Method and plant for processing a feed mixture comprising krypton, xenon, methane and oxygen
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LINDE AG
- Filing Date
- 2026-01-14
- Publication Date
- 2026-07-30
Smart Images
Figure EP2026050780_30072026_PF_FP_ABST
Abstract
Description
[0001] P40374-EP
[0002] February 4, 2025 - Imhof
[0003] 1
[0004] Description
[0005] Method and plant for processing a feed mixture containing krypton, xenon, methane and oxygen
[0006] The present disclosure relates to a process and a plant for processing a feed mixture containing krypton, xenon, methane and oxygen.
[0007] background
[0008] The production of air products in liquid or gaseous states by cryogenic air separation in air separation plants is well-known and extensively described in the technical literature. Among many others, reference can be made to H.-W. Häring (ed.), "Industrial Gases Processing", Wiley-VCH, 3006, in particular section 2.2.5, "Cryogenic Rectification". Unless explicitly defined otherwise, the terms used below have their usual meanings in the technical literature.
[0009] The noble gases krypton and xenon, which are present in atmospheric air at concentrations of approximately 1 ppm and 0.09 ppm (parts per million), can be obtained by processing larger volumes of air in air separation plants. The boiling points of krypton and xenon are significantly higher than those of nitrogen and oxygen. Therefore, krypton and xenon accumulate along with hydrocarbons in liquid oxygen in the rectification columns commonly used. The production of krypton and / or xenon products involves enrichment to obtain a krypton / xenon mixture, followed by the separation of this mixture, as explained in more detail below.
[0010] The aim of the present invention is to improve the processing of mixtures containing krypton and xenon and, in particular, to reduce the loss of krypton and xenon.
[0011] Overview
[0012] Against this background, a process and a plant for processing a feed mixture containing krypton, xenon, methane and oxygen are described with the P40374-EP
[0013] February 4, 2025 - Imhof
[0014] 2
[0015] Features of the independent claims are proposed. Further embodiments are the subject of the dependent claims and the explanations below.
[0016] The proposed method for processing a feed mixture containing krypton, xenon, methane, and oxygen comprises the use of a catalytic arrangement, an adsorption arrangement with two adsorber vessels, and a rectification arrangement. Each of the adsorber vessels is operated sequentially in a first operating mode, a second operating mode, a third operating mode, and a fourth operating mode. The adsorber vessels are operated in such a time-off manner that whenever one of the adsorber vessels is operating in the second operating mode, the other is operating in the fourth operating mode.
[0017] In the first operating mode, gas from the catalytic assembly is supplied to the adsorber vessel, and gas is withdrawn and fed to the rectification assembly. In the second operating mode, gas from the other adsorber vessel is supplied to the adsorber vessel, and gas is withdrawn and also fed to the rectification assembly. In the third operating mode, regeneration gas is supplied to the adsorber vessel, and gas is withdrawn that is not fed to the rectification assembly. In the fourth operating mode, gas from the catalytic assembly is supplied to the adsorber vessel, and gas is withdrawn and fed to the other adsorber vessel.
[0018] The proposed method is based in particular on the finding that a significant proportion of product, especially xenon but also krypton, is conventionally lost during regeneration in the adsorption arrangement. This loss is particularly noticeable when transferring the product from one adsorber container to another. The noble gas losses were recently confirmed by measurements in a real production plant, as explained in more detail below.
[0019] The losses of krypton and xenon in conventional processes result from the fact that, during the adsorption phase, in addition to the desired adsorbates water and carbon dioxide, a certain amount of krypton and xenon is also adsorbed onto the adsorbent. These valuable substances are lost during the regeneration of the adsorber containers without further measures. This results in yield losses on the order of P40374-EP.
[0020] February 4, 2025 - Imhof
[0021] 3
[0022] 5 to 7%. The proposed procedure therefore increases the efficiency of the overall process, as such losses are reduced.
[0023] The first operating mode in the proposed method essentially corresponds to conventional adsorption operation at an adsorption pressure, which is hereinafter also referred to as a "first pressure level". The third operating mode essentially corresponds to conventional regeneration operation at a regeneration pressure, in particular atmospheric pressure, which is hereinafter also referred to as a "second pressure level".
[0024] By operating both adsorber vessels in series between the second and fourth operating modes, as described in the proposed method, the loss of xenon and krypton into the regeneration gas is almost completely avoided. The feed gas, i.e., the gas from the catalytic arrangement, is fed to the adsorption vessel operating in the fourth mode and then, in the same direction, through the loaded but not yet depressurized adsorber vessel operating in the second mode. Adsorbed xenon and krypton in the adsorber vessel operating in the second mode are thus displaced from the loaded vessel towards the downstream rectification arrangement.
[0025] The gas from the catalytic arrangement contains at least krypton, xenon, water, and carbon dioxide. The duration of the second and fourth operating modes is determined such that the gas supplied from the rectification arrangement in the second operating mode contains less than a predetermined amount of water and carbon dioxide. In other words, the second operating mode is carried out only until the more readily desorbed components krypton and, in particular, xenon have been displaced from the adsorber vessel in the second operating mode, but before carbon dioxide and water have desorbed. The predetermined amount of carbon dioxide and water can also be essentially zero, or a correspondingly low value can be chosen.
[0026] The duration of the second and fourth operating modes can also be specifically designed so that xenon is transferred between the adsorber containers in less than a predetermined quantity. (See P40374-EP.)
[0027] February 4, 2025 - Imhof
[0028] 4
[0029] In this way, it can be ensured that the transferred gas consists essentially of oxygen and therefore no non-adsorbable xenon is transferred from the regenerated adsorber container in the fourth operating mode to the loaded adsorber container in the second operating mode. As has been determined, the duration of the fourth operating mode can be selected such that xenon, and to some extent also krypton, is essentially completely retained in the adsorber container operating in the fourth mode.
[0030] It is expedient that the duration of the second operating mode is identical to the duration of the fourth operating mode, so that these operating modes can be carried out in the manner described.
[0031] The duration of the second and fourth operating modes can be determined, in particular, by measuring the concentration of xenon, carbon dioxide, and / or water. The measurement can be taken at different locations. For example, in the second and fourth operating modes, a measurement can be taken between the adsorber containers, which are then connected in series. The second or fourth operating mode can be terminated when xenon breaks through from the upstream of the two series-connected adsorbers, i.e., when it exceeds a predefined threshold. Alternatively, in the second and fourth operating modes, a measurement can be taken at the outlet of the second of the series-connected adsorber containers. The second or fourth operating mode can then be terminated when no more xenon is being discharged or when the xenon concentration falls below a corresponding threshold. Both options can be considered roughly equivalent.Alternatively or additionally, it is also possible to determine the duration of the second operating mode and the fourth operating mode based on a computational prediction of the content of xenon, carbon dioxide and / or water, for example by means of a simulation or based on a model of the adsorption arrangement.
[0032] In the proposed method, the first, second, and fourth operating modes are carried out at a first pressure level, and the third operating mode is carried out at a second pressure level below the first pressure level. Between the second and third operating modes, P40374-EP
[0033] February 4, 2025 - Imhof
[0034] 5
[0035] In particular, pressure relief is provided, and between the third and fourth operating modes, pressure build-up is provided.
[0036] In the proposed process and its embodiments, in particular using the catalytic arrangement, the methane in the feed mixture, or a part thereof, is reacted with oxygen to form water and carbon dioxide.
[0037] The gas supplied to the rectification arrangement in the first and second operating modes contains, in particular, oxygen, krypton, and xenon, and this gas is depleted of oxygen in the rectification arrangement. The gas not supplied to the rectification arrangement in the third operating mode, or a portion thereof, can be released, in particular, into the atmosphere.
[0038] The proposed plant for processing a feed mixture containing krypton, xenon, methane and oxygen comprises a catalysis arrangement, an adsorption arrangement with two adsorber containers and a rectification arrangement, wherein the plant is configured to operate each of the adsorber containers successively in a first operating mode, a second operating mode, a third operating mode and a fourth operating mode, operating the adsorber containers in such a time-off manner that whenever one of the adsorber containers is operated in the second operating mode, the other of the adsorber containers is operated in the fourth operating mode.
[0039] The system is designed to supply gas from the catalytic arrangement to the adsorber container in the first operating mode, as well as to extract gas and supply it to the rectification arrangement; to supply gas from the other adsorber container to the adsorber container in the second operating mode, as well as to extract gas and supply it to the rectification arrangement; to supply a regeneration gas to the adsorber container in the third operating mode, as well as to extract gas and not supply it to the rectification arrangement; and to supply gas from the catalytic arrangement to the adsorber container in the fourth operating mode, as well as to extract gas and supply it to the other adsorber container.
[0040] The proposed method and its embodiments include, in particular, that the starting mixture contains 100 to 500 ppm, for example approximately 200 ppm, on P40374-EP
[0041] February 4, 2025 - Imhof
[0042] 6
[0043] The proposed method and its embodiments are therefore particularly suitable for use with typical crude krypton / xenon from cryogenic air separation or a so-called C1 unit, as explained below. The solution contains xenon by volume, 1,000 to 5,000 ppm (e.g., 2,500 ppm), krypton by volume, and more than 99% oxygen by volume.
[0044] For further features and advantages of the proposed plant and its configurations, reference is expressly made to the features and advantages of the proposed process and its configurations explained above, as these apply to the plant in essentially the same way.
[0045] The same applies to a facility which, according to a design proposed here, may be set up to carry out a procedure according to a corresponding design.
[0046] Drawings
[0047] The embodiments are described below purely as examples with reference to the attached drawing, whereby
[0048] Figure 1 illustrates a system for processing a feed mixture containing krypton and xenon, which may form the basis of an embodiment;
[0049] Figures 2A to 2D illustrate partial views of a system for processing a krypton and xenon-containing feed mixture according to a proposed design in different operating modes;
[0050] Figures 3A to 3D illustrate the loading of adsorption beds in the operating modes shown in Figures 2A to 2D according to a proposed embodiment in the form of diagrams; and
[0051] Figure 4 illustrates xenon concentrations at the outlet of an adsorption container. P40374-EP
[0052] February 4, 2025 - Imhof
[0053] 7
[0054] Designs
[0055] The embodiments and configurations described below are provided solely to assist the reader in understanding the claimed and previously explained features. They represent only representative examples and are not intended to be considered exhaustive or limiting with regard to the features of the proposed methods and devices.
[0056] It is understood that the advantages, embodiments, examples, functions, features, structures and / or other aspects described above and below are not to be considered as limitations of the scope of the claims or as limitations of equivalents thereto, and that other embodiments may be used and modifications made without deviating from the scope of the claims.
[0057] Different embodiments may include, feature, consist of, or essentially consist of further advantageous combinations of the described elements, components, features, parts, steps, means, etc., even if such combinations are not specifically described herein. Furthermore, other embodiments may be included that are not currently claimed but could be claimed in the future, particularly if they are within the scope of the independent claims.
[0058] Explanations relating to devices, apparatus, arrangements, systems, etc., according to proposed embodiments may also apply to procedures, processes, methods, etc., according to other embodiments, and vice versa. Identical, functionally equivalent, structurally identical, or comparable elements, process steps, etc., may be indicated with identical reference numerals.
[0059] The following explanations and definitions relating to some fundamental aspects of the invention may apply to all or part of the embodiments presented here, and the explanation of certain aspects relating to only one part or one of the embodiments should not be understood as P40374-EP
[0060] February 4, 2025 - Imhof
[0061] 8
[0062] It will be assumed that these aspects cannot also be realized with other or all designs, insofar as technically possible and sensible.
[0063] The conjunction "and / or," when used before the last item in a list, should be understood to mean that all items mentioned before and after it can be combined in any way. In other words, "A, B and / or C" means "A and / or B and / or C" or "at least one of the elements A, B, and C in any combination."
[0064] In the sense understood here, an "operating cycle" is characterized by a sequence of process steps or "operating modes" that are repeated in essentially the same way in another operating cycle. In the case of an adsorption process, this most simply consists of an adsorption step followed by a desorption step, or corresponding operating modes. Due to the saturation of the adsorbent with the gas component to be adsorbed, such a repeated, or "cyclical," sequence of process steps is necessary. Operating cycles can also include different durations for the individual process steps, for example, due to changing compositions, temperatures, and the like. Typically, the process steps themselves do not change.
[0065] In particular, the direction of feed, flow direction, speed, etc. of gases into certain apparatus can be reversed or changed between different operating cycles.
[0066] In an adsorption arrangement, two or more adsorption units, typically in the form of adsorber containers filled with a suitable adsorbent material, are provided to ensure continuous operation. The adsorber containers are operated sequentially, so that at least one of the adsorption units is always in adsorption mode and at least one other adsorption unit is being regenerated simultaneously. Regeneration can be carried out, in particular, using a regeneration gas stream that is heated and passed countercurrently (with respect to the adsorption mode) through the adsorption units. Such operation requires switching between the adsorption containers. P40374-EP
[0067] February 4, 2025 - Imhof
[0068] 9
[0069] In the figures described below, components of comparable or identical function and / or design are indicated with identical reference numerals. Repeated explanations are omitted solely for the sake of clarity. Explanations relating to systems or their components apply accordingly to process steps carried out with them, and vice versa.
[0070] The production of krypton and xenon based on cryogenic air separation can be carried out in three subunits or steps, typically referred to as C1, C2, and C3. The C1 unit or step is generally part of an air separation plant or is carried out in such a plant, as described above. This produces so-called crude krypton / xenon, which has comparatively low concentrations of krypton and xenon and contains approximately 99.3% oxygen. In embodiments of the present invention, this can be used as a feed mixture.
[0071] The crude krypton / xenon from several air separation plants can be collected and transported to a C2 plant. Embodiments of the present invention may relate in particular to such a C2 plant or a process carried out therein. A C2 step serves to purify the crude krypton / xenon, mainly by removing the oxygen and catalytically converting methane, which may also be present in the crude krypton / xenon, as it accumulates in the main condenser of an air separation plant.
[0072] The product of the C2 unit or a corresponding process step is essentially a mixture of krypton and xenon with traces of impurities. The removed oxygen is typically used as a gaseous oxygen product at low pressure. Mixtures formed in several C2 units can be fed to a C3 unit or a corresponding process step to produce pure krypton and xenon. The designation of the units or steps as C1, C2, and C3 is not restrictive, and the present invention can be used with other arrangements of unit components or process steps.
[0073] Figure 1 shows a system for processing a feed mixture containing krypton, xenon, methane, and oxygen, in particular the aforementioned raw krypton / xenon. The system illustrated in Figure 1 can be configured in various ways (P40374-EP).
[0074] February 4, 2025 - Imhof
[0075] 10
[0076] the present invention is based on, but does not necessarily itself constitute an embodiment of the present invention.
[0077] The system illustrated in Figure 1 can represent a conventional C2 unit as just described. The system can, for example, include a tank 101 which can be filled, for instance, via tanker trucks with raw krypton / xenon from several C1 units, as abstracted as C1 in Figure 1. The raw krypton / xenon from tank 101 can, as mentioned, represent the component mixture referred to elsewhere in this disclosure as the feed mixture.
[0078] The feed mixture can be directed into a separation vessel 102, from which a flash gas can be released into the atmosphere A or liquefied and returned to the tank. The liquid from the separation vessel 102 can be pumped using a pump 103, partially buffered in a buffer tank 104, and passed through a heat exchanger 105, which is operated with water W, steam, or ambient air, before optionally being combined with other liquids from tanks or pressurized gas containers 106 and 107, such as an externally supplied product from a C2 unit in a tank 106, a gas from a gas balloon of a C3 unit in a tank 107, or a gas from a gaseous oxygen collector 108 of another C2 unit. The units 102 to 105 can be provided in varying numbers in the system and each can hold a portion of the raw krypton / xenon.
[0079] The crude krypton / xenon is then fed in the form of a mass stream 1 to a catalytic arrangement 110 in the system illustrated in Figure 1. The catalytic arrangement comprises a counterflow heat exchanger 111, an (electric) heater 112, a catalyst bed 113, a water-cooled cooler 114, and a condenser tank 115 for removing condensate C. In the catalyst bed 113 of the catalytic arrangement 110, traces of methane contained in the crude krypton / xenon can be converted into carbon dioxide and water. The resulting water (and any water already present) can be condensed into condensate C in a condenser tank 115.
[0080] February 4, 2025 - Imhof
[0081] 11
[0082] It should be emphasized that the description of certain plant components or apparatus as belonging to a subunit, for example the catalysis arrangement 110, is not to be understood as restrictive and serves only for reference.
[0083] A mass stream 2 from the catalysis arrangement 110, or a portion thereof in the form of a corresponding mass stream 3, is fed to an adsorption arrangement 120, which comprises a pair of adsorber containers 201, 202. These containers may, for example, contain a molecular sieve material as an adsorbent, which is configured for regeneration using a regeneration gas R. Gaseous nitrogen or so-called waste oxygen may be used as the regeneration gas R. The regeneration gas R can be heated by means of an electric heater 117 and, after use for regeneration in the adsorption arrangement 120, released into the atmosphere A as a loaded adsorption gas stream. In the adsorption arrangement 120, water and carbon dioxide are adsorbed in particular, and the crude krypton / xenon thereby purified can be conveyed as a mass stream 6 via a counterflow heat exchanger 118 to a rectification arrangement 130.
[0084] The rectification arrangement 130, as shown in Figure 1, comprises a single rectification column 131 with a top condenser 132 and re-evaporators 133, which can be electrically operated. The top condenser 132 is cooled with liquid nitrogen N, which evaporates in an evaporation chamber of the top condenser 132 and is then, for example, vented into the atmosphere A as shown in Figure 1, with the corresponding mass stream being drawn off from the top condenser 132 on the left. A bottom stream from the rectification column 131 can be transferred to a C3 unit or a corresponding reaction step, as indicated by C3, or stored in a cylinder bundle 134 or transferred to a storage tank. Such options are not shown separately in Figure 1.
[0085] In the example shown in Figure 1, head gas from the rectification column 131 is either vented to atmosphere A as waste oxygen, with or without passing through the countercurrent heat exchanger 118, or partially used as regeneration gas R for regenerating the adsorption unit 120, as previously explained with reference to regeneration gas R. P40374-EP
[0086] February 4, 2025 - Imhof
[0087] 12
[0088] In the system shown in Figure 1, the crude krypton / xenon, and thus the first material stream, can contain, for example, approximately 200 ppm xenon and 2500 ppm krypton, trace amounts of methane, and, in the remaining residue, typically more than 99 mol% oxygen. The crude krypton / xenon is purified in the adsorption unit 120 using a conventional molecular sieve process.
[0089] In particular, water and carbon dioxide are retained adsorbably in the adsorption unit 120. However, a disadvantage is that krypton and especially xenon are also adsorbed in the adsorption unit 120. Therefore, when the adsorber containers 201, 202 are changed, i.e., when the pressure is reduced and the regeneration process is carried out, the adsorbed noble gases, especially xenon, are lost, since the loaded regeneration gas is typically released into the atmosphere A in conventional processes.
[0090] This is where embodiments of the present invention come into play. The aim here is to enable the highest possible yield of the noble gases krypton and xenon contained in the crude krypton / xenon. In other words, product losses in the process, particularly in the molecular sieve process, are to be reduced to a minimum.
[0091] The aspects just mentioned can be confirmed by measurements. For example, a measurement of xenon at the outlet of adsorber containers 201 and 202 after initiating adsorption operation shows that xenon, in particular, is no longer detectable for approximately 20 minutes or half an hour. This demonstrates that xenon is completely adsorbed by the adsorption material within this timeframe. During this period, virtually pure oxygen flows out of the corresponding adsorber containers 201 and 202, as water and carbon dioxide are also adsorbed.
[0092] In the proposed process and its embodiments, appropriately purified gas is fed onto the feed side of the adsorber vessel 201, 202 to be regenerated. While the highly adsorbing components water and krypton remain adsorbed, xenon and krypton are initially flushed out of this adsorber vessel 201, 202 towards the separation unit, i.e., the cryogenic separation arrangement. The loss of the adsorbed fractions of these two valuable substances can thus be almost completely avoided. Shortly before the corresponding adsorber vessel 201, 202 is fully loaded with xenon, the serial P40374-EP is activated.
[0093] February 4, 2025 - Imhof
[0094] 13
[0095] Operation is complete and the gas from the corresponding adsorption vessel 201, 202 flows directly to the separation unit. This prevents the re-adsorption of xenon and krypton in the adsorption vessel 201, 202 being regenerated. After this time, the outlet concentration of xenon increases until it reaches a value similar to the inlet concentration.
[0096] Figures 2A to 2D illustrate partial views of a system according to an embodiment of the invention in different operating modes, each designated by 100. The integration of the components illustrated in Figures 2A to 2D is particularly evident from the corresponding designations of the catalysis arrangement 110 and the rectification arrangement 130, which can be identical or comparable to the system illustrated in Figure 1. The same applies to the material streams 3 and 6. The adsorber containers are designated 201 and 202 in Figures 2A to 2D, as before.
[0097] As illustrated in Figure 2A, the adsorber container 202 is in an adsorption mode, also referred to here as the "first operating mode," and is thus integrated between the catalysis arrangement 110 and the rectification arrangement 130. In this way, the previously mentioned third mass stream 3 can be freed of water and carbon dioxide in the adsorber container 202, and a correspondingly purified mass stream 6 flows into the rectification arrangement 130. Simultaneously, the adsorber container 201 is in a regeneration mode, also referred to here as the "third operating mode," in which regeneration gas R flows through the adsorber container 201 and is, for example, released into the atmosphere A.
[0098] After the adsorber tank 202 is fully loaded and the adsorber tank 201 is fully regenerated, the system conventionally switches between adsorption and regeneration modes after a corresponding pressure release in the adsorber tank 202 and a pressure build-up in the adsorber tank 201, resulting in a state as shown in Figure 2C. In contrast, the method proposed here and the system 100 include an intermediate step, which is shown in Figure 2B.
[0099] The proposed procedure also involves a pressure build-up in adsorber vessel 201, but initially no pressure relief in P40374-EP.
[0100] February 4, 2025 - Imhof
[0101] 14
[0102] Adsorber container 202. The pressure build-up in adsorber container 201 is achieved in particular by introducing the gas 3 into the adsorber container 201.
[0103] As illustrated in Figure 2B, in a corresponding intermediate step, which is also referred to here as the "second operating mode" with respect to the adsorber container 202 and as the "fourth operating mode" with respect to the adsorber container 201, gas flowing out of the adsorber container 201, as illustrated in Figure 2B in the form of a mass flow 9, is transferred to the adsorber container 202, while gas flowing out of the adsorber container 202 is transferred to the rectification arrangement 130.
[0104] In the second and fourth operating modes, both adsorber containers 201, 202 are pressurized, and a pressure relief, for example to the atmosphere, follows with respect to adsorber container 202.
[0105] After pressure relief and a corresponding switchover, as illustrated in Figure 2C, the adsorber vessel 202 is operated in conventional regeneration mode, while the adsorber vessel 201 is now in adsorption mode. The regeneration gas R flows through the adsorber vessel 202 in the opposite direction to a conventional feed gas 3.
[0106] Figure 2D illustrates a further intermediate step, which is essentially the same as intermediate step 2B, except that the operation of the adsorber containers 201, 202 is reversed compared to intermediate step 2B.
[0107] Figures 3A to 3D illustrate the loading states of the respective adsorption beds in the catalyst bed of the adsorber vessel 202 according to Figures 2A to 2D, whereby it is understood that the corresponding explanations also apply to the adsorber vessel 201 in a subsequent operating cycle. The loading states are illustrated for the end of a corresponding operating mode.
[0108] In all figures 3A to 3D, the loading states are shown as carbon dioxide in the form of reclining squares, as water in the form of triangles, and as xenon in the form of squares standing on their points, in dimensionless sizes on the P40374-EP.
[0109] February 4, 2025 - Imhof
[0110] 15
[0111] The vertical axis is shown in relation to the length of the catalyst bed in meters on the horizontal axis. The flow direction in the first, second, and fourth operating modes is from left to right in Figures 3A, 3B, and 3D, respectively; in the third operating mode, as shown in Figure 3C, it is reversed. The xenon loading states are multiplied by a factor of 1000 to ensure comparability in the diagrams.
[0112] As mentioned, Figure 3A depicts the end of the first operating mode for the adsorber container 202 according to Figure 2A. As shown, the adsorber container 202 is heavily loaded with water at the beginning of the adsorption bed up to a depth of approximately 0.5 meters. This is followed by a region of approximately 0.5 meters to 2 meters in which the adsorber container 202 is essentially loaded with carbon dioxide. At the end of the adsorption bed, from approximately 2 meters to 3 meters, there is a region where the loading is essentially with xenon. This would be lost during a conventional, immediately subsequent regeneration.
[0113] As also mentioned, Figure 3B relates to the end of the second operating mode for the adsorber vessel 202 according to Figure 2B. This second operating mode is characterized by the fact that, as mentioned, essentially pure oxygen is transferred from the other adsorber vessel 201 into the adsorber vessel 202. The xenon previously adsorbed at the end of the adsorption bed, approximately 2 to 3 meters long, can thus be discharged from the adsorber vessel 202 and transferred to the downstream rectification arrangement 130.
[0114] At the end of the third operating mode for the adsorber tank 202 according to Figure 3C or 2C, which relates to a normal regeneration operation, the components are essentially removed from the adsorption bed.
[0115] At the end of the fourth operating mode for the adsorber container 202 according to Figure 3D or 2D, xenon is essentially adsorbed in a range from 0.5 meters to 2 meters and partially to the end.
[0116] Figure 4 illustrates the time course of the xenon content at the outlet of the adsorption unit 120 according to a proposed embodiment. This corresponds to the xenon content in the gas stream supplied to the rectification unit 130. P40374-EP
[0117] February 4, 2025 - Imhof
[0118] 16
[0119] The vertical axis shows the xenon concentration at the outlet of adsorption unit 120 in percent, while the horizontal axis illustrates a time in minutes. Vertical dashed lines delineate the operating modes: up to approximately 100 minutes, the product originates from the adsorber operating in the second mode; from approximately 100 to 1,500 minutes, it originates from the adsorber operating in the first mode; and from approximately 1,500 minutes onward, it originates from an adsorber operating in the second mode.
Claims
P40374-EP February 4, 2025 - Imhof 17 Patent claims 1. Method for processing a feed mixture (1) containing krypton, xenon, methane and oxygen, wherein a catalysis arrangement (110), an adsorption arrangement (120) with two adsorber containers (201, 202) and a rectification arrangement (130) is used, wherein Each of the adsorber containers (201, 202) is operated successively in a first operating mode, a second operating mode, a third operating mode and a fourth operating mode, The adsorber containers (201, 202) are operated in such a time-off manner that one of the adsorber containers (201, 202) is always operated in the second operating mode when the other of the adsorber containers (201, 202) is operated in the fourth operating mode. In the first operating mode, gas from the catalytic arrangement (110) is supplied to the adsorber container (201, 202) and gas is withdrawn and supplied to the rectification arrangement (130). In the second operating mode, gas is supplied to the adsorber container (201, 202) from the other adsorber container (201, 202) and gas is withdrawn, which is supplied to the rectification arrangement (130), in the third operating mode a regeneration gas (R) is supplied to the adsorber container (201, 202) and gas is withdrawn that is not supplied to the rectification arrangement (130), In the fourth operating mode, gas from the catalytic arrangement (110) is supplied to the adsorber container (201, 202) and gas is withdrawn, which is supplied to the other adsorber container (201 , 202).
2. The method of claim 1, wherein the gas from the catalytic arrangement (110) contains krypton, xenon, water and carbon dioxide.
3. The method of claim 2, wherein the duration of the second operating mode and the fourth operating mode is dimensioned such that the gas supplied from the rectification arrangement (130) in the second operating mode contains less than a predetermined amount of water and carbon dioxide. P40374-EP February 4, 2025 - Imhof 18 4. Method according to claim 3, wherein the duration of the second operating mode and the fourth operating mode is dimensioned such that xenon is transferred between the adsorber containers (201, 202) in less than a predetermined amount.
5. Method according to one of claims 3 or 4, wherein the duration of the second operating mode is identical to the duration of the fourth operating mode.
6. Method according to one of claims 3 to 5, wherein the determination of the duration of the second operating mode and the fourth operating mode is based on a measurement of a content of xenon, carbon dioxide and / or water.
7. Method according to one of claims 3 to 5, wherein the determination of the duration of the second operating mode and the fourth operating mode is based on a prediction of the content of xenon, carbon dioxide and / or water.
8. A method according to any of the preceding claims wherein the first, second and fourth operating modes are carried out at a first pressure level, and the third operating mode is carried out at a second pressure level below the first pressure level.
9. A method according to any of the preceding claims, wherein, using the catalytic arrangement (110), the methane in the feed mixture, or a part thereof, is reacted with oxygen to form water and carbon dioxide.
10. Method according to one of the preceding claims, wherein the gas supplied to the rectification arrangement (110) in the first operating mode and in the second operating mode contains oxygen, krypton and xenon, and this gas is depleted of oxygen in the rectification arrangement (110).
11. Method according to one of the preceding claims, wherein the gas not supplied to the rectification arrangement (130) in the third operating mode, or a part thereof, is released to the atmosphere (A).
12. Plant (100) for processing a feed mixture (1) containing krypton, xenon, methane and oxygen, comprising a catalytic arrangement (110), a P40374-EP February 4, 2025 - Imhof 19 Adsorption arrangement (120) and a rectification arrangement (130) with two adsorber containers (201, 202), wherein the system (100) is configured for this purpose, to operate each of the adsorber containers (201, 202) successively in a first operating mode, a second operating mode, a third operating mode and a fourth operating mode, to operate the adsorber containers (201, 202) in such a time-off manner that one of the adsorber containers (201, 202) is always operated in the second operating mode when the other of the adsorber containers (201, 202) is operated in the fourth operating mode, to supply gas from the catalytic arrangement (110) to the adsorber container (201, 202) in the first operating mode, and to extract gas and supply it to the rectification arrangement (130), to supply gas from the other adsorber container (201, 202) to the adsorber container (201, 202) in the second operating mode, as well as to extract gas and supply it to the rectification arrangement (130), to supply a regeneration gas (R) to the adsorber container (201, 202) in the third operating mode and to withdraw gas and not supply it to the rectification arrangement (130), gas from the catalytic arrangement (110) is supplied to the adsorber container (201, 202) in the fourth operating mode, and gas is extracted and supplied to the other adsorber container (201, 202).
13. System (100) according to claim 12, which is set up to carry out a method according to any one of claims 1 to 11.