Adsorbent bed with improved hydrothermal stability

Abstract

Disclosed in certain embodiments are methods of removing water, mercaptans, C5+ or C6+ hydrocarbons, or any combination thereof from a gaseous feed stream during an adsorption step of an adsorption cycle.

Description

[0001] Cross-reference to related applications

[0002] This application claims the priority benefit of U.S. Provisional Patent Application No. 63 / 170,157, filed April 2, 2021, the disclosure of which is hereby incorporated in its entirety. Background Technology

[0003] Dehydrating natural gas to cryogenic specifications is crucial in the pretreatment process for liquefied natural gas (LNG) production. Zeolite molecular sieves are used in this process because they allow the natural gas to meet the dew point required for liquefaction. Failure to meet this dew point requirement can lead to an inability to maintain the necessary gas flow to the liquefaction zone, potentially limiting or halting LNG production.

[0004] Hydrothermal damage and reverse condensation in the dehydrator vessel during regeneration and adsorption lead to degradation of the molecular sieve adsorbent through leaching of the clay binder and loss of adsorption capacity. Furthermore, the presence of thiols can lead to H₂S formation under process conditions, which can also have a detrimental effect on the molecular sieve. Each of these effects can result in increased pressure drop and uneven distribution of the adsorption and / or regeneration flow, ultimately necessitating premature adsorbent replacement. Summary of the Invention

[0005] The following is a simplified overview of various aspects of this disclosure to provide a basic understanding of these aspects. This summary is not an exhaustive summary of this disclosure. It is not intended to identify key or essential elements of this disclosure, nor is it intended to depict any scope of any particular embodiment or claim of this disclosure. The sole purpose of the summary is to present some concepts of this disclosure in a simplified form as a prelude to the more detailed description that follows.

[0006] In one aspect, a method for removing water from a gas feed stream during an adsorption step of an adsorption cycle includes: directing a gas feed stream having an initial water mole fraction to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: a first adsorbent layer for removing water from the gas feed stream, the first adsorbent layer comprising a water-stabilized adsorbent; a second adsorbent layer located downstream of the first adsorbent layer to remove additional water, the second adsorbent layer comprising a microporous adsorbent; and a third adsorbent layer located downstream of the second adsorbent layer, the third adsorbent layer comprising one or more zeolites. In at least one embodiment, when the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced water mole fraction maintained for at least 90% of the duration of the adsorption step. In at least one embodiment, the reduced water mole fraction does not exceed about 90% of the initial water mole fraction.

[0007] In at least one embodiment, the reduced water mole fraction does not exceed about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, about 1%, about 0.1%, about 0.01%, or about 0.001% of the initial water mole fraction. In at least one embodiment, the reduced water mole fraction does not exceed about 20% of the initial water mole fraction.

[0008] In at least one embodiment, the reduced water mole fraction is maintained for at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the duration of the adsorption step. In at least one embodiment, the reduced water mole fraction is maintained for 100% of the duration of the adsorption step.

[0009] In at least one embodiment, the reduced water mole fraction does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, about 5 ppm, or about 1 ppm.

[0010] In at least one embodiment, the reduced water mole fraction does not exceed about 100 ppm, about 50 ppm, about 10 ppm, about 9 ppm, about 8 ppm, about 7 ppm, about 6 ppm, about 5 ppm, about 4 ppm, about 3 ppm, about 2 ppm, about 1 ppm, about 0.1 ppm, or about 0.01 ppm.

[0011] In another aspect, a method for removing thiols from a gas feed stream during an adsorption step in an adsorption cycle includes: directing a gas feed stream having an initial thiol molar fraction to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: a first adsorbent layer for removing thiols from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; a second adsorbent layer downstream of the first adsorbent layer for removing additional thiols, the second adsorbent layer comprising a microporous adsorbent; and a third adsorbent layer downstream of the second adsorbent layer, the third adsorbent layer comprising one or more zeolites. In at least one embodiment, when the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced thiol molar fraction maintained for at least 90% of the duration of the adsorption step. In at least one embodiment, the reduced thiol molar fraction does not exceed about 90% of the initial thiol molar fraction.

[0012] In at least one embodiment, the reduced molar fraction of thiol does not exceed about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, or about 1%, about 0.1%, or about 0.01% of the initial molar fraction of thiol.

[0013] In at least one embodiment, the reduced molar fraction of thiol before reaching the third adsorbent layer does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, or about 5 ppm, or about 1 ppm.

[0014] In another aspect, a method for removing C5+ or C6+ hydrocarbons from a gas feed stream during an adsorption step in an adsorption cycle includes: directing a gas feed stream having an initial molar fraction of C5+ or C6+ hydrocarbons to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: a first adsorbent layer for removing C5+ or C6+ hydrocarbons from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; a second adsorbent layer downstream of the first adsorbent layer for removing additional C5+ or C6+ hydrocarbons, the second adsorbent layer comprising a microporous adsorbent; and a third adsorbent layer downstream of the second adsorbent layer, the third adsorbent layer comprising one or more zeolites and additional microporous adsorbents. In at least one embodiment, the C5+ or C6+ compounds include one or more of pentane, hexane, benzene, heptane, octane, nonane, toluene, ethylbenzene, xylene, or neopentane. In at least one embodiment, when the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced molar fraction of aromatic compounds and / or aliphatic C8+ or C9+ hydrocarbons maintained for at least 90% of the duration of the adsorption step. In at least one embodiment, the reduced molar fraction does not exceed about 90% of the initial molar fraction.

[0015] In at least one embodiment, the reduced mole fraction does not exceed about 90%, about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, or about 1% of the initial mole fraction.

[0016] In at least one embodiment, the reduction in molar fraction before reaching the third adsorbent layer does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, about 5 ppm, or about 1 ppm.

[0017] In at least one embodiment, the one or more adsorbent beds further include a fourth adsorbent layer located downstream of the first adsorbent layer and upstream of the second adsorbent layer. In at least one embodiment, the fourth adsorbent layer comprises one or more of an amorphous silica adsorbent, an amorphous silica-alumina adsorbent, or a high-silica zeolite adsorbent. In at least one embodiment, the third adsorbent layer comprises a high-silica zeolite adsorbent. In at least one embodiment, the high-silica zeolite adsorbent comprises ZSM-5, zeolite Y, or β-zeolite.

[0018] In another aspect, a method of processing a gas feed stream includes: directing a gas feed stream having an initial water mole fraction to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: a first adsorbent layer for removing water from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; and a second adsorbent layer downstream of the first adsorbent layer, the second adsorbent layer comprising a microporous adsorbent. In at least one embodiment, when the gas feed stream exits the second adsorbent layer, the gas feed stream has a reduced water mole fraction.

[0019] In at least one embodiment, the reduced water mole fraction is below the maximum cryogenic value produced by liquefied natural gas (LNG) or natural gas condensate (NGL).

[0020] In at least one embodiment, the one or more adsorbent beds further include a third adsorbent layer located downstream of the first adsorbent layer and upstream of the second adsorbent layer. In at least one embodiment, the third adsorbent layer comprises one or more of an amorphous silica adsorbent, an amorphous silica-alumina adsorbent, or a high-silica zeolite adsorbent. In at least one embodiment, the third adsorbent layer comprises a high-silica zeolite adsorbent. In at least one embodiment, the high-silica zeolite adsorbent comprises ZSM-5, zeolite Y, or β-zeolite.

[0021] In at least one embodiment, one or more zeolites in any of the foregoing embodiments include one or more of zeolite 3A, zeolite 4A or zeolite 5A.

[0022] In at least one embodiment, one or more zeolites in any of the foregoing embodiments include one or more of zeolite 5A or zeolite X.

[0023] In at least one embodiment, one or more zeolites in any of the foregoing embodiments comprise zeolite 13X.

[0024] In at least one embodiment, one or more zeolites in any of the foregoing embodiments comprise zeolite 4A.

[0025] In at least one embodiment, one or more zeolites of the aforementioned embodiments are exchanged with an element selected from Li, Na, K, Mg, Ca, Sr or Ba.

[0026] In at least one embodiment, the water-stable adsorbent in any of the foregoing embodiments comprises an amorphous silica adsorbent or an amorphous silica-alumina adsorbent.

[0027] In at least one embodiment, the gas feed stream of any of the foregoing embodiments is a natural gas feed stream.

[0028] In at least one embodiment, after contact with one or more adsorbent beds, the water mole fraction of the gas feed stream is less than 1 ppm or less than 0.1 ppm.

[0029] In at least one embodiment, after contact with one or more adsorbent beds, the molar fraction of thiol in the gas feed stream is less than 10 ppm or less than 1 ppm.

[0030] In at least one embodiment, after contact with one or more adsorbent beds, the C5+ or C6+ mole fraction of the gas feed stream is less than 10 ppm or less than 1 ppm.

[0031] In at least one embodiment, the third adsorbent layer of any of the foregoing embodiments is located in an adsorbent bed separate from the first adsorbent layer and the second adsorbent layer.

[0032] In at least one embodiment, the method of any of the foregoing embodiments further includes: forming liquefied natural gas products from a gas feed stream after contact with the second adsorbent layer.

[0033] In at least one embodiment, the method of any of the foregoing embodiments further includes: forming a C2+ or C3+ natural gas condensate feed stream from the gas feed stream after contacting the second adsorbent layer.

[0034] In at least one embodiment, the contact in any of the foregoing embodiments is performed as part of a temperature-switching adsorption process having a cycle time of no more than about 8 hours, no more than about 7 hours, no more than about 6 hours, no more than about 5 hours, no more than about 4 hours, no more than about 3 hours, no more than about 2 hours, or no more than about 1 hour.

[0035] In at least one embodiment, the gas feed stream of any of the foregoing embodiments further comprises non-thiol hydrocarbons. In at least one embodiment, one or more components of the non-thiol hydrocarbons in the gas feed stream are reduced molarly by 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 5% relative to the initial concentration of that component in the gas feed stream before reaching the second adsorbent layer. In at least one embodiment, one or more components are selected from benzene, C9 hydrocarbons, C8 hydrocarbons, C7 hydrocarbons, or C6 hydrocarbons.

[0036] In at least one embodiment, the method of any of the foregoing embodiments further includes: modifying the adsorbent bed by removing at least a portion of the previously existing adsorbent and replacing at least a portion of the previously existing adsorbent with one or more of a first adsorbent layer or a second adsorbent layer before directing the gas feed stream to the adsorbent bed.

[0037] On the other hand, one or more adsorbent units adapted to remove one or more of water, thiols or heavy hydrocarbons from a gas feed stream include at least one adsorbent bed of any of the foregoing embodiments.

[0038] On the other hand, the natural gas purification system includes at least one adsorbent bed of any of the aforementioned embodiments. Attached Figure Description

[0039] The disclosure is illustrated by way of example, not limitation, in the accompanying drawings, in which:

[0040] Figure 1A An adsorber unit according to one embodiment of the present disclosure is shown;

[0041] Figure 1B Another embodiment according to this disclosure is shown. Figure 1A Variations of the configuration;

[0042] Figure 2A An adsorber unit according to another embodiment of the present disclosure is shown;

[0043] Figure 2B Another embodiment according to this disclosure is shown. Figure 2A Variations of the configuration;

[0044] Figure 2C Another embodiment according to this disclosure is shown. Figure 2B Variations of the configuration;

[0045] Figure 3A An adsorber unit according to another embodiment of the present disclosure is shown;

[0046] Figure 3B Another embodiment according to this disclosure is shown. Figure 3A Variations of the configuration;

[0047] Figure 4 A method for processing a gas feed stream according to one embodiment of the present disclosure is shown;

[0048] Figure 5 The simulated H2O curve of the zeolite 4A bed at the end of adsorption is shown;

[0049] Figure 6 The adsorption of Durasorb at the end of the adsorption period was shown. TM Simulated H2O curves of HD and zeolite 4A beds; and

[0050] Figure 7 The outlet composition and temperature of various simulated adsorbent beds are shown. Detailed Implementation

[0051] This disclosure relates in its entirety to a method for removing water, thiols, heavy hydrocarbons (such as C5+ or C6+ hydrocarbons), or any combination thereof, from a gas feed stream containing hydrocarbons and water during the adsorption step of an adsorption cycle, and to an adsorbent bed for use in this method. Some embodiments relate to a single adsorbent bed for removing hydrocarbons (e.g., thiols and heavy hydrocarbons, such as C5+ or C6+ hydrocarbons) and / or water to cryogenic specifications for the production of liquefied natural gas (LNG), rather than using two or more separate adsorbent beds. Other embodiments relate to using multiple adsorbent beds to perform the same operation.

[0052] Molecular sieves, such as zeolite 3A and zeolite 4A, are commonly used for drying natural gas feed streams. While these materials are beneficial for removing water from natural gas under operating unit conditions (i.e., high-pressure methane and high water concentration), they are susceptible to hydrothermal damage. Although other mechanisms that can damage molecular sieves (e.g., reflux) can mitigate this, hydrothermal damage appears unavoidable. Silica-based materials have been shown to be highly robust in such applications, based on practical field experience where adsorbents have been used for over a decade in similar environments. However, these materials are generally not used to remove water to the cryogenic specifications required for the formation of liquefied natural gas.

[0053] Some embodiments described herein advantageously utilize amorphous silica adsorbents, amorphous silica-alumina adsorbents, high-silica zeolite adsorbents (e.g., β-zeolite, ZSM-5, high-silica Y-zeolite, etc.), microporous adsorbents, or combinations thereof, combined with adsorbents of lower hydrothermal stability (e.g., zeolite 3A or zeolite 4A) as a separate adsorbent layer to produce robust, more durable adsorbent systems. In such embodiments, the molar fraction of water entering the portion of the adsorbent bed containing the lower-hydrothermal-stability adsorbent is reduced by the upstream layer of the adsorbent bed. Because the molar fraction of water entering the lower-hydrothermal-stability adsorbent during the adsorption step is lower, less water is desorbed during the regeneration step, and therefore a lower vapor environment is generated during regeneration. This is advantageous because those skilled in the art know that a vapor environment can damage the zeolite. Furthermore, the molar fraction of heavy hydrocarbons (e.g., pentane, hexane, benzene, heptane, octane, nonane, toluene, ethylbenzene, xylene, neopentane, etc.) and / or thiols (which can form H2S) is also reduced by the upstream layer of the adsorbent bed. It is believed that reducing H2S formation can reduce damage to less stable adsorbents (e.g., due to coke deposition, sulfur deposition, or acidic degradation), where it is not desirable to be bound by theory. While the adsorbent layer can be arranged within one or more adsorbent beds (i.e., in separate containers), some embodiments also advantageously allow hydrocarbon adsorption (including thiols and C5+ or C6+ hydrocarbons) and water adsorption in a single adsorbent bed, while reducing the water molar fraction below its cryogenic maximum. This reduces the total number of adsorbent units required, thereby reducing the physical size of the natural gas processing equipment.

[0054] The adsorption process of this disclosure for removing mercaptans, heavy hydrocarbons (e.g., C5+ or C6+ components), water, or any combination thereof from a gas feed stream (e.g., a natural gas feed stream) can be achieved by temperature-switched adsorption (TSA). TSA processes are generally known in the art for various types of adsorption separations. Typically, TSA processes utilize process steps of adsorption at a low temperature, regeneration with a hot purge gas at a high temperature, and subsequent cooling to the adsorption temperature. TSA processes are commonly used for drying gases and liquids, as well as for purification to remove trace impurities. TSA processes are typically employed when the component to be adsorbed is strongly adsorbed onto the adsorbent, thus requiring heat for regeneration.

[0055] A typical TSA process includes adsorption cycles and regeneration (desorption) cycles, each cycle comprising multiple adsorption and regeneration steps, as well as cooling and heating steps. The regeneration temperature is higher than the adsorption temperature to achieve desorption of water, thiols, heavy hydrocarbons, or any combination thereof. For example, during the first adsorption step, in which thiols are adsorbed from a gas stream (e.g., a raw natural gas feed stream) using an adsorbent, in some embodiments the temperature is maintained below 150℉ (66°C), and in other embodiments the temperature is maintained from about 60℉ (16°C) to about 120℉ (49°C). In the regeneration step of this disclosure, water and thiols initially adsorbed in the adsorbent bed are released from the adsorbent bed, thereby regenerating the adsorbent in some embodiments at a temperature from about 300℉ (149°C) to about 550℉ (288°C).

[0056] In the regeneration step, a portion of one of the gas streams (e.g., a natural gas stream), the product effluent from the adsorber unit, or the waste stream from a downstream process may be heated, and the heated stream is circulated through the adsorbent bed to desorb the adsorbed components. In some embodiments, it is advantageous to use a thermal purge stream comprising heated raw natural gas to regenerate the adsorbent.

[0057] In some implementations, the pressure used during the adsorption and regeneration steps is typically increased to 700 psig to 1500 psig. Generally, heavy hydrocarbon adsorption is carried out at pressures close to the feed stream pressure, and the regeneration step can be performed at approximately the adsorption pressure or at reduced pressure. Regeneration can advantageously be carried out at approximately the adsorption pressure when a portion of the adsorption effluent is used as purge gas, particularly when, for example, the waste stream or purge stream is reintroduced into the original natural gas stream.

[0058] As used herein, “thiol” refers to organic sulfur-containing compounds, including but not limited to methyl mercaptan (C1-RSH), ethyl mercaptan (C2-RSH), propyl mercaptan (C3-RSH), butyl mercaptan (C4-RSH), dimethyl sulfide (DMS), and dimethyl disulfide (DMDS).

[0059] While embodiments of this disclosure are described with respect to natural gas purification processes, those skilled in the art will understand that, in addition to LGN and natural gas condensate (NGL) applications, the embodiments described herein can also be used or are applicable to other types of industrial applications requiring the removal of mercaptans and / or water.

[0060] Figure 1AAn adsorber unit 100 according to one embodiment of the present disclosure is shown, which is suitable for use in a TSA process. In some embodiments, the adsorber unit 100 includes a single container 102 housing an adsorbent bed 101. Other embodiments may utilize multiple containers and adsorbent beds, for example, when implementing a continuous TSA process, where one or more adsorbent beds undergo adsorption cycles while one or more beds undergo regeneration cycles. For example, in some embodiments, the adsorber unit 100 may comprise two or more containers and adsorbent beds, which are replicas of container 102 and adsorbent bed 101 (not shown). While the adsorbent bed 101 undergoes adsorption cycles, the repeated adsorbent bed undergoes regeneration cycles, for example, using the product gas produced by the adsorption cycle performed by the adsorbent bed 101.

[0061] Adsorbent bed 101 includes adsorbent layers 110 and 120, each respectively housed within container 102. The flow direction indicates the flow of the gas feed through the inlet of container 102, through adsorbent layer 110, and then through adsorbent layer 120 before reaching the outlet of container 102. Based on this flow direction, adsorbent layer 120 is referred to as being downstream of adsorbent layer 110. In some embodiments, each adsorbent layer may contain its respective adsorbent in the form of adsorbent beads having, for example, a diameter from about 1 mm to about 5 mm. The relative dimensions of the adsorbent layers are not necessarily drawn to scale, although in some embodiments, the weight percentage (wt.%) of adsorbent layer 110 relative to the total weight of adsorbent bed 101 (i.e., the total weight of adsorbent layer 110 and any additional layers) may be greater than 50 wt.%, greater than 60 wt.%, greater than 70 wt.%, greater than 80 wt.%, or greater than 90 wt.%.

[0062] In some embodiments, the adsorbent layer 110 comprises a water-stable adsorbent, such as Durasorb. TM HD (purchased from BASF), including, for example, silica or silica-alumina.

[0063] In some embodiments, the adsorbent layer 120 comprises an adsorbent with preferential selectivity for thiols. In some embodiments, the adsorbent layer 120 comprises an adsorbent with preferential selectivity for C5+ or C6+ hydrocarbons. As used herein, the terms “preferential selectivity for” or “selectivity for” indicate that the adsorbent adsorbs a specific compound at a greater equilibrium load than methane, further described by the following formula: Selectivity = (load C6+ / concentration C6+) / (load C1 / concentration C1), where C1 is methane, and where the load is defined as the number of moles of the component adsorbed per gram of adsorbent. In some embodiments, the C5+ or C6+ compound may include one or more of pentane, hexane, benzene, heptane, octane, nonane, toluene, ethylbenzene, xylene, or neopentane.

[0064] In some embodiments, the adsorbent layer 120 comprises one or more of an amorphous silica adsorbent, an amorphous silica-alumina adsorbent, or a high-silica zeolite adsorbent. In some embodiments, the adsorbent layer 120 comprises an amorphous silica adsorbent and / or an amorphous silica-alumina adsorbent. The amorphous silica adsorbent and the amorphous silica-alumina adsorbent may be at least partially crystalline. In some embodiments, the amorphous silica adsorbent or the amorphous silica-alumina adsorbent may be at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or 100% amorphous. In some embodiments, the amorphous silica adsorbent or the amorphous silica-alumina adsorbent may also contain other components, such as adsorbed cations. An exemplary adsorbent used in the adsorbent layer 120 may be Durasorb. TM HC (purchased from BASF). In some embodiments, the adsorbent layer 110 comprises a high-silica zeolite adsorbent, such as β-zeolite, ZSM-5, Y-zeolite, or combinations thereof. As used herein, "high-silica zeolite" refers to a material having a silica / alumina ratio of at least 5, 10, 20, 30, 50, 100, 150, 200, 250, 300, 350, 400, 450, or 500 moles. In some embodiments, the silica / alumina ratio is in the range of 20 to 500.

[0065] Figure 1B An adsorbent unit 150, a variant of adsorbent unit 100, is shown, having an adsorbent bed 151 in a container 152, wherein adsorbent layer 120 is replaced by adsorbent layer 130. In some embodiments, adsorbent layer 130 comprises a microporous adsorbent. As used herein, the term "microporous adsorbent" refers to an adsorbent material having a relative micropore surface area (RMA), which is the ratio of the micropore surface area to the Brunauer-Emmett-Teller (BET) surface area, and the RMA is at least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, or at least about 30%. The microporous adsorbent may also have one or more of the following: a total pore volume of pores with diameters between 500 nm and 20,000 nm, as measured by mercury intrusion porosimetry, which is at least about 5 mm². 3 / g, at least about 10mm 3 / g, at least about 20mm 3 / g, at least about 30mm 3 / g, at least about 40mm 3 / g, at least about 45mm3 / g, or at least about 50mm 3 / g; pore volume (e.g., Barrett-Joyner-Halenda (BJH) pore volume), which is at least about 0.40 cm³. 3 / g, from approximately 0.40cm 3 / g to approximately 0.50cm 3 / g or from approximately 0.425cm 3 / g to approximately 0.475cm 3 / g; or BET surface area, which is at least about 400m² 2 / g, at least about 500m 2 / g, at least about 600m 2 / g, at least about 700m 2 / g, at least about 800m 2 / g or at least about 900m 2 / g. Micropore surface area and BET surface area can be measured using, for example, Micromeritics. The 2000 porosity measurement system characterizes porosity through nitrogen porosity measurement. It can be used by, for example, Thermo Scientific. TM The Pascal 140 / 240 porosimeter was used to perform mercury porosimetry.

[0066] As used herein, "micropore surface area" refers to the total surface area associated with pores having a diameter of less than 200 angstroms. In some embodiments, the micropore surface area of ​​the microporous adsorbent is at least about 40 m². 2 / g, at least about 50m 2 / g, at least about 100m 2 / g, at least about 150m 2 / g, at least about 200m 2 / g or at least about 230m 2 / g. In some embodiments, the microporous adsorbent has a micropore surface area ranging from approximately 40 m². 2 / g to approximately 300m 2 / g, from approximately 50m 2 / g to approximately 300m 2 / g, from approximately 100m 2 / g to approximately 300m 2 / g, from approximately 150m 2 / g to approximately 300m 2 / g, from approximately 200m 2 / g to approximately 300m 2 / g or from approximately 230m 2 / g to approximately 300m 2 / g. In some embodiments, the relative microporous surface area is from about 5% to about 10%, from about 10% to about 15%, from about 15% to about 20%, from about 20% to about 25%, from about 25% to about 30%, or any range defined therein (e.g., from about 15% to about 25%). In some embodiments, the corresponding BET surface area of ​​the microporous adsorbent ranges from about 650m². 2 / g to approximately 850m 2 / g.

[0067] In some embodiments, the microporous adsorbent comprises at least about 85%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% by weight of amorphous SiO2. In some embodiments, the microporous adsorbent further comprises at most 20% (i.e., from more than about 0% to about 20%), at most about 15%, at most about 10%, at most about 9%, at most about 8%, at most about 7%, at most about 6%, at most about 5%, at most about 4%, at most about 3%, at most about 2%, or at most about 1% by weight of Al2O3.

[0068] In some embodiments, the total pore volume of the microporous adsorbent, with pores having diameters between 500 nm and 20000 nm, is at least about 20 mm. 3 / g, at least about 40mm 3 / g, at least about 70mm 3 / g, at least about 100mm 3 / g, at least about 120mm 3 / g, at least about 140mm 3 / g, at least about 150mm 3 / g, at least about 160mm 3 / g or at least about 170mm 3 / g. In some embodiments, the total pore volume of the microporous adsorbent, with pores having diameters between 500 nm and 20000 nm, is from about 20 mm². 3 / g to approximately 200mm 3 / g, from approximately 40mm 3 / g to approximately 200mm 3 / g, from approximately 70mm 3 / g to approximately 200mm 3 / g, from approximately 100mm 3 / g to approximately 200mm 3 / g, from approximately 120mm 3 / g to approximately 200mm 3 / g, from approximately 140mm 3 / g to approximately 200mm 3 / g, from approximately 150mm 3 / g to approximately 200mm 3 / g, from approximately 160mm 3 / g to approximately 200mm 3 / g, from approximately 170mm 3 / g to approximately 200mm 3 / g or any range defined therein.

[0069] In some implementations, the BET surface area of ​​the microporous adsorbent is from approximately 400 m². 2 / g to approximately 1000m 2 / g, from approximately 500m 2 / g to approximately 1000m 2 / g, from approximately 600m 2 / g to approximately 1000m 2 / g, from approximately 700m 2 / g to approximately 1000m 2 / g, from approximately 800m 2 / g to approximately 1000m 2 / g, from approximately 900m 2 / g to approximately 1000m 2 / g or any range defined therein.

[0070] In some implementations, the bulk density of the microporous adsorbent is less than 600 kg / m³. 3 In some implementations, the bulk density of the microporous adsorbent is at least 600 kg / m³. 3 From approximately 600 kg / m 3 Approximately 650 kg / m 3 Approximately 650 kg / m 3 Approximately 700 kg / m 3 From approximately 700 kg / m 3 Approximately 750 kg / m 3 From approximately 750 kg / m 3 Approximately 800 kg / m 3 From approximately 850 kg / m 3 Approximately 900 kg / m 3 From approximately 950 kg / m 3 Approximately 1000 kg / m 3 Or within any range defined therein.

[0071] In some embodiments, the relative dimensions of the adsorbent layers 110 and 120 or 130 can be adjusted to remove water such that the treated gas stream is below cryogenic specifications (e.g., water mole fraction below 1 ppm or below 0.1 ppm).

[0072] Figure 2AAn adsorber unit 200 according to another embodiment of the present disclosure is shown. The adsorber unit 200 includes adsorbent layers 110, 120, and 130 in an adsorbent bed 201 within a container 202. Similar to adsorbent bed 151, in some embodiments, the relative dimensions of the adsorbent layers may be adjusted to remove water such that the treated gas stream is below cryogenic specifications (e.g., water mole fraction below 1 ppm or below 0.1 ppm).

[0073] Figure 2B An adsorber unit 250 is shown as a variant of adsorber unit 200, wherein the adsorbent layer 120 in the adsorbent bed 251 within container 252 is removed, and the adsorbent layer 140 is inserted downstream of the adsorbent layer 130.

[0074] In some embodiments, adsorbent layer 140 comprises zeolite, which may have lower hydrothermal stability than other layers in adsorbent bed 251. In some embodiments, adsorbent layer 140 comprises one or more of zeolite A, zeolite X (e.g., zeolite 13X, which is zeolite X that has been exchanged with sodium ions), or zeolite Y. An exemplary adsorbent used in adsorbent layer 140 may be Durasorb. TM HR4 (purchased from BASF). In some embodiments, adsorbent layer 140 comprises one or more of zeolite 3A, zeolite 4A, zeolite 5A, or zeolite X. In some embodiments, the zeolite is exchanged with any element in columns I and II of the periodic table (such as Li, Na, K, Mg, Ca, Sr, or Ba). In some embodiments, adsorbent layer 140 may comprise one or more zeolite sublayers, which may be different. For example, the upper sublayer may contain zeolite 5A, and the lower sublayer may contain zeolite 13X, or vice versa. As another example, the upper sublayer may contain zeolite 4A, and the lower sublayer may contain zeolite 5A, or vice versa.

[0075] While it is envisioned that a single adsorber unit can be used with the various embodiments described herein, two or more adsorber units can be used with the various embodiments described herein. Figure 2C It shows Figure 2B Variations of this design utilize separate adsorbent units 260 and 270, each with separate containers 262 and 272 for housing adsorbent beds 261 and 271, respectively. As shown, adsorbent layers 110 and 130 are housed in container 262 of adsorbent unit 260, and adsorbent layer 140 is housed in container 272 of adsorbent unit 270, wherein adsorbent unit 270 is located downstream of adsorbent unit 260. In some embodiments, adsorbent unit 260 is used to adsorb and remove heavy hydrocarbons from the gas feed stream, and adsorbent unit 270 is used for dehydration and / or methanol removal from the gas feed stream. Although Figure 2C Simplified views of adsorber units 260 and 270 are provided, but it should be understood that various other components may be present, including heaters, coolers, various valves and connecting elements, and controllers, to regulate mass flow into and out of adsorber units 260 and 270 and between adsorber units. Each adsorber unit 260 and 270 may include repeatable containers and adsorbent beds for facilitating the implementation of continuous TSA processes. Furthermore, dual-adsorber unit or multi-adsorber unit configurations are envisioned for use with adsorber units 100, 150, 200, and 250.

[0076] Figure 3A An adsorber unit 300 according to another embodiment of the present disclosure is shown. The adsorber unit 300 is similar to the adsorber unit 250, except that it also includes an adsorbent layer 120 located between adsorbent layers 110 and 130 in the adsorbent bed 301 within the container 302. Figure 3B Adsorber units 360 and 370 are shown as variations of adsorber unit 300, wherein separate adsorbent beds 361 and 371 are contained in separate containers 362 and 372, respectively.

[0077] It is envisioned that dual-unit or multi-unit configurations can be applied to any of the adsorber units 100, 150, 200, 250, 260 and 270, 300 or 360 and 370. In some embodiments, for implementations where the adsorbent bed is part of the TSA process, the cycle time can vary for different adsorber units in the multi-unit configuration. For example, refer to... Figure 1A Adsorber unit 100 (whose adsorbent bed 101 can accommodate, for example, amorphous silica adsorbent, amorphous silica-alumina adsorbent, or high-silica zeolite adsorbent) can withstand cycle times not exceeding about 8 hours, not exceeding about 7 hours, not exceeding about 6 hours, not exceeding about 5 hours, not exceeding about 4 hours, not exceeding about 3 hours, not exceeding about 2 hours, or not exceeding about 1 hour. Adsorber unit 260 (whose adsorbent bed 261 can accommodate, for example, microporous adsorbent) can withstand cycle times longer than adsorber unit 270, such as greater than about 10 hours and at most about 24 hours, at most about 48 hours, or at most about 72 hours. Similar variations in cycle time can be applied to each of the aforementioned configurations.

[0078] Figure 4A method 400 for removing water, thiols, heavy hydrocarbons (e.g., C5+ or C6+ hydrocarbons), or any combination thereof, from a gas feed stream according to one embodiment of the present disclosure is illustrated. At block 402, one or more adsorbent beds (e.g., any one of adsorbent beds 100, 150, 200, 250, 260 and 270, 300, 360 and 370, or variations thereof) are provided, the adsorbent bed comprising at least a first adsorbent layer (e.g., adsorbent layer 110), a second adsorbent layer (e.g., adsorbent layer 120 or adsorbent layer 130), and a third adsorbent layer (e.g., adsorbent layer 140 or adsorbent layer 130). In some embodiments, the adsorbent bed may include additional layers (e.g., adsorbent bed 300) or utilize one or more containers to contain one or more adsorbent layers (e.g., adsorbent beds 360 and 370 contained in containers 362 and 372, respectively).

[0079] At box 404, a gas feed stream having an initial water molar fraction, an initial thiol molar fraction, an initial C5+ or C6+ molar fraction, or any combination thereof, is directed to the adsorbent bed. In some embodiments, the gas feed stream includes a natural gas feed stream. In some embodiments, contact is performed as part of the TSA process. The TSA process may have an adsorption cycle time of no more than about 8 hours, about 7 hours, about 6 hours, about 5 hours, about 4 hours, about 3 hours, about 2 hours, or about 1 hour.

[0080] Before entering the adsorbent bed and contacting the first adsorbent layer, the gas feed stream may have an initial water molar fraction, an initial thiol molar fraction, an initial C5+ or C6+ hydrocarbon molar fraction, or any combination thereof. After passing through the first adsorbent layer (e.g., a water-stable adsorbent) and / or the second adsorbent layer (e.g., a microporous adsorbent), when the gas feed stream reaches the third adsorbent layer, it has a reduced water molar fraction, a reduced thiol molar fraction, a reduced C5+ or C6+ (e.g., aromatic compounds or aliphatic C8+ or C9+) hydrocarbon molar fraction, or any combination thereof, compared to the corresponding initial water molar fraction, initial thiol molar fraction, or C5+ or C6+ hydrocarbon molar fraction (this is particularly advantageous when the third adsorbent layer contains zeolite). In some embodiments, box 404 corresponds to the adsorption step in the adsorption cycle of the TSA process. In some embodiments, the reduced water molar fraction is maintained for at least 90% of the duration of the adsorption step. In other words, the hydrothermal stability of the third adsorbent layer, which is lower than that of the first adsorbent layer, involves less contact with water compared to the first and / or second adsorbent layers. This increases the overall lifetime of the third adsorbent layer over several TSA cycles. In some embodiments, the reduced molar fraction of water, thiol, or C5+ or C6+ hydrocarbons, or any combination thereof, is maintained for at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% of the duration of the adsorption step before reaching the third adsorbent layer.

[0081] In some embodiments, the reduction in water mole fraction does not exceed about 90% of the initial water mole fraction. In some embodiments, the reduction in water mole fraction does not exceed about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, about 1%, about 0.1%, about 0.01%, or about 0.001% of the initial water mole fraction. In some embodiments, the reduction in water mole fraction does not exceed about 20% of the initial water mole fraction. In some embodiments, the reduced water mole fraction does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, or about 5 ppm. In other embodiments, the reduced water mole fraction does not exceed about 100 ppm, about 50 ppm, about 10 ppm, about 9 ppm, about 8 ppm, about 7 ppm, about 6 ppm, about 5 ppm, about 4 ppm, about 3 ppm, about 2 ppm, or about 1 ppm.

[0082] In some embodiments, the reduction in the molar fraction of thiol does not exceed about 90% of the initial molar fraction of thiol. In some embodiments, the reduction in the molar fraction of thiol does not exceed about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, about 1%, about 0.1%, about 0.01%, or about 0.001% of the initial molar fraction of thiol. In some implementations, the reduced molar fraction of thiol does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, about 5 ppm, or about 1 ppm.

[0083] In some embodiments, the C5+ or C6+ hydrocarbons may include one or more of pentane, hexane, benzene, heptane, octane, nonane, toluene, ethylbenzene, xylene, or neopentane. In some embodiments, the reduction in molar fraction of aromatic compounds (e.g., one or more of benzene, toluene, xylene, or other aromatic compounds) or aliphatic C8+ or C9+ hydrocarbons is less than or equal to 90% of the initial molar fraction before reaching the third adsorbent layer. In some embodiments, the reduction in molar fraction of the aromatic compound or aliphatic C8+ or C9+ hydrocarbon does not exceed about 80%, about 70%, about 60%, about 50%, about 40%, about 30%, about 20%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3%, about 2%, about 1%, about 0.1%, about 0.01%, or about 0.001% of the initial molar fraction. In some embodiments, the reduced molar fraction of the aromatic compound or aliphatic C8+ or C9+ hydrocarbon does not exceed about 500 ppm, about 450 ppm, about 400 ppm, about 350 ppm, about 300 ppm, about 250 ppm, about 200 ppm, about 150 ppm, about 100 ppm, about 50 ppm, about 40 ppm, about 30 ppm, about 20 ppm, about 10 ppm, about 5 ppm, or about 1 ppm.

[0084] In some embodiments, one or more non-thiol hydrocarbons in the gas feed stream are reduced molarly by 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 5% relative to the initial concentration of that component in the gas feed stream. In at least one embodiment, one or more components are selected from benzene, C9 hydrocarbons, C8 hydrocarbons, C7 hydrocarbons, C6 hydrocarbons, or C5 hydrocarbons. That is, for a given component in the gas feed stream (e.g., benzene), the concentration of the component in the gas feed stream after passing through the adsorbent bed will be reduced molarly by a specific amount relative to the initial concentration.

[0085] At box 406, the treated gas feed stream is directed to one or more additional downstream processes, such as an additional adsorption step. In some embodiments, if the treated gas feed stream meets cryogenic specifications, the downstream process may be the formation of liquefied natural gas products from the gas feed stream. For example, after contact with the second adsorbent layer, the final water molar fraction of the gas feed stream may be less than 1 ppm or less than 0.1 ppm. In some embodiments, after contact with the second adsorbent layer, the final mercaptan molar fraction of the gas feed stream may be less than 10 ppm or less than 1 ppm. In some embodiments, the downstream process may be the formation of a C2+ or C3+ natural gas condensate feed stream from the gas feed stream.

[0086] In some embodiments, during the regeneration of the adsorbent bed, the product gas stream / treated gas feed stream can be used to heat and cool the adsorbent bed. In some embodiments, during the regeneration of the adsorbent bed, the gas feed stream can be used to cool the adsorbent bed, and the product gas stream / treated gas feed stream can be used to heat the adsorbent bed.

[0087] In some embodiments, the adsorbent bed can be modified or refilled by removing at least a portion of the previously present adsorbent and replacing at least a portion of the previously present adsorbent with one or more of a first adsorbent layer or a second adsorbent layer. Modification may include installing internal insulation into the container (e.g., container 102), changing the adsorption time, changing the heating time, changing the cooling time, changing the regeneration gas flow rate, and changing the regeneration gas temperature. In some embodiments, hydrothermally damaged zeolite material can be replaced with zeolite adsorbent that has not been hydrothermally damaged or still has sufficient adsorption capacity (e.g., adsorbent layer 140).

[0088] Illustrative Examples

[0089] The following embodiments are illustrated to aid in understanding this disclosure, and these embodiments should not, of course, be construed as specifically limiting the embodiments described and claimed herein. Such variations, changes in formulations, or minor changes in experimental design of the disclosed embodiments, which are to be understood by those skilled in the art as substitutes for all equivalents now known or subsequently developed, are considered to fall within the scope of the embodiments incorporated herein.

[0090] Example 1

[0091] A zeolite 4A bed was simulated using a water feed of 450 ppm. The bed contained 30,000 kg of zeolite with a volume of 43 m³. 3 The bed was constructed using zeolite. It operated at 25°C and 62 bar. A simulated pressure of 176,000 Nm was achieved. 3 The flow rate is / hr (standard cubic meters per hour). Figure 5The H2O curve of the zeolite 4A bed at the end of adsorption is shown.

[0092] Example 2

[0093] Durasorb was simulated using a water feed of 450 ppm. TM HD 24000kg and zeolite 4A bed. This bed contains 6000kg of material with a volume of 43m³. 3 The bed was constructed using zeolite. It operated at 25°C and 62 bar. A simulated pressure of 176,000 Nm was achieved. 3 The flow rate is / hr. Figure 6 The adsorption of Durasorb at the end of the adsorption period was shown. TM H2O curves of HD and zeolite 4A sieve beds.

[0094] Examples 3-6

[0095] The following examples show that if the water content of the zeolite 4A layer is reduced, then the amount of water at high temperatures during bed regeneration can be reduced, which in turn reduces the degree of hydrothermal damage.

[0096] For the remaining embodiments, the same volume (43m³) was simulated. 3 The adsorbent was zeolite 4A. A feed at 25°C and 62 bar was added to the bed. All beds were allowed to run until the entire bed was saturated under the feed conditions. For example, in Example 3, 450 ppm of water left the bed at the end of adsorption. Similarly, in Example 6, 10 ppm of water left the bed during adsorption. All beds were operated at 295°C with 14500 Nm³ of adsorption. 3 Gas regeneration per hr.

[0097] Figure 7 Simulated outlet compositions and temperatures for each of Examples 3 (450 ppm water feed), 4 (180 ppm water feed), 5 (10 ppm water feed), and 6 (5 ppm water feed) are shown. As clearly shown, the combination of water concentration, temperature, and time decreases as the amount of water in the feed to the zeolite portion decreases. For example, a 5 ppm water feed is at its maximum water concentration for approximately 70 minutes, while a 450 ppm water feed is at its maximum water concentration for approximately 170 minutes. It is not shown but is implied that when the zeolite concentration is high, the water and temperature will decrease for a fixed regeneration flow as the zeolite portion of the bed decreases. Therefore, Examples 3-6 represent the worst-case scenario, where if the zeolite constitutes only 20% of the bed in those cases, the timescale of its exposure to the elevated water will be further reduced by a factor of 5, thus further reducing the degree of hydrothermal damage in all cases.

[0098] Example 7

[0099] Similar to Example 2, consider using Durasorb. TM HD bed, followed by zeolite 13X. Durasorb TM The HD bed is sized to remove most thiols, thereby reducing the amount of thiols entering the zeolite 13X portion of the bed. As described by A.F. Carlsson, T. Last, and J.B. Rajani at the 84th Annual GPA Convention, 2005, in "How to Avoid Excessive Molecule Sieve Deactivation when used for Mercaptan Removal," by reducing the level of thiols entering the zeolite 13X portion, the deactivation rate of the zeolite 13X portion will be reduced. The deactivation rate is further reduced because reducing the amount of adsorbed thiols also reduces the concentration during desorption, further reducing the deactivation rate.

[0100] The foregoing description has set forth numerous specific details, such as specific materials, dimensions, and process parameters, to provide a thorough understanding of the embodiments of this disclosure. In one or more embodiments, particular features, structures, materials, or properties may be combined in any suitable manner. As used herein, the terms “example” or “exemplary” mean used as an example, instance, or illustration. Any aspect or design described herein as an “example” or “exemplary” is not necessarily to be construed as superior to or better than other aspects or designs. Rather, the use of the terms “example” or “exemplary” is intended to present the concepts in a concrete manner.

[0101] As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless otherwise stated or obvious from the context, "X includes A or B" is intended to mean any natural inclusion. That is, if X includes A; then X includes B; or if X includes both A and B, then "X includes A or B" is satisfied in any of the above cases. Additionally, unless otherwise stated or obvious from the context concerning the singular form, the article "a (type)" as used in this application and the appended claims should generally be interpreted as meaning "one (type) or more (types)".

[0102] As used herein, the term "about" in conjunction with a measured quantity refers to the normal variation of that measured quantity, as would be expected by a person skilled in the art when performing the measurement and exercising a degree of care commensurate with the accuracy of the measurement target and the measuring equipment. In some embodiments, the term "about" includes ±10% of the listed figures, such that "about 10" would include 9 to 11.

[0103] Throughout the specification, references to “implementation,” “certain implementations,” or “an implementation” mean that at least one implementation includes a particular feature, structure, or characteristic described in connection with the implementation. Therefore, the phrases “implementation,” “certain implementations,” or “an implementation” appearing throughout the specification do not necessarily refer to the same implementation, and such references mean “at least one.”

[0104] It should be understood that the above description is intended to be illustrative and not restrictive. Many other embodiments will be apparent to those skilled in the art upon reading and understanding the above description. Therefore, the scope of this disclosure should be determined by referring to the appended claims and the full scope of the equivalents conferred by such claims.

Claims

1. A method for removing water from a gas feed stream during the adsorption step of a temperature-switching adsorption process, the method comprising: The gas feed stream having an initial water mole fraction is directed to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: A first adsorbent layer, the first adsorbent layer being used to remove water from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; A second adsorbent layer, located downstream of the first adsorbent layer to remove additional water, comprises a microporous adsorbent; and A third adsorbent layer is located downstream of the second adsorbent layer, and the third adsorbent layer contains one or more zeolites; When the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced water mole fraction maintained for at least 90% of the duration of the adsorption step, and wherein the reduced water mole fraction does not exceed 90% of the initial water mole fraction.

2. The method according to claim 1, wherein the reduced water mole fraction does not exceed 80% of the initial water mole fraction.

3. The method according to claim 1, wherein the reduced water mole fraction does not exceed 20% of the initial water mole fraction.

4. The method according to claim 1, wherein the reduced water mole fraction does not exceed 70% of the initial water mole fraction.

5. The method according to claim 1, wherein the reduced water mole fraction does not exceed 60% of the initial water mole fraction.

6. The method of claim 1, wherein the reduced water mole fraction does not exceed 50% of the initial water mole fraction.

7. The method of claim 1, wherein the reduced water mole fraction does not exceed 40% of the initial water mole fraction.

8. The method of claim 1, wherein the reduced water mole fraction does not exceed 30% of the initial water mole fraction.

9. The method of claim 1, wherein the reduced water mole fraction does not exceed 10% of the initial water mole fraction.

10. The method of claim 1, wherein the reduced water mole fraction does not exceed 9% of the initial water mole fraction.

11. The method of claim 1, wherein the reduced water mole fraction does not exceed 8% of the initial water mole fraction.

12. The method of claim 1, wherein the reduced water mole fraction does not exceed 7% of the initial water mole fraction.

13. The method of claim 1, wherein the reduced water mole fraction does not exceed 6% of the initial water mole fraction.

14. The method of claim 1, wherein the reduced water mole fraction does not exceed 5% of the initial water mole fraction.

15. The method of claim 1, wherein the reduced water mole fraction does not exceed 4% of the initial water mole fraction.

16. The method of claim 1, wherein the reduced water mole fraction does not exceed 3% of the initial water mole fraction.

17. The method of claim 1, wherein the reduced water mole fraction does not exceed 2% of the initial water mole fraction.

18. The method of claim 1, wherein the reduced water mole fraction does not exceed 1% of the initial water mole fraction.

19. The method of claim 1, wherein the reduced water mole fraction does not exceed 0.1% of the initial water mole fraction.

20. The method of claim 1, wherein the reduced water mole fraction does not exceed 0.01% of the initial water mole fraction.

21. The method of claim 1, wherein the reduced water mole fraction does not exceed 0.001% of the initial water mole fraction.

22. The method according to any one of claims 1-21, wherein the reduced water mole fraction is maintained for at least 95% of the duration of the adsorption step.

23. The method of claim 22, wherein the reduced water mole fraction is maintained for at least 96% of the duration of the adsorption step.

24. The method of claim 22, wherein the reduced water mole fraction is maintained for at least 97% of the duration of the adsorption step.

25. The method of claim 22, wherein the reduced water mole fraction is maintained for at least 98% of the duration of the adsorption step.

26. The method of claim 22, wherein the reduced water mole fraction is maintained for at least 99% of the duration of the adsorption step.

27. The method of claim 22, wherein the reduced water mole fraction is maintained for 100% of the duration of the adsorption step.

28. The method according to any one of claims 1-21, wherein the reduced water mole fraction does not exceed 500 ppm.

29. The method of claim 28, wherein the reduced water mole fraction does not exceed 100 ppm.

30. The method of claim 28, wherein the reduced water mole fraction does not exceed 450 ppm.

31. The method of claim 28, wherein the reduced water mole fraction does not exceed 400 ppm.

32. The method of claim 28, wherein the reduced water mole fraction does not exceed 350 ppm.

33. The method of claim 28, wherein the reduced water mole fraction does not exceed 300 ppm.

34. The method of claim 28, wherein the reduced water mole fraction does not exceed 250 ppm.

35. The method of claim 28, wherein the reduced water mole fraction does not exceed 200 ppm.

36. The method of claim 28, wherein the reduced water mole fraction does not exceed 150 ppm.

37. The method of claim 28, wherein the reduced water mole fraction does not exceed 50 ppm.

38. The method of claim 28, wherein the reduced water mole fraction does not exceed 40 ppm.

39. The method of claim 28, wherein the reduced water mole fraction does not exceed 30 ppm.

40. The method of claim 28, wherein the reduced water mole fraction does not exceed 20 ppm.

41. The method of claim 28, wherein the reduced water mole fraction does not exceed 10 ppm.

42. The method of claim 28, wherein the reduced water mole fraction does not exceed 9 ppm.

43. The method of claim 28, wherein the reduced water mole fraction does not exceed 8 ppm.

44. The method of claim 28, wherein the reduced water mole fraction does not exceed 7 ppm.

45. The method of claim 28, wherein the reduced water mole fraction does not exceed 6 ppm.

46. ​​The method of claim 28, wherein the reduced water mole fraction does not exceed 5 ppm.

47. The method of claim 28, wherein the reduced water mole fraction does not exceed 4 ppm.

48. The method of claim 28, wherein the reduced water mole fraction does not exceed 3 ppm.

49. The method of claim 28, wherein the reduced water mole fraction does not exceed 2 ppm.

50. The method of claim 28, wherein the reduced water mole fraction does not exceed 1 ppm.

51. The method of claim 28, wherein the reduced water mole fraction does not exceed 0.1 ppm.

52. The method of claim 28, wherein the reduced water mole fraction does not exceed 0.01 ppm.

53. A method for removing thiols from a gas feed stream during an adsorption step in an adsorption cycle, the method comprising: The gas feed stream having an initial thiol molar fraction is directed to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: A first adsorbent layer, the first adsorbent layer being used to remove thiols from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; A second adsorbent layer, located downstream of the first adsorbent layer to remove additional thiols, comprises a microporous adsorbent; and A third adsorbent layer is located downstream of the second adsorbent layer, and the third adsorbent layer contains one or more zeolites; When the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced thiol molar fraction maintained for at least 90% of the duration of the adsorption step, and wherein the reduced thiol molar fraction does not exceed 90% of the initial thiol molar fraction.

54. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 80% of the initial molar fraction of thiol.

55. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 70% of the initial molar fraction of thiol.

56. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 60% of the initial molar fraction of thiol.

57. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 50% of the initial molar fraction of thiol.

58. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 40% of the initial molar fraction of thiol.

59. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 30% of the initial molar fraction of thiol.

60. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 20% of the initial molar fraction of thiol.

61. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 10% of the initial molar fraction of thiol.

62. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 9% of the initial molar fraction of thiol.

63. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 8% of the initial molar fraction of thiol.

64. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 7% of the initial molar fraction of thiol.

65. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 6% of the initial molar fraction of thiol.

66. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 5% of the initial molar fraction of thiol.

67. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 4% of the initial molar fraction of thiol.

68. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 3% of the initial molar fraction of thiol.

69. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 2% of the initial molar fraction of thiol.

70. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 1% of the initial molar fraction of thiol.

71. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 0.1% of the initial molar fraction of thiol.

72. The method of claim 53, wherein the reduced molar fraction of thiol does not exceed 0.01% of the initial molar fraction of thiol.

73. The method according to any one of claims 53-72, wherein the reduced molar fraction of thiol does not exceed 500 ppm before reaching the third adsorbent layer.

74. The method of claim 73, wherein the reduced thiol molar fraction does not exceed 450 ppm before reaching the third adsorbent layer.

75. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 400 ppm before reaching the third adsorbent layer.

76. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 350 ppm before reaching the third adsorbent layer.

77. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 300 ppm before reaching the third adsorbent layer.

78. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 250 ppm before reaching the third adsorbent layer.

79. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 200 ppm before reaching the third adsorbent layer.

80. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 150 ppm before reaching the third adsorbent layer.

81. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 100 ppm before reaching the third adsorbent layer.

82. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 50 ppm before reaching the third adsorbent layer.

83. The method of claim 73, wherein the reduced molar fraction of thiol does not exceed 40 ppm before reaching the third adsorbent layer.

84. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 30 ppm before reaching the third adsorbent layer.

85. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 20 ppm before reaching the third adsorbent layer.

86. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 10 ppm before reaching the third adsorbent layer.

87. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 5 ppm before reaching the third adsorbent layer.

88. The method of claim 73, wherein the reduction in thiol molar fraction does not exceed 1 ppm before reaching the third adsorbent layer.

89. A method for removing C5+ or C6+ hydrocarbons from a gas feed stream during an adsorption step of an adsorption cycle, wherein the C5+ or C6+ compound comprises one or more of pentane, hexane, benzene, heptane, octane, nonane, toluene, ethylbenzene, xylene, or neopentane, and wherein the method comprises: The gas feed stream having an initial molar fraction of the C5+ or C6+ hydrocarbons is directed to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: A first adsorbent layer, the first adsorbent layer being used to remove C5+ or C6+ hydrocarbons from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent. A second adsorbent layer, located downstream of the first adsorbent layer to remove additional C5+ or C6+ hydrocarbons, comprises a microporous adsorbent; and A third adsorbent layer, located downstream of the second adsorbent layer, comprises one or more zeolites and additional microporous adsorbents. When the gas feed stream reaches the third adsorbent layer, the gas feed stream has a reduced molar fraction of aromatic compounds and / or aliphatic C8+ or C9+ hydrocarbons maintained for at least 90% of the duration of the adsorption step, and wherein the reduced molar fraction does not exceed 90% of the initial molar fraction.

90. The method of claim 89, wherein the reduced mole fraction does not exceed 80% of the initial mole fraction.

91. The method of claim 89, wherein the reduced mole fraction does not exceed 70% of the initial mole fraction.

92. The method of claim 89, wherein the reduced mole fraction does not exceed 60% of the initial mole fraction.

93. The method of claim 89, wherein the reduced mole fraction does not exceed 50% of the initial mole fraction.

94. The method of claim 89, wherein the reduced mole fraction does not exceed 40% of the initial mole fraction.

95. The method of claim 89, wherein the reduced mole fraction does not exceed 30% of the initial mole fraction.

96. The method of claim 89, wherein the reduced mole fraction does not exceed 20% of the initial mole fraction.

97. The method of claim 89, wherein the reduced mole fraction does not exceed 10% of the initial mole fraction.

98. The method of claim 89, wherein the reduced mole fraction does not exceed 9% of the initial mole fraction.

99. The method of claim 89, wherein the reduced mole fraction does not exceed 8% of the initial mole fraction.

100. The method of claim 89, wherein the reduced mole fraction does not exceed 7% of the initial mole fraction.

101. The method of claim 89, wherein the reduced mole fraction does not exceed 6% of the initial mole fraction.

102. The method of claim 89, wherein the reduced mole fraction does not exceed 5% of the initial mole fraction.

103. The method of claim 89, wherein the reduced mole fraction does not exceed 4% of the initial mole fraction.

104. The method of claim 89, wherein the reduced mole fraction does not exceed 3% of the initial mole fraction.

105. The method of claim 89, wherein the reduced mole fraction does not exceed 2% of the initial mole fraction.

106. The method of claim 89, wherein the reduced mole fraction does not exceed 1% of the initial mole fraction.

107. The method according to any one of claims 89-106, wherein the reduction in molar fraction does not exceed 500 ppm before reaching the third adsorbent layer.

108. The method of claim 107, wherein the reduction in molar fraction does not exceed 450 ppm before reaching the third adsorbent layer.

109. The method of claim 107, wherein the reduction in molar fraction does not exceed 400 ppm before reaching the third adsorbent layer.

110. The method of claim 107, wherein the reduction in molar fraction does not exceed 350 ppm before reaching the third adsorbent layer.

111. The method of claim 107, wherein the reduction in molar fraction does not exceed 300 ppm before reaching the third adsorbent layer.

112. The method of claim 107, wherein the reduction in molar fraction does not exceed 250 ppm before reaching the third adsorbent layer.

113. The method of claim 107, wherein the reduction in molar fraction does not exceed 200 ppm before reaching the third adsorbent layer.

114. The method of claim 107, wherein the reduction in molar fraction does not exceed 150 ppm before reaching the third adsorbent layer.

115. The method of claim 107, wherein the reduction in molar fraction does not exceed 100 ppm before reaching the third adsorbent layer.

116. The method of claim 107, wherein the reduction in molar fraction does not exceed 50 ppm before reaching the third adsorbent layer.

117. The method of claim 107, wherein the reduction in molar fraction does not exceed 40 ppm before reaching the third adsorbent layer.

118. The method of claim 107, wherein the reduction in molar fraction does not exceed 30 ppm before reaching the third adsorbent layer.

119. The method of claim 107, wherein the reduction in molar fraction does not exceed 20 ppm before reaching the third adsorbent layer.

120. The method of claim 107, wherein the reduction in molar fraction does not exceed 10 ppm before reaching the third adsorbent layer.

121. The method of claim 107, wherein the reduction in molar fraction does not exceed 5 ppm before reaching the third adsorbent layer.

122. The method of claim 107, wherein the reduction in molar fraction does not exceed 1 ppm before reaching the third adsorbent layer.

123. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, and 108-122, wherein the one or more adsorbent beds further comprise: A fourth adsorbent layer is located downstream of the first adsorbent layer and upstream of the second adsorbent layer, wherein the fourth adsorbent layer comprises one or more of amorphous silica adsorbent, amorphous silica-alumina adsorbent, or high silica zeolite adsorbent.

124. The method of claim 123, wherein the third adsorbent layer comprises the high silica zeolite adsorbent.

125. The method according to claim 124, wherein the high silica zeolite adsorbent comprises ZSM-5, zeolite Y, or β-zeolite.

126. A method for processing a gas feed stream, the method comprising: The gas feed stream having an initial water mole fraction is directed to one or more adsorbent beds of one or more adsorbent units, the one or more adsorbent beds comprising: A first adsorbent layer, the first adsorbent layer being used to remove water from the gas feed stream, the first adsorbent layer comprising a water-stable adsorbent; A second adsorbent layer, located downstream of the first adsorbent layer, comprises a microporous adsorbent; and When the gas feed stream leaves the second adsorbent layer, the gas feed stream has a reduced water mole fraction. The one or more adsorbent beds further include: A third adsorbent layer is located downstream of the first adsorbent layer and upstream of the second adsorbent layer, wherein the third adsorbent layer comprises one or more of amorphous silica adsorbent, amorphous silica-alumina adsorbent, or high silica zeolite adsorbent.

127. The method of claim 126, wherein the reduced water mole fraction is below the maximum cryogenic value produced by liquefied natural gas (LNG) or natural gas condensate (NGL).

128. The method of claim 126, wherein the third adsorbent layer comprises the high silica zeolite adsorbent.

129. The method according to claim 128, wherein the high silica zeolite adsorbent comprises ZSM-5, zeolite Y, or β-zeolite.

130. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, wherein the one or more zeolites comprise one or more of zeolite 3A, zeolite 4A, or zeolite 5A.

131. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, wherein the one or more zeolites comprise one or more of zeolite 5A or zeolite X.

132. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, wherein the one or more zeolites comprise zeolite 13X.

133. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, wherein the one or more zeolites comprise zeolite 4A.

134. The method of claim 130, wherein one or more zeolites are exchanged with an element selected from Li, Na, K, Mg, Ca, Sr or Ba.

135. The method of claim 131, wherein one or more zeolites are exchanged with an element selected from Li, Na, K, Mg, Ca, Sr or Ba.

136. The method of claim 132, wherein one or more zeolites are exchanged with an element selected from Li, Na, K, Mg, Ca, Sr or Ba.

137. The method of claim 133, wherein one or more zeolites are exchanged with an element selected from Li, Na, K, Mg, Ca, Sr or Ba.

138. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the water-stable adsorbent comprises an amorphous silica adsorbent or an amorphous silica-alumina adsorbent.

139. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the gas feed stream is a natural gas feed stream.

140. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the water mole fraction of the gas feed stream is less than 1 ppm after contacting the one or more adsorbent beds.

141. The method of claim 140, wherein the water mole fraction of the gas feed stream is less than 0.1 ppm after contact with the one or more adsorbent beds.

142. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the molar fraction of thiol in the gas feed stream is less than 10 ppm after contact with the one or more adsorbent beds.

143. The method of claim 142, wherein the molar fraction of thiol in the gas feed stream is less than 1 ppm after contact with the one or more adsorbent beds.

144. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the C5+ or C6+ mole fraction of the gas feed stream is less than 10 ppm after contacting the one or more adsorbent beds.

145. The method of claim 144, wherein after contacting the one or more adsorbent beds, the C5+ or C6+ mole fraction of the gas feed stream is less than 1 ppm.

146. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the third adsorbent layer is located in an adsorbent bed separate from the first adsorbent layer and the second adsorbent layer.

147. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, and 134-137, further comprising: The gas feed stream forms liquefied natural gas products after contact with the second adsorbent layer.

148. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, further comprising: After contact with the second adsorbent layer, the gas feed stream forms a C2+ or C3+ natural gas condensate feed stream.

149. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, wherein the contact is performed as part of a temperature-switching adsorption process having a cycle time of no more than 8 hours.

150. The method of claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 7 hours.

151. The method of claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 6 hours.

152. The method according to claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 5 hours.

153. The method according to claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 4 hours.

154. The method of claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 3 hours.

155. The method according to claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 2 hours.

156. The method according to claim 149, wherein the temperature-switching adsorption process has a cycle time of no more than 1 hour.

157. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, 150-156, wherein the gas feed stream further comprises non-thiol hydrocarbons, wherein one or more components of the non-thiol hydrocarbons in the gas feed stream are reduced in molar terms by 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, or 5% relative to the initial concentration of the component in the gas feed stream before reaching the second adsorbent layer, wherein the one or more components are selected from benzene, C9 hydrocarbons, C8 hydrocarbons, C7 hydrocarbons, or C6 hydrocarbons.

158. The method according to any one of claims 1-21, 23-27, 29-52, 53-72, 74-88, 89-106, 108-122, 124, 125, 126-129, 134-137, and 150-156, further comprising: Before directing the gas feed stream to the adsorbent bed, the adsorbent bed is modified by removing at least a portion of the previously present adsorbent and replacing the at least a portion of the previously present adsorbent with one or more of the first adsorbent layer or the second adsorbent layer.

159. One or more adsorbent units, said one or more adsorbent units being adapted to remove one or more of water, thiols or heavy hydrocarbons from a gas feed stream, said one or more adsorbent units comprising at least one adsorbent bed according to any one of claims 1-158.

160. A natural gas purification system comprising at least one adsorbent bed according to any one of claims 1-158.

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