing the catalyst under vacuum alternating with pressure increases in the catalysis section (6).

12. Installation according to any one of the preceding claims, characterized in that the activation and / or regeneration device comprises at least one member (12) for determining the dew point, the temperature and / or the humidity level of the flow of sweeping gas having swept the catalysis section (6) and in that the installation (1) is configured to carry out or interrupt the gas sweeping of the catalyst of the catalysis section (6) as a function of a signal from the at least one determination member (12).

13. Method for activating and / or regenerating the catalyst of a catalysis section (6) of an installation according to any one of the preceding claims, the method comprising a step of hot gas sweeping of the catalyst of the catalysis section (6) with a sweep gas flow having a temperature greater than 20°C, for example greater than 50°C, for example 65°C or 80°C or 100°C or more.

14. Method according to the preceding claim, characterized in that the scanning step is carried out before starting the installation and / or during at least partial shutdown of the installation (1).

15. Method according to any one of claims 13 or 14, characterized in that the sweeping step is interrupted as a function of a measurement or calculation of a temperature or the humidity level or the dew point of the sweep gas flow having swept the catalysis section (6).

16. Method according to any one of claims 13 to 15, characterized in that the sweeping gas is supplied by at least one source from among: an electrolyser, a gas network, a PSA, the sweeping gas being supplied at a determined hot temperature above 20°C by the source and / or heated downstream of the source, the outlet of a stage of a compression stage at a temperature above 20°C of a refrigeration cycle of a cycle gas of the installation (1).

17. Method according to any one of claims 13 to 16, characterized in that the flushing step is preceded by at least one cycle comprising placing the catalysis section (6) under vacuum followed by increasing the pressure of the catalysis section (6).

18. Method according to the preceding claim, characterized in that the vacuuming and / or the pressure increase is carried out at a determined temperature above 20°C.

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