Installation for the separation of a gas mixture by adsorption with an optimized footprint

Abstract

Adsorption assembly (301) for the separation by adsorption of a gaseous mixture, said assembly comprising: - at least two adsorbers, - a common feed manifold (90), - a common low-pressure discharge manifold (91), each adsorber comprising an adsorption tank (1, 2, …, 8), an inlet line (11, 51) fluidically connected to the tank to supply the tank (1, 2, …, 8) with a feed gas and a distribution and switching system arranged to connect the inlet line (11, 51) of the adsorber in question with the common feed manifold (90) or to connect the inlet line (11, 51) of the adsorber in question with the common low-pressure discharge manifold (91), characterized in that the distribution and switching system (13, 53) of a first adsorber and the distribution and switching system (13, 53) of a second adsorber are superimposed vertically on each other.Abbreviated figure: Fig. 1.

Description

Title of the invention: Installation for the separation of a gaseous mixture by adsorption with optimized floor footprint

[0001] The present invention relates to an adsorption unit and the installation for separating a gas mixture incorporating an adsorption unit, and to the use of said installation in a process for separating a gas mixture by adsorption. More specifically, the invention makes it possible to significantly reduce the footprint usually required for this type of installation.

[0002] Adsorption processes are of several types depending on whether the adsorbent is regenerable in situ or not. Three main families of adsorption processes can then be distinguished: lost-charge processes, TSA (Temperature Swing Adsorption) processes, and finally PSA (Pressure Swing Adsorption) processes.

[0003] In lost charge processes - often referred to in this case as a guard bed - a new charge is put in place when the one in use is saturated by impurities or more generally when it can no longer play its protective role sufficiently.

[0004] In contrast, TSA and PSA processes are cyclic processes that continuously link adsorption and regeneration phases. In TSA processes, the adsorbent at the end of its use is regenerated in situ; that is, the trapped impurities are removed so that the adsorbent recovers most of its adsorption capacity and can begin a new purification cycle. The essential regeneration effect is due to a temperature increase. Finally, in PSA processes, the adsorbent at the end of the production phase is regenerated by desorption of the impurities achieved by reducing their partial pressure. This pressure reduction can be achieved by lowering the total pressure and / or by purging with a gas that is free of impurities or contains few impurities.

[0005] A strong trend in recent decades has been to process increasingly large flow rates in units using adsorption, whether for the separation or purification of gas mixtures. This is particularly true today for the production of high-purity hydrogen, as hydrogen is seen as a potential energy carrier that could replace a portion of the hydrocarbons used, for example, in transportation. This is also becoming true for the separation of carbon dioxide (CO2) contained in gases from various industrial processes. Indeed, CO2 capture is the technological advance that is attracting the most attention and could prove necessary in the fight against climate change. One of the processes The most promising method is CO2 capture by adsorption, particularly using a PSA-type process. It may eventually be necessary to dry this CO2 in a TSA-type unit before storing it or using it in industrial processes.

[0006] Technologically, there is no limit to the flow rate of gas that can be treated by adsorption, these units generally being made up of identical adsorbers operating cyclically and whose number can be adapted to the flow rate to be treated.

[0007] A limitation that is emerging with the increasing size of these units is the floor space required to accommodate both the number of adsorbers present (for example, 16, 20, 28...) and the associated manifold networks, valves, and instrumentation necessary for proper operation. For example, it has been estimated that a site of 1500 m² is required for a PSA-type unit comprising sixteen adsorbers with a diameter of five meters, with an optimized layout of two rows of eight adsorption tanks and a central frame, called a valve and manifold skid, including the associated equipment. To this would need to be added the control room and the gas storage capacity(s), which can, however, be more easily located remotely.To handle even larger flow rates, such as those planned for hydrogen production and the decarbonation of various industrial gases, or to be able to implement units in a more limited available space, it is necessary to be able to compact all the constituent elements in order to significantly reduce their footprint or, for a given size, to be able to integrate more elements.

[0008] It should be noted, however, that such a compaction solution originally designed for large units is also applicable to small or medium capacity PSAs or to TSAs implementing a plurality of adsorbers, for example four or more, provided that the available space is incompatible with a classic layout.

[0009] The invention relates to an adsorption assembly for the separation by adsorption of a gaseous mixture, said assembly comprising:

[0010] - at least two adsorbers,

[0011] - a common feed manifold for each of the at least two adsorbers the gaseous mixture,

[0012] - a common low-pressure discharge manifold, configured to discharge a the most adsorbable fraction of the gaseous mixture from each of the at least two adsorbers,

[0013] each adsorber comprising an adsorption tank, an inlet line fluidly connected to the tank to supply the tank with a feed gas, and a distribution and switching system arranged to establish communication fluidic the inlet pipe of the adsorber in question with the common feed manifold or connect the inlet pipe of the adsorber in question with the common low-pressure discharge manifold,

[0014] characterized in that the distribution and switching system of a first adsorber and the distribution and switching system of a second adsorber are vertically superimposed on each other.

[0015] The invention also relates to an adsorption assembly for the separation by adsorption of a gaseous mixture, said assembly comprising:

[0016] - at least two adsorbers,

[0017] - a common feed manifold for each of the at least two adsorbers the gaseous mixture,

[0018] - a common low-pressure discharge manifold, configured to discharge a the most adsorbable fraction of the gaseous mixture from each of the at least two adsorbers,

[0019] - a common high-pressure discharge manifold, configured to discharge a the least adsorbable fraction of the gaseous mixture from each of the at least two adsorbers,

[0020] - a common gas exchange manifold, configured to transfer a gas from one of at least two adsorbers towards another of said at least two adsorbers,

[0021] each adsorber comprising:

[0022] - an adsorption tank,

[0023] - an inlet pipe fluidically connected to the tank to supply the tank with a feed gas,

[0024] - an outlet pipe fluidly connected to the tank to collect a gas discharge from the tank,

[0025] - an input distribution and switching system arranged for selectively to connect the inlet pipe of the adsorber in question to the common supply manifold or to connect the inlet pipe of the adsorber in question to the common low-pressure discharge manifold,

[0026] - an output distribution and switching system arranged for selectively to connect the outlet pipe of said adsorber in question to the common high-pressure discharge manifold and / or to connect the outlet pipe of the adsorber in question to the common gas exchange manifold,

[0027] characterized in that one of the input distribution and switching systems and one of the output distribution and switching systems are vertically superimposed on each other.

[0028] In particular, the input distribution and switching system of a first adsorber and the output distribution and switching system of said first adsorber are vertically superimposed on each other.

[0029] According to one embodiment, each adsorber includes an outlet line fluidly connected to the tank to collect a discharge gas from the tank.

[0030] According to one embodiment, the adsorption assembly includes a common high-pressure discharge manifold, configured to discharge a least adsorbable fraction of the gas mixture from each of the at least two adsorbers.

[0031] According to one embodiment, the adsorption assembly includes a common gas exchange collector configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers.

[0032] According to one embodiment, each of said distribution and switching systems is an input distribution and switching system and each adsorber includes an output distribution and switching system arranged to connect the outlet line of the adsorber in question with the common high-pressure discharge manifold and / or to connect the outlet line of the adsorber in question with the common gas exchange manifold.

[0033] According to one embodiment, the common gas exchange manifold is a first common gas exchange manifold and the adsorption assembly includes a second common gas exchange manifold configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers and the output distribution and switching system of each of the at least two adsorbers is arranged to connect the outlet line of the adsorber in question with the high-pressure common discharge manifold, to connect the outlet line of the adsorber in question with the first common gas exchange manifold and / or to connect the outlet line of the adsorber in question with the second common gas exchange manifold.

[0034] According to one embodiment, the adsorption assembly comprises a third common gas exchange manifold configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers, and the outlet distribution and switching system of each of the at least two adsorbers is arranged to connect the outlet line of the adsorber in question with the common high-pressure discharge manifold, and to connect the outlet line of the adsorber in question with the first common gas exchange collector, connect the outlet pipe of the adsorber in question with the second common gas exchange collector and / or connect the outlet pipe of the adsorber in question with the third common gas exchange collector.

[0035] According to one embodiment, the output distribution and switching system of one adsorber and the output distribution and switching system of another adsorber are vertically superimposed. In particular, the output distribution and switching system of said first adsorber and the output distribution and switching system of said second adsorber are vertically superimposed.

[0036] According to one embodiment, the inlet distribution and switching system of an adsorber and the outlet distribution and switching system of that adsorber are vertically superimposed. In particular, the inlet distribution and switching system of said first adsorber and the outlet distribution and switching system of said first adsorber are vertically superimposed.

[0037] According to one embodiment, the inlet distribution and switching system of one adsorber and the outlet distribution and switching system of another adsorber are vertically superimposed. In particular, the inlet distribution and switching system of said first adsorber and the outlet distribution and switching system of said second adsorber are vertically superimposed.

[0038] According to one embodiment, the distribution and switching systems or inlet distribution and switching systems are fluidly connected to the inlet line of the adsorber considered by a flange and / or the outlet distribution and switching systems are fluidly connected to the outlet line of the adsorber considered by a flange.

[0039] According to one embodiment, the at least two adsorbers comprise N adsorbers, with N an even integer greater than or equal to two, and the adsorption assembly comprises N supply isolation valves, each of said N supply isolation valves being arranged to fluidly isolate from the common supply manifold the distribution and switching system or inlet distribution and switching system of one of said N adsorbers.

[0040] According to one embodiment, the adsorption assembly comprises N low-pressure discharge isolation valves, each of said N low-pressure discharge isolation valves being arranged to fluidly isolate from the common low-pressure discharge manifold the distribution and switching system or inlet distribution and switching system of one of said N adsorbers.

[0041] According to one embodiment, the adsorption assembly comprises N high-pressure discharge isolation valves, each of said N high-pressure discharge isolation valves being arranged to fluidly isolate the output distribution and switching system of one of said N adsorbers from the common high-pressure discharge manifold.

[0042] According to one embodiment, the adsorption assembly comprises N gas exchange isolation valves, each of said N gas exchange isolation valves being arranged to fluidly isolate the output distribution and switching system of one of said N adsorbers from the common gas exchange manifold.

[0043] According to one embodiment, the at least two adsorbers comprise at least N adsorbers, where N is an even integer greater than or equal to four, the adsorbers being arranged in N / 2 pairs of adsorbers, and the adsorption assembly comprises N / 2 common supply isolation valves, each of said N / 2 common supply isolation valves being arranged to fluidly isolate from the common supply manifold the distribution and switching system or inlet distribution and switching system of one adsorber of a given pair and to fluidly isolate from the common supply manifold the distribution and switching system or inlet distribution and switching system of the other adsorber of said given pair. The at least four adsorbers optionally comprise an additional adsorber not arranged in a pair with another adsorber.

[0044] According to one embodiment, the adsorption assembly comprises N / 2 common low-pressure discharge isolation valves, each of said N / 2 common low-pressure discharge isolation valves being arranged to fluidly isolate from the common low-pressure discharge manifold the distribution and switching system or inlet distribution and switching system of one adsorber of a considered pair and to fluidly isolate from the common low-pressure discharge manifold the distribution and switching system or inlet distribution and switching system of the other adsorber of said considered pair.

[0045] According to one embodiment, the adsorption assembly comprises N / 2 common high-pressure discharge isolation valves, each of said N / 2 common high-pressure discharge isolation valves being arranged to fluidly isolate from the common high-pressure discharge manifold the output distribution and switching system of one adsorber of a considered pair and to fluidly isolate from the common high-pressure discharge manifold the output distribution and switching system of the other adsorber of said considered pair.

[0046] According to one embodiment, the adsorption assembly comprises N / 2 common gas exchange isolation valves, each of said N / 2 isolation valves gas exchange commons being arranged to fluidly isolate from the common gas exchange manifold the output distribution and switching system of one adsorber of a considered pair and to fluidly isolate from the common gas exchange manifold the output distribution and switching system of the other adsorber of said considered pair.

[0047] According to one embodiment, the distribution and switching system or input distribution and switching system of an adsorber of a first pair and the distribution and switching system or input distribution and switching system of an adsorber of a second pair are vertically superimposed on each other.

[0048] According to one embodiment, the output distribution and switching system of an adsorber of the first pair and the output distribution and switching system of an adsorber of the second pair are vertically superimposed on each other.

[0049] According to one embodiment, the adsorption assembly comprises a chassis comprising at least two levels superimposed vertically with each other, of which a first level and a second level, each of the levels comprising at least one grating for the movement of an operator on the level in question, the distribution and switching system or the input distribution and switching system of said first adsorber being arranged at the first level and the distribution and switching system or the input distribution and switching system of said second adsorber being arranged at the second level.

[0050] According to one embodiment, the output distribution and switching system of the first adsorber is arranged at the first level and the output distribution and switching system of the second adsorber is arranged at the second level.

[0051] In an embodiment where the output distribution and switching system(s) is / are arranged to put the output line of an adsorber with a greater number of common collectors than the input distribution and switching system(s) (the output distribution and switching system(s) comprising more circulation paths than the input distribution and switching systems), having at each level of the chassis at least one input distribution and switching system with at least one output distribution and switching system makes it possible to optimize the dimensions of the chassis, by avoiding concentrating at the same level all the output distribution and switching systems taking up more space on a level of the chassis than the input distribution and switching systems.

[0052] According to one embodiment, each level of the chassis is delimited by a three-dimensional frame, the frame notably consisting of a three-dimensional assembly of beams (for example, IPN-type beams or profile beams). transversal in I), in particular metal beams. Each of the frames is in particular a parallelepiped frame.

[0053] According to one embodiment, the adsorption assembly includes at least one staircase arranged to allow the movement of an operator from the first level to the second level and vice versa.

[0054] According to one embodiment, the distribution and switching systems, input distribution and switching systems, and / or output distribution and switching systems are fixed to the chassis.

[0055] According to one embodiment, the adsorption assembly includes equipment fixed to the chassis, said equipment being selected from valves, purges, vents, instrumentation for flow, temperature, pressure, level or other analysis ports, circuits such as instrument air, nitrogen inerting, electricity, wiring related to information transfer, installation safety, starting, stopping or a combination thereof.

[0056] According to one embodiment, the at least two adsorbers comprise at least three adsorption tanks arranged in a row with each other.

[0057] According to one embodiment, at least one of the common manifolds among the common supply manifold, the common low pressure discharge manifold, the common high pressure discharge manifold, the common gas exchange manifold or the first common gas exchange manifold, optionally the second common gas exchange manifold and optionally the third common gas exchange manifold extends parallel to the row of at least three tanks, in particular extends parallel to a longitudinal direction of the chassis.

[0058] According to one embodiment, the distribution and switching systems, input distribution and switching systems, and / or output distribution and switching systems are arranged between the adsorbers of each pair of adsorbers. In particular, the chassis is arranged between the adsorbers of each pair of adsorbers.

[0059] According to one embodiment, each of the adsorption tanks comprises an adsorbent mass configured to adsorb a most adsorbable fraction of the gaseous mixture.

[0060] According to one embodiment, the adsorption tanks are cylindrical tanks with a vertical axis.

[0061] In one embodiment, for each of the adsorbers, the inlet line is fluidly connected to the tank to supply the tank with the gas mixture to be separated during an adsorption step of the adsorber in question. In particular, the outlet line is fluidly connected to the tank to collect a gas of discharge corresponding to the least adsorbable fraction of the gaseous mixture, coming from the tank, during an adsorption step of the adsorber considered.

[0062] The invention also relates to an installation for the separation by adsorption of a gaseous mixture, the installation comprising at least one adsorption unit as described above.

[0063] According to one embodiment, said installation comprises a vertical superposition between them of at least two adsorption sets as described above.

[0064] According to one embodiment, said installation comprises at least one vertical superposition of at least two chassis together, in particular at least one vertical stacking of at least two chassis together.

[0065] According to one embodiment, said installation comprises at least one vertical stacking of at least two adsorption tanks. In particular, each of the adsorption tanks is arranged in a stacking of at least two adsorption tanks.

[0066] According to one embodiment, the installation comprises P chassis levels, with P an even integer, and each of said vertical stacks of at least two adsorption tanks comprises P / 2 adsorption tanks.

[0067] According to one embodiment, the common supply manifold and / or the common low-pressure discharge manifold and / or the common high-pressure discharge manifold and / or the common gas exchange manifold or first common gas exchange manifold and / or where applicable the second common gas exchange manifold and / or where applicable the third common gas exchange manifold each comprises or comprise a plurality of parallel fluid flow paths, each of said parallel flow paths being arranged at a different level of the chassis or at a different level of said vertical superposition of the at least two chassis.

[0068] According to one embodiment, the installation is configured for pressure-modulated adsorption separation and the common gas exchange manifold or at least one of the common gas exchange manifolds is arranged for the transfer of a balancing, elution, repressurization, in particular final repressurization or rinsing gas.

[0069] According to one embodiment, the installation is configured for temperature-modulated adsorption separation and the common gas exchange manifold or at least one of the common gas exchange manifolds is arranged for the transfer of a regeneration gas from the adsorbent mass.

[0070] According to one embodiment, the chassis is configured to receive said equipment before transporting the chassis with said equipment fixed to it on a site for the installation of the adsorption system or site for the construction of the installation.

[0071] The invention also relates to the use of the installation as described above, in a separation process by adsorption of a gaseous mixture, such as a hydrogen purification process or a carbon dioxide (CO2) capture process.

[0072] The invention will now be described in connection with figures 1 to 4.

[0073] A gas separation installation by adsorption comprises several parts: adsorbers, including the adsorption tanks themselves as well as the manifolds, valves, and equipment associated with each of these tanks; a control system, often located in a control room; and possibly buffer tanks to regulate flow, dampen composition fluctuations, temporarily store a quantity of gas during each cycle; and various other equipment such as compressors and heat exchangers. This discussion focuses primarily on the adsorbers as defined above. For large-capacity PSAs at least, these adsorbers represent by far the largest floor area of ​​the installation, with stricter placement constraints than for the other parts of the installation mentioned above (control room, tanks, etc.), which can generally be located remotely.

[0074] Since PSAs process tens, or even hundreds, of thousands of Nm3 / h of gas mixture, the installation of the adsorbers is carried out according to the same principle. The collectors, valves, and instrumentation of all the adsorbers are housed in a frame placed on the ground, with the adsorption tanks arranged lengthwise on one side of the frame or arranged on either side of this frame, in a central position.

[0075] This frame is generally known as the PSA valve and manifold skid. Each tank is then connected to the frame elements by pipes. Depending on the solution chosen, the surface area required for the installation of this frame corresponds to rectangles of varying lengths and widths. An example of such an installation was given in the introduction and illustrated in [Fig. 1].

[0076] This [Fig. 1] is therefore a schematic representation of a PSA installation showing only the adsorbers. The main manifolds for supplying the gas mixture to all the adsorbers from another unit, for the high-pressure and low-pressure discharge flows from the adsorbers to other units, the control room, and the buffer tank on the low-pressure discharge flow are not shown. Sixteen adsorption tanks 20 are located on either side of the central frame 21, represented by a parallelepiped. This central frame 21 contains most of the manifolds, valves, and instrumentation necessary for the proper functioning of the entire system. Note The inlet and outlet pipes of the adsorption tanks 20, running from their ends to the central frame 21, are also not shown. This longitudinally oriented frame may be made up of several pieces joined together depending on the dimensions and transport constraints. It is generally placed on the ground on pre-prepared concrete pads to which it is fixed. A key installation requirement is that operators must be able to perform maintenance on the equipment fixed to the central frame 21. In particular, it must be possible to remove a valve from the structure (these valves can weigh over 100 kg), check sensors, and access manual valves. Therefore, this equipment cannot be too compact in width, length, or height, which leads to the dimensions mentioned previously, in particular a required length exceeding 70 m.It should be noted in passing that the adsorption tanks 20 must generally be spaced at a minimum distance to allow the passage of lifting equipment necessary for the removal or installation of at least some of the valves.

[0077] These dimensions naturally increase in conjunction with the increased processing capacity of the units, but a second phenomenon amplifies this effect. With very high flow rates, the pursuit of the best possible performance, in terms of extraction efficiency and specific energy, becomes paramount compared to the resulting increase in investment. For example, the hydrogen PSA cycle, which for a very long time did not exceed three balancing stages for the most efficient units, can now include four, five, or even more, for a gain of around 1% or even less, while this translates into a significant decrease in productivity and the addition of extra valves and manifolds for each of the adsorption tanks 20.Similarly, it is understood that PSAs with more than two production stages, or those implementing purging, recycling, or rinsing steps, such as some CO2 PSAs, require a greater number of associated equipment for each adsorption tank. The diameter of the adsorbers, for an equivalent treated flow rate, generally does not tend to increase, and it is usually their height that compensates for the necessary increase in adsorbent volume. However, the dimensions of the central frame must be increased accordingly, with the space constraints that this entails.

[0078] Before going into the details of the invention, it is necessary to recall the operating principles of a gas mixture separation unit implementing a cycle alternating adsorption and regeneration stages. To simplify the description, only the case of a PSA-type installation is considered in order to precisely define the valve and piping components involved in the invention, as the vocabulary used may differ from one process to another, such as, for example, for the adsorbent regeneration stage, the elution gas for the PSA unit. and heating and cooling gas for the TSA unit. The choice of PSA stems from the fact that the said invention applies in particular, but not exclusively, to the latter due to their significantly higher number of adsorbers on average.

[0079] Generally speaking, the term PSA refers to any gas purification or separation process that employs a cyclic variation of the pressure experienced by the adsorbent between a high pressure, known as the adsorption pressure, and a low pressure, known as the regeneration pressure. This is referred to as a pressure swing adsorption (PSA) purification or separation process. Thus, the generic term PSA is used interchangeably to designate the following cyclic processes, which are also commonly given more specific names depending on the pressure levels involved or the time required for an adsorbent to return to its initial state (cycle time):

[0080] - VSA processes in which adsorption occurs substantially at pressure atmospheric, preferably between 0.95 and 1.25 bar abs and the desorption pressure is lower than atmospheric pressure, typically from 50 to 400 mbar abs;

[0081] - MPSA or VPSA processes in which adsorption takes place at a pressure high pressure above atmospheric pressure, typically between 1.35 and 6 bar abs, and desorption at a low pressure below atmospheric pressure, generally between 200 and 650 mbar abs;

[0082] - The PSA processes themselves in which the high pressure is substantially above atmospheric pressure, typically between 3 and 50 bar abs and low pressure substantially equal to or above atmospheric pressure, generally between 1 and 9 bar abs.

[0083] It should be noted that these various designations are not standardized and that, in particular, the indicated limits are subject to variation. Other designations also exist based on the cycle time (RPSA processes for Rapid PSA, or even URPSA for Ultra Rapid PSA). It should be noted that, unless otherwise specified, the use of the term PSA here covers at least all of these variants.

[0084] An adsorber will begin an adsorption period until it is loaded with the constituent(s) to be stopped at high pressure. It will then be regenerated by depressurization and extraction of the adsorbed compounds before being refurbished to begin a new adsorption period. The adsorber has thus completed a pressure cycle, and the very principle of the PSA process is to chain these cycles together. It is therefore a cyclic process. In principle, each adsorber follows the same cycle with a time lag known as the phase time or simply the phase.

[0085] There are many different PSA cycles, varying in the type and number of steps used. However, a large majority of units will include a series of steps such as adsorption at the high cycle pressure and production of a fraction enriched in the least adsorbable constituents of the gas mixture, a plurality of decompressions by balancing between adsorbers, the supply of elution gas, final depressurization to the low cycle pressure, elution, a plurality of compressions by balancing between adsorbers, and final repressurization to the high cycle pressure. Additional steps are sometimes used, such as high-pressure or medium-pressure scavenging (rinsing) steps, temporary gas storage in a tank integrated into the cycle, or the removal of a third fraction at medium pressure.

[0086] Generally, a PSA-type unit comprises a plurality of identical adsorbers which, as previously described, follow the same cycle with a time offset of one phase time. In theory, all geometric types of adsorption tanks can be used, and in particular with a cylindrical shell with a horizontal axis, cylindrical shell with a vertical axis, spherical shell, radial flow shell, or parallelepiped shell.

[0087] The tank preferably used in PSAs is of the cylindrical shell type with a vertical axis. In particular, it allows for the easy implementation of successive layers of adsorbents of different types in order to best adapt to the composition of the gas mixture to be treated and the operating conditions. Such a tank has an upper end and a lower end. These ends have, respectively, an upper and a lower orifice, often equipped with a flange, through which the gas flows entering or exiting the adsorber circulate. Generally, the gas mixture to be separated enters through the bottom of the tank, flows from bottom to top through the adsorbent mass, and the unadsorbed fraction exits through the top, but the reverse situation also exists, and the invention applies equally to both configurations.By convention, the inlet of the tank is the end corresponding to the entry of the feed gas mixture during the adsorption phase, and the outlet is the opposite end through which the gas flow corresponding to the least adsorbed fraction of this mixture exits. The inlet and outlet of the tank are connected, generally by flanges, to an inlet pipe and an outlet pipe, respectively. These pipes are then connected to various manifolds mounted on a metal structure. It should be noted that the terms "inlet" and "outlet" of the tanks, as well as the associated terms "inlet pipe" and "outlet pipe," are used to distinguish the ends of the adsorbers and that these terms do not imply the direction of flow of other gases through them; for example, the low-pressure flow is discharged from the adsorber through its inlet.

[0088] It should be noted that the inlet line of a tank must therefore be connected to both the common gas mixture manifold and the common low-pressure discharge manifold, which removes the most adsorbed fraction of this same gas mixture. Similarly, the outlet line of a tank must be connected to the common high-pressure discharge manifold, which removes the least adsorbed fraction of this same gas mixture, and to the manifolds enabling gas transfers between adsorbers (balancing, elution gas, etc.). This configuration is typically achieved by a system of at least two valves, generally flow or pressure regulating valves, between each of the inlet or outlet lines on one side and the corresponding common manifolds on the other.This allows, for example, on the inlet side and depending on the stage, the tank to be supplied with a gas mixture from the common gas mixture manifold, the low-pressure flow to be discharged to the low-pressure discharge manifold, or the tank inlet to be isolated from these two manifolds. Since the gas mixture supply and the low-pressure flow discharge are obviously not simultaneous, one valve will be open and the other closed during these stages. They can both be closed during certain stages. The same configuration is found on the outlet side. Such systems, which are systematically found at the inlet and outlet of each tank, are now called "distribution and switching systems."Schematically and as an example, such a system will include on one side a tee or distribution manifold connecting at one end, generally by flange, to the pipe coming from the tank, and on the other side will include connections to fluidly link the valves to the corresponding manifolds.

[0089] It should be noted that the common collector is here defined as the circuit which, depending on the case, supplies the various adsorbers with a gas mixture or evacuates the gases discharged by these various adsorbers; said circuit may have parallel branches to optimize distribution. This point will be discussed later in the description.

[0090] Historically, valves, manifolds, and associated equipment have been installed in different ways. Initially, small, simple-function valves, often on / off with an opening limiter, and the instrumentation could be directly supported by the manifolds, some of which were simply attached to the tanks. Even today, some small installations still have a vertical panel attached to the tanks, serving to support both the valves and manifolds, as well as the local instrumentation, primarily pressure gauges. As the size of the units and the weight of the equipment increased, most valves and manifolds were placed on the floor on individual supports, and later on a common frame. The advantage of this solution is that it becomes possible to manufacture this frame in the workshop, integrating the equipment in question, and then transport the entire assembly to the site. This solution This remains the preferred solution, and this ground-mounted assembly is usually called a valve skid. A new method of positioning these various components is therefore proposed, allowing for a significant reduction in the footprint required for their installation. Furthermore, depending on its various possible implementations, the invention considerably reduces not only the surface area required for the manifolds and valves but also for the entire assembly of adsorbers, which, according to the definition adopted here, includes both these elements and the multiple tanks whose placement can then also be favorably impacted.

[0091] An embodiment of an adsorption assembly according to the invention is shown in [Fig. 2]. Assembly 301 comprises:

[0092] - eight adsorbers,

[0093] - a common supply manifold 90 for each of the at least two adsorbers in the gaseous mixture,

[0094] - a common low-pressure discharge manifold 91, configured to discharge a the most adsorbable fraction of the gaseous mixture from each of the at least two adsorbers,

[0095] - a common high-pressure discharge manifold 92, configured to discharge a least adsorbable fraction of the gaseous mixture from each of the at least two adsorbers,

[0096] - a common gas exchange manifold (not shown), configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers,

[0097] each adsorber comprising:

[0098] - an adsorption tank 1, 2, ..., 8,

[0099] - an inlet pipe 11.51 fluidically connected to the adsorption tank 1, 2, ..., 8, to supply the tank with a feed gas,

[0100] - an outlet line 12, 52 fluidically connected to the adsorption tank 1, 2, ..., 8, to collect a discharge gas from the tank,

[0101] - an input distribution and switching system 13, 53 arranged for selectively connect the inlet pipe of the adsorber in question to the common supply manifold 90 or connect the inlet pipe of the adsorber in question to the common low-pressure discharge manifold 91,

[0102] - an output distribution and switching system 14, 54 arranged for selectively connect the outlet pipe of said adsorber in question to the common high-pressure discharge manifold 92 or connect fluidic communication the outlet duct of the considered adsorber with the common gas exchange manifold.

[0103] In particular, the input distribution and switching system 13, 53 of a first adsorber and the input distribution and switching system 13, 53 of a second adsorber are vertically superimposed on each other.

[0104] More specifically, the inlet distribution and switching systems 13, 53 advantageously comprise a first flow path for the gas mixture from the common supply manifold 90 to the inlet line 11, 51 of the adsorber in question, and a second flow path for the most adsorbable fraction of the gas mixture from the inlet line 11, 51 of the adsorber in question to the common low-pressure discharge manifold 91. The inlet distribution and switching systems 13, 53 include, in particular, a switching device (not shown) for switching from the first path to the second path and vice versa. This switching device may be a three-way valve, but more commonly it will consist of two two-way valves, control valves, or on / off valves, operated by the plant's control system according to the selected operating cycle.

[0105] The inlet distribution and switching system 13, 53 corresponds to the supply of the gas mixture and the discharge of the low-pressure discharge gas. The manifolds and valves corresponding to them are generally the largest, or at least among the largest, of those associated with a tank 1, 2, ..., 8. Indeed, at the other end of the tank 1, 2, ..., 8, the high-pressure discharge gas has a reduced flow rate because it no longer contains the constituents that have been adsorbed, while the low-pressure discharge gas, precisely because of its low pressure, generally has a higher volumetric flow rate, in actual cubic meters, than all the other flows.

[0106] “Vertically superimposed” or “vertical superposition” in the context of the present invention means in particular a superposition of two elements along a straight line or a plane perpendicular to a horizontal reference plane which corresponds to the installation ground of the adsorption assembly or the construction ground of the installation.

[0107] Vertically superimposing does not therefore mean that there is contact between the two superimposed elements, nor that there is no third element located at least partly between the two elements in question.

[0108] Superimposing the two inlet distribution and switching systems for adjacent tanks may necessitate taking all necessary precautions for their maintenance, in particular the removal of valves, their possible transport to the workshop, and their reinstallation. Sufficient clearance above the system is required to allow for these operations. It is understood that this is This involves a more complex layout choice than the prior art solution where both systems are positioned at the same level on a skid itself placed on the ground. However, it frees up approximately 25 to 30% more space compared to a layout where all the equipment is placed side by side. It is then possible to rearrange the other equipment on the chassis to convert this gain into a reduction in its length, a reduction that can reach 20% and be sufficient to allow the chassis to fit within the available space.

[0109] It should be noted that if this reduction in length is the initial aim of the invention, this new superimposed arrangement of the input distribution and switching systems can allow, at the same dimensions, the accommodation of equipment corresponding to a more efficient adsorption cycle, for example by adding an additional balancing.

[0110] Alternatively, according to an embodiment not shown, one of the input distribution and switching systems and one of the output distribution and switching systems are vertically superimposed. In particular, the input distribution and switching system of a first adsorber and the output distribution and switching system of said first adsorber are vertically superimposed. In particular, the output distribution and switching system of a first adsorber is placed vertically above the input distribution and switching system of said first adsorber.

[0111] Such an arrangement is a second way of saving space on the skid of valves and manifolds as they are usually designed. This can have the advantage of being easier to implement, especially if the output distribution and switching system includes elements with a smaller diameter and weight than those of the input system.

[0112] An example at the end of the description relating to CO2 capture in an industrial site corresponds in part to this arrangement.

[0113] Generally, each adsorber includes an outlet line fluidly connected to the tank to collect a discharge gas from the tank.

[0114] This is essentially the gas produced during the adsorption step, the pressure of which is close to the pressure of the gas mixture, up to pressure losses.

[0115] The common high-pressure discharge manifold 92 is configured to discharge this fraction, the least adsorbable of the gas mixture, from each of the at least two adsorbers.

[0116] The common gas exchange manifold (not shown) is configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers.

[0117] Thus, the aforementioned distribution and switching system relating to the gas mixture and the low pressure discharge gas is an inlet distribution and switching system 13, 53 and each adsorber therefore further comprises an outlet distribution and switching system 14, 54 arranged to connect the outlet line of the adsorber in question with the common high pressure discharge manifold and / or to connect the outlet line of the adsorber in question with the common gas exchange manifold.

[0118] The outlet distribution and switching systems 14, 54 then advantageously include a first flow path for the least adsorbable fraction of the gas mixture from the outlet line of the adsorber in question to the common high-pressure discharge manifold, and at least one other flow path for a gas from the outlet line to the common gas exchange manifold, or, where applicable, to one of the gas exchange manifolds. By "essentially on the same level," it is meant that these pieces of equipment are in similar positions in height, taking into account the different dimensions of the equipment themselves and / or that the cradles or systems supporting them rest on the same horizontal structure. This concept of equipment installation levels will be discussed in more detail later in the description.

[0119] It is understood that in this way, up to 50% of space can be freed up on the skid usually used, allowing further optimization of the entire manifold and valve assembly.

[0120] According to an embodiment not shown, the inlet distribution and switching system of an adsorber and the outlet distribution and switching system of that adsorber are vertically superimposed. In particular, the inlet distribution and switching system of said first adsorber and the outlet distribution and switching system of said first adsorber are vertically superimposed.

[0121] Here we have another arrangement that allows us to further compact the entire manifold and valve assembly by vertically superimposing the inlet and outlet distribution and switching systems of the same adsorber, while simultaneously superimposing the inlet system of another adsorber onto the inlet system of that adsorber. Given the general meaning of "superimpose" or "superposition," as stated at the beginning of this document, this corresponds to the fact that, vertically and from the lower level to the upper level, we will place, for example, the inlet system of the first adsorber, the inlet system of a second adsorber, and then the outlet system of the first adsorber, or alternatively, the inlet system of the first adsorber, the output system of that same adsorber, then the input system of a second adsorber.

[0122] Following the same logic, an embodiment can be adopted in which the input distribution and switching system of one adsorber and the output distribution and switching system of another adsorber are vertically superimposed. In particular, the input distribution and switching system of said first adsorber and the output distribution and switching system of said second adsorber are vertically superimposed.

[0123] The same comment as in the previous paragraph applies and we will place vertically from a lower level to a higher level, for example the inlet system of the first adsorber, the inlet system of a second adsorber and the outlet system of this same second adsorber.

[0124] The superposition methods described above are not mutually exclusive, particularly because of the meaning given to the words superpose and superposition, and it appears that from the embodiments described, it is possible to implement arrangements that are certainly sophisticated when compared to the valve skid equipping current PSAs, but feasible as will be shown later in the description, arrangements which allow us to go very far in reducing the necessary floor space of gas separation installations by adsorption and to push back the capacity or performance limits that appeared in recent projects.

[0125] In the examples given at the end of the description, we will then focus particularly on two implementations:

[0126] The first, already partially described, consists of superimposing the inlet and outlet systems of one adsorber onto the inlet and outlet systems of a second adsorber, knowing that this set can be duplicated at a minimum by superimposing on it in the same way the inlet and outlet systems of a third and a fourth adsorber.

[0127] The second method consists of vertically superimposing from bottom to top the inlet system of a first adsorber, the outlet system of the same first adsorber, the inlet system of a second adsorber and the outlet system of the same second adsorber, knowing that it is possible to continue in the same way with at least a third adsorber whose inlet and outlet systems will be superimposed above those of the second.

[0128] As mentioned in the introduction, hydrogen purification or CO2 capture plants include numerous adsorbers, for example eighteen or more. Furthermore, an adsorber typically has between five and ten valves, depending on the cycle used. Although these valves are highly reliable, there is a non-negligible probability that one of them may have a problem, for example, that it may not be The valve is no longer watertight when closed. This will be enough to disrupt the system's operation and force it to shut down while the valve is being serviced and restarted. This restart generally takes a considerable amount of time, corresponding to several complete cycles, before the nominal flow rate and required purity are restored. As soon as PSAs (Plant Protection Systems) had more than five or six adsorbers, a solution was found to avoid a complete unit shutdown. The design incorporates so-called degraded operating modes during which the system runs with, for example, one or two fewer adsorbers than in the nominal cycle. These degraded operating modes are programmed into the control system just like the nominal operating mode. During these less efficient modes, which still allow production to continue, the adsorber is serviced while stopped.This absolutely requires that the adsorber in question be completely isolated from the other operating adsorbers beforehand. This isolation must be achieved between the various common manifolds and the distribution and switching systems, as it is very often on one of the valves within these distribution and switching systems that action is required. Isolation is accomplished by installing a valve, normally an on / off type, with a high level of sealing. Note that secondary equipment is necessary to ensure the complete safety of the adsorber. This will be discussed later, but the isolation valves are by far the most substantial pieces of equipment in terms of volume and weight. These isolation valves are not shown for the sake of simplicity.

[0129] Thus, according to one embodiment, the adsorption assembly comprises:

[0130] - eight supply isolation valves, each of said eight isolation valves the power supply being arranged to fluidly isolate the inlet distribution and switching system of one of said eight adsorbers from the common power supply collector,

[0131] - eight low-pressure discharge isolation valves, each of said eight valves low-pressure discharge isolation being arranged to fluidly isolate from the common low-pressure discharge manifold the inlet distribution and switching system of one of said eight adsorbers,

[0132] - eight high-pressure discharge isolation valves, each of said eight valves high-pressure discharge isolation being arranged to fluidly isolate the output distribution and switching system of one of said eight adsorbers from the common high-pressure discharge manifold,

[0133] - eight gas exchange isolation valves, each of said eight valves gas exchange isolation being arranged to fluidly isolate from the common gas exchange manifold the output distribution and switching system of one of said eight adsorbers.

[0134] As indicated, each of the collectors connected to a tank must be isolated before working on an adsorber.

[0135] When the number of adsorbers in an installation is significant, for example, six or more, it has been considered to isolate the adsorbers in pairs rather than individually. This is done to reduce investment by sharing not only the isolation valve but also some of the associated safety equipment, such as the purge or inerting valve, between two adsorbers. However, the degraded cycle corresponding to the isolation of a pair of adsorbers is sometimes less efficient than when isolating a single adsorber. This is the case, for example, when switching from a cycle using six adsorbers to one using four adsorbers instead of five. Nevertheless, it is understood that for units with a large number of adsorbers, for example, sixteen, removing one or two adsorbers makes little difference.This is especially true since it is generally simpler to remove two adsorbers from a complex cycle than just one, for example by removing both associated steps of the same balancing process, namely depressurization and repressurization.

[0136] Therefore, the adsorption assembly comprises:

[0137] - four common supply isolation valves, each of said four Common supply isolation valves are arranged to fluidly isolate from the common supply manifold the distribution and switching system or inlet distribution and switching system of one adsorber in a given pair, and to fluidly isolate from the common supply manifold the distribution and switching system or inlet distribution and switching system of the other adsorber in said pair. The at least four adsorbers optionally include an additional adsorber not arranged in a pair with another adsorber.

[0138] - four common low-pressure discharge isolation valves, each of said four common low-pressure discharge isolation valves being arranged to fluidly isolate from the common low-pressure discharge manifold the distribution and switching system or inlet distribution and switching system of one adsorber of a considered pair and to fluidly isolate from the common low-pressure discharge manifold the distribution and switching system or inlet distribution and switching system of the other adsorber of said considered pair,

[0139] - four common high-pressure discharge isolation valves, each of said four common high-pressure discharge isolation valves being arranged to fluidly isolate the distribution and switching outlet system of an adsorber of a given pair from the common high-pressure discharge manifold and to fluidly isolate from the common high-pressure discharge manifold the distribution and switching outlet system of the other adsorber of said pair considered,

[0140] - four common gas exchange isolation valves, each of said four common gas exchange isolation valves being arranged to fluidly isolate from the common gas exchange manifold the outlet distribution and switching system of one adsorber of a considered pair and to fluidly isolate from the common gas exchange manifold the outlet distribution and switching system of the other adsorber of said considered pair.

[0141] It should be noted that by doing so, the two tanks in a pair can save on piping lengths and facilitate installation. Sharing sections of manifolds between a larger number of tanks is possible, for example, for four tanks. Given the simplification this can bring to the manifold layout, such arrangements in pairs or groups of four, for example, can be made without isolating each group.

[0142] It has been shown that superimposing the inlet and / or outlet systems for one and / or two tanks creates a free space compared to their conventional placement on a skid supporting all the manifolds and valves, a gain that significantly reduces the required footprint. The fact that the tanks are grouped together does not preclude the superposition of the distribution and switching systems, provided that their placement takes this coupling into account.

[0143] For example, the distribution and switching system or inlet distribution and switching system of an adsorber of a first pair and the distribution and switching system or inlet distribution and switching system of an adsorber of a second pair are vertically superimposed on each other and / or the distribution and switching system of an adsorber of the first pair and the distribution and switching system of an adsorber of the second pair are vertically superimposed on each other.

[0144] It was explained previously that the vertical superposition of two distribution and switching systems did not mean that one directly supported the other, but rather that an independent support structure could be provided, sufficiently spaced from the system below to allow for its dismantling, removal, and reinstallation. When there are multiple tanks, say four or more, it becomes preferable, instead of multiple independent supports, to create a common support structure; that is, in practice, to provide a higher level to which the elements located above the others will be attached. The advantage of having a second level has already been mentioned previously without going into detail.

[0145] Thus, in the embodiment of [Fig.2], the adsorption assembly comprises a frame 100 comprising at least two levels superimposed vertically, of which a first level 101 and a second level 102, each of the levels comprising at least one grating for the movement of an operator on the level in question, with:

[0146] - the distribution and switching system or distribution and inlet switching of the adsorbers with tanks 1, 4, 5 and 8 being arranged on the first level and the distribution and switching system or inlet distribution and switching system of the adsorbers with tanks 2, 3, 6 and 7 being arranged on the second level,

[0147] - the distribution and switching system for the output of the adsorbers with the tanks Components 1, 4, 5, and 8 are arranged on the first level, and the distribution and switching system for the adsorbers' output, along with tanks 2, 3, 6, and 7, is arranged on the second level. By placing the components on a two-level frame, there is greater flexibility in installation compared to fixing components to supports or cradles resting solely on the lower level, where the other equipment is already housed.

[0148] For example, in an embodiment where the output distribution and switching system(s) is / are arranged to put the output line of an adsorber with a greater number of common collectors than the input distribution and switching system(s) (the output distribution and switching system(s) comprising more circulation paths than the input distribution and switching systems), at each level of the chassis at least one input distribution and switching system with at least one output distribution and switching system can be provided, thus optimizing the dimensions of the chassis, by avoiding concentrating at the same level all the output distribution and switching systems taking up more space on a level of the chassis than the input distribution and switching systems.

[0149] Other considerations may lead to a different layout. It may be advantageous to place all the inlet distribution and switching systems of the adsorption unit on the first level and all the outlet distribution and switching systems on the other level. In this way, the common gas mixture supply manifolds and the common low-pressure discharge manifolds will be located on this first level only, while the common high-pressure discharge manifolds and the common gas exchange manifolds will be located on the second level only, thus simplifying the installation of these circuits.

[0150] In the previous configuration, which has other advantages, each level must include at least one branch of each of the different common collectors.

[0151] The chassis will be all the easier to make if each of the levels it comprises has the same length and the same width, their height being able to be different without inconvenience.

[0152] According to a preferred embodiment, each level of the chassis is delimited by a three-dimensional frame, the frame being in particular made up of a three-dimensional assembly of beams (for example, IPN type beams or I-beams), in particular metal beams. Each of the frames is in particular a parallelepiped frame.

[0153] The adsorption assembly includes at least one staircase (not shown) arranged to allow an operator to move from one level of the chassis to another.

[0154] The distribution and switching systems, input distribution and switching systems, and / or output distribution and switching systems are fixed to the chassis at the corresponding level.

[0155] Similarly, the adsorption assembly includes various equipment fixed to the chassis, said equipment being selected from valves, drains, vents, instrumentation for flow, temperature, pressure, level or other analytical measurements, circuits such as the instrument air circuit, nitrogen inerting circuit, electrical circuit, wiring related to information transfer, installation safety, start-up, shutdown or a combination thereof. This equipment is not shown for the sake of simplicity.

[0156] Namely, in the embodiment of [Fig.2], the assembly comprises two rows of four tanks, tanks which are arranged parallel to a longitudinal direction of the chassis.

[0157] The two rows are arranged on either side of the frame. This arrangement is generally preferred when the number of adsorbers is greater than six or eight.

[0158] In particular, the distribution and switching systems, inlet distribution and switching systems and / or outlet distribution and switching systems are arranged between the tanks of each of the pairs of adsorbers.

[0159] The choice of installing the adsorbers, particularly the tanks, in one or two rows depends primarily on the available land for installation. A plot of land too short to align the tanks of the installation will lead to a two-row tank arrangement, provided the width of the plot allows it. As will be shown in the examples, the application of the invention, possibly in its most developed form, offers certain advantages. The first and most important, as already explained, is that the footprint of the chassis is significantly smaller than that of a conventional valve skid.

[0160] The common collectors are fixed to the chassis at least over the majority of their respective circuit.

[0161] In particular, according to an embodiment not shown, at least one of the common manifolds among the common supply manifold, the common low-pressure discharge manifold, the common high-pressure discharge manifold, the common gas exchange manifold or the first common gas exchange manifold, optionally the second common gas exchange manifold and optionally the third common gas exchange manifold extends parallel to a longitudinal direction of the chassis.

[0162] It should be noted that a common manifold typically connects all the tanks in the adsorption assembly, but the corresponding circuit layout can vary. The common gas mixture manifold is taken as an example. This manifold generally runs from another unit, such as a syngas production unit, to the immediate vicinity of the adsorption separation unit's chassis. This section typically includes an isolation valve at this end, as well as associated equipment such as a purge valve, a downstream circuit pressurization valve, and / or possibly a filter.This manifold can then continue within the chassis, running from one end to the other, generally at the lower level of the chassis, and supply, via a plurality of parallel sections, all the initial distribution and switching units arranged at the various levels of the chassis, either individually, in pairs, or even in groups of four, depending on the design choice. All parallel sections are generally in complete fluid flow without any blockages up to the isolation valves or, since these are very often open, up to the inlet system valves. These sections are then considered part of the common supply manifold for the entire system.

[0163] Note that, in the case of a very large collector, one meter in diameter for example, which may be the case of the common low pressure discharge collector, it may be advisable to run it along the chassis or under the chassis, the first level of which will be raised for this purpose, branches, as mentioned previously, then supplying the level(s) concerned allowing connection to the inlets of the tanks.

[0164] Conventionally, each of the adsorption tanks comprises an adsorbent mass configured to adsorb the most adsorbable fraction of the gas mixture and discharge the least adsorbable fraction. The main output can be either the most or the least adsorbable fraction.

[0165] According to a preferred embodiment, the adsorption tanks are cylindrical tanks with a vertical axis. As explained, this is the most favorable geometry from where the adsorbent mass is made up of a superposition of several layers of adsorbent of different nature or size.

[0166] All the tanks of the adsorption assembly are geometrically identical in the embodiment shown.

[0167] Generally, the gas mixture entering through the bottom of the tank and the high-pressure discharge gas is evacuated through the top of the tank, but the reverse also exists, sometimes leading to the possibility of reducing the diameter of the tank.

[0168] All the tanks of the adsorption assembly are installed in the same way with respect to the respective position of the inlets and outlets.

[0169] Consequently, in the most conventional embodiment, for each of the adsorbers, the inlet line is fluidly connected to the tank to supply the tank with the gas mixture to be separated during an adsorption step of the adsorber in question. In particular, the outlet line is fluidly connected to the tank to collect a discharge gas corresponding to the least adsorbable fraction of the gas mixture, coming from the tank during an adsorption step of the adsorber in question.

[0170] Figure 3 represents an installation for the separation of a gas mixture by adsorption according to one embodiment, said installation comprising two adsorption units 301, 302 as described above, said units being vertically superimposed on each other. The installation will also include, in addition to this adsorption unit, a control room from which the information necessary for carrying out the selected adsorption cycle, such as setpoints, originates, and to which all site information arrives, such as sensor readings, possibly buffer tanks such as a low-pressure tank for the residual, machines such as a vacuum pump, and various equipment upstream or downstream of the adsorption unit such as a cooling exchanger, heater, filter, or metering station, elements which are not shown for the sake of simplicity.

[0171] Thus, the installation 400 of [Fig.3] comprises a vertical superposition of two chassis 100, 200 between them, in this case a vertical stacking of two chassis between them.

[0172] In this way, the manifolds and valves, which are usually fixed on the single level of the manifold and valve skid of a conventional unit, are superimposed on at least four chassis levels 101, 102, 201, 202 (see [Fig. 4]). This leads to a considerable reduction in the footprint used, admittedly at the expense of the required height, which does not appear to be a constraint at all when considering, for example, the height of the distillation and scrubbing columns, reactors, or furnaces present in the numerous industrial sites where the gas mixture separation installations by adsorption that are the subject of this invention must be installed.

[0173] With such a reduction in the size of the manifolds and valves, the length of land required for installation generally becomes linked to the placement of the adsorption tanks near the frame(s). In the installation shown in [Fig. 3], this involves a plurality of eight cylinders, typically ranging in diameter from 2 to 5 meters, which must be spaced approximately 1 to 2.5 meters apart to allow passage for transport vehicles used for valve maintenance.

[0174] The first solution is to arrange the tanks on either side of the frame or stacked frames. This will generally not be sufficient to optimize the overall layout, as the tanks themselves take up a length considerably greater than the length of the frame. An additional degree of flexibility is to arrange the tanks, at least in pairs, one behind the other, perpendicular to the longitudinal axis of the frame, possibly offsetting them slightly to facilitate the passage of the inlet and outlet pipes for the tanks furthest from the frame. Visually, this results in two rows of tanks on either side of the frame. Following the same principle, the tanks can also be installed in a staggered pattern on either side of the central frame.

[0175] The solution shown consists of a vertical stacking of two adsorption tanks. In particular, each of the adsorption tanks is arranged in a stacking of at least two adsorption tanks.

[0176] Depending on the number of tanks stacked, we will gain a factor of, for example, two or three on the space required and thus bring the length constraint relating to the placement of the tanks closer to the length relating to the placement of the collectors and valves.

[0177] Thus, in the embodiment of [Fig.3], the installation comprises four chassis levels and eight vertical superpositions of two adsorption tanks superimposed on each other.

[0178] This is true regardless of the respective positions of the distribution and switching systems relative to these tanks. The examples at the end of the description will relate to such arrangements.

[0179] The arrangement of the various common collectors relating to these superimposed tanks is not complicated but on the contrary generally simplified compared to the case where all the tanks are on the ground.

[0180] Not shown, the common supply manifold and / or the common low-pressure discharge manifold and / or the common high-pressure discharge manifold and / or the common gas exchange manifold or first common gas exchange manifold and / or, where applicable, the second common gas exchange manifold and / or, where applicable, the third common gas exchange manifold comprises or comprise each a plurality of parallel fluidic circulation lanes or sections, each of said parallel circulation lanes being arranged at a different level of the chassis or at a different level of said vertical superposition of the at least two chassis.

[0181] As mentioned in the introduction, the invention relates in particular to PSA-type installations, especially those comprising eight or more adsorbers. In this case, more precisely, the installation is configured for pressure-modulated adsorption separation and the common gas exchange manifold or at least one of the common gas exchange manifolds is arranged for the transfer of a balancing, elution, repressurization, in particular final repressurization, or rinsing gas.

[0182] The invention can nevertheless be advantageously applied to certain TSA-type units using, for example, more than three adsorbers. This may be the case, for example, when purifying very large flow rates with an adsorption step taking place over several phases, or when it is necessary to minimize the amount of regeneration gas to be evacuated from the unit, in which case said regeneration may be carried out in several successive stages and require a plurality of tanks.

[0183] According to this embodiment, the installation is configured for temperature-modulated adsorption separation and the common gas exchange manifold or at least one of the common gas exchange manifolds is arranged for the transfer of a regeneration gas from the adsorbent mass.

[0184] According to one embodiment, the chassis is configured to receive the various equipment it contains before transporting the chassis with said equipment fixed on it, to an installation site for the adsorption assembly or construction site for the installation.

[0185] The solution proposed here retains the advantage of complete fabrication in a specialized and well-equipped workshop of all manifolds, valves, and associated equipment, rather than local construction on-site. Once the structure is finished, it is transported to its location on the site, possibly in several packages depending on the constraints of the route. These packages, once delivered to the site, are either erected vertically, placed side-by-side, and connected to each other, or laid horizontally, stacked, and connected to each other to reconstitute the installation's frame. In the case of transport by packages, the connection between the packages involves the metal structure itself as well as the common manifolds, the fluid continuity of which is ensured by flanges, welding, or other suitable means.

[0186] According to one embodiment, the installation of most of the electrical wiring or sampling circuits for analysis is carried out once the superstructure in place to avoid or minimize the number of junction boxes.

[0187] Most of the time, the chassis of the installation forms a whole, installed on the site in a straight line from one end to the other, with the adsorption tanks or preferably the superpositions of tanks, also installed in an essentially straight line on one side or preferably on both sides of the chassis.

[0188] When this arrangement proves impossible because of the shape of the terrain, another implementation is conceivable in which the chassis is composed of at least two straight parts making an angle  between them, with 90° <  < 180°C.

[0189] The invention also relates to the use of the installation as described above, in a separation process by adsorption of a gaseous mixture, such as a hydrogen purification process or a carbon dioxide (CO2) capture process.

[0190] The invention will now be explained by two examples of PSA type installation.

[0191] The first example concerns an installation comprising sixteen adsorbers. Figures 2 to 4 correspond to this example.

[0192] To facilitate description, [Fig.2] represents only half of this installation, namely an adsorption assembly comprising eight adsorbers whose tanks 1,2...7,8 are arranged on the ground on either side of the frame 100 comprising two levels 101, 102.

[0193] The tanks on either side of the frame and opposite each other, such as tanks 1 and 5 or tanks 2 and 6, and so on, are paired. The inlet distribution and switching systems 13 and 53 are connected on one side to the inlet lines 11 of tank 1 and 51 of tank 5, and on the other side to the common gas mixture supply manifold 90 and the common low-pressure discharge manifold 91, the inlet and outlet of which are shown respectively in the foreground. More precisely, the fluid connection is made with each common manifold via a section common to the pair in question. The isolation valves for the pair in question will be located on these common sections.

[0194] Similarly, the outlet lines 12 and 52 of these same tanks 1 and 5 are connected to the outlet distribution and switching systems 14 and 54. These outlet systems are themselves connected on one side to the common high-pressure discharge manifold 92 and on the other side to the three gas exchange manifolds corresponding to the transfer of the balancing gas flows and the elution flow, the details of which beyond the outlet systems are not shown.

[0195] Note:

[0196] - the symmetry in the layout of the inlet and outlet manifolds of adsorbers 1 and 5 which promotes proper balancing of flow rates between tanks 1 and 5, regardless of the stage of the adsorption cycle.

[0197] - the juxtaposition on the same level, here the first with regard to the adsorbers 1 and 5, input distribution and switching systems 13, 53 and output distribution and switching systems 14 and 54. This arrangement was chosen because the input and output distribution and switching systems are of significantly different widths and alternating these two systems on one level optimizes the length of the chassis.

[0198] Adsorbers 2 and 6, also in pairs, are a reproduction of the implantation scheme just described but at the second level.

[0199] Adsorbers 3 and 7 on the one hand and 4 and 8 on the other hand reproduce symmetrically with respect to a central plane perpendicular to the longitudinal axis of the chassis the arrangement of the first four adsorbers.

[0200] This provides a smaller installation compared to the conventional solution and is perfectly balanced in terms of distribution. Indeed, the difference in height between the levels has no impact on the operating pressures, whether due to pressure losses in the straight sections of the manifolds or the effect of gravity, which are negligible compared to the rest of the overall circuit.

[0201] Fig. 3 schematically shows an installation of sixteen adsorbers made according to the invention by superimposing two assemblies as described above and by vertically superimposing two tanks to form eight superpositions, four on each side of the frame which then has four levels.

[0202] The chassis as represented can possibly be transported in a single package (by barge) or more probably either in two packages, each corresponding to four superpositions of two tanks facing each other, in which case the packages of four levels each will be arranged vertically, or in two packages, each corresponding to two levels, in which case the packages will be juxtaposed.

[0203] Figure 4 is a view highlighting chassis levels 101, 102, 201, and 202 containing the distribution and switching systems for the sixteen adsorbers after the four tank stacks in the foreground have been removed. At each level, a grating (not shown) allows access for maintenance personnel. This figure further illustrates the symmetrical spatial distribution of the inlet and outlet systems, promoting efficient flow distribution between tanks.

[0204] The second example concerns a CO2 capture installation to be added to an existing industrial complex. The unit is of intermediate size for this type of unit, but the limited space does not allow for a conventional installation. More specifically, it is an installation comprising eight adsorbers having as The main distinguishing feature of the inlet distribution and switching systems is that they not only supply the CO2-containing gas mixture (the low-pressure discharge gas, which in this case is captured CO2) as is typical, but also a third stream rich in CO2 and impurities that returns to the industrial complex. The common low-pressure discharge manifold has the largest diameter, and its actual flow rate is several times greater than that of the other PSA streams.

[0205] The output distribution and switching system of each adsorber is identical to those previously described.

[0206] Optimizing the placement of the eight adsorbers in the adsorption assembly then leads to selecting a four-level chassis to place the said input distribution and switching systems and to positioning the tanks on either side of the chassis, with two rows of vertical superpositions of two tanks on each side of the central chassis.

[0207] In an embodiment not shown, the input distribution and switching systems of the tanks are superimposed, but the overall arrangement differs from the a priori more classic one of the previous example in that those of the tanks located in the lower position in the superposition are all located on the first level of the chassis, while those of the tanks located in the upper position in the superposition are all located on the third level.

[0208] Similarly, the distribution and switching systems for the output of the tanks are superimposed and fixed to the second and fourth levels of the chassis.

[0209] The main reason for this choice is a significant reduction in the height of the chassis compared to the arrangement of the previous example, said reduction having no effect on its length and width.

[0210] Indeed, a level on which a valve relating to the low-pressure discharge gas, i.e., in this case the captured CO2, is located must have sufficient clearance above this valve to allow its removal from the chassis for maintenance. Given the weight and dimensions of this valve, in order to facilitate its dismantling, extraction from the chassis, and subsequent placement on a rolling vehicle for transport to the workshop, a lifting system is provided, in particular one associated with a rail, such as an overhead crane, allowing, for example, the valve to be brought to the end of the chassis for simplified retrieval.

[0211] Since the valves relating to the distribution and switching systems for the outlets of the tanks are significantly smaller, the corresponding level height is actually fixed to allow access for monitoring or maintenance personnel and is therefore lower. The chosen arrangement saves twice the difference in height and therefore requires a lower chassis, easier to transport and to set up, particularly in an existing industrial site.

Claims

1.

2. Demands An adsorption assembly (301) for the adsorption separation of a gaseous mixture, said assembly comprising: - at least two adsorbers, - a common feed manifold (90) for each of the at least two adsorbers into the gaseous mixture, - a common low-pressure discharge manifold (91), configured to discharge a more adsorbable fraction of the gaseous mixture from each of the at least two adsorbers, each adsorber comprising an adsorption tank (1, 2, ..., 8), an inlet line (11, 51) fluidly connected to the tank to feed the tank (1, 2, ..., 8) in a feed gas and a distribution and switching system arranged to connect the inlet pipe (11, 51) of the adsorber considered with the common feed manifold (90) or to connect the inlet pipe (11, 51) of the adsorber considered with the common low pressure discharge manifold (91), characterized in that the distribution and switching system (13, 53) of a first adsorber and the distribution and switching system (13, 53) of a second adsorber are vertically superimposed on each other. Assembly (301) according to the preceding claim, wherein each adsorber comprises an outlet line (12, 52) fluidically connected to the tank (1, 2, ..., 8) for collecting a discharge gas from the tank (1, 2, ..., 8), the adsorption assembly comprising a common high-pressure discharge manifold (92), configured to discharge a less adsorbable fraction of the gas mixture from each of the at least two adsorbers and a common gas exchange manifold configured to transfer a gas from one of the at least two adsorbers to another of said at least two adsorbers, assembly wherein each of said distribution and switching systems is an inlet distribution and switching system (13, 53) and each adsorber comprises an outlet distribution and switching system (14, 54) arranged to fluidically connect the outlet line of the adsorber considered with the common high-pressure discharge manifold (92) and / or connect the outlet pipe (12, 52) of the adsorber considered with the common gas exchange manifold, the outlet distribution and switching system (14, 54) of one adsorber and the outlet distribution and switching system (14, 54) of another adsorber being vertically superimposed on each other.

3. Assembly (301) according to any one of the preceding claims, wherein the distribution and switching systems (13, 53) or inlet distribution and switching systems (13, 53) are fluidly connected to the inlet line (11, 51) of the adsorber considered by a flange and / or the outlet distribution and switching systems (14, 54) are fluidly connected to the outlet line (12, 52) of the adsorber considered by a flange.

4. Assembly (301) according to any one of the preceding claims, wherein the at least two adsorbers comprise N adsorbers, with N an even integer greater than or equal to two, and the adsorption assembly (301) comprises N supply isolation valves, each of said N supply isolation valves being arranged to fluidly isolate from the common supply manifold (90) the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of one of said N adsorbers.

5. Assembly (301) according to the preceding claim, comprising N low pressure discharge isolation valves, each of said N low pressure discharge isolation valves being arranged to fluidly isolate from the common low pressure discharge manifold (91) the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of one of said N adsorbers.

6. Assembly (301) according to any one of claims 1 to 3, wherein the at least two adsorbers comprise at least N adsorbers, with N an even integer greater than or equal to four, the adsorbers being arranged in N / 2 pairs of adsorbers and the adsorption assembly comprises N / 2 common supply isolation valves, each of said N / 2 common supply isolation valves being arranged to fluidly isolate the distribution and switching system (13, 90) from the common supply manifold (90). 53) or input distribution and switching system (13, 53) of an adsorber of a considered pair and to fluidly isolate from the common supply collector (90) the distribution and switching system (13, 53) or input distribution and switching system (13, 53) of the other adsorber of said considered pair.

7. Assembly (301) according to the preceding claim, comprising N / 2 common low-pressure discharge isolation valves, each of said N / 2 common low-pressure discharge isolation valves being arranged to fluidly isolate from the common low-pressure discharge manifold (91) the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of one adsorber of a considered pair and to fluidly isolate from the common low-pressure discharge manifold (91) the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of the other adsorber of said considered pair.

8. Assembly (301) according to any one of claims 6 or 7, wherein the distribution and switching systems (13, 53), inlet distribution and switching systems (13, 53) and / or outlet distribution and switching systems (14, 54) are arranged between the tanks (1,2, ..., 8) of each of the pairs of adsorbers.

9. Assembly (301) according to any one of the preceding claims, comprising a frame (100) comprising at least two levels (101, 102) superimposed vertically with each other, of which a first level (101) and a second level (102), each of the levels (101, 102) comprising at least one grating for the movement of an operator on the level in question, the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of said first adsorber being arranged at the first level (101) and the distribution and switching system (13, 53) or inlet distribution and switching system (13, 53) of said second adsorber being arranged at the second level (102).

10. Installation (400) for the separation by adsorption of a gaseous mixture, the installation (400) comprising at least one adsorption assembly (301) according to any one of the preceding claims.

11. Installation (400) according to the preceding claim, comprising a vertical overlap between them of at least two adsorption assemblies (301, 302) according to any one of claims 1 to 10.

12. Installation (400) according to any one of claims 10 or 11, comprising at least one vertical superposition of at least two adsorption tanks (1, 2, 8) with each other, the installation comprising P chassis levels, with P an even integer, and each of said vertical superpositions of at least two adsorption tanks comprises P / 2 adsorption tanks.

13. Use of an installation (400) according to any one of claims 10 to 12, in a process for separating a gaseous mixture by adsorption, such as a hydrogen purification process or a carbon dioxide (CO2) capture process.

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