WO2023107808A1

WO2023107808A1 - Dehydration processes using microporous aluminophosphate-based materials

Info

Publication number: WO2023107808A1
Application number: PCT/US2022/079932
Authority: WO
Inventors: Yu Wang; JR. Edward W. CORCORAN; Bennett D. Marshall; Chien-Chiang Chen; Avelino Corma Canos; Susana Valencia; Fernando Rey Garcia; Manuel Moliner Marin
Original assignee: ExxonMobil Technology and Engineering Company
Priority date: 2021-12-10
Filing date: 2022-11-16
Publication date: 2023-06-15

Abstract

Methods are provided for removing water from a feed stream. The methods involve performing a swing adsorption process by: a) performing an adsorption step comprising passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed, wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle. The dehydration adsorbent materials have high working capacities and low heat regeneration.

Description

DEHYDRATION

MICROPOROUS ALUMINOPHOSPHATE-BASED MATERIALS

FIELD

This disclosure relates to a method and system for removing water from a feed stream using microporous aluminophosphate-based adsorbent materials, including unsubstituted AlPOs (e.g., A1PO-42, A1PO-34, and A1PO-5), and substituted AlPOs (e.g., silicoaluminophosphates, and germanoaluminophosphates) The dehydration adsorbent materials have high working capacities, ideally above about 5 mol/kg, and low heat regeneration, ideally below about 140°C. Particularly, the method and system relate to natural gas processing within a subsurface environment using A1PO-42.

BACKGROUND OF THE INVENTION

Gas separation is important in various industries and can typically be accomplished by flowing a mixture of gases over an adsorbent that preferentially adsorbs a more readily adsorbed component relative to a less readily adsorbed component of the mixture. One of the more important gas separation techniques is pressure swing adsorption (PSA). PSA processes rely on the fact that under pressure gases tend to be adsorbed within the pore structure of microporous adsorbent materials or within the free volume of polymeric materials. The higher the pressure, the more gas is adsorbed. When the pressure is reduced, the adsorbed gas is released, or desorbed. PSA processes can be used to separate gases from a mixture of gases because different gases tend to adsorb in the micropores or free volume of the adsorbent to different extents.

For example, if a gas mixture such as natural gas is passed under pressure through a vessel containing polymeric or microporous adsorbent that fills with more water than it does methane, part or all of the water will stay in the sorbent bed, and the gas coming out of the vessel will be enriched in methane. When the bed reaches the end of its capacity to adsorb water, it can be regenerated by reducing the water partial pressure, thereby releasing the adsorbed water. It is then ready for another cycle. When the desorption step is performed at sub-ambient pressures the process is referred to as vacuum pressure swing adsorption (VPSA).

Another important gas separation technique is temperature swing adsorption (TSA). TSA processes also rely on the fact that under pressure gases tend to be adsorbed within the pore structure of the microporous adsorbent materials or within the free volume of a polymeric material. When the temperature of the adsorbent is increased, the gas is released, or desorbed. By cyclically swinging the temperature of adsorbent beds, TSA processes can be used to separate gases in a mixture when used with an adsorbent that selectively adsorbs one or more of the components in the gas mixture relative to another. Combined PSA/TSA processes may also be utilized in the art for adsorption processes. In such combined PSA/TSA processes the pressure is decreased while the temperature is also increased during a desorption step in order to facilitate desorption of the components adsorbed in the adsorbent material. A purge gas may also be utilized during the desorption step or in an adjoining purge step to further facilitate removal of the adsorbed components by lowering the partial pressure of the adsorbed components, raising the temperature of the adsorbent material (e.g., by utilizing a heated purge gas), or a combinations thereof.

Yet another gas separation technique is referred to as partial pressure purge swing adsorption (PPSA). In this process the adsorbent is cyclically regenerated by passing a gas past the adsorbent material that can remove the adsorbed component. In one embodiment the regenerating gas can be competitively adsorbed in which case it can displace the previously adsorbed species. In another embodiment the regenerating gas is not adsorbed or weakly adsorbed in which case the gas removes the adsorbed component by reducing its fugacity (i.e. partial pressure).

All of these methods are examples of swing adsorption processes and throughout this application PSA, VPSA, TSA, PPSA, combinations of them as well as other swing adsorption processes (noted further herein) will be referred to as swing adsorption processes.

Adsorbents for swing adsorption processes are typically very porous materials chosen because of their large surface area. Typical adsorbents are activated carbons, silica gels, aluminas, and zeolites. In some cases a polymeric material can be used as the adsorbent material. Though the gas adsorbed on the interior surfaces of microporous materials may consist of a layer of only one, or at most a few molecules thick, surface areas of several hundred square meters per gram enable the adsorption of a significant portion of the adsorbent's weight in gas.

Different molecules can have different affinities for adsorption into the pore structure or open volume of the adsorbent. This provides one mechanism for the adsorbent to discriminate between different gases. In addition to their affinity for different gases, zeolites and some types of activated carbons, called carbon molecular sieves, may utilize their molecular sieve characteristics to exclude or slow the diffusion of some gas molecules into their structure. This provides a mechanism for selective adsorption based on the size of the molecules and usually restricts the ability of the larger molecules to be adsorbed. Either of these mechanisms can be employed to selectively fill the micropore structure of an adsorbent with one or more species from a multi-component gas mixture.

Physisorption isotherms were grouped into six types by IUPAC recommendations [M. Thommes, K. Kaneko, A.V. Neimark, J.P. Olivier, F. Rodriguez-Reinoso, J. Rouquerol, K.S.W. Sing, Physisorption of gases, with special reference to the evaluation of surface area and pore size distribution (IUPAC Technical Report), Pure Appl. Chem. (2015).] A Type I isotherm is concave to the p/pO axis and the amount adsorbed approaches a limiting value. Reversible Type II isotherms are given by the physisorption of most gases on nonporous or macroporous adsorbents. The shape is the result of unrestricted monolayer-multilayer adsorption up to high p/pO. If the knee is sharp, Point B - the beginning of the middle almost linear section - usually corresponds to the completion of monolayer coverage. Type III is characteristic of non-porous sorbents with low energy of adsorbent- adsorbate interaction. In the case of a Type III isotherm, there is no Point B and therefore no identifiable monolayer formation.

A sigmoidal course of an adsorption isotherm or S-shaped isotherm is caused by lateral attracting interactions between the adsorbed species. It is identical with type V of the IUPAC classification and is part of type IV and VI isotherms. It covers the adsorption of water on microporous solids such as aluminum phosphate (ALPO), silicon aluminum phosphate (SAPO) and similar zeolite analog materials, metal organic frameworks (MOFs) and activated carbon. [C. Buttersack, Modeling of type IV and V sigmoidal adsorption isotherms, PCCP 21 (2019) 5614- 5626.]

When natural gas is transported by pipeline with large quantities of water vapor, metal corrosion can occur, and blockages may also arise due to the formation of natural gas hydrates. Depending on the water specification required for a specific pipeline, either absorption or adsorption may be employed to remove the water, both for gas transport as well as for subsequent cryogenic separations. For dehydration using adsorbents, synthetic zeolites Linde Type A (LTA) and Faujasite (Type X and Y), both anionic in nature, have been utilized in desiccant wheels since the 1970s, exhibiting a very rapid and effective decrease in moisture content at low partial pressures for the strongly bound water molecules, which, in turn, then requires high temperature regeneration (300°C and above). In contrast, regular density (RD) microporous silica gel adsorbents exhibit linear water uptake, through a wide range of water concentrations, achieving reasonable quantities of dehydration working capacities.

An important need in the industry involves the dehydration (water removal) of process feed streams. These feed streams can be comprised of water and carbon dioxide (CO2) which can combine to form “what is known in the industry as “wet CO2” or “acid gas”. The process feed streams may also comprise other components, such as hydrocarbons (particularly light hydrocarbon gas feed streams such as methane, ethane, propane and/or butane), nitrogen (N2), hydrogen sulfide (H2S), and other components/contaminants. Particularly problematic feed streams can contain water and CO2 (and optionally H2S) as these components can be considered to be “acid gases” which have a low pH and can be detrimental to swing adsorbent units by physically deteriorating mechanical components, adsorbent materials, and/or deteriorating the transport properties of the adsorbent material (for example slowing down of the transport kinetics by forming surface barriers or reducing bulk diffusion coefficients or by lowering the adsorption capacity).

Dehydration of feed streams to certain threshold levels is important in the industry as removal of water from such feed streams may be required to meet specifications and process requirements for such things as pipeline specifications, cryogenic applications, dehydration for air separation processes including nitrogen purification/production as well as Ch/Ar separation, and miscellaneous intermediate process steps, particularly in the oil and gas industry. When cryogenic processes are used to meet product specifications the dehydration may have to be conducted to levels of 10 ppm, or 1 ppm or 0.01 ppm by volume (or mole fraction).

In recent years, significant efforts have gone into developing subsea separation systems to physically separate the natural gas, oil, water, and sand that may be found in hydrocarbon production streams. During the production of hydrocarbon fluids from underground reservoirs, the produced fluids, which include primarily natural gas and oil, may also include water, both as a free liquid phase and as water vapor. When production wells are located offshore in deep water, it may be advantageous to complete the wells subsea and produce the well stream into a flowline. The well stream may be transported via flowline to shore, tied back to a host facility on the topsides, or processed subsea. However, the presence of water can result in hydrate formation, corrosion, and scaling in the flowlines, resulting in blockages, reduced production, and integrity issues. Moreover, the water vapor may condense along the flowline because of the lower ambient temperature in the subsea environment. In natural gas production, the condensation of liquid (e.g., hydrocarbon and/or water) may also increase the pressure drop because of the multiphase nature of the flow.

Chemicals, such as methanol or glycol, are often injected into the flow to prevent or slow the formation of hydrates. Similarly, chemical corrosion inhibitors are also often injected into the flow. These chemicals add to operating costs for the overall hydrocarbon production system. To address corrosion concerns, the flowline is often designed to be cleaned and inspected by periodic “pigging”. In this case, the flowline design becomes more complex and costly due to facilities for launching the pig, catching the pig, and the like.

The removal of water from natural gas is a critical part of producing a saleable gas stream. In general, natural gas must be dehydrated down to a specified maximum water content to avoid operational issues. The maximum water content is determined such that the water vapor is removed down to a specified dewpoint so that condensation will not occur at the expected minimum temperature within the flowline/pipeline. The conventional approaches for dehydrating natural gas in onshore or topsides facilities are to contact the natural gas stream with a liquid or solid desiccant with an affinity for water. This contacting usually takes place in a pressure vessel, such as towers for absorption via liquid desiccant or vessels that hold solid desiccant. The water is removed by the liquid or solid desiccant, and the desiccant is then typically regenerated and reused. However, much of the equipment used to implement these conventional approaches is not well suited for subsea environments, where external pressures are high and the equipment must be designed to be easily retrievable. Moreover, even when such equipment is capable of being implemented within subsea environments, it is often difficult, time-consuming, and/or cost prohibitive to do so. Accordingly, there exists a need for improved systems and methods for the subsea dehydration of natural gas.

SUMMARY OF THE INVENTION

This disclosure relates to highly stable, high working capacity, low heat regeneration, microporous aluminophosphate-based adsorbent materials, and their use in removing water from feed streams, in particular, swing adsorption processes for dehydration of process feed streams. The microporous aluminophosphate-based adsorbent materials and processes of this disclosure provide swing adsorption processes with high stability, high working capacity, and more effective regeneration at lower temperatures. Accordingly, the microporous aluminophosphate- based adsorbent materials and processes of this disclosure overcome the drawbacks of conventional prior art and provide a novel solution to industry problems, including those associated with natural gas processing within a subsurface (e.g., subsea) environment, described above. The microporous aluminophosphate-based adsorbent materials useful in this disclosure include unsubstituted AlPOs (e.g., A1PO-42, A1PO-34, and A1PO-5), and substituted AlPOs (e.g., silicoaluminophosphates, germanoaluminophosphates and metalloaluminophosphates).

This disclosure relates in part to a method for removing water from a feed stream. The method involves performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the microporous adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle. The microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C. After 250 cycles of adsorption/desorption, water capacity of the microporous adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the microporous adsorbent material. The method can be conducted in a subsurface (e.g., subsea) environment.

This disclosure also relates in part to a swing adsorption system for removing water from a feed stream. The system includes: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor. The adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof. The swing adsorption system is configured to perform steps involving: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the microporous adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle. The microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C. After 250 cycles of adsorption/desorption, water capacity of the microporous adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the microporous adsorbent material. The system can be configured to operate in a subsurface (e.g., subsea) environment.

It has been surprisingly found that, in accordance with this disclosure, certain microporous adsorbent materials (e.g., A1PO-42) can be used for dehydration applications with swing adsorption processes to remove bulk water from gas streams. The microporous adsorbent materials exhibit a unique S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C. Also, the microporous adsorbent materials exhibit significant cycling stability. After 250 cycles of adsorption/desorption, water capacity of the adsorbent materials drop by less than about 10 percent, as compared to the initial water capacity of the adsorbent materials. The unique S-shaped water adsorption isotherm allows the adsorbent materials to have large adsorptive capacities with low regeneration or desorption temperatures.

It has also been surprisingly found that, in accordance with this disclosure, A1PO- 42 with LTA structure shows higher working capacity than other aluminophosphate materials, such as A1PO-5 with AFI structure and A1PO-34 with CHA structure.

Other objects and advantages of the present disclosure will become apparent from the detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1 shows an X-ray diffraction (XRD) pattern of A1PO-42 in the as-made form and after calcination.

Fig. 2 shows scanning electron microscope (SEM) images of A1PO-42 at different magnifications, in accordance with the Examples.

Fig. 3 shows X-ray diffraction (XRD) patterns of A1PO-42 calcined in-situ at 600°C in the XRD instrument (red pattern, a) and rehydrated under ambient atmosphere (blue pattern, a), and subsequent dehydration process by flowing dry air (b), in accordance with the Examples.

Fig. 4 shows N2 adsorption isotherms of calcined A1PO-42 measured at different storing times at ambient conditions, in accordance with the Examples.

Fig. 5 shows water isotherms on A1PO-42 at multiple temperatures, where pronounced S-shaped isotherms are presented, in accordance with the Examples.

Fig. 6 shows a comparison of water capacity at 25 °C for A1PO-42, silica gel, and zeolite 4A, in accordance with the Examples.

Fig. 7 shows a comparison of isotherm model (curves) to experimental data (symbols) for the adsorption of water on A1PO-42 as a function of temperature and water activity, in accordance with the Examples.

Fig. 8 shows a schematic of pressure temperature swing adsorption (PTSA) dehydration process using A1PO-42, in accordance with the Examples. Fig. 9 shows a separation factor of dehydration process as a function of feed temperature, in accordance with the Examples.

Fig. 10 shows the relationship between optimal regeneration temperature T_r and regeneration pressure P_r in a pressure temperature swing adsorption (PTSA) dehydration process with an A1PO-42 adsorbent, in accordance with the Examples.

Fig. 11 shows is a schematic of a testing apparatus and arrangement used in the stability screening tests, in accordance with the Examples.

Fig. 12 shows A1PO-42 performance for the first 50 temperature swing cycles between 30 to 80°C for temperature cycles and corresponding weight change, in accordance with the Examples.

Fig. 13 shows A1PO-42 performance for the first 50 temperature swing cycles between 30 to 80°C for temperature cycles and corresponding water loadings, in accordance with the Examples.

Fig. 14 shows the results obtained for the synthesis of A1PO-42 materials prepared at different conditions (xiFhO/AhCh ratio), in accordance with the Examples.

Fig. 15 shows the comparison of water vapor uptakes on ALPO-42 with commercial AQSOA-Z01, Z02 and AQSOA-Z05 at 25 °C, in accordance with the Examples.

Fig. 16 is a schematic of a sub-sea dehydration process, in accordance with the Examples.

Fig. 17 shows water take versus number of cycles for an A1PO-42 material.

DETAILED DESCRIPTION OF THE INVENTION

This disclosure relates to the use of microporous adsorbent materials (e.g., neutral zeolite A1PO-42) for general dehydration to remove bulk water from gas streams. The microporous adsorbent materials exhibit a distinct S-shaped water isotherm, permitting water removal within a shallow concentration range, and also exhibit very high water capacities, nearly double that of commercial zeolite LTA. Multi-temperature water isotherms for microporous adsorbent materials (e.g. A1PO-42) reveal important features indicating that they can be easily utilized within a small range of temperatures and concentrations for adsorption/desorption, show a large working capacity for water, and can be regenerated relatively inexpensively at relatively low temperatures. Based on these distinct water isotherms, a general pressure-temperature swing adsorption cycle can be developed for illustrating the separation performance for the materials. This disclosure includes microporous adsorbent materials and their use in swing adsorption processes for dehydration of process feed streams, particularly feed streams comprising water and CO2. In particular, a microporous adsorbent material is utilized in pressure swing adsorption processes (PSA), temperature swing adsorption processes (TSA), partial pressure swing adsorption processes (PPSA), rapid cycle temperature swing adsorption (RCTSA), rapid cycle pressure swing absorption (RCPSA), rapid cycle partial pressure swing adsorption (RCPPSA), or a combination thereof, which may be collectively referred to herein as “swing adsorption processes” unless further defined. The term “rapid cycle swing adsorption processes” refer to rapid cycle temperature swing adsorption (RCTSA), rapid cycle pressure absorption (RCPSA), rapid cycle partial pressure swing adsorption (RCPPSA), or a combination thereof. The term “rapid cycle swing adsorption processes” will include such processes as mentioned wherein the total cycle time or period for the rapid cycle swing adsorption processes to go through a full cycle, such as feed/product step(s), desorption step(s), purge step(s) and repressurization step(s) and back to the next feed/product step(s), is a period greater than 1 second and less than 600 seconds. In preferred embodiments, total cycle time or period for the rapid cycle swing adsorption processes is greater than 2 seconds and less than 300 seconds.

These swing adsorption processes may be used to separate gases of a gas mixture because different gases tend to fill the micropore of the adsorbent material to different extents. Conventional PSA, TSA, or such techniques are generally operated with cycle times (particularly adsorption steps or cycles) of sufficient duration to allow the adsorption of the components to come to near equilibrium conditions (i.e., allowing the adsorbent to selectively adsorb the amount of one component relative to another simply by the inherent equilibrium selectivity of the adsorbent at adsorption conditions).

In some other rapid cycle processes the kinetics of the transport do not provide discrimination between different species and selectivity is achieved from the competitive equilibrium adsorption isotherm which is related to the relative adsorption strength of different molecules. For an example related to the dehydration processes herein it is preferred that the kinetic adsorption rate of water be fast enough to reach equilibrium water loadings in the adsorbent within the time allotted for the adsorption step. It is even more preferred that the kinetics of the water adsorption process be fast enough to reach equilibrium water loadings in the adsorbent within one-fifth of the time allotted for the adsorption step. It is also preferred that the equilibrium selectivity for water in the adsorbent be greater than for any of the other components in the feed stream. In a more preferred embodiment the kinetic selectivity for water uptake is faster than for other components in the feed stream. In a most preferred embodiment, the kinetic uptake rate of the other components in the feed stream does not allow them to reach equilibrium loadings in the time of the adsorption step.

If a gas mixture, such as natural gas containing water (or water vapor), is passed under pressure through a vessel containing an adsorbent material that is more selective towards water vapor than it is for methane, at least a portion of the water vapor is selectively adsorbed by the adsorbent material, and the gas exiting the vessel is enriched in methane. As such, the adsorbent would be considered to have a “selectivity” (or “greater selectivity”) for water over methane which can come from either equilibrium loading (competitive adsorption), kinetics (relative adsorption rates) or combinations of these effects. Before the adsorbent material reaches the end of its capacity to adsorb water vapor it is switched from an adsorption step (or “cycle”) to a desorption step. Desorption can be accomplished by raising the temperature of the adsorbent (TSA), purging the adsorbent with a dry stream (PPSA), reducing the pressure of the adsorbent (PSA) or by combinations of these methods. Once the adsorbent has gone through a desorption step it is ready for another adsorption step. Other additional steps such as depressurization, purging, repressurization, reheating, or cooling may alternatively be included in the overall process steps. The combination of the overall steps from the beginning of one adsorption step to the next adsorption step may be referred to as the “total cycle” or the “swing adsorption process cycle” or simply the “adsorption/desorption cycle”. Such cycles would also apply in the case of both conventional swing adsorption processes and rapid cycle swing adsorption processes.

While not limiting, the swing adsorption processes herein preferably further include the use of an adsorbent comprising a microporous adsorbent material, wherein the feed stream is comprised of water, and optionally, other components such as hydrocarbons, CO2, nitrogen (N2), and/or hydrogen sulfide (H2S); and further wherein at least a portion of the water is preferentially removed from the feed stream of the swing adsorption processes wherein the swing adsorption processes produces a product stream wherein the term preferentially removal of water (or the like) means that the weight % of water in the product stream (based on the total product stream) is less than the weight % of water in the feed stream (based on the total feed stream). This is equivalent to the statement that the mole % of water in the product stream (based on the total product stream) is less than the mole % of water in the feed stream (based on the total feed stream).

Embodiments of the disclosure are applicable to swing adsorption processes that rigorously dehydrate the feed stream alone or in combination of other cationic zeolites. Rigorous dehydration is achieved when the product stream from the swing adsorption process contains less than 10 ppm (mole fraction) of water, preferable less than 1 ppm (mole fraction) of water, and even more preferably less than 0.1 ppm (mole fraction) of water. Embodiments of the disclosure may also be utilized for the removal of water from such feed streams may be required to meet specifications and process requirements for such things as pipeline specifications, cryogenic applications, dehydration for air separation processes including nitrogen purification/production as well as C /Ar separation, and miscellaneous intermediate process steps, particularly in the oil and gas industry.

This disclosure utilizes microporous adsorbent materials for dehydration of feed streams (e.g., natural gas and flue gas). The microporous adsorbent materials possess significant stability for the feed streams.

As used herein, the term “microporous adsorbent materials” refers to microporous aluminophosphate-based adsorbent materials that possess at least the following properties. The adsorbent materials exhibit a unique S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C. Also, the adsorbent materials exhibit significant cycling stability. After 250 cycles of adsorption/desorption, water capacity of the adsorbent materials drop by less than about 10 percent, as compared to the initial water capacity of the adsorbent materials. The unique S-shaped water adsorption isotherm allows the adsorbent materials to have large adsorptive capacities with low regeneration or desorption temperatures. The adsorbent materials can have heteroatoms in the skeletal structure thereof, but the heteroatoms do not include iron and/or gallium. Illustrative microporous aluminophosphate-based adsorbent materials useful in this disclosure include, for example, unsubstituted AlPOs (e.g., A1PO-42, A1PO-34, and A1PO-5), and substituted AlPOs (e.g., silicoaluminophosphates, germanoaluminophosphates and metalloaluminophosphates).

As used herein, the term “S-shaped water adsorption isotherm” refers to and depicts the relationship between water uptake by a microporous adsorbent material at a specified pressure and temperature. The relationship is displayed graphically by a S-shaped curve. A sigmoidal course of an adsorption isotherm or S-shaped isotherm is caused by lateral attracting interactions between the adsorbed species. It is identical with type V of the IUPAC classification and is part of type IV and VI isotherms (see M. Thommes et al., supra). It covers the adsorption of water on microporous solids such as aluminum phosphate (ALPO), silicon aluminum phosphate (SAPO) and similar zeolite analog materials, metal organic frameworks (MOFs) and activated carbon (see C. Buttersack, supra). In accordance with this disclosure, the microporous adsorbent materials exhibit a unique S-shaped water adsorption isotherm. For example, the microporous adsorbent materials of this disclosure having a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C, exhibit a S-shaped water adsorption isotherm curve. The unique S-shaped water adsorption isotherm allows the adsorbent materials to have large adsorptive capacities with low desorption temperatures. The adsorbent materials exhibiting a distinct S-shaped water isotherm, permit water removal within a shallow concentration range, and also exhibit very high water capacities, nearly double that of commercial zeolite LTA. Multitemperature water isotherms for A1PO-42, A1PO-34 and A1PO-5 reveal important features indicating that they can be easily utilized within a small range of temperatures and concentrations for adsorption/desorption, show a large working capacity for water, and can be operated relatively inexpensively at relatively low temperatures. Based on these distinct water isotherms, general pressure-temperature swing adsorption cycles can be developed to illustrate the separation performance for the material.

Illustrative S-shaped isotherms for A1PO-42 are shown in Fig. 5. This unique S- shaped feature of water isotherms can allow large adsorptive capacity with low desorption temperature. As shown in Fig. 5, the water isotherm measured at 60°C clearly demonstrates negligible water capacity less than 1 mol/kg even at 0.035 bar of water pressure, while water isotherm measured at 25 °C reaches 20 mol/kg at 0.003 bar.

As used herein, “working capacity” refers to the amount of water uptake by the microporous adsorbent material when used in the method of this disclosure. It has been surprisingly found that the microporous adsorbent materials useful in the method of this disclosure have high working capacity. In particular, the microporous adsorbent materials useful in the method of this disclosure have a working capacity of at least about 5 mol/kg, or at least about 10 mol/kg, or at least about 15 mol/kg, or at least about 20 mol/kg, or greater.

As used herein, “regeneration temperature” refers to the desorption temperature of the microporous adsorbent material used in the method of this disclosure. It has been surprisingly found that the microporous adsorbent materials useful in the method of this disclosure have a low regeneration temperature. In particular, the microporous adsorbent materials useful in the method of this disclosure have a regeneration temperature from about 50°C to about 140°C, preferably from about 60°C to about 120°C, and more preferably from about 60°C to about 100°C. In contrast, conventional dehydration adsorbents have much higher regeneration temperatures, for example, 175-235°C for silica gel, alumina, and zeolite 3A, and 290°C for zeolite 4A and 5A. Illustrative microporous adsorbent materials useful in this disclosure include microporous aluminophosphate-based adsorbent materials. Illustrative microporous aluminophosphate-based adsorbent materials useful in this disclosure include, for example, unsubstituted AlPOs (e.g., A1PO-42, A1PO-34, and A1PO-5), and substituted AlPOs (e.g., silicoaluminophosphates, germanoaluminophosphates and metalloaluminophosphates). Preferred microporous aluminophosphate-based adsorbent materials include, for example, A1PO-42, A1PO- 34, A1PO-5, and combinations thereof. A most preferred microporous adsorbent material is A1PO- 42.

The microporous adsorbent materials which are substantially free from change in structure upon subjecting them to adsorption and desorption of water, exhibit high stability. In an embodiment, the high stability of the microporous adsorbent materials means, for example, that the amount of water adsorption thereof at a relative humidity of 0.25 in the adsorption isotherm measured at a temperature of 25 °C after subjecting the zeolite to 250 adsorption and desorption cycles is not less than 70%, preferably not less than 80%, more preferably not less than 90% of the amount of water adsorption of the zeolite before being subjected to the adsorption and desorption cycles.

The framework of the microporous adsorbent materials can vary over a wide range, for example, A1PO-42 has an LTA framework, A1PO-34 has a CHA framework, and A1PO-5 has an AFI framework.

Other framework examples of microporous adsorbent materials used in this disclosure include CLO, ACO,AEI, AEL, AEN, AET, AFI, AFN, AFO, AFR, AFS, AFT, AFV, AFX, AFY, AHT, ANA, ANO, APC, APD, AST, ATN, ATO, ATS, ATT, ATV, AVE, AVE, AWO, AWN, BCT, BPH, CHA, DFO, DFT, GDI, ERI, EZT, FAU, GIS, IFO, JNT, JRY, JSN, JSW, LEV, LTA, MEI, MER, MSO, OSI, OWE, PHI, PON, POR, PSI, RHO, SAF, SAO, SAS, SAT, SAW, SBE, SBS, SBT, SFO, SIV, SOD, SWY, THO, VFI, and ZON when expressed by codes prescribed by International Zeolite Association (IZA), the framework descriptions of which are incorporated herein by reference. Among these zeolite structures, preferred are LTA, CHA and AFI.

The microporous adsorbent materials used in the present invention may contain, in addition to Al and P, other elements in a skeletal structure thereof. Examples of the other elements may include silicon, magnesium, titanium, zirconium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, germanium, arsenic, tin, and boron. In an embodiment, the structure for A1PO-42 is comprised of alternating Al and P tetrahedral sites, such that each Al is surrounded by four P atoms, and each P atom is surrounded by 4 Al atoms. The overall structure is charge neutral (i.e., no charge balancing cations are present). The structure also has a variety of compositional variants, i.e., isostructural materials with different framework atoms from Al and P, including the silicoaluminophosphates such as SAPO-42, which are negatively charged, and require charge-balancing cations in the framework. Compositional variants can be used alone or with other microporous adsorbent materials in various applications in accordance with this disclosure. For example, A1PO-42 and zeolite 3A/4A/5A can be used in multiple adsorbent beds for deep dehydration in accordance with this disclosure.

The average crystal size of the microporous adsorbent materials of this disclosure can range from about 0.05 microns to about 20 microns, preferably from about 0.05 microns to about 1 micron, and more preferably from about 0.05 microns to about 0.5 microns. Small crystal sizes allow for fist kinetics and more usable capacities for similar operating conditions.

The conditions for production of the microporous adsorbent materials (e.g., aluminophosphates) used in the present invention are not particularly limited. Typically, the aluminophosphate may be produced by mixing a template with an aluminum source and a phosphorus source, and then subjecting the resultant mixture to hydrothermal synthesis. In the following, an example of the production of an aluminophosphate is described. First, the aluminum source and phosphorus source are mixed with the template. Examples of the aluminum source are not particularly limited and may usually include pseudo-boehmite, aluminum alkoxides such as aluminum isopropoxide and aluminum triethoxide, aluminum hydroxide, alumina sol, etc. Among these aluminum sources, pseudo-boehmite is preferred from the standpoint of good handing property and high reactivity.

As the phosphorus source, there may be usually used phosphoric acid, phosphorous pentoxide and there may also be used aluminum phosphate. Also, the aluminophosphate may also contain in its skeletal structure, the other elements unless the adsorption and desorption properties are adversely affected by addition thereof. Examples of the other elements may include silicon, lithium, magnesium, titanium, zirconium, vanadium, chromium, manganese, cobalt, nickel, iron, palladium, copper, zinc, germanium, arsenic, tin, calcium and boron.

Examples of the template may include quaternary ammonium salts such as tetramethyl ammonium, tetraethyl ammonium, tetrapropyl ammonium and tetrabutyl ammonium; and primary, secondary and tertiary amines and polyamines such as morpholine, dim-propylamine, tri-n-propylamine, triisopropylamine, triethylamine, triethanolamine, piperidine, piperazine, cyclohexylamine, 2-methylpyridine, N,N-dimethylbenzylamine, N,N-diethylethanolamine, dicyclohexylamine, N,N-dimethylethanolamine, coline, N,N'-dimethyl piperazine, 1,4- diazabicyclo(2,2,2)octane, 1,4,8,11-tetraazacyclotetradecane, cyclam, N-methyldiethanolamine, N-methylethanolamine, N-methyl piperidine, 3-methyl piperidine, N-methylcyclohexylamine, 3- methylpyridine, 4-methylpyridine, quinuclidine, N,N'-dimethyl-l,4-diazabicyclo(2,2,2)octane ion, di-n-butylamine, neopentylamine, di-n-pentylamine, isopropylamine, t-butylamine, ethylenediamine, pyrrolidine, 2-imidazoline, di-isopropyl-ethylamine, dimethylcyclohexylamine, cyclopentylamine, N-methyl-n-butylamine and hexamethyleneimine. These templates may be used in the form of a mixture of any two or more thereof. Among these templates, from the standpoint of high reactivity, triethylamine, isopropylamine, diisopropylamine, tri-n-propylamine and tetraethyl ammonium hydroxide are preferred, and triethylamine is more preferred from the standpoint of industrial availability with more inexpensiveness. These templates may be used alone or in combination of any two or more thereof.

The above aluminum source, phosphorus source and template are mixed with each other in the form of an aqueous gel. Although the mixing order of the respective components varies depending upon the conditions, usually, the phosphorus source and aluminum source are first mixed with each other, and then the resultant mixture is mixed with the template.

The aqueous gel of the aluminophosphate has such a composition that the molar ratio of P2O5/AI2O3 is from 0.6 to 1.7, and preferably from 0.7 to 1.6, more preferably from 0.8 to

1.5 from the standpoint of facilitated synthesis. In addition, as to the lower limit of water content, the molar ratio of water to AI2O3 is not less than 3, and preferably not less than 5, more preferably not less than 10 from the standpoint of facilitated synthesis. As to the upper limit of water content, the molar ratio of water to AI2O3 is not more than 200, and preferably not more than 150, more preferably not more than 120 from the standpoints of facilitated synthesis and high productivity. The pH value of the aqueous gel is from 4 to 10, and preferably from 5 to 9, more preferably from

5.5 to 8.5 from the standpoint of facilitated synthesis.

The aqueous gel may also contain components other than the above components, if required. Examples of the other components may include hydroxides or, hydrophilic organic solvents such as alcohols, etc.

The hydrothermal synthesis may be conducted by placing the aqueous gel in a pressure container and allowing the aqueous gel to stand with or without stirring at the predetermined temperature under a spontaneous pressure or under a pressure of gases having no adverse influence on crystallization thereof. The temperature condition of the hydrothermal synthesis can be from about 75 to about 220°C, and preferably from about 85 to about 200°C, more preferably from about 100 to about 200°C from the standpoint of facilitated synthesis.

The reaction time for the hydrothermal synthesis can be from about 1 hour or less to about 6 days or greater, preferably from about 2 hours to about 5 days, more preferably from about 2 hours to about 4 days from the standpoint of facilitated synthesis. After completion of the hydrothermal synthesis, the reaction product is separated from the reaction mixture, washed with water, dried, and then calcined using air, etc., to remove a part or whole of organic substances contained therein, thereby obtaining a crystalline aluminophosphate. It is possible that the synthesis time could be reduced dramatically in a continuous system with very fast heating and at high temperatures.

In an embodiment, the, the microporous adsorbent materials can be useful in removing water from feed streams (dehydration) wherein the water content is at least about 150 ppm (by volume or mole fraction), preferably at least about 200 ppm (by volume or mole fraction. In a preferred embodiment, the swing adsorption process in which the microporous adsorbent materials are utilized to dehydrate the feed stream, produce a product stream that contains less than 100 ppm (mole fraction) of water, more preferable less than 80 ppm (mole fraction) of water, and even more preferably less than 40 ppm (mole fraction) of water.

In an embodiment, the water content of the feed stream can be from about 1000 ppm mole fraction to about 50000 ppm mole fraction, preferably from about 1000 ppm mole fraction to about 5000 ppm mole fraction, and more preferably from about 200 ppm mole fraction to about 1000 ppm mole fraction. The water content of the product stream can be from about 10 ppm mole fraction to about 150 ppm mole fraction, preferably from about 20 ppm mole fraction to about 100 ppm mole fraction, and more preferably from about 30 ppm mole fraction to about 50 ppm mole fraction.

In some embodiments, the feed stream may also comprise hydrocarbons, and the method herein are utilized to dehydrate the hydrocarbon containing feed stream. In particular embodiments, the hydrocarbon may be natural gas. The feed stream may also be comprised of methane, ethane or a combination thereof. In particular embodiments, the feed stream may contain at least 50 wt % hydrocarbons, or more preferably, at least 90 wt % hydrocarbons. It has been discovered that the selectivity of the microporous adsorbent materials of this disclosure is such that the swing adsorption dehydration process can be conducted using these zeolites to remove water from a hydrocarbon containing feed stream in a manner such that at least 90 wt % of the hydrocarbons present in the feed stream remain present in the product gas from the swing adsorption process, more preferably at least 95 wt % of the hydrocarbons present in the feed stream remain present in the product gas from the swing adsorption process, and even more preferably, at least 98 wt % of the hydrocarbons present in the feed stream remain present in the product gas from the swing adsorption process. This can be achieved while dehydrating the hydrocarbon containing feed stream to less than about 50 ppm mole fraction, whether or not acid gas conditions are present in the feed stream. In an embodiment, the microporous adsorbent materials of this disclosure possess rapid water kinetics which make them particularly advantageous for use as an adsorbent in rapid cycle swing dehydration processes.

In performing swing adsorption processes the microporous adsorbent materials (i.e., crystals) are incorporated into a contactor that can be in the form of a structured contactor or unstructured (pelletized) contactor. Incorporating zeolite crystals into contactors usable in a swing adsorption processes can be carried out by conventional methods. When the zeolite is formulated into a contactor for a swing adsorption process, it may be bound together or held together in a coating with inorganic oxides, metals, other zeolites, other microporous materials such as MOFs, carbons, or polymers. In some instances, the crystals are bound into the form of a pellet. In other instances, the crystals may be coated onto the surface of a monolith with the aid of a binding agent. In other instances, the crystals are grown on the surface of a monolith. In other instances, the crystals are extruded with a binding agents to form a monolithic structure. In preferred embodiments, the mass of microporous adsorbent materials in the adsorbent bed of the contactor or contactors used in the swing adsorption dehydration process is more than 10 wt %, preferably more than 25 wt % and even more preferably greater than 50 wt % of the total adsorbent bed materials.

As described herein, swing adsorption processes may be used to remove water vapor (or simply “water” herein) from a feed stream (such as a gas mixture) because water selectively may adsorb into the micropore of the adsorbent material, and may fill the micropores in certain situations with a greater selectivity than other components of the gas mixture. The swing adsorption processes (e.g., PSA and TSA) may be used to separate gases of a gas mixture because different gases tend to fill the micropore of the adsorbent material to different extents.

The microporous adsorbent materials used in the swing adsorption dehydration process can be in a non-dehydrated form, a dehydrated form, or a calcined form.

For an example related to the dehydration processes herein, if a feeds stream, such as natural gas containing water (or water vapor), is passed under pressure through a vessel containing an adsorbent material that is more selective towards water vapor than it is for methane, at least a portion of the water vapor is selectively adsorbed by the adsorbent material, and the gas exiting the vessel is enriched in methane. As such, the adsorbent would be considered to have a “selectivity” (or “greater selectivity”) for water over methane. Before the adsorbent material reaches the end of its capacity to adsorb water vapor it is switched from an adsorption step (or “cycle”) to a desorption step. Desorption can be accomplished by raising the temperature of the adsorbent (TSA), purging the adsorbent with a dry stream (PPSA), reducing the pressure of the adsorbent (PSA) or by combinations of these methods. Once the adsorbent has gone through a desorption step it is ready for another adsorption step. Other additional steps such as depressurization, purging, repressurization, or reheating, may alternatively be included in the overall process steps. The combination of the overall steps from the beginning of one adsorption step to the next adsorption step may be referred to as the “total cycle” or the “swing adsorption process cycle” or simply “adsorption/desorption cycle”.

In an embodiment, the adsorption temperature can range from about 0°C to about 40°C, preferably from about 5 °C to about 30°C, and more preferably from about 10°C to about 25°C. The desorption temperature can range from about 50°C to about 140°C, preferably from about 60°C to about 120°C, and more preferably from about 60°C to about 100°C.

In an embodiment, the adsorption pressure can be from about 1 bar to about 100 bar, preferably from about 1 bar to about 80 bar, and more preferably from about 1 bar to about 75 bar. The desorption pressure can be from about 0.1 bar to about 100 bar, preferably from about 0.1 bar to about 60 bar, and more preferably from about 0.1 bar to about 50 bar. The relative pressure P/Ps (relative humidity) can range from about 0.0001 to about 1, preferably from about 0.001 to about 0.5, more preferably from about 0.001 to about 0.25.

Rigorous dehydration is the removal of water so that the concentration of water in the product gas or stream (e.g., the gas exiting the adsorbent bed during the adsorption step) to typically less than 10 ppm on a mole basis, preferably less than 1 ppm on a mole basis or even more preferably less than 0.1 ppm on a mole basis.

In performing rapid cycle swing adsorption system, the adsorbent bed (e.g., in one embodiment a substantially parallel channel contactor) is regenerated before the adsorbent material reaches the end of its capacity to adsorb water vapor. PSA processes can be used to regenerate the adsorbent used for dehydration, but sufficient regeneration involves low pressures (e.g., vacuum pressures) and long periods of time for regeneration. For rapid cycle dehydration processes, after the adsorption step, the adsorbent bed will undergo a desorption step wherein a desorption step product is produced (enriched in water) using rapid cycle PSA, rapid cycle TSA and/or rapid cycle PPSA processes, or a combination thereof (e.g., the desorption step may include both a “pressure swing” in combination with a “temperature swing”). After the desorption step, the adsorbent material may be optionally purged, repressurized, and/or cooled prior to the next adsorption step. The adsorbent material is thus prepared for another adsorption cycle.

In particular, the microporous adsorbent materials herein may be utilized in the swing adsorption processes described herein. The rapid cycle swing adsorption processes will include processes wherein the total cycle time or period for the rapid cycle swing adsorption processes to go through a full cycle, such as feed/product step(s), desorption step(s), purge step(s) and repressurization step(s) and back to the next feed/product step(s), is a period greater than 1 second and less than 600 seconds. In preferred embodiments, total cycle time or period for the rapid cycle swing adsorption processes is greater than 2 seconds and less than 300 seconds. For example, the total cycle times may be less than 600 seconds, preferably less than 300 seconds. In rapid cycle processes the residence time of the gas contacting the adsorbent material in the adsorbent bed during the adsorption step is typically short.

Substantially parallel channel contactors can be constructed by coating thin layers of the microporous adsorbent material and a binder onto a monolith. Substantially parallel channel contactors, such as monoliths, provide very low pressure drop as compared to conventional pellet or other packed beds, which provides a mechanism for the economic use of significantly higher gas velocities and hence higher productivity. One of the primary factors to the performance of a substantially parallel channel contactor and its application for rapid cycle swing adsorption systems is to avoid or minimize mass transfer resistances, and thus allow the intrinsic speed of the primary adsorbent to operate in the kinetic adsorption regime. Avoidance of mass transfer resistances in rapid cycle contactors provide the conditions to facilitate the generation of sharp adsorption fronts, particularly for strong Type 1 isotherm adsorption systems, such as water, in the adsorbent material. Sharp fronts within the length of the contactor provide efficient adsorbate removal to very low concentrations.

Minimization of mass transfer resistance may be accomplished in a substantially parallel channel contactor by several steps. Gas film transfer resistance is minimized by making the gas channels in the contactor of small diameter, such that the distance any adsorbate species has to diffuse in the gas phase is limited to one half the diameter of the gas channel. Gas channel diameters, or heights, of less than 2 millimeters are preferred, less than 1 millimeter are more preferred, and less than 600 microns are most preferred. Secondly, limiting the thickness of adsorbate containing coatings reduces the distance that adsorbate species has to diffuse through the macropores and mesopores of the composited adsorbate coating. Preferably, the volume of the microporous adsorbent material is greater than that of the binder and thickness of the layer is less than 800 microns, preferably less than 200 microns and even more preferably less than 125 microns, most preferably less than 60 microns. Further, it is beneficial to minimize the amount of mesopores within the coating layer, with a predominance of macropores being preferred due to the faster diffusion speeds of gas species in macropores as compared to mesopores. It is preferred that at least 50% of the pore volume of the adsorbate coating layer is in macropores, i.e. pore diameters greater than 50 nanometers, more preferably at least 75%, and most preferably greater than 90%. Lastly, adsorbent coating layers with low intrinsic tortuosity are preferred.

While not limiting, suitable contactors may be constructed of adsorbate coatings on ceramic monoliths, or spaced laminated support sheets of metal, metal mesh, polymer, or polymer mesh, or various screens when laminated and spaced with spacers or other means to provide a gas flow channel parallel to the coating layers. Corrugated metal sheets, either layered or spiral wound coated with an adsorbent layer are particularly useful and flexible in their possible designs and gas channel characteristics. Contactors constructed from multiple monoliths or other such structures stacked in series are also particularly useful, as spaces between the monoliths or such provide gas mixing and can minimize front dispersion caused by variations in adsorbate coating thicknesses or gas channel diameters.

Included herein is a method for removing water from a feed stream, the method comprising performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C; and wherein, after 250 cycles of adsorption/desorption, water capacity of the adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the adsorbent material.

In preferred embodiments, the gaseous feed stream comprises from 0.00001 to 0.3 bar of water (H2O) partial pressure, and from 0.005 to 3.0 bar of carbon dioxide (CO2) partial pressure. In preferred embodiments, the water uptake capacity of the microporous adsorbent materials after 250 cycles is preferably at least 80%, more preferably at least 90%, and even more preferably at least 95% of the initial water uptake capacity of the microporous adsorbent materials. In preferred embodiments, this stability initial water uptake capacity of the microporous adsorbent materials after 250 cycles is based on utilization in a rapid cycle temperature swing adsorption process wherein the temperature difference between the adsorption step and the desorption step is at least 100°C.; more preferably at least 150°C., and/or when the desorption temperature is at least 150°C., at least 200°C., or at least 250°C.

As further enhancements, the process may include some additional variations to the process. For example, the rapid cycle swing adsorption process may comprise a rapid cycle pressure swing adsorption process, a rapid cycle temperature swing adsorption process, a rapid cycle partial pressure swing adsorption process, or any combination thereof; the desorption step may further comprise performing a purge step, wherein the purge step comprises passing a purge stream into the adsorbent bed unit to remove at least a portion of the water from the substantially parallel channel contactor to form a purge product stream; the rapid cycle swing adsorption process may comprise a rapid cycle pressure swing adsorption process; may include performing one or more depressurization steps after step b) and prior to step c), wherein the pressure within the adsorbent bed unit is reduced by a predetermined amount with each successive depressurization step; may include heating the substantially parallel channel contactor to promote the removal of at least a portion of the water from the substantially parallel channel contactor to form a purge product stream; and may include passing a heated purge stream through the substantially parallel channel contactor to promote the removal of at least a portion of the water from the substantially parallel channel contactor to form a purge product stream.

The pressure of the feed stream may be in the range between 400 pounds per square inch absolute (psia) and 1500 psia, or in the range from 600 psia to 1200 psi.; wherein the gaseous feed stream may be a hydrocarbon containing stream having greater than one volume percent hydrocarbons based on the total volume of the feed stream; wherein the cycle duration is greater than 2 seconds and less than 300 seconds; wherein residence time for gas in the gaseous feed stream contacting the adsorbent material in the substantially parallel channel contactor during the adsorption step is less than 5.0 seconds, is less than 1.0 seconds or is less than 0.5 seconds; and/or wherein the concentration of water in the product stream is less than 50 parts per million on a mole basis, is less than 1 parts per million on a mole basis or is less than 0.1 parts per million on a mole basis.

The present techniques involve one or more adsorbent bed units to perform a swing adsorption process or groups of adsorbent bed units configured to perform a series of swing adsorption processes. Each adsorbent bed unit may be configured to perform a specific cycle or cycles, which may include an adsorption step and a desorption step. As noted, additional steps may be further included.

In certain configurations, the swing adsorption unit, which includes the adsorbent material, may process a feed stream that comprises hydrocarbons along with water and CO2. For example, the feed stream may be a hydrocarbon containing stream having greater than one volume percent hydrocarbons based on the total volume of the feed stream. By way of example, the stream may include H2O and CO2 as one or more contaminants and the gaseous feed stream may comprise H2O in the range of 100 parts per million (ppm) molar to 1,500 ppm molar; or in the range of 500 ppm to 1,500 ppm molar; and CO2 in the range of 50 parts per million (ppm) molar to 2 molar %; or in the range of 500 ppm to 2 molar %. Moreover, the feed stream may include hydrocarbons and H2O, wherein the H2O is one of the one or more contaminants and the feed stream comprises H2O in the range of two ppm molar to saturation levels in the feed stream.

In certain configurations, the adsorbent material may be used in a rapid cycle swing adsorption process, such as a rapid cycle PSA process, to remove moisture from the feed stream. The specific level may be related to dew point of desired output product (e.g., the water content should be lower than the water content required to obtain a dew point below the lowest temperature of the stream in subsequent processing and is related to the feed pressure). As a first approximation, and not accounting for fugacity corrections as a function of pressure, the water concentration in ppm that yields a certain dew point varies inversely with the pressure. For example, the output stream from the adsorbent bed may be configured to be the cryogenic processing feed stream, which satisfies the cryogenic processing specifications (e.g., approximately -150°F (-101.1°C) dew point for NGE processes or approximately -60°F (-51.1 °C) for Controlled Freeze Zone (CFZ) processes. The cryogenic processing feed stream specification may include a water content in the stream (e.g., output stream from the adsorbent bed or feed stream to the to be cryogenic processing) to be in the range between 0.0 ppm and 10 ppm, in the range between 0.0 ppm and 5.0 ppm, in the range between 0.0 ppm and 2.0 ppm, or in the range between 0.0 ppm and 1.0 ppm. The resulting output stream from the adsorbent beds during the purge step may include a water content in the stream to be in the range between 0.0 ppm and 7 pounds per standard cubic feet (Ib/MSCF).

In one or more embodiments, the present techniques can be used for any type of swing adsorption process. Non- limiting swing adsorption processes for which the present techniques may include pressure swing adsorption (PSA), vacuum pressure swing adsorption (VPSA), temperature swing adsorption (TSA), partial pressure purge swing adsorption (PPPSA), rapid cycle pressure swing adsorption (RCPSA), rapid cycle thermal swing adsorption (RCTSA), rapid cycle partial pressure swing adsorption (RCPPSA), as well as combinations of these processes, such as pressure and/or temperature swing adsorption. Exemplary swing adsorption processes are described in U.S. Patent Application Publication Nos. 2008/0282892, 2008/0282887, 2008/0282886, 2008/0282885, 2008/0282884 and 2014/0013955, which are each herein incorporated by reference in their entirety.

Further, in certain configurations of the system, the present techniques may include a specific process flow to remove contaminants, such as water (H2O), in the swing adsorption system. For example, the process may include an adsorbent step and a desorption step, which form the cycle. The adsorbent step may include passing a feed stream at a feed pressure and feed temperature through an adsorbent bed unit having an adsorbent material (e.g., adsorbent bed or substantially parallel channel contactor) to separate one or more contaminants from the feed stream to form a product stream. The feed stream may be passed through the substantially parallel channel contactor in a forward direction (e.g., from the feed end of the substantially parallel channel contactor to the product end of the substantially parallel channel contactor). Then, the flow of the feed stream may be interrupted for a regeneration step.

The regeneration step may include one or more depressurization steps, one or more purge steps and/or one or more re-pressurization steps. The depressurization steps may include reducing the pressure of the adsorbent bed unit by a predetermined amount for each successive depressurization step, which may be a single step and/or may be a blowdown step. The depressurization step may be provided in a forward direction or may preferably be provided in a countercurrent direction (e.g., from the product end of the substantially parallel channel contactor to the feed end of the substantially parallel channel contactor). The purge step may include passing a purge stream into the adsorbent bed unit, which may be a once through purge step and the purge stream may be provided in countercurrent flow relative to the feed stream. The purge product stream from the purge step may be conducted away and recycled to another system or in the system. Then, the one or more re-pressurization steps may be performed, wherein the pressure within the adsorbent bed unit is increased with each re-pressurization step by a predetermined amount with each successive re-pressurization step.

Additionally included herein is a swing adsorption system for removing water from a feed stream, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C; and wherein, after 250 cycles of adsorption/desorption, water capacity of the adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the adsorbent material.

In preferred embodiments, the adsorbent bed is a parallel channel contactor.

In an embodiment, adsorbent bed configurations useful in this disclosure can include, for example, multiple adsorbent beds of one microporous adsorbent material, or multiple adsorbent beds of more than one microporous adsorbent material. The number of adsorbent beds and microporous adsorbent materials depends on the particular operation. Layers of a microporous adsorbent material (e.g., A1PO-42) and silica gel can extend capacity range. A combination of A1PO-42 and zeolite 3A/4A/5A can be used for deep dehydration.

Also, the present techniques may be integrated into a various configurations, which may include a variety of compositions for the streams. Adsorptive separation processes, apparatus, and systems, as described above, are useful for development and production of hydrocarbons, such as gas and oil processing.

These rapid cycle swing adsorption processes provide enhancements of using less adsorbent, reducing size of equipment to have less capital cost and footprint. In addition, the rapid cycle swing adsorption processes make possible a mobile system to be used in remote areas, offshore, and other hard to reach places.

The microporous adsorbent materials (e.g. A1PO-42) can be effective and advantaged for offshore dehydration applications, such as floating LNG facilities, to remove water from gas prior to transport. Owing to the space and energy limitations typical of these plants, adsorption processes utilizing the microporous adsorbent materials (e.g., A1PO-42) offers the potential to minimize space requirements, owing to its high water capacity, and can use waste energy (below 100°C) for low temperature regeneration. This is in contrast to the current commercial TEG technology which requires large glycol stripping towers, and higher temperature (~400°F) regeneration. This disclosure can be useful in applications for subsea transport to utilize advantage of low heat regeneration from the microporous adsorbent materials (e.g., A1PO-42).

Other applications for the microporous adsorbent materials (e.g., A1PO-42) of this disclosure include dehydration of natural gas flue gas, concentrating CO2 via gas dehydration, which greatly simplifies CO2 capture from N2, permitting utilization of highly selective CO2 sorbents which typically cannot be employed owing to the competitive nature of water sorption over CO2 on these materials. The microporous adsorbent materials and variants thereof can have high CO2 capacities.

Herein listed are non-limiting embodiments of the disclosure as disclosed.

Embodiment 1. A method for removing water from a feed stream, the method comprising performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the microporous adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle; wherein the microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C; and wherein, after 250 cycles of adsorption/desorption, water capacity of the microporous adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the microporous adsorbent material.

Embodiment 2. The method of Embodiment 1 wherein the microporous adsorbent material is a microporous aluminophosphate (A1PO) material, a microporous silicoaluminophosphate (SAPO) material, a microporous aluminophosphate-based material, a microporous germanoaluminophosphate material, a microporous metalloaluminophosphate material, a microporous aluminophosphate (A1PO) zeolite, a microporous silicoaluminophosphate (SAPO) zeolite, a microporous aluminophosphate-based zeolite, a microporous germanoaluminophosphate zeolite, a microporous metalloaluminophosphate zeolite, or combinations thereof.

Embodiment 3. The method of Embodiment 1 wherein the microporous adsorbent material is a microporous aluminophosphate zeolite selected from the group consisting of A1PO- 42, A1PO-34 and A1PO-5.

Embodiment 4. The method of Embodiment 1 wherein the microporous adsorbent material is A1PO-42.

Embodiment 5. The method of Embodiment 1 wherein the microporous adsorbent material further contains one or more of magnesium, titanium, zirconium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, germanium, arsenic, tin, and boron, in the skeletal structure thereof.

Embodiment 6. The method of Embodiment 1 wherein the microporous adsorbent material has a framework type selected from the group consisting of LTA, CHA and AFI.

Embodiment 7. The method of Embodiment 1 wherein the microporous adsorbent material has a water adsorbent swing capacity greater than about 20 mol/kg at a temperature swing between about 25°C and about 140°C, and a relative pressure P/Ps swing between about 0.0001 and about 1.

Embodiment 8. The method of Embodiment 1 wherein the feed stream is natural gas, flue gas, impure natural gas, or a feed stream containing natural gas. Embodiment 9. The method of Embodiment 8 wherein the flue gas contains water, N2 and CO2.

Embodiment 10. The method of Embodiment 1 wherein the feed stream comprises hydrocarbons.

Embodiment 11. The method of Embodiment 10 wherein the feed stream further comprises an acid gas.

Embodiment 12. The method of Embodiment 1 wherein the water content of the feed stream is at least about 100 ppm mole fraction, and the water content of the product stream is less than about 50 ppm mole fraction.

Embodiment 13. The method of Embodiment 1 wherein the product stream comprises at least 90 wt % of the hydrocarbons present in the feed stream.

Embodiment 14. The method of Embodiment 1 wherein the microporous adsorbent material has a water adsorptive capacity of at least about 10 mol/kg.

Embodiment 15. The method of Embodiment 1 wherein the adsorption step is operated at a temperature from about 10 °C to about 40 °C.

Embodiment 16. The method of Embodiment 1 wherein the desorption step is operated at a temperature from about 60°C to about 120°C.

Embodiment 17. The method of Embodiment 1 wherein the adsorption step is operated at a pressure from about 1 bar to about 100 bar.

Embodiment 18. The method of Embodiment 1 wherein the desorption step is operated at a pressure from about 0.1 bar to about 100 bar.

Embodiment 19. The method of Embodiment 1 wherein the adsorption step is operated at a relative pressure P/Ps from about 0.0001 to about 1.

Embodiment 20. The method of Embodiment 1 wherein the desorption step is operated at a relative pressure P/Ps from about 0.0001 to about 1.

Embodiment 21. The method of Embodiment 1 wherein the microporous adsorbent material has an LTA, CHA or AFI structure as represented by a code of International Zeolite Association (IZA).

Embodiment 22. The method of Embodiment 1 wherein the product stream is exposed to the microporous adsorbent material at effective conditions for performing equilibrium separation of the first component from the second component. Embodiment 23. A method for removing water from a feed stream, wherein the method is conducted in a subsea environment, the method comprising performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle; wherein the microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

Embodiment 24. The method of Embodiment 23 wherein the desorption step is executed through use of a heating loop in which a regeneration gas is heated and used to desorb water from the microporous adsorbent material, and wherein an effluent gas is cooled to condensate at least a portion of the water from the effluent gas, and the effluent gas is then reheated to the desorption temperature and reused as a regeneration gas.

Embodiment 25. The method of Embodiment 23 wherein the desorption step is operated at a temperature of about 80°C to about 120°C.

Embodiment 26. The method of Embodiment 23 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the effluent gas in the desorption step.

Embodiment 27. The method of Embodiment 23 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the feed stream prior to the adsorption step.

Embodiment 28. A swing adsorption system for removing water from a feed stream, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the microporous adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the microporous adsorbent material exhibits a S- shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C; and wherein, after 250 cycles of adsorption/desorption, water capacity of the microporous adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the microporous adsorbent material.

Embodiment 29. The system of Embodiment 28 wherein the microporous adsorbent material is a microporous aluminophosphate (A1PO) material, a microporous silicoaluminophosphate (SAPO) material, a microporous aluminophosphate-based material, a microporous germanoaluminophosphate material, a microporous metalloaluminophosphate material, a microporous aluminophosphate (A1PO) zeolite, a microporous silicoaluminophosphate (SAPO) zeolite, a microporous aluminophosphate-based zeolite, a microporous germanoaluminophosphate zeolite, a microporous metalloaluminophosphate zeolite, or combinations thereof.

Embodiment 30. The system of Embodiment 28 wherein the adsorbent bed is a parallel channel contactor.

Embodiment 31. The system of Embodiment 28 wherein the mass of the microporous adsorbent material in the adsorbent bed is more than about 20 percent by weight of the total materials making up the adsorbent bed. Embodiment 32. The system of Embodiment 28 wherein the microporous adsorbent material is a microporous aluminophosphate zeolite selected from the group consisting of A1PO-42, A1PO-34 and A1PO-5.

Embodiment 33. The system of Embodiment 28 wherein the microporous adsorbent material is A1PO-42.

Embodiment 34. The method of Embodiment 28 wherein the microporous adsorbent material further contains one or more of lithium, magnesium, titanium, zirconium, vanadium, chromium, manganese, cobalt, nickel, palladium, copper, zinc, germanium, arsenic, tin, calcium and boron, in the skeletal structure thereof.

Embodiment 35. The system of Embodiment 28 wherein the microporous adsorbent material has a framework type selected from the group consisting of LTA, CHA and AFI.

Embodiment 36. The system of Embodiment 28 wherein the microporous adsorbent material has a water adsorbent swing capacity greater than about 20 mol/kg at a temperature swing between about 25°C and about 140°C, and a relative pressure P/Ps swing between about 0.0001 and about 1.

Embodiment 37. The system of Embodiment 28 wherein the feed stream is natural gas, flue gas, impure natural gas, or a feed stream containing natural gas.

Embodiment 38. The system of Embodiment 37 wherein the flue gas contains water, N2 and CO2.

Embodiment 39. The system of Embodiment 28 wherein the feed stream comprises hydrocarbons.

Embodiment 40. The system of Embodiment 39 wherein the feed stream further comprises an acid gas.

Embodiment 41. The system of Embodiment 28 wherein the water content of the feed stream is at least about 100 ppm mole fraction, and the water content of the product stream is less than about 50 ppm mole fraction.

Embodiment 42. The system of Embodiment 28 wherein the product stream comprises at least 90 wt % of the hydrocarbons present in the feed stream.

Embodiment 43. The system of Embodiment 28 wherein the microporous adsorbent material has a water adsorptive capacity of at least about 10 mol/kg.

Embodiment 44. The system of Embodiment 28 wherein the adsorption step is operated at a temperature from about 10 °C to about 40 °C. Embodiment 45. The system of Embodiment 28 wherein the desorption step is operated at a temperature from about 60°C to about 120°C.

Embodiment 46. The system of Embodiment 28 wherein the adsorption step is operated at a pressure from about 1 bar to about 100 bar.

Embodiment 47. The system of Embodiment 28 wherein the desorption step is operated at a pressure from about 0.1 bar to about 100 bar.

Embodiment 48. The system of Embodiment 28 wherein the adsorption step is operated at a relative pressure P/Ps from about 0.0001 to about 1.

Embodiment 49. The system of Embodiment 28 wherein the desorption step is operated at a relative pressure P/Ps from about 0.0001 to about 1.

Embodiment 50. The system of Embodiment 28 wherein the zeolite has an LTA, CHA or AFI structure as represented by a code of International Zeolite Association (IZA).

Embodiment 51. The system of Embodiment 28 wherein the product stream is exposed to the microporous adsorbent material at effective conditions for performing equilibrium separation of the first component from the second component.

Embodiment 52. A swing adsorption system for removing water from a feed stream, wherein the system is configured to operate in a subsea environment, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

Embodiment 53. The system of Embodiment 52 wherein the desorption step is executed through use of a heating loop in which a regeneration gas is heated and used to desorb water from the microporous adsorbent material, and wherein an effluent gas is cooled to condensate at least a portion of the water from the effluent gas, and the effluent gas is then reheated to the desorption temperature and reused as a regeneration gas.

Embodiment 54. The system of Embodiment 52 wherein the desorption step is operated at a temperature of about 80°C to about 120°C.

Embodiment 55. The system of Embodiment 52 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the effluent gas in the desorption step.

Embodiment 56. The system of Embodiment 52 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the feed stream prior to the adsorption step.

The following non-limiting examples are provided to illustrate the disclosure.

A1PO-42 shows high swing capacities (working capacities) greater than 20 mol/kg using small temperature swings between 25 to 140°C, and water partial pressure swings between 0.001 to 0.05bar. A general pressure-temperature swing adsorption process was evaluated to indicate the separation performance based on relative temperature and pressure chosen. The relationship between optimal regeneration temperature T_r and regeneration water pressure P_r in a PTSA dehydration process was derived to design a dehydration process using an A1PO-42 adsorbent. and Characterization of A1PO-42 Zeolite

The synthesis of neutral A1PO-42 (LT A) was based on the original recipe reported previously (Micropor. Mesopor. Mater. 2010, 129, 90-99), using Kryptofix-2,2,2 (K222) as the template and HF. The aluminum source was aluminum triisopropoxide (98 %), and the phosphorus source was phosphoric acid (85 %). The crystallization was carried out at 175°C in static conditions for 4 hours. The gel composition was:

AI2O3 : P2O5 : 0.5 K222 : 0.5 HF : 80 H₂O The XRD pattern of the solid recovered after the crystallization confirms that it corresponds to the LTA structure with high crystallinity, as can be seen in Fig. 1. The SEM images are displayed in Fig. 2 and show the presence of cubic shaped crystals characteristic of LTA structure with sizes of around 10-20pm.

The thermal stability of A1PO-42 was studied by in situ calcination in the XRD instrument. The material was calcined at 600°C in a dry air atmosphere, and the XRD pattern obtained corresponded to a highly crystalline LTA structure (Fig. 3a, red pattern). The temperature was then decreased, and cal

In fact, it was possible to determine two different cell parameters, 11.905 A and 11.710 A, corresponding to the dehydrated and hydrated phases, respectively. The calcined hydrated A1PO-42 material was then submitted to dehydration by flowing dry air, and the XRD peaks intensities were gradually restored upon dehydration, recovering the high intense XRD pattern similar to the recently calcined material after flowing dry air for 2 hours at 200°C (Fig. 3b). These results confirm that the structure is stable after calcination and suggests high structural flexibility.

In order to confirm the stability of A1PO-42 after calcination, the corresponding N2 adsorption isotherm at 77K was measured, and the textural properties were determined. The isotherm is shown in Fig. 4 and the BET surface area resulted to be 623m²/g, whereas the /-plot micropore volume was 0.292cm²/g. These results confirm the highly crystalline character of the A1PO-42 material despite the appearance of the XRD pattern of the calcined material. It has to be noticed that the calcined material was stored at ambient conditions prior to the adsorption measurement, and it was submitted to the standard outgassing protocol at 400°C under vacuum before the N2 adsorption. With the aim of checking the stability with time of the calcined A1PO- 42, the N2 adsorption isotherm was measured at different times of storing the sample at ambient conditions. The results showed that it is stable at least for five weeks after the calcination date, as the N2 adsorption isotherm obtained was similar to the original one measured along the first week of storing under ambient conditions.

A1PO-42 Water Isotherm Measurement

The isotherm measurements were conducted using Hiden Isochema Intelligent Gravimetric Analyzer (IGA-002), a gravimetric unit using a microbalance with a resolution of 0.1 pg. The system is capable of measuring vapor adsorption from 0 to 0.99 relative saturated pressure (P/Po) with P_o at temperatures of up to 50°C with built-in anti-condensation protection. The systematic evaluation of water capacities with temperature is shown in Fig. 5, where a pronounced S shape water isotherms are presented. This unique feature of water isotherms can allow large adsorptive capacity with low desorption temperature. The water isotherm measured at 60°C clearly demonstrate negligible water capacity less than 1 mol/kg even at 0.035 bar of water pressure, while water isotherm measured at 25 °C reaches 20 mol/kg at 0.003 bar.

As the A1PO-42 shows very high water uptake at room temperature with water partial pressure over 5mbar, it can remove moisture in the gas stream for gas dehydration application. The comparison of water isotherm at 25 °C with conventional zeolite 4A and silica gel can be found in Fig. 6, where A1PO-42 shows 20mol/kg H2O capacity at 5mbar, while silica gel has 5mol/kg and zeolite 4A has 14mol/kg in comparison. A smaller bed can be utilized with an adsorbent that has higher water capacity. Potential dual adsorbents bed is also advantageous with A1PO-42 to remove bulk water and zeolite 4A for polishing to deep dehydration specification.

A1PO-42 shows higher water capacities than other A1PO materials having S shape water isotherms. Fig. 15 shows the comparison of water vapor uptakes on ALPO-42 with commercial AQSOA-Z01, Z02 and AQSOA-Z05 at 25°C. AQSOA-Z01 and AQSOA-Z05 are A1PO materials with AFI structure, while AQSOA-Z02 is A1PO material with CHA structure. A1PO-42 (LTA structure) behaves hydrophobic from Henry region up to the relative pressure (P/Ps) of 0.1, when P/Ps > 0.1, the amount of water vapor increases sharply. The trend is very similar to the commercial AQSOA Z01, but the water capacity of ALPO-42 is much higher, about 0.35g/g at saturation compared to 0.18 g/g for both AQSOA Z01 and Z05 (A1PO-5). The relative water capacity is also about 20% higher compared to AQSOA Z02 (A1PO-34).

Fig. 15 shows a comparison of water vapor uptakes on ALPO-42 with commercial AQSOA-Z01(AlPO-5), Z02 and AQSOA-Z05 (A1PO-5) at 25°C. Data of AQSOA Z01, Z02, and Z05 from Sun and Chakraborty [Sun, B.; Chakraborty, A. Thermodynamic Formalism of Water Uptakes on Solid Porous Adsorbents for Adsorption Cooling Applications. Appl. Phys. Lett. 2014, 104, p 201901.

Adsorptive Dehydration Process using A1PO-42

The application of A1PO-42 to enact a dehydration of a gaseous stream at a feed temperature Tf, pressure Pf and water mole fraction jy to a final water product mole fraction y_p is described. All process embodiments will be composed of an adsorption step as well as a regeneration step. During the adsorption step, the wet feed gas is fed into the adsorption bed until the bed becomes nearly saturated with water. At which point, the adsorption bed will be regenerated by decreasing pressure, and / or increasing temperature, and / or stripping via a purge gas. Once an adsorption bed has been regenerated, it is cooled and then placed back on adsorption at the conditions Tf, pressure Pf and water mole fraction jy. The process will contain several such beds which cycle in unision to satisfy any required steady flow constraints.

A specific embodiment of a general pressure and temperature swing (PTSA) process is described. To begin, the adsorption data from Fig. 5 is correlated as a function of activity a, which is defined as the ratio partial pressure of water P_w to the water vapor pressure P_w,_sat

. P_w a^{= r} Pw -,sat

The activity at the location of the step d_step is given by

where a_o is the step activity at temperature T_o, and H is a constant related to both the enthalpy of adsorption and the enthalpy of vaporization.

The adsorption isotherm q is split into contributions below qi and above qn the step.

For a < d_step the isotherm is q_L = Aa^N where A and N are adjustable constants.

Above the step d > d_step we use a dual mode form

wherein B, C and D are adjustable constants.

The upper and lower portions are blended with the function w q = (1 - w)q_L + wq_v

The blending function is given by

where y and are adjustable constants.

The isotherm constants are adjusted to reproduce the temperature dependent adsorption data of water on A1PO-42 which is taken in Fig. 5. The table of constants is given in Table 1, and a graph illustrating the model agreement is given in Fig. 7.

Table 1

Isotherm Parameters for Water on A1PO-42

Using this isotherm, a PTSA process is described . Fig. 8 gives a pictorial diagram of the cycle, and the steps of the process are listed as follows: wet gas is fed into the adsorption bed at conditions 7/, Pf, y/ until the adsorption bed is saturated; the pressure in the saturated adsorption bed is then decreased to P_r and the bed is heated to T_r resulting in the desorption of the water; the adsorption bed is repressurized to high pressure; the adsorption bed is cooled by flowing the cool effluent from the adsorption step of another adsorption bed in the process; heat transfer in this way will be highly timing dependent; it may be necessary to cool the adsorption effluent using a heat exchanger with an external cooling fluid (e.g., water); and the bed returns to the adsorption step, completing the cycle.

Using the model isotherm, this process can be evaluated. Assuming a low pressure drop across the bed, from the type V isotherm form, the product mole fraction y_p is approximately

Further, if it is assumed that the feed is water saturated, then w.sat yr = ~

Combining the two equations above the separation factor K is obtained

From the isotherm model for _step the separation factor as a function 7/is illustrated graphically in Fig. 9. As is clearly demonstrated in Fig. 9, separation performance increases as Tf is decreased. Hence, better dehydration can be expected from cool streams. This phenomena is a result of the step activity a_step increasing as temperature is increased. In the regeneration step, the pressure is decreased to P_r and heat is added to the system to desorb the adsorbed water. The desorption pressure is now related to the desorption temperature T_r in the following analysis. Given the high water capacity of the A1PO-42, the gas exiting the adsorption bed on the regeneration step will be overwhelmingly dominated by water, such that the exit composition of water can approximated to be y_r « 1. On regeneration, the optimal conditions will be such that the regeneration operates at the activity which coincides with the step of the isotherm = d_step . It is at this location, that a minimal amount of heat will need to be added at a fixed P_r. From this constraint, for a given regeneration pressure P_r, the regeneration temperature T_r is calculated in Fig. 10.

At regeneration pressures higher than atmospheric, T_r is only weakly pressure dependent. However, at vacuum pressures where P_r < 0.5 bar, T_r becomes a strong function of P_r and rapidly decreases with decreasing pressure.

Stability Testing and Regeneration with Low Temperature

A stability screening test was carried out using a commercial thermal gravimetric analysis (TGA) instrument. A schematic of the testing apparatus and arrangement is shown in Fig. 11. A feed stream of CO2 205, N2 210, water (H2O) 215 (via an entrained N2 stream 220), was controlled at a set flow rate via mass flow controllers MFC1, MCF2 and MCF3 as shown. A sample of the zeolite to be tested was placed in a sample holder 225 within the oven 230 wherein the temperature could be controlled. The feed stream mixture was passed through the oven 230 containing the sample holder 225 and then vented 235. Depending on whether the sample was being simulated in an adsorption or desorption step, the sample weight changed accordingly and was continuously monitored through the microbalance 235. The oven temperature was been controlled in the way to mimic temperature swing cycles, i.e., using a high temperature for desorption/regeneration and low temperature for adsorption. The cycles were performed with adsorption at 30°C with wet N2 P/Ps ~ 0.6 and desorption at 80°C with dry N2. The sample was continuously exposed to various temperature cycles, and the performance of the sample was been evaluated by one point H2O uptake at 30°C, which has been carried out before and after cycle treatments with in-situ regeneration at 400°C for 30 minutes. By comparing the H2O uptake capacity measured at beginning and the final capacity after nth temperature swing cycles, the stability of adsorbent can be evaluated. The first 50 cycles are shown in Figs. 12 and 13 - A1PO- 42 showing water loadings swing between ~1 to 15 mol/kg between 30 to 80°C TSA cycles. No obvious degradation of material was found which indicates reasonable stable structures. Low temperature regeneration can also be demonstrated with this experiment. Fig. 12 shows A1PO-42 performance for the first 50 temperature swing cycles between 30 to 80°C for temperature cycles and corresponding weight change.

Fig. 13 shows A1PO-42 performance for the first 50 temperature swing cycles between 30 to 80°C for temperature cycles and corresponding water loadings.

Further evaluation on material stability was carried out up to 850 cycles. Gradual degradation of materials were found over almost one thousand cycles, however, the water capacity was maintained at ~28 wt% compared to initial 34 wt% from fresh A1PO-42. The final water capacity after 850 cycles is higher than fresh dehydration adsorbent such as zeolite 3A, 4A, and 5 A. This is illustrated in Fig. 17.

Adjusting Crystal Sizes by Controlling Synthesis Temperature and Water Content

Synthesis of A1PO-42 was optimized to achieve small crystals while maintaining high crystallinity. Water content in the synthesis gel is a parameter that allows controlling the crystal size of A1PO-42 material. Small crystals allow fast kinetics, and more usable capacities for similar operating conditions. Fig. 14 shows a comparison of A1PO-42 samples with different synthesis conditions to control crystals sizes over 0.05 - 20 pm. In particular, samples 1, 4 and 5’ in Fig. 14 exhibit large (10-20 pm), intermediate (0.2-1 pm) and small (< 0.2 pm) crystals with micropore volume values close to 0.3 cm3/g.

To increase kinetics, the synthesis method was optimized to tune the crystals sizes. Thus, several synthesis experiments were done (summarized in Fig. 14) for gels of the following molar composition:

AI2O3 : P2O5 : 0.5 K222 : 0.5 HF : x H₂O

Fig. 14 shows the results obtained for the synthesis of A1PO-42 materials prepared at different conditions (x^O/AhCh ratio and temperatures of crystallization). A1PO-42 material crystallized in concentrated synthesis gels (i.e. low H2O/AI ratio) shows smaller averaged crystal size than samples synthesized in more diluted crystallization media (i.e., high H2O/AI ratio). Crystallization temperature of A1PO-42 also has some influence, but less pronounced that water content.

As described in U.S. Publication No. 2021/0113952, zeolite LTA used in swing adsorption processes has poor thermal and/or hydrothermal stability, especially in wet CO2 feed stream environments. Also, as shown in U.S. Publication No. 2021/0113952, zeolite RHO does not exhibit S-shaped water adsorption isotherm, a high working capacity of at least about 5 mol/kg, and a low regeneration temperature from about 50°C to about 140°C. As described in U.S. Patent No. 7,422,993, A1PO materials not having iron and/or gallium in the skeletal structure thereof, exhibited undesired water adsorption and suffered structural change from adsorption/desorption cycles.

Sub-Sea

Heated

Dehydration of natural gas is required before it is transported via pipeline. Sub-sea applications are challenging due to the remote, even underwater, nature of the process. In accordance with this disclosure, a process is provided which allows for the low temperature regeneration of a microporous adsorbent material (e.g., A1PO-42) for sub-sea applications. The process is illustrated in Fig. 16.

Fig. 16 is a schematic of a sub-sea dehydration process. The process involves three adsorption beds which operate in unison. At all times one bed is on adsorption, meaning wet natural gas 1 is flowing through the bed and the water being adsorbed. Bed 1 in Fig. 16 is on adsorption. The elapsed time of the adsorption step is chosen such that the full bed is nearly saturated with water. The dehydrated gas 2 exits Bed 1 to a pipeline.

At all times another bed is on regeneration, which is Bed 3 in Fig. 16. In the regeneration step, water is desorbed by through use of a heating loop in which natural gas is heated and used to desorb water. The effluent from this step is water saturated. This gas 3 is then compressed to make up for any pressure loses and then cooled to a temperature Tc resulting in the condensation of water. The resulting gas 4 is then reheated to the elevated temperature Tp and reused as regeneration gas 5. The regeneration gas flow is less than 5% of feed gas flow. The relative small flow rate of the regeneration loop gas enables a smaller equipment footprint and duty in the regeneration loop.

The third bed which is neither on adsorption or regeneration. Bed 2 in Fig. 16 is in a transition step preparing to switch to adsorption or regeneration. An example cycle schedule is given in the table below. The table shows an example cycle schedule, where the step durations are given in seconds.

Step Duration (s)

Transition 1 1000

Regeneration 2000

Transition 2 1000

Adsorption 2000

The advantage of utilizing a microporous adsorbent material of this disclosure (e.g.,

A1PO-42) over conventional adsorbents is the comparatively low regeneration temperature. Process simulations were performed for the process illustrated in Fig. 16 with timings given in the above table. The process temperatures, pressures and mole fractions are listed in the table below. Using a low regeneration temperature of 90°C, the ALPO-42 is successfully regenerated. The table below shows example process conditions and performance for subsea dehydration with ALPO-42, with the stream number corresponding to the stream number in Fig. 16.

Stream T (°C) P(Bar) Mole fraction water

1 12.7 100 230 ppm

2 12.7 99 26.2 ppm

3 85 99 2991 ppm

4 12.7 100 230 ppm

5 90 100 230 ppm

The cycle successfully decreases the water content of the feed natural gas from 230 ppm to 26.2 ppm, successfully meeting the typical pipeline specification (water content of 4 Ib/MMscf or ~84 ppm) and subsea pipeline specification (water content of 1.5 Ib/MMscf or ~32 PPm).

A subsea environment provides additional advantages of the adsorption configuration of Fig. 16 over TEG, including low ambient temperature to condense more water out in the regeneration loop, and lower water specification requirement (1.5 Ib/MMscf for subsea pipeline vs. 4-7 Ib/MMscf for non-subsea pipeline) that is difficult to achieve with TEG even with enhanced regeneration schemes (e.g., excess stripping gas, vacuum stripping, and the like).

A related application, U.S. Patent Application Serial No. 63/142,741, filed January 28, 2021, discloses subsea dehydration of natural gas using a solid desiccant, the disclosure of which is incorporated herein by reference in its entirety.

PCT and EP Clauses:

1. A method for removing water from a feed stream, the method comprising performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle; wherein the microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

2. The method of clause 1 wherein the microporous adsorbent material is a microporous aluminophosphate (A1PO) material, a microporous silicoaluminophosphate (SAPO) material, a microporous aluminophosphate-based material, a microporous germanoaluminophosphate material, a microporous aluminophosphate (A1PO) zeolite, a microporous silicoaluminophosphate (SAPO) zeolite, a microporous aluminophosphate-based zeolite, a microporous germanoaluminophosphate zeolite, or combinations thereof.

3. The method of clauses 1 and 2 wherein the microporous adsorbent material is a microporous aluminophosphate zeolite selected from the group consisting of A1PO-42, A1PO- 34 and A1PO-5.

4. The method of clauses 1-3 wherein the adsorbent material has a water adsorbent swing capacity greater than about 20 mol/kg at a temperature swing between about 25 °C and about 140°C, and a relative pressure P/Ps swing between about 0.0001 and about 1.

5. The method of clauses 1-4 wherein the feed stream is natural gas, flue gas, impure natural gas, or a feed stream containing natural gas.

6. The method of clauses 1-5 wherein the adsorption step is operated at a temperature from about 10°C to about 40°C, and the desorption step is operated at a temperature from about 60°C to about 120°C; and wherein the adsorption step is operated at a pressure from about 1 bar to about 100 bar, and the desorption step is operated at a pressure from about 0.1 bar to about 100 bar.

7. The method of clauses 1-6 wherein the adsorption step is operated at a relative pressure P/Ps from about 0.0001 and about 1.

8. The method of clauses 1-7 wherein, after 250 cycles of adsorption/desorption, water capacity of the adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the adsorbent material.

9. A swing adsorption system for removing water from a feed stream, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

10. A method for removing water from a feed stream, wherein the method is conducted in a subsea environment, the method comprising performing a swing adsorption process by: a) performing an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream, wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; b) interrupting the flow of the feed stream; c) performing a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and d) repeating the steps a) to c) for at least one additional cycle; wherein the microporous adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

11. The method of clause 10 wherein the desorption step is executed through use of a heating loop in which a regeneration gas is heated and used to desorb water from the microporous adsorbent material, and wherein an effluent gas is cooled to condensate at least a portion of the water from the effluent gas, and the effluent gas is then reheated to the desorption temperature and reused as a regeneration gas.

12. The method of clauses 10 and 11 wherein the desorption step is operated at a temperature of about 80 °C to about 120 °C.

13. The method of clauses 10-12 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the effluent gas in the desorption step.

14. The method of clauses 10-13 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the feed stream prior to the adsorption step.

15. A swing adsorption system for removing water from a feed stream, wherein the system is configured to operate in a subsea environment, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least

(i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.

The present disclosure is well adapted to attain the ends and advantages mentioned as well as those that are inherent therein. The particular embodiments disclosed above are illustrative only, as the present disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular illustrative embodiments disclosed above may be altered, combined, or modified and all such variations are considered within the scope and spirit of the present disclosure. The disclosure illustratively disclosed herein suitably may be practiced in the absence of any element that is not specifically disclosed herein and/or any optional element disclosed herein.

While compositions and methods are described in terms of “comprising,” “containing,” or “including” various components or steps, the compositions and methods can also “consist essentially of’ or “consist of’ the various components and steps. All numbers and ranges disclosed above may vary by some amount. Whenever a numerical range with a lower limit and an upper limit is disclosed, any number and any included range falling within the range is specifically disclosed. In particular, every range of values (of the form, “from about a to about b,” or, equivalently, “from approximately a to b,” or, equivalently, “from approximately a-b”) disclosed herein is to be understood to set forth every number and range encompassed within the broader range of values. Also, the terms in the claims have their plain, ordinary meaning unless otherwise explicitly and clearly defined by the patentee. Moreover, the indefinite articles “a” or “an,” as used in the claims, are defined herein to mean one or more than one of the element that it introduces.

All priority documents are herein fully incorporated by reference for all jurisdictions in which such incorporation is permitted. Further, all documents cited herein, including testing procedures, are herein fully incorporated by reference for all jurisdictions in which such incorporation is permitted. All priority documents are herein fully incorporated by reference for all jurisdictions in which such incorporation is permitted. Further, all documents cited herein, including testing procedures, are herein fully incorporated by reference for all jurisdictions in which such incorporation is permitted.

Claims

- 45 - CLAIMS What is claimed is

2. The method of claim 1 wherein the microporous adsorbent material is a microporous aluminophosphate (A1PO) material, a microporous silicoaluminophosphate (SAPO) material, a microporous aluminophosphate-based material, a microporous germanoaluminophosphate material, a microporous aluminophosphate (A1PO) zeolite, a microporous silicoaluminophosphate (SAPO) zeolite, a microporous aluminophosphate-based zeolite, a microporous germanoaluminophosphate zeolite, or combinations thereof.

3. The method of any of claims 1 to 2 wherein the microporous adsorbent material is a microporous aluminophosphate zeolite selected from the group consisting of A1PO- 42, A1PO-34 and A1PO-5.

4. The method of any of claims 1 to 3 wherein the adsorbent material has a water adsorbent swing capacity greater than about 20 mol/kg at a temperature swing between about 25 °C and about 140°C, and a relative pressure P/Ps swing between about 0.0001 and about 1.

5. The method of any of claims 1 to 4 wherein the feed stream is natural gas, flue gas, impure natural gas, or a feed stream containing natural gas. - 46 -

6. The method of any of claims 1-5 wherein the adsorption step is operated at a temperature from about 10°C to about 40°C, and the desorption step is operated at a temperature from about 60°C to about 120°C; and wherein the adsorption step is operated at a pressure from about 1 bar to about 100 bar, and the desorption step is operated at a pressure from about 0.1 bar to about 100 bar.

7. The method of any of claims 1-6 wherein the adsorption step is operated at a relative pressure P/Ps from about 0.0001 and about 1.

8. The method of any of claims 1-7 wherein, after 250 cycles of adsorption/desorption, water capacity of the adsorbent material drops by less than about 10 percent, as compared to the initial water capacity of the adsorbent material.

- 47 -

11. The method of claim 10 wherein the desorption step is executed through use of a heating loop in which a regeneration gas is heated and used to desorb water from the microporous adsorbent material, and wherein an effluent gas is cooled to condensate at least a portion of the water from the effluent gas, and the effluent gas is then reheated to the desorption temperature and reused as a regeneration gas.

12. The method of any of claims 10 to 11 wherein the desorption step is operated at a temperature of about 80°C to about 120°C.

13. The method of any of claims 10 to 12 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the effluent gas in the desorption step.

14. The method of any of claims 10 to 13 wherein a low ambient temperature experienced within the subsea environment is utilized to cool the feed stream prior to the adsorption step.

15. A swing adsorption system for removing water from a feed stream, wherein the system is configured to operate in a subsea environment, the system comprising: a) at least one adsorbent contactor containing at least one adsorbent bed; b) a fluid stream inlet fluidly connected to the at least one adsorbent contactor; and c) a product stream outlet fluidly connected to the at least one adsorbent contactor; wherein the adsorbent bed comprises a microporous adsorbent material containing at least (i) aluminum and (ii) phosphorus, in a skeletal structure thereof; wherein the swing adsorption system is configured to perform steps comprising: i) perform an adsorption step, wherein the adsorption step comprises passing a feed stream comprising water through an adsorbent bed unit comprising at least one adsorbent bed wherein water is selectively separated from the feed stream to form a product stream which has a lower molar fraction of water than the feed stream; ii) interrupt the flow of the feed stream; iii) perform a desorption step, wherein the desorption step comprises removing at least a portion of the water from the adsorbent material; and iv) repeat the steps i) to iii) for at least one additional cycle; wherein the adsorbent material exhibits a S-shaped water adsorption isotherm, a working capacity of at least about 5 mol/kg, and a regeneration temperature from about 50°C to about 140°C.