Laminate carbon molecular sieve membranes, methods of manufacturing, and use thereof

Abstract

A laminate carbon molecular sieve (CMS) membrane may comprise a microcapillary laminate comprising: two or more microcapillary films, each microcapillary film comprising a first lengthwise face, a second lengthwise face, a first widthwise face, and a second widthwise face; one or more widthwise spacers; and two or more lengthwise spacers, wherein: the one or more widthwise spacers and the two or more lengthwise spacers are interposed between each of the two or more microcapillary films, at least one widthwise spacer is positioned proximal to the first widthwise face of the two or more microcapillary films; at least one lengthwise spacer is positioned proximal to the first lengthwise face of the two or more microcapillary films; at least one lengthwise spacer is positioned proximal to the second lengthwise face of the two or more microcapillary films, and the two or more microcapillary films comprise a polyvinylidene chloride (PVDC) copolymer.

Description

LAMINATE CARBON MOLECULAR SIEVE MEMBRANES, METHODS OF MANUFACTURING, AND USE THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 661,308 filed June 18, 2024, the contents of which are incorporated in their entirety herein.FIELD

[0002] The present disclosure relates to the field of gas separation using a carbon molecular sieve membranes. More particularly, it relates to methods of producing carbon molecular sieve membranes, particularly laminate membranes, for the separation of gases, as well as methods for the separation of gases from a gaseous mixture by passing the gaseous mixture through the laminate membranes, as detailed herein.BACKGROUND

[0003] In the chemical industry, decarbonization technologies are continually being developed due to carbon dioxide (CO2) emissions being a source of global climate change. One potential decarbonization strategy is the development of hydrogen fuel gas from fuel gases such as methane. However, in this process carbon dioxide is still a by-product, resulting in the need for carbon capture and sequestration strategies from mixed hydrogen-carbon dioxide streams. Common separation methods may include amine sweetening. However, amine sweetening has significant downsides in that thermal energy derived from hydrocarbons is often required to drive the process, on top of the fact that amine itself is toxic and corrosive.SUMMARY

[0004] Accordingly, methods are desired which can separate carbon dioxide from hydrogen and other gases while limiting reliance on amine or hydrocarbon-sourced thermal energy. Carbon molecular sieves (CMS) membranes are one such means that have traditionally been used to separate gas mixtures. CMS membranes may be prepared from a variety of resins in hollow fiber or film orientations that may have a plurality of micropores and / or microcapillaries. These fibers or films may be pyrolyzed at various temperatures and conditions. The pyrolysis reduces the resinsin the fibers or films to carbon, but maintains at least some porosity in the pyrolyzed product, often in the form of micropores.

[0005] The fibers or films thus formed may then be bundled or stacked as appropriate and used in conventional gas separations equipment employing adsorption of particular gases. For example, gas mixtures may be flowed across the fibers and films, i.e., through the CMS membrane, and thus separated into a permeate stream passing into the micropores and microcapillary channels of the fiber or film and a retentate stream not passing through the micropores.

[0006] CMS membranes may also be sub-categorized based on selectivity. Particularly, CMS membranes may be classified as being normally selective or reverse-selective. Reverse-selective membranes may be desired to effect gas separations of larger molecules from smaller molecules. Selectivity may depend on the micropore size and adsorbate-adsorbent surface interactions.

[0007] However, one issue in carbon dioxide separation processes with reverse selective membranes is the size of the secondary gas molecule. Particularly, some molecules, such as hydrogen, are of such a small size that they can often pass through the membrane even if the membrane is designed be reverse-selective. Accordingly, methods of producing reverse-selective CMS membranes are desired that provide high reverse-selectivity to effect gas separation, particularly separations involving carbon dioxide and hydrogen or other relatively small gas molecules.

[0008] Further, selectivity alone may not be an adequate measure of a CMS membranes’ suitability for carbon dioxide separation processes. Particularly, a second issue in carbon dioxide separation is permeance, which is an expression of the permeability of the membrane divided by the effective thickness of the membrane. As permeance decreases, the surface area of the individual fibers or films needed to separate a given flowrate of gas mixture proportionally increases. As the CMS membranes incorporating these fibers and / or films need to be housed in sealed units to contain the gas, fabrication and maintenance costs can escalate, damaging economic viability of the process. Further, if the CMS membranes and / or individual fibers and films are too closely stacked to counteract the escalation in size, increased frictional losses (through pressure drop and maldistribution of gases) through the CMS membrane may result in net losses to efficiency.

[0009] Accordingly, methods of producing reverse-selective CMS membranes are desired that have high reverse selectivity and permeance, while limiting frictional loss and maldistribution through the CMS membrane, such as laminate CMS membrane. Methods of manufacture arediscussed herein that produce laminate CMS membranes with the aforementioned benefits. Particularly, formed laminate CMS membranes according to one or more embodiments herein are rendered reverse selective by pyrolysis and oxidation of a polyvinylidene chloride (PVDC) copolymer film, which may be arranged into a microcapillary laminate of the films, at specific temperature and time thresholds. Further, CMS membranes according to one or more embodiments herein are rendered reverse selective towards carbon dioxide-hydrogen separations in particular by an additional annealing step between the pyrolysis and oxidation steps.

[0010] Thus, stable carbon structures with consistent pore sizing may be achieved to allow substantial carbon dioxide permeance while maintaining high carbon dioxide-hydrogen reverse selectivity. This increased carbon dioxide permeance may then be leveraged by reducing the spacing of individual microcapillary film layers of laminate CMS membranes, reducing the size of modules incorporating the same and increasing economic viability to the process.

[0011] According to one embodiment, a laminate carbon molecular sieve (CMS) membrane may comprise a microcapillary laminate comprising: two or more microcapillary films, each microcapillary film comprising a first lengthwise face, a second lengthwise face, a first widthwise face, and a second widthwise face; one or more widthwise spacers; and two or more lengthwise spacers.

[0012] Further, according to the previous embodiment, the one or more widthwise spacers and the two or more lengthwise spacers may be interposed between each of the two or more microcapillary films. The at least one widthwise spacer may be positioned proximal to the first widthwise face of the two or more microcapillary films. At least one lengthwise spacer may be positioned proximal to the first lengthwise face of the two or more microcapillary films. At least one lengthwise spacer may positioned proximal to the second lengthwise face of the two or more microcapillary films, and the two or more microcapillary films may comprise a polyvinylidene chloride (PVDC) copolymer.

[0013] According to another embodiment, a process for separating a gas mixture comprising a first gas and a second gas may comprise introducing the gas mixture to a first module comprising a first laminate CMS membrane, the first laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming a first permeate stream rich in the first gas, and a first retentate stream rich in the second gas, wherein the second gas has a lesser representative molecular diameter than the first gas.

[0014] According to the previous embodiment, the process may further comprise introducing the first retentate stream to a second module comprising a second laminate CMS membrane, the second laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming a second permeate stream rich in the first gas and a second retentate stream rich in the second gas, wherein the second retentate stream has a greater percentage of the second gas than the first retentate stream.

[0015] According to the previous embodiment, the process may further comprise introducing the first permeate stream to a third module comprising a third laminate CMS membrane, the third laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming a third retentate stream, and a first gas product stream rich in the first gas; and recycling the second permeate stream and the third retentate stream to the first module.

[0016] Additional features and advantages of the embodiments described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described, including the detailed description and the claims which are provided infra.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings in which:

[0018] Figure (FIG.) 1A is an illustration of a microcapillary laminate or resulting carbon molecular sieve (CMS) membrane from the microcapillary laminate, according to one or more embodiments herein;

[0019] FIG. IB illustrates a variation of the microcapillary laminate or resulting CMS membrane of FIG. 1A, according to one or more embodiments herein;

[0020] FIG. 2A is a cross-sectional view of a gas separation module incorporating one or more laminate CMS membranes, according to one or more embodiments herein;

[0021] FIG. 2B illustrates a variation of the gas separation module cross-section of FIG. 2A, according to one or more embodiments herein;

[0022] FIG. 2C illustrates a vessel containing a gas separation module, according to one or more embodiments herein;

[0023] FIG. 2D illustrates a variation of the vessel of FIG. 2C containing one or more horizontal dividers, according to one or more embodiments herein;

[0024] FIG. 2E illustrates another variation of the vessels of FIG. 2D, according to one or more embodiments herein;

[0025] FIG. 2F illustrates a zoomed in view of FIG. 2C, illustrating the inlet to the vessel, according to one or more embodiments herein;

[0026] FIG. 2G illustrates a zoomed in view of FIG. 2D, illustrating the inlet to the vessel, according to one or more embodiments herein;

[0027] FIG. 3A is a schematic illustration for a process for separating gas mixtures utilizing one or more of the CMS membranes, gas separation modules, and / or vessels, according to one or more embodiments herein;

[0028] FIG. 3B is a schematic illustration of a variation of the process illustrated in FIG. 3A additionally incorporating a pressure swing absorption unit, according to one or more embodiments herein; and

[0029] FIG. 3C is a schematic illustration of a variation of the process illustrated in FIG. 3A additionally incorporating an amine sweetening system, according to one or more embodiments herein.

[0030] For the purpose of describing the simplified schematic illustrations and descriptions of the relevant figures, the numerous valves, temperature sensors, electronic controllers and the like that may be employed and well known to those of ordinary skill in the art of certain chemical processing operations are not included. It should be understood that these components are within the spirit and scope of the present embodiments disclosed. However, operational components, such as those described in the present disclosure, may be added to the embodiments described in this disclosure.

[0031] It should further be noted that arrows in the drawings refer to process streams. However, the arrows may equivalently refer to transfer lines, which may serve to transfer process streams between two or more system components. Additionally, arrows that connect to system components define inlets or outlets in each given system component. The arrow direction corresponds generally with the major direction of movement of the materials of the stream contained within the physical transfer line signified by the arrow. Furthermore, arrows, which do not connect two or more system components, signify a product stream, which exits the depicted system, or a system inlet stream, which enters the depicted system. Product streams may be furtherprocessed in accompanying chemical processing systems or may be commercialized as end products. System inlet streams may be streams transferred from accompanying chemical processing systems or may be non-processed feedstock streams. Some arrows may represent recycle streams, which are effluent streams of system components that are recycled back into the system. However, it should be understood that any represented recycle stream, in some embodiments, may be replaced by a system inlet stream of the same material, and that a portion of a recycle stream may exit the system as a product.

[0032] Additionally, arrows in the drawings may schematically depict process steps of transporting a stream from one system component to another system component. For example, an arrow from one system component pointing to another system component may represent “passing” a system component effluent to another system component, which may include the contents of a process stream “exiting” or being “removed” from one system component and “introducing” the contents of that product stream to another system component.

[0033] It should be understood that according to the embodiments presented in the relevant figures, an arrow between two system components may signify that the stream is not processed between the two system components. In other embodiments, the stream signified by the arrow may have substantially the same composition throughout its transport between the two system components. Additionally, it should be understood that in embodiments, an arrow may represent that at least 75 wt.%, at least 90 wt.%, at least 95 wt.%, at least 99 wt.%, at least 99.9 wt.%, or even 100 wt.% of the stream is transported between the system components. As such, in embodiments, less than all of the stream signified by an arrow may be transported between the system components, such as if a slip stream is present.

[0034] It should be understood that two or more process streams are “mixed” or “combined” when two or more lines intersect in the schematic flow diagrams of the relevant figures. Mixing or combining may also include mixing by directly introducing both streams into a like reactor, separation unit, or other system component. For example, it should be understood that when two streams are depicted as being combined directly prior to entering a separation unit or reactor, that in embodiments the streams could equivalently be introduced into the separation unit or reactor and be mixed in the reactor. Alternatively, when two streams are depicted to independently enter a system component, they may in embodiments be mixed together before entering that system component.

[0035] Reference will now be made in greater detail to various embodiments, some embodiments of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts.DETAILED DESCRIPTION

[0036] Embodiments described herein generally relate to carbon molecular sieve (CMS) membranes, and in particular laminate CMS membranes formed from microcapillary laminates of individual microcapillary fdms, as well as methods of manufacturing and processes for utilizing the same.

[0037] The gas permeation properties of a membrane, such as the laminate CMS membranes described in further detail herein, may be determined by gas permeation experiments. Two intrinsic properties have utility in evaluating separation performance of a membrane material: its "permeability," a measure of the membrane's intrinsic productivity; and its "selectivity," a measure of the membrane's separation efficiency. One typically determines "permeability" (Pz) in Barrer( 1 Barrer — 10~10cm2 s cmH) calculated as the flux (nz) divided by the partial pressure difference between the membrane upstream and downstream (Apz). and multiplied by the thickness of the membrane (1), wherein z is the target gas being measured. In the embodiments herein, the thickness of the membrane may be generally expressed as the wall thickness, (OD- ID)* / 2, of the microcapillary film (1): Pt=

[0038] Another term, "permeance," is defined herein as productivity of the CMS membraneand is typically measured in Gas Permeation Units (GPU) ( 1 GPU — 10-6—cm-2 -s cmHg ) > determined by dividing permeability by effective membrane separation layer thickness: =

[0039] Finally, "selectivity" is defined herein as the ratio of one gas's permeability through the membrane or permeance relative to the same property of another gas. It is measured as a unitless. ratio:

[0040] As used herein, the term “proximal” means closer to an element. The term “distal” means further from the element.

[0041] As previously stated, embodiments herein are directed to carbon molecular sieve (CMS) membranes, and in particular laminate CMS membranes formed from microcapillarylaminates. Accordingly, as used herein, all descriptions of the structure of microcapillary laminates may also apply to laminate CMS membranes, as the microcapillary laminates are the precursor to the laminate CMS membranes.

[0042] Now referring to FIG. 1A, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom, as previously explained, is illustrated. As shown in FIG. 1A, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may comprise two or more microcapillary fdms 110, one or more widthwise spacers 120, and two or more lengthwise spacers 130. As illustrated in FIG. 1A, the two or more microcapillary fdms 110 comprise a plurality of microcapillary channels 111 running along the length of each of the microcapillary fdms 110. Although not shown, it is contemplated that each of the two or more microcapillary fdms 110 comprise porous and permeable top and bottom surfaces 112 / 113 that may be fluidly connected to the plurality of microcapidary channels 111.

[0043] In embodiments, the two or more microcapillary fdms 110 may comprise a copolymer, such as, but not limited to, a polyvinylidene chloride (PVDC) copolymer. The copolymer may also comprise at least one of the following comonomers: a vinyl monomer, a vinyl chloride monomer, an acrylate monomer, a methacrylate monomer, a styrenic monomer, acrylonitrile, methacrylonitrile, itaconic acid, and pyrolyzed chlorotrifluoroethylene. In embodiments, the PVDC copolymer may comprise at least 60 wt.%, or alternatively at least 70 wt.%, vinylidene chloride, based on the total weight of the copolymer.

[0044] Still referring to FIG. 1A, and as previously stated the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may comprise the one or more widthwise spacers 120 and the two or more lengthwise spacers 130. The one or more widthwise spacers 120 and / or the two or more lengthwise spacers 130 may comprise a metal, a composite, cloth, an epoxy resin, a copolymer, or combinations thereof. For example, the one or more widthwise spacers 120 and / or the two or more lengthwise spacers 130 may comprise the PVDC copolymer, which may be similar or identical in some or ad aspects to the PVDC copolymer-based microcapidary fdms 110. In other words, the one or more widthwise spacers 120 and / or the two or more lengthwise spacers 130 may themselves be microcapidary fdms 110 having a plurahty of microcapidary channels.

[0045] The one or more widthwise spacers 120 may be parahel with the widthwise face 140, the lengthwise face 150, or both, of the two or more microcapidary fdms 110. In embodiments, and as shown in FIG. 1A, the one or more widthwise spacers 120 may be ahgned with the widthwise face 140, may be ahgned with the lengthwise face 150, or both, although ahgning theone or more widthwise spacers 120 with the widthwise face 140 may not be required. Particularly, the one or more widthwise spacers 120 may be offset from, i.e. proximal to, the widthwise face 140. The one or more widthwise spacers 120 may additionally or alternatively be offset from, i.e. proximal to, the lengthwise face 150 (not shown). As shown in FIG. 1, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may alternatively comprise two or more widthwise spacers 120, such as widthwise spacers 120 aligned with or offset from each of the widthwise faces 140.

[0046] As explained in further detail below, offsetting the one or more widthwise spacers 120 from at least the widthwise face 140 may be of benefit when sealing an interface 115 between the one or more widthwise spacers 120 and the top surface 112 of the microcapillary films 110, the bottom surface 113 of the microcapillary films 110, or both. Particularly, without being limited by theory, when the one or more widthwise spacers 120 are offset from the widthwise face 140 it may reduce the risk of accidentally sealing the plurality of microcapillary channels 111 of the two or more microcapillary films 110 with a subsequently applied adhesive, as explained in further detail herein. However, in at least some embodiments, the plurality of microcapillary channels 111 may be intentionally sealed at one of the widthwise faces 140. Without being limited by theory, sealing the plurality of microcapillary channels 111 at one of the widthwise faces 140 may allow capillary flow to be directed to the opposite face, which may be of some benefit in achieving a ‘dead-flow pattern’ when attempting to isolate the permeate and retentate streams, as explained in further detail herein.

[0047] Alternatively, in the event the one or more widthwise spacers 120 are aligned with one or both of the widthwise faces 140, the concern of sealing the plurality of microcapillary channels 111 with the adhesive may be addressed by removing at least a portion of the microcapillary laminate proximate one or both of the widthwise faces 140 after application of the adhesive, thereby re-exposing the plurality of microcapillary channels 111.

[0048] Further, additionally aligning the one or more widthwise spacers 120 with the lengthwise face 150 may have additional benefits if the one or more widthwise spacers 120 are relatively impermeable in the direction of the plurality of microcapillary channels 111. Particularly, this configuration may allow the lengthwise face 150 to be isolated from the remainder of the microcapillary laminate 100 or the laminate CMS membrane formed therefrom, such as when a sealing element and / or horizontal divider is arranged around the one or morewidthwise spacers 120 and the two or more microcapillary fdms 110, as explained in further detail herein.

[0049] As previously stated, the one or more widthwise spacers 120 may comprise the PVDC copolymer. Although not shown, the one or more widthwise spacers 120 may comprise two or more of the microcapillary fdms 110 stacked vertically. In such an embodiment, it is contemplated that arranging the two or more microcapillary fdms 110 and the one or more widthwise spacers 120 into the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may have the advantage of forming a seal between the microcapillary fdms and the spacers. Particularly, it is contemplated that the PVDC copolymers of the widthwise spacers 120 and the PVDC copolymers of the microcapillary fdms 110 may bond and / or partially fuse together during the placement of the adhesive, or during pretreatment, pyrolysis, and annealing, as explained in further detail hereinbelow.

[0050] Furthermore, the addition of a solvent when using microcapillary fdms 110 as the one or more widthwise spacers 120 may operate to soften the PVDC copolymers making up the two or more microcapillary fdms 110 and the one or more widthwise spacers 120 and promote additional bonding and / or fusing, as explained in further detail hereinbelow. Particularly, the solvent may be added to an interface 115 between the two or more microcapillary fdms 110 and the one or more widthwise spacers 120. Alternatively or additionally, the solvent may be added to an interface between individual microcapillary fdms of the one or more widthwise spacers 120. The solvent may include, but may not be limited to, tetrahydrofuran.

[0051] Alternatively, or additionally, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may further comprise an adhesive, as previously described. The adhesives may include, but may not be limited to polyimide, polyvinylidene chloride, polyvinyl chloride, an acrylic, or combinations thereof. Similar to the solvent, the adhesive may be added to the interfaces between the two or more microcapillary fdms 110 and the one or more widthwise spacers 120, or individual microcapillary fdms making up the one or more widthwise spacers 120, to seal the individual layers of the microcapillary laminate 100 or the laminate CMS membrane formed therefrom.

[0052] Still referring to FIG. 1A, the one or more widthwise spacers 120 may be positioned proximal to (either aligned with or offset from) the widthwise faces 140. As also shown in FIG. 1A, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may further comprise the two or more lengthwise spacers 130. As previously stated, the two or morelengthwise spacers 130 may be similar or identical to the one or more widthwise spacers 120. Moreover, the adhesives or solvents previously described may be similarly applied to the two or more lengthwise spacers 130.

[0053] As also shown in FIG. 1A, the two or more lengthwise spacers 130 may be interposed between the two or more microcapillary fdms 110, as well as interposed between the one or more widthwise spacers 120. Additionally or alternatively, the two or more lengthwise spacers 130 may be aligned with, or offset from, i.e. proximal to, the lengthwise faces 150 of the two or more microcapillary fdms 120, such that the degree of offset impacts the width of the gap 131.

[0054] Still referring to FIG. 1A, in some embodiments, the two or more lengthwise spacers 130 may be offset from the one or more widthwise spacers 120. In such embodiments, the two or more microcapillary fdms 110, the one or more spacers 120, and the two or more lengthwise spacers 130 may collectively define two or more openings 132 into and out of the microcapillary laminate 100 or the laminate CMS membrane formed therefrom proximal the widthwise faces 140.

[0055] In embodiments, the two or more lengthwise spacers 130 may be relatively impermeable. Accordingly, without being limited by theory, a gas feed entering the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may be forced to travel along the face of the two or more microcapillary fdms 110 until exiting at one of the openings 132 and / or entering the micropores of the two or more microcapillary fdms 110 and subsequently traveling along the plurality of microcapillary channels 111 to either of the widthwise faces 140. Without being limited by theory, this may be of considerable benefit in achieving a so-called countercurrent flow pattern where the flow direction of feed and permeate are opposite, as explained in further detail herein.

[0056] As previously stated, the two or more lengthwise spacers 130 may be offset from the one or more widthwise spacers 120. Thus, in such embodiments, the two or more lengthwise spacers 130 may be offset from the widthwise faces 140. However, in at least some embodiments, and now referring to FIG. IB, the two or more lengthwise spacers 130 may alternatively be aligned with a single widthwise face 140 of the microcapillary laminate 100 or the laminate CMS membrane formed therefrom, and offset from the widthwise spacer 120 aligned at the opposite widthwise face 140. Accordingly, as shown in FIG. IB, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may further define one or more openings 132 having upper and lower surfaces defined by adjacent microcapillary films 110. The one or more opening132 may further have side surface defined by the widthwise spacer 120 and the lengthwise spacer 130. Accordingly, as shown in FIG. IB, the configuration of the widthwise spacer 120, the lengthwise spacers 130, and the microcapillary films 110 may together be configured such that a gas mixture may have forced entry at the one or more openings and forced exit at the widthwise face 140 distal the one or more openings, or vice versa entry and exit.

[0057] Referring to FIGS. 1A-1B, the microcapillary laminate 100 or the laminate CMS membrane formed therefrom may further comprise one or more reinforcement panels 160 disposed on the top surface 112 of the microcapillary films 110, the bottom surface 113 of the microcapillary films 110, or both. The one or more reinforcement panels 160 may also be separated from directly contacting the two or more microcapillary films 110 by the one or more widthwise spacers 120 and the two or more lengthwise spacers 130. As previously stated, the two or more microcapillary films 110 of the microcapillary laminate 100 may be relatively rigid post formation into the laminate CMS membrane. However, without being limited by theory, the two or more microcapillary films 110 of the laminate CMS membrane may still be susceptible to shattering when exposed to bending forces. Accordingly, the one or more reinforcement panels 160 may be added to the microcapillary laminate 100 or the laminate CMS membrane formed therefrom to provide bend and / or shatter resistance. Additionally, so as not to significantly reduce the performance of the laminate CMS membrane in later operation, the one or more reinforcement panels 160 may be porous and / or permeable. The one or more reinforcement panels 160 may comprise metal, plastic, carbon fiber, paper, cloth, or combinations thereof.

[0058] As previously discussed, embodiments herein may also be directed to laminate CMS membranes, which may be any of the microcapillary laminates 100 previously discussed post pyrolysis, annealing, and oxidation, as explained in further detail below. As previously discussed, the laminate CMS membranes may have a permeance, expressed as the permeability to flow a gas over the membrane layer thickness. However, the laminate CMS membranes may have different permeances for different sized gases. As previously discussed, the ratio of these different permeances may be expressed as a selectivity for a given gas. For instance, the laminate CMS membrane may selectively separate different gases from each other. As discussed in further detail below, this may allow the laminate CMS membranes to act as a preferential separator of different sized gases. The laminate CMS membranes herein may also be reverse-selective. In other words, they may preferentially reject a smaller gas molecule from the membrane while accepting (and passing through) a larger gas molecule.

[0059] In embodiments, in an at least a carbon dioxide and hydrogen environment, the laminate CMS membranes herein may have a carbon dioxide permeance of at least 1000 GPU or of at least 2000 GPU, such as from 1000 GPU to 1500 GPU, from 1500 GPU to 2000 GPU, from 2000 GPU to 2500 GPU, from 2500 GPU to 3000 GPU, or any combination of the previous ranges or smaller range therein, such as from 1000 GPU to 3000 GPU. The laminate CMS membranes herein may also have a hydrogen permeance of less than or equal 900 to 40 GPU, such as from 40 GPU to 30 GPU, from 30 GPU to 20 GPU, from 20 GPU to 10 GPU, from 10 GPU to 1 GPU, or any combination of the previous ranges or smaller range therein, such as from 1 GPU to 40 GPU.

[0060] The laminate CMS membranes herein may also have a carbon dioxide / hydrogen mixed gas selectivity of greater than 50, such as from 50 to 70, from 70 to 80, from 80 to 100, from 100 to 120, from 120 to 140, from 140 to 160, from 160 to 180, from 180 to 200, or any combination of the previous ranges or smaller range therein, such as from 80 to 200 or 50 to 200 at ambient temperature. Without being limited by theory, the above selectivities may allow the laminate CMS membranes to preferentially separate the heavier carbon dioxide gas molecules from the lighter hydrogen molecules.

[0061] Without being limited by theory, permeance and selectivity may be dependent on temperature and pressure. Accordingly, the aforementioned permeances and selectivities may be understood to occur at ambient temperature (20 °C) and 350 kPa gauge pressure and equimolar feed, and thus may also be understood to change with respect to different temperatures and / or pressure. Particularly, it is contemplated that CO2 permeance may be understood to increase if measured at temperatures above ambient, and decrease at temperatures below ambient. The CO2 / H2 selectivity may be understood to increase at lower temperature, and decrease at higher temperature.

[0062] In embodiments herein, a spacing between each of the two or more microcapillary fdms 110 of the laminate CMS membrane may be less than 1000 microns, such as from 100 microns to 300 microns, from 300 microns to 500 microns, from 500 microns to 700 microns, from 700 microns to 900 microns, from 900 microns to 1000 microns, or any combination of the previous ranges or smaller range therein, such as from 100 microns to 1000 microns or from 200 microns to 300 microns. In other words, the one or more widthwise spacers 120, the two or more lengthwise spacers 130, or both may comprise a thickness of less than 1000 microns, such as from 200 microns to 300 microns, from 300 microns to 500 microns, from 500 microns to 700 microns, from 700 microns to 900 microns, from 900 microns to 1000 microns, or any combination of theprevious ranges or smaller range therein, such as from 200 microns to 1000 microns or from 200 microns to 300 microns.

[0063] In embodiments, the two or more microcapillary films 110 may each have a thickness of from 100 microns to 500 microns, such as from 100 microns to 300 microns, from 300 microns to 400 microns, from 400 microns to 500 microns, or any combination of the previous ranges or smaller range therein. Accordingly, laminate CMS membranes according to embodiments herein may have a film surface area density of from 200 to 4000 square meters (m2) microcapillary film per cubic meter (m3) of laminate CMS membrane, such as from 200 to 400, from 400 to 800, from 800 to 1200, from 1200 to 2000, from 2000 to 3000, or from 3000 to 4000 m2film per m3of laminate CMS membrane, or any combination of the previous ranges or smaller range therein, such as from 400 to 4000 m2film per m3of laminate CMS membrane or from 2000 to 4000 m2film per m3of laminate CMS membrane. Without being limited by theory, this increased film surface area density of the laminate CMS membrane may allow smaller vessels 210 over what was previously required to enable gas separation. Moreover, as the scaling of vessels 210 are often the dominant cost, the laminate CMS membranes herein are of considerable benefit in the field of membrane separation.

[0064] As previously stated, embodiments herein are also directed to methods of manufacturing carbon molecular sieve (CMS) membranes, and particularly laminate CMS membranes, from the two or more microcapillary films 110 or the microcapillary laminate 100. The method may initially comprise forming a copolymer into two or more microcapillary films 110, which may be any of the microcapillary films 110 previously discussed. The method may also comprise pretreating the two or more microcapillary films 110 by heating at a first temperature of from 120 °C to 200 °C with air, an inert gas, under vacuum, or combinations thereof. The method may also comprise pyro lyzing the two or more microcapillary films 110 at a second temperature of from 600 °C to 700 °C with inert gas or under vacuum. The method may also comprise arranging the two or more microcapillary films 110 into a microcapillary laminate 100 comprising one or more widthwise spacers 120 and two or more lengthwise spacers 130 interposed between each of the two or more microcapillary films 110, which may occur before or after the pyrolyzing step. The method may further comprise annealing the two or more microcapillary films 110 at a third temperature of from 900 °C to 1500 °C with inert gas or under vacuum. The method may furthermore comprise oxidizing the two or more microcapillary films 110. The two or more microcapillary films 110 may be oxidized at a fourth temperature of from300 °C to 400 °C, or at a fifth temperature of from 700 °C to 900 °C. The two or more microcapillary films 110 may be oxidized with air, carbon dioxide, or both. Additionally or alternatively, the two or more microcapillary films 110 may be oxidized with a carbon dioxideinert gas mixture.

[0065] As previously stated, methods may initially comprise forming the copolymer into a microcapillary film. The copolymer may include, but may not be limited to, a polyvinylidene chloride (PVDC) copolymer.

[0066] In embodiments, the copolymer may be formed through copolymerization of the copolymer with a comonomer, such as those comonomers previously described. Following the copolymerization, the copolymer may be formed into the two or more microcapillary films 110 by any suitable method known to those known in the art. For example, the microcapillary films 110 may be produced by biaxial stretching using known film processes for copolymers.

[0067] As previously stated, the method may further comprise arranging the two or more microcapillary films 110 into the microcapillary laminate 100, which may be any of the microcapillary laminates 100 previously discussed. However, as previously stated, the arranging step may occur before or after the pyrolyzing step. For example, and in embodiments, the copolymers may be arranged into the microcapillary laminate 100 or the graphitized copolymers may be arranged into the microcapillary laminate 100.

[0068] Without being limited by theory, arranging the two or more microcapillary films 110 into the microcapillary laminate 100 prior to pyro lyzing may have the advantage of the films being less susceptible to shattering when arranging into the microcapillary laminate 100.

[0069] Alternatively, arranging the two or more microcapillary films 110 into the laminate after pyro lyzing may have the advantage of not needing to use as many lengthwise spacers 130 in the microcapillary laminate 100, as the microcapillary films 110 may have a greater degree of stiffness post pyrolysis.

[0070] As previously stated, in at least some embodiments, the method may further comprise pretreating the two or more microcapillary films 110 by heating at a first temperature of from 120 °C to 200 °C with air, inert gas, under vacuum or combinations thereof. In embodiments, the pretreatment of the two or more microcapillary films 110 may be used to stabilize, or “lock,” the copolymer structure prior to pyrolysis / carbonization thereof, such as when the copolymer is the PVDC copolymer.

[0071] The first temperature may also be at any temperature range within 120 °C to 200 °C. For example, the two or more microcapillary films 110 may be heated at the first temperature of from 120 °C to 130 °C, from 130 °C to 150 °C, from 150 °C to 160 °C, from 160 °C to 180 °C, from 180 to 190 °C, from 190 to 200, or any combination of ranges or smaller range therein. In embodiments, heating at any of these temperatures may also crosslink an interior of the two or more microcapillary films 110.

[0072] Pretreating the two or more microcapillary films 110 may further comprise contacting the two or more microcapillary films 110 with air, inert gas, or both. Contacting the two or more microcapillary films 110 with air or inert gas may occur at a rate sufficient to purge the pretreatment gas products, such as methane, hydrogen, carbon monoxide, and carbon dioxide, thereby preventing secondary reactions of the pretreatment gas products on the carbon surface.

[0073] In at least those embodiments wherein the arranging step occurs before the pretreating step, the method may further comprise applying a solvent, an adhesive, or both to one or both of the interfaces 115, such as any of the solvents or adhesive previous described. Without being limited by theory, the application of the solvent and / or adhesive to the microcapillary laminate 100 may increase the degree of sealing between the two or more microcapillary films 110 and the one or more widthwise spacers 120 and / or the two or more lengthwise spacers 130. Additionally, the method may further comprise, prior to pretreating, applying a compressive force to the microcapillary laminate 100. Without being limited by theory, applying a compressive force to the microcapillary laminate 100 may operate to increase the degree of fusing and / or bonding between the layers in addition to or alternatively from (in the case of PVDC copolymer widthwise spacers 120 or lengthwise spacers 130) the solvent and adhesive.

[0074] Alternatively or additionally, prior to pretreating, the method may further comprise inserting the microcapillary laminate 100 into a graphite mold shaped to conform to the microcapillary laminate 100. Without being limited by theory, the use of the graphite mold may reduce the chance of the two or more microcapillary films 110 warping during the pretreating, pyrolyzing, annealing, and oxidation processes, and thus increase the degree of seal between the two or more microcapillary films 110, the one or more widthwise spacers 120, and the two or more lengthwise spacers 130.

[0075] As previously stated, the method may further comprise pyrolyzing the two or more microcapillary films 110 at the second temperature of from 600 °C to 700 °C with inert gas or under vacuum. The second temperature may also be at any narrower temperature range within the600 to 700 °C. For example, the two or more microcapillary films 110 may be pyrolyzed at the second temperature of from 600 °C to 625 °C, from 625 to 650 °C, from 650 °C to 675 °C, from 675 °C to 700 °C, or any combination of ranges or smaller range therein, such as from 625 °C to 675 °C. As previously stated, pyrolyzing the two or more microcapillary films 110 at the second temperature may further comprise contacting the two or more microcapillary films 110 with inert gas.

[0076] In embodiments, inert gas may comprise carbon dioxide, nitrogen, any noble gas (including but not limited to argon), or combinations thereof. Contacting the two or more microcapillary films 110 with inert gas may occur at a rate sufficient to purge away the pyrolysis gas products, thereby preventing secondary reactions of the pyrolysis gas products on the carbon surface.

[0077] As previously stated, the method may further comprise annealing the two or more microcapillary films 110 at the third temperature of from 900 °C to 1500 °C with inert gas or under vacuum. The third temperature may also be from 900 °C to 1000 °C, from 1000 °C to 1100 °C, from 1100 °C to 1200 °C, from 1200 °C to 1300 °C, from 1300 °C to 1400 °C, from 1400 °C to 1500, or combinations of the previous ranges or smaller ranges therein, such as from 1200 °C to 1500 °C.

[0078] As previously stated, the method may alternatively or additionally comprise oxidizing the two or more microcapillary films 110 at the fourth temperature of from 300 °C to 400 °C, such as with air. The fourth temperature may also be from 300 °C to 310 °C, from 310 °C to 350 °C, from 350 °C to 375 °C, from 375 °C to 400 °C, or any combination of ranges or smaller range therein.

[0079] As previously stated, the method may alternatively or additionally comprise oxidizing the two or more microcapillary films 110 at the fifth temperature of from 700 °C to 900 °C, such as with carbon dioxide. The fifth temperature may also be from 700 °C to 710 °C, from 710 °C to 750 °C, from 750 °C to 800 °C, from 800 °C to 850 °C, from 850 °C to 890 °C, from 890 °C to 900 °C, or any combination of ranges or smaller range therein.

[0080] In embodiments, in the oxidizing step, the two or more microcapillary films 110 may comprise substantially no oxygen molecules if the oxidation occurs at the fifth temperature. Without being limited by theory, the oxygen content of air may impact the rate of oxidation of the two or more microcapillary films 110. For instance, at greater oxygen contents, the oxidation rate of the two or more microcapillary films 110 may correspondingly increase. It is also known thatsteam and CO2 may be milder oxidants than air. Accordingly, without being limited by theory, a similar level of oxidation and pore opening may be achievable with steam and / or CO2 at higher temperatures than for air.

[0081] The CMS membranes formed according to methods herein may have an oxygen content of from 5 atom% (atomic ratio) to 17 atom%, such as from 5 atom% to 7 atom%, from 7 atom% to 9 atom%, from 9 atom% to 12 atom%, from 12 atom% to 16 atom%, from 16 atom% to 17 atom%, or any combination of ranges or smaller range therein.

[0082] With respect to the previous oxygen content ranges, it is contemplated that a certain degree of oxidation may be needed to reach a particular level of pore opening. Particularly, during oxidation with carbon dioxide, two reactions may be occurring: oxygenate formation on carbon surface and CO gas formation. Accordingly, the oxygen content of the CMS membranes may correlate with the extent of pore opening and / or the degree of oxidation. In embodiments, the CMS membrane may comprise an oxygen content of from 5 atom% to 17 atom%.

[0083] In embodiments wherein the two or more microcapillary fdms 110 are oxidized with carbon dioxide instead of oxygen, the two or more microcapillary fdms 110 post-oxidation (or the CMS membranes formed utilizing the same) may comprise a reduced Henry’s adsorption constant to water than equivalent microcapillary fdms 110 or CMS membranes formed utilizing oxygen molecules as an oxidant. For example, and in embodiments, the two or more microcapillary fdms 110 post-oxidation (or the CMS membranes formed utilizing the same) may comprise a Henry’s adsorption constant to water of from 0.25 to 2.5 grams H2O per 100 grams microcapillary fdm per kilopascal of pressure, assuming measurement at 35 °C and 30% relative humidity.

[0084] As previously stated, the method may comprise applying an adhesive and / or a solvent to the interfaces 115 / 116 of the microcapillary laminate 100, such as prior to pretreating. However, in at least some embodiments the adhesive and / or solvent may be applied to the microcapillary laminate 100 after any one of the pyro lyzing, annealing, or oxidizing steps, such as if the microcapillary laminate 100 is arranged between any two of the pyrolyzing, annealing, or oxidizing steps (whereas if the microcapillary laminate 100 is arranged after the oxidizing step the laminate CMS membrane would be formed, i.e. the two or more microcapillary fdms would be two or more CMS membranes). Further, post-oxidation and arranging, the method may comprise applying an additional amount of adhesive to the microcapillary laminate 100, now the laminate CMS membrane. Without being limited by theory, the applying of the additional amount of adhesive may operate to fdl any remaining gaps in the interfaces 115 / 116.

[0085] Now referring to FIGS. 2A-2B, illustrated is a front-facing cross-sectional view of a vessel 210 containing a gas separation module 200, as explained in further detail below. Particularly, as shown in FIGS. 2A-2B one or more of the laminate CMS membranes (also labeled 100), may be formed into a gas separation module 200, which may be placed in a vessel 210. As shown in FIGS. 2A-2D, the vessel 210 may comprise an internal chamber 211 that may be sized to receive the gas separation module 200. In at least some embodiments, the internal chamber 211 may be sized to form a tight fit around the gas separation module 200. Alternatively or additionally, it is also contemplated that the tight fit may be accomplished through the use of a filler material, or flexible gasket, or adhesive surrounding the gas separation module. However, in some embodiments, the internal chamber 211 may not be sized to form a tight fit around the gas separation module 200. In such embodiments, it is contemplated that the internal chamber 211 may comprise one or more grooves and / or hangers for suspending the gas separation module 200, such as the one or more horizontal dividers as explained in further detail herein with respect to FIGS. 2C-2E.

[0086] As previously stated, the gas separation module 200 may comprise one or more of the laminate CMS membranes 100. Particularly, as shown in FIGS. 2A-2B, the gas separation module 200 may comprise a simple vertical stack of the laminate CMS membranes 100 (FIG. 2A), or the gas separation module may comprise variously sized laminate CMS membranes 100 (FIG. 2B) to conform to the shape of the vessel 210 or the internal chamber 211 of the same.

[0087] Now referring to FIGS. 2C-2G, illustrated are various perspective views of the vessel 210. Particularly, FIG. 2C illustrates the vessel 210 wherein entry and exit through the laminate CMS membrane 100 is controlled through a tight fight surrounding an inlet port 212 and a retentate outlet port 214, whereas the permeate gas exits through the microcapillary channels and out through permeate outlet port(s) 213, as explained in further detail hereinbelow. FIG. 2D illustrates the vessel 210 wherein entry and exit through the laminate CMS membrane is controlled through a plurality of horizontal dividers 218 isolating the inlet port 212, the permeate outlet port(s) 213, and the retentate outlet port 214, as explained in further detail herein. FIG. 2E illustrates the vessel 210 wherein entry and exit through the laminate CMS membrane is controlled through a combination of the tight fit, horizontal dividers 218, and fluid coupling of one end of the laminate CMS membrane 100 to the one of the ends of the vessel 210, as explained in further detail herein. FIGS. 2F and 2G illustrate zoomed-in views of the inlet port 212 and the openings 132 for FIGS. 2C and 2D, respectively.

[0088] As shown in FIGS. 2C-2E, the vessel 210 may be cylindrical, although this is not required and the vessel 210 may be any shape of vessel suitable to house the gas separation module 200. As shown in FIGS. 2C-2E, the vessel 210 comprises at least a first end 216, a second end 217, and an internal chamber 211. Moreover, at least one of the first end 216 or the second end 217 may further comprise a removable cover 215 that may be removable from the vessel 210 utilizing paired threads to the vessel 210, although other mechanisms for attaching the removable cover 215 to the vessel 210 are contemplated, such as but not limited to magnetic connections, close tolerance fits, or any other fastening mechanisms understood in the art. Accordingly, in embodiments the gas separation module 200, and thus the laminate CMS membrane 100 may be inserted into the vessel 210 after removing the removable cover 215.

[0089] The vessel 210 may also comprise the inlet port 212, the permeate outlet port 213, the retentate outlet port 214, or combinations thereof. In some embodiments, there may be two permeate outlet ports 213, such that at least one of the permeate outlet ports 213 may be configured to operate as a purge port 219. As shown in FIG. 2C, the inlet port 212 may be positioned proximal the first end 216 and the retentate outlet port 214 may be positioned proximal to the second end 217, or vice versa.

[0090] As previously stated, the gas separation modules 200, and the laminate CMS membrane 100 therein, may be used to effect separations of a gas mixture. Particularly, the laminate CMS membrane 100 may absorb certain gases of the gas mixture into the micropores and the plurality of microcapillary channels while other non-absorbed gases continue to flow along the two or more microcapillary films 110. However, and without being bound by theory, gas mixtures may preferentially avoid entering the gas separation module 200 / laminate CMS membrane 100 if an easier flow path is present, such as through void space in the vessel 210 surrounding the gas separation module 200. Accordingly, the laminate CMS membranes 100, the gas separation modules 200, and the vessels 210 herein may be collectively configured to minimize these effects, and thus decrease the amount of gas bypassing the laminate CMS membrane 100.

[0091] For example, and as previously stated, the internal chamber 211 of the vessel 210 may be sized to form a tight fit around the gas separation module 200. Additionally, the inlet port 212 and the retentate outlet port 214 may be configured to form a tight fit on the lengthwise face 150 of the laminate CMS membrane 100, such as by encompassing the openings 132 into the laminate CMS membrane 100, as previously described. This is shown for example in FIG. 2C. Accordingly, a gas mixture entering the inlet port 212 may be forced into the laminate CMS membrane 100 ofthe gas separation module 200 at the inlet port 212 and only permitted to exit at the retentate outlet port 213. The permeate stream may then be free to travel along the plurality of microcapillary channels to exit at the permeate outlet port 213. In embodiments, the tight fit of the inlet port 212, the retentate outlet port 214, or both may be accomplished through the use of an o-ring or gasket, although any known gas-tight sealing mechanism is contemplated.

[0092] Now referring to FIGS. 2D-2E, and as previously mentioned, in some embodiments the internal chamber 211 may not comprise a tight fit on the gas separation module 200. In such embodiments, and without being limited by theory, undesired diversion of the gas around the laminate CMS membrane 100 through the internal chamber 211 may be reduced by including the one or more horizontal dividers 218. Particularly, the one or more horizontal dividers 218 may be configured to form an external seal around the gas separation module 200, and thus isolate given lengths of the vessel 210 in combination with the two or more lengthwise spacers 130. Accordingly, it is contemplated that by the strategic placement of the one or more horizontal dividers 218 on either side of the openings 132 into the laminate CMS membrane 100, as previously described, flow may be directed through the laminate CMS membrane 100 to the retentate outlet port 214 and the permeate outlet port 213, as appropriate.

[0093] As previously stated, an adhesive may be applied to one of the widthwise faces 140 of the laminate CMS membrane 100 to seal the plurality of microcapillary channels 111 at that widthwise face 140 and thus direct gas flow through the plurality of microcapillary channels to the opposite widthwise face 140. In embodiments, the adhesive may be applied at the widthwise face 140 proximal the retentate outlet port 214. Sealing the plurality of microcapillary channels 111 in this manner may direct permeate gas flow through the plurality of microcapillary channels counter-directionally of the gas mixture passing towards the retentate outlet port 214. It is contemplated that this counter-directional flow through the plurality of microcapillary channels 111 may increase desired gas separation by maximizing the driving force for permeation, i.e., the partial pressure difference.

[0094] Now referring to FIG. 2E, the gas separation module 200 may be fluidly coupled to at least one of the first end 216 or the second end 217, such as by an adhesive and / or tight fit of the vessel internal chamber 211 surrounding the laminate CMS membrane 100. In such embodiments, the laminate CMS membrane 100 of the gas separation module 200 may be one or more of the microcapillary laminates 100 shown for example in FIG. IB. Accordingly, the widthwise face 140 of the laminate CMS membrane 100 not comprising the spacer 120 may be coupled to either thefirst end 216 or the second end 217, wherein the respective first end 216 or the second end 217 also comprises the inlet port 212. In such an embodiment, and as previously stated, the same widthwise face 140 not comprising the spacer 120 may have the plurality of microcapillary channels sealed, such that flow through the plurality of microcapillary channels is directed towards the permeate outlet port 213 positioned on the other of the first end 216 or the second end 217. In embodiments, the gas separation module 200 may be fluidly coupled to the first end 216 or the second end 217 by pairing to one or more internal grooves (not illustrated) at the first end 216 or the second end 217, which may be subsequently sealed through the use of an o-ring, a flexible gasket, applying an adhesive to an overlapping portion of the gas separation module 200 and the end 216 / 217, or combinations thereof.

[0095] As stated above, embodiments herein are also directed to processes for separating gases from a gas mixture. The gas mixture may comprise first gas molecules and second gas molecules. The second gas molecules, such as hydrogen, nitrogen, methane, or combinations thereof, may have a lesser representative molecular diameter than the first gas molecules, which may include carbon dioxide. Generally, the process may comprise manufacturing a laminate CMS membrane, which may be any of the laminate CMS membranes, or any of the processes for manufacturing the same, previously stated. The method may also comprise flowing the gas mixture through the CMS membrane to produce a permeate stream and a retentate stream. The permeate first stream may have an increased concentration of the first gas molecules as compared to the second retentate stream, which in turn may have an increased concentration of the second gas molecules as compared to the permeate first stream. In this way, the CMS membrane used in the process may operate to separate the first gas molecules and the second gas molecules from each other, and may be reverse-selective.

[0096] As previously stated, determining the micropore / molecular sizing of the CMS membranes is important to determine the CMS membranes’ suitability for particular separations. Different ways to determine the molecular size have been developed. One commonly employed approach has been to determine a given molecule's "kinetic diameter." A reference listing a variety of these kinetic diameters, based upon their use in zeolite applications, is D.W. Breck, Zeolite Molecular Sieves: Structure, Chemistry and Use, John Wiley & Sons, Inc. (New York, N.Y. 1974), 636, and these determinations are frequently used even with respect to non-zeolite, carbon molecular sieves that are known to have slit- shaped pores. In view of the above and for purposes hereof, then, the following kinetic diameters, taken from the Breck reference cited supra, are usedherein as the representative molecular diameters for the following molecules: He (2.6 Angstroms, A), H2(2.89 A), N2(3.64 A), CO2(3.3 A), CH4(3.8 A), C2H4(3.9 A), C3H8(4.3 A), i-C4Hio (5.0 A), SFe (sulfur hexafluoride) (5.5 A), and i-CsHis (iso-octane) (6.2 A). However, because that reference table lacks a kinetic diameter for ethane, and the kinetic diameter given therein for propylene is believed by at least some researchers to be inaccurate for CMS materials per se, the Lennard-Jones collision diameters are used herein, instead of the Breck kinetic diameters, for those two materials. These Lennard-Jones collision diameters are, respectively, C2He (4.1 A), and C3H6 (4.0 A). See, for example, Staudt-Bickel C., Koros W. J., "Olefin / paraffin gas separations with 61-DA-based polyimide membranes," J. Membr. Sci. (2000) 170 (2), 205-214 for further discussion. The kinetic diameters and Lennard-Jones collision diameters are referred to together as "representative molecular diameters."

[0097] In additional detail, and with reference to FIGS. 3A-3C, the process may comprise separating the gas mixture 2 utilizing a system 300, which may comprise any combination of the units described below. The process may comprise introducing the gas mixture 2 to a first module 310, thereby forming a first permeate stream 6 rich in the first gas and a first retentate stream 4 rich in the second gas. The first module 310 may comprise any of the laminate CMS membranes, gas separation modules, or vessels previously described. In embodiments, the gas mixture 2 may be introduced to the system at a high pressure, such as greater than 5 bar or greater than 20 bar, such as from 5 bar to 10 bar, from 10 bar to 15 bar, from 15 bar to 20 bar, from 20 bar to 23 bar, from 23 bar to 25 bar, from 25 bar 50 bar, or combinations of the previous ranges or smaller ranges therein, such as from 23 bar to 50 bar.

[0098] In embodiments, the first module 310 may have a pressure differential between retentate and permeate sides of greater than 5 bar, such as from 5 bar to 10 bar, from 10 bar to 15 bar, from 15 bar to 20 bar, from 20 bar to 23 bar, from 23 bar to 25 bar, from 25 bar 50 bar, or combinations of the previous ranges or smaller ranges therein, such as from 23 bar to 50 bar. For example, an in embodiments the retentate side of the various modules described herein may have a relatively greater pressure than the corresponding permeate side.

[0099] The process may also comprise introducing the first retentate stream 4 to a second module 312, thereby forming a second permeate stream 10 rich in the first gas, and a second retentate stream 8 rich in the second gas, wherein the second retentate stream 8 has a greater percentage of the second gas than the first retentate stream 4. The second module 312 may comprise any of the laminate CMS membranes, gas separation modules, or vessels previouslydescribed. In embodiments, the second module 312 310 may have a pressure differential between retentate and permeate sides of greater than 5 bar, such as from 5 bar to 10 bar, from 10 bar to 15 bar, from 15 bar to 20 bar, from 20 bar to 23 bar, from 23 bar to 25 bar, from 25 bar 50 bar, or combinations of the previous ranges or smaller ranges therein, such as from 23 bar to 50 bar.

[0100] Still referring to FIGS. 3A-3C, the process may further yet comprise introducing the first permeate stream 6 to a third module 314, thereby forming a third retentate stream 12 and a first gas product stream 14 rich in the first gas. The third module 314 may comprise any of the laminate CMS membranes, gas separation modules, or vessels previously described. In embodiments, the third module 314 310 may have a pressure differential between retentate and permeate sides of greater than 5 bar, such as from 5 bar to 10 bar, from 10 bar to 15 bar, from 15 bar to 20 bar, from 20 bar to 23 bar, from 23 bar to 25 bar, from 25 bar 50 bar, or combinations of the previous ranges or smaller ranges therein, such as from 23 bar to 50 bar.

[0101] The process may additionally comprise recycling the second permeate stream 10 and the third retentate stream 12 to the first module 310, such as to produce additional first permeate stream 6 and first retentate stream 4. In certain embodiments, the second permeate stream 10 may instead be mixed with the first permeate stream 6 and sent to the third module 314.

[0102] In at least some embodiments, the process may further comprise introducing the gas mixture to one or more refrigerant units 302. Similarly, the process may further comprise introducing one or more of the second permeate stream 10, the third retentate stream 12, or both to the one or more refrigerant units 302 prior to recycling to the first module 310. Also similarly, the process may further comprise introducing the first permeate stream 6 to the one or more refrigerant units 302 prior to introduction into the third module 314. In embodiments, introducing a stated stream to the one or more refrigerant units 302 may operate to cool the stated stream to a temperature of less than or equal to 50 °C, such as from 50 °C to 20 °C, from 20 °C to 15 °C, from 15 °C to 10 °C, from 10 °C to 5 °C, from 5 °C to 0 °C, from 0 °C to -10 °C, from -10 °C to -20 °C, from -20 °C to -50 °C, or any combination of the previous ranges or smaller range therein, such as from 20 °C to -20 °C, from 20 °C to 0 °C, or from 0 °C to -20 °C.

[0103] Still referring to FIGS. 3A-3C, the process may further comprise introducing the gas mixture 2 to a drier 304, a H2O scavenger bed 306, or both. The gas mixture 2 may be introduced to the drier 304 or the H2O scavenger bed 306 prior to introducing into the one or more refrigerant units 302, after introducing into the one or more refrigerant units 302, prior to introducing into the first module 310, or combinations thereof.

[0104] Still referring to FIGS. 3 A-3C, the process may further comprise introducing the second retentate stream 8, the first gas product stream 14, or both to one or more heat exchangers 308, wherein the one or more heat exchangers are in thermal communication with the gas mixture.

[0105] Now referring to FIG. 3B, the process may further comprise introducing the second retentate stream 8 to a pressure swing absorption unit 316 to form a raffinate stream 20 rich in the second gas and a third effluent stream 18 rich in the first gas. In embodiments, including the pressure swing absorption unit 316 in the system 300 and the processes previously described may be of substantial benefit in purifying the second retentate stream 8 for sale and / or use of the second gas. Particularly, it is contemplated that the modules 310 / 312 / 314 may be effective in removing a substantial portion of the first gas from the gas mixture. The pressure swing absorption unit may then subsequently be included to remove a substantial portion of the remaining first gas from the gas mixture to produce the raffinate stream 20 containing very little first gas. As also shown in FIG. 3B, the process may further comprise sending the third effluent stream 18 to one of a number of locations. For example, and as shown in FIG. 3B, the third effluent stream 18 may be introduced to the third module 314, recycled to the first module 310, or sent to be mixed with the first gas product stream 14. Without being limited by theory, the decision of where to send the third effluent stream 18 may be dependent on the percentage of second gas in the third effluent stream. For example, if the percentage of second gas is low, the third effluent stream 18 may be mixed with the first gas product stream 14. If the percentage of second gas is still sufficiently high, the third effluent stream 18 may be recycled to either the first module 310 or the third module 312 for further separation.

[0106] Now referring to FIG. 3C, the process may further comprise introducing the second retentate stream 8 to an amine sweetening system 318 to form the raffinate stream 20 rich in the second gas and the third effluent stream 18 rich in the first gas. In embodiments, including the amine sweetening system 318 in the system 300 and the processes previously described may be of substantial benefit in purifying the second retentate stream 8 for sale and / or use of the second gas. Particularly, it is contemplated that the modules 310 / 312 / 314 may be effective in removing a substantial portion of the first gas from the gas mixture 2. The amine sweetening system 318 may then subsequently be included to remove a substantial portion of the remaining first gas from the gas mixture 2 to produce the raffinate stream 20 being relatively rich in the second gas and poor in the first gas. Moreover, the initial separation of the gas mixture in the modules 310 / 312 / 314 may reduce the dependence on the amine sweetening system 318 alone to separate the gas mixture2, resulting in reduced greenhouse gas emissions of the process in general. In embodiments, the amine sweetening system 318 may be any amine sweetening system known in the art, including but not limited to a Girbotol process.

[0107] Still referring to FIG. 3C, as amine sweetening systems generally involve the use of boilers and steam to remove certain gases from a gas mixture, the process may further comprise introducing the second retentate stream 8 to a heater 320 prior to introduction into the amine sweetening system 318. The heater 320 may heat the second retentate stream 8 to a temperature of greater than or equal to 20 °C prior to introduction into the amine sweetening system 318. Furthermore, although not illustrated, should the third effluent stream 18 be recycled back into any one of the modules 310 / 312 / 314, the process may further comprise introducing the third effluent stream to the one or more refrigeration units 302 prior to recycling.EXAMPLES

[0108] Microcapillary fdms and microcapillary laminates of the same were formed according to embodiments herein for permeation testing, as explained in further detail hereinbelow.

[0109] Microcapillary Film Preparation

[0110] Microcapillary fdms, according to embodiments herein, were extruded using PVDC resins obtained from SK Global SARAN, particularly SBR711, which is a PVDC copolymer resin containing approximately 8.5 wt.% methyl acrylate. In particular, the microcapillary fdm die had a simple split body design with a two-inch wide air manifold insert that contained 42 parallel hollow pins positioned near the exit of the die used to introduce air into the polymer melt forming microcapillaries. The extruder pumping rate and air flow rate were adjusted to achieve the desired microcapillary diameter.

[0111] A 0.75 -inch diameter single screw extruder with three-barrel temperature zones was used to extrude the PVDC microcapillary fdm samples. An elbow adaptor was fabricated to position the microcapillary fdm die such that the extruded tape will be directed down into a water bath. The elbow and die were heated using metal heating elements that were clamped in place. The temperatures of the three zones of the extruder, the elbow, and die were increased from 155 °C to 170 °C until no unmelt resin was seen in the extruded fdm. The temperatures were kept as low as possible to avoid the thermal decomposition of PVDC resin. Polyethylene (PE) resin was periodically fed into the extruder to flush out char build up periodically.

[0112] Upon extrusion from the die, the microcapillary fdm was quenched into a room temperature water bath where upon it was wrapped around a guide roll at the bottom of the bathand then pulled out of the bath by a winder. The fdm was stretched by increasing the speed of the winder. Stretching occurred near the exit of the die and reduced the fdm thickness as well as the fdm width. The extruded microcapillary fdms were then cut into approximately 3 -foot strips and laid out on the top of a flat lab bench in atmospheric conditions to fully crystallize the PVDC for approximately one week.

[0113] Permeation and Selectivity Testing

[0114] The microcapillary fdms previously described were then formed into microcapillary laminates and / or laminate CMS membranes, as described below, and tested for gas permeation and selectivity. This was accomplished by building custom made ring permeation cell “modules.” The ring cell has a five-inch outer diameter, a three inch inner diameter, four half-inch wide openings on the wall with 9 / 16 inch o-ring fitting and quarter-inch thick covers at two side with the o-ring seal. The o-rings were provided by SAE / MS. The lengthwise end of the laminate CMS membranes was inserted into one of the half- inch wide openings. A dam was then made using Gorilla All Purpose Putty Epoxy Stick, with Scotch Weld DP 100 epoxy used to fill the top of the Gorilla Putty Epoxy as well as seal the other end of the laminate CMS membrane.

[0115] Mixture gas permeation was tested using the modules. Mixed gases were first cleaned through an activated carbon guard bed, then fed into the reservoir inside the ring cell. The feed was a equimolar 52 psi gauge carbon dioxide / hydrogen feed, to reflect the feed from hydrogen fuel gas creation. The permeate side of the module was held at 1 psi gauge, with the retentate held at 0 psi gauge (atmospheric pressure). The permeance was calculated using the permeate flow rate, normalized by the cross-membrane pressure difference and the total membrane surface area. For microcapillary film, the membrane area is the product of un-sealed film length, width, and number of microcapillary films times two (each microcapillary film has two surfaces). The unit of permeance is GPU: 1 x10-6 cm3(S.T.P) / (s.cm2.cm Hg). The results of the permeation testing are shown below in the tables and paragraphs below. Each of the Examples hereinbelow included spacers having a thickness of approximately 1000 microns where laminates were formed.

[0116] Examples 1-3 are for comparison, and include laminates formed without annealing or oxidation. Example 1 includes 10 mil (1 mil equals approximately 25.4 microns) laminates pyro lyzed at 550 °C and laminated using Gorilla Tough & Clear ™ double-sided tape as the spacer and adhesive, having a thickness of approximately 1000 microns. Example 2 includes 20 mil laminates pyrolyzed at 550 °C and laminated using 3M 5925 VHB™ acrylic foam tape as the spacer and adhesive. Separations using equimolar H2 / CO2 / CH4 and equimolar C3H6 / C3H8 wereconducted. Single layer microcapillary fdms were formed for comparison for Examples 1 and 2. Example 3 includes 20 mil 10-layer laminates pyro lyzed at 600 °C and laminated using Gorilla All Purpose Epoxy Stick putty adhesive as the spacer and adhesive.

[0117] Table 1: Non- Annealed & Non-Oxidized Permeation Performance

[0118] As shown in Table 1 above, the non-annealed non-oxidized laminates did not show appreciable levels of carbon dioxide / hydrogen selectivity, nor carbon dioxide permeance in general. Rather, the membranes and laminates thereof showed more suitability for propylene / propane separations. Without being limited by theory, this shows that annealing and oxidizing, as well as the temperatures chosen therefor, have an appreciable impact on membrane performance.

[0119] Finally, Examples 4 and 5 are similar three and five-layer laminates utilizing microcapillary films as the spacers, wherein each spacer comprises multiple layers of microcapillary films, as shown in FIG. 2. Particularly, in Examples 4 and 5, like in FIG. 2, each of the spacers comprises three microcapillary films arranged in a stack. A solvent, tetrahydrofuran, was also applied between each of the microcapillary films in the spacers and in the layers of the microcapillary laminate in general.

[0120] The Example 4 laminates were then pretreated at 130 °C and pyrolyzed at 600 °C. The Example 5 laminates were pretreated at 130 °C, pyrolyzed at 600 °C, annealed at 1200 °C, and oxidized in air at about 275 °C for 8 hours. The permeation results for Examples 4 and 5 are shown below in Table 3.

[0121] Table 2: Examples 4 and 5 Permeation Performance

[0122] As shown in Table 3 above, both examples 4 and 5 exhibited selectivities of a variety of gas mixtures, indicating that the solvent bonded satisfactorily and maintained a seal between the laminate layers.

[0123] To determine the impact of temperature on the microcapillary laminate / laminate CMS membrane’s performance, Examples 6 and 7 were prepared and oxidized in air and carbon dioxide respectively. Example 6 was prepared as a single layer microcapillary fdm pretreated at 130 °C, pyro lyzed at 600 °C, and then annealed at 1200 °C. It was then oxidized in air at about 350 °C for 8 hours. Two modules were prepared and tested at different temperature with an equimolar CO2 / H2 feed at 52 psig. The feed was sent directly from the gas cylinder without going through a scavenger bed. The permeation result is shown in Table 3. As shown in Table 3 below, the CO2 / H2 selectivities more than doubles for every 20 °C temperature drop.

[0124] Table 3: Performance of Example 6 Membranes vs. Temperature

[0125] Example 7 was single layer micro capillary fdm pretreated at 130 °C, pyrolyzed at 600 °C, and then annealed at 1200 °C. It was then oxidized in CO2 at about 800 °C for 6 hours. One module was prepared and tested at different temperature with an equimolar CO2 / H2 feed at 52 psig. The feed was sent directly from the gas cylinder without going through a scavenger bed. The permeation result is shown in Table 4. Tike example 6, the CO2 / H2 selectivities more than doubles for every 20 °C temperature drop. The performance also recovers fully after cycles of temperature change.

[0126] Table 4: Performance of Example 7 Membranes vs. Temperature

[0127] Further testing of the microcapillary films of Example 7 showed at least 500 hours of stable performance at relevant blue hydrogen process conditions (300 psig, 22°C). The feed gas (about 500 seem) in such testing was purified by an activated carbon scavenger bed (about 10- 30g) before reaching the Example 7 membrane module. During the full 500-hour run, the scavenger bed was not changed.

[0128] To determine the impact of CO2 concentration on membrane performance, the Example 7 membrane was also simulated at different CO2 concentrations at 0 °C and 300 psig feed pressure. As shown in Table 5, selectivity of the membrane was observed to remain relatively stable at greater concentrations. Further, as CO2 concentration decreased, the CO2 permeance and selectivity were observed to increase. Without being limited by theory, this may demonstrate the capability of the membrane to conduct both bulk separations of carbon dioxide as well as further refined separations of retentate streams containing lesser amounts of carbon dioxide. This is shown for example in Table 5 below.

[0129] Table 5: Concentration vs. Permeance and Selectivity for Example 7 Membranes

[0130] Simulations based on the systems in FIGS. 3A-3B, were also conducted to model the performance of the aforementioned laminates, based on the observed permeances and selectivities, as explained in further detail herein below.

[0131] Particularly, a first simulation was conducted according to the system depicted in FIG. 3 A, in which a gas feed of 74.0% hydrogen, saturated water vapor (0.9%), and 25.0 mol% carbon dioxide was first dehydrated and exposed to a scavenger before being cooled to a temperature ofapproximately 0 °C prior to entry into the first module. Separations for the individual streams, and sizinf are shown below in Table 6.

[0132] Table 6: Simulated FIG. 3A Separation Performance

[0133] A second simulation was also conducted according to the system depicted in FIG. 3B, in which a gas feed of hydrogen, entrained water, and carbon dioxide was first dehydrated and exposed to a scavenger before being cooled to a temperature of approximately 0 °C prior to entry into the first module. Separations for the individual streams are shown below in Table 7.

[0134] Table 7: Simulated FIG. 3B Separation Performance

[0135] A third simulation was also conducted according to the system depicted in FIG. 3C, in which a gas feed of hydrogen, entrained water, and carbon dioxide was first dehydrated andexposed to a scavenger before being cooled to a temperature of approximately 0 °C prior to entry into the first module. Separations for the individual streams are shown below in Table 8.

[0136] Table 8: Simulated FIG. 3C Separation Performance

[0137] As shown in Tables 6-8, the systems and the modules incorporating the laminate CMS membranes exhibited the ability to consistently separate extremely high percentages of carbon dioxide from a mixed gas stream, reducing the burden on pressure swing absorption units or amine sweetening processes to carry out the bulk separations. Further, as shown in Table 5, the performance / efficiency of the laminate CMS membrane actually improves at decreasing CO2 concentration. Accordingly, the laminate CMS membranes herein may be suitable to conduct both initial bulk separation of CO2 rich streams as well as subsequent refined separations. This may result in the capture of up to 95% CO2, while pressure swing absorption and amine sweetening may provide the approximately remaining 5% of separations to the gas mixture. As previously stated, this may result in considerable cost savings and reduced CO2 emissions over just using amine sweetening or pressure swing absorption alone.

[0138] According to a first aspect, a laminate carbon molecular sieve (CMS) membrane may comprise two or more microcapillary films, each microcapillary film comprising a first lengthwise face, a second lengthwise face, a first widthwise face, and a second widthwise face; one or more widthwise spacers; and two or more lengthwise spacers, wherein: the one or more widthwise spacers and the two or more lengthwise spacers are interposed between each of the two or more microcapillary films, at least one widthwise spacer is positioned proximal to the first widthwise face of the two or more microcapillary films; at least one lengthwise spacer ispositioned proximal to the first lengthwise face of the two or more microcapillary films; at least one lengthwise spacer is positioned proximal to the second lengthwise face of the two or more microcapillary films, and the two or more microcapillary films comprise a poly vinylidene chloride (PVDC) copolymer.

[0139] A second aspect may comprise the first aspect, wherein the microcapillary laminate comprises two or more widthwise spacers interposed between each of the two or more microcapillary films; and at least one widthwise spacer of the two or more widthwise spacers is positioned proximal to the second widthwise face of the two or more microcapillary films.

[0140] A third aspect may comprise any previous aspect, wherein the at least one widthwise spacer, the two or more lengthwise spacers, or both comprise PVDC copolymer.

[0141] A fourth aspect may comprise any previous aspect, and may further comprise an adhesive on an interface between the two or more microcapillary films and the at least one widthwise spacer, on an interface between the two or more microcapillary films and the two or more lengthwise spacers, or both.

[0142] According to a fifth aspect, which may comprise any previous aspect, a process for separating a gas mixture comprising a first gas and a second gas utilizing laminate CMS membranes may comprise: introducing the gas mixture to a first module comprising a first laminate CMS membrane, the first laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous aspects, thereby forming: a first permeate stream rich in the first gas, and a first retentate stream rich in the second gas, wherein the second gas has a lesser representative molecular diameter than the first gas; introducing the first retentate stream to a second module comprising a second laminate CMS membrane, the second laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous aspects, thereby forming: a second permeate stream rich in the first gas, and a second retentate stream rich in the second gas, wherein the second retentate stream has a greater percentage of the second gas than the first retentate stream; introducing the first permeate stream to a third module comprising a third laminate CMS membrane, the third laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous aspects, thereby forming: a third retentate stream, and a first gas product stream rich in the first gas; and recycling the second permeate stream and the third retentate stream to the first module.

[0143] A sixth aspect may comprise the fifth aspect, wherein the first gas is carbon dioxide and the second gas is hydrogen.

[0144] A seventh aspect may comprise any of the fifth through sixth aspects, and may further comprise cooling the gas mixture to less than 20 °C prior to introduction to the first module.

[0145] An eighth aspect may comprise any of the fifth through seventh aspects, and may further comprise introducing the gas mixture to a H2O scavenger bed prior to introduction to the first module.

[0146] A ninth aspect may comprise any of the fifth through eighth aspects, and may further comprise cooling the first permeate stream to a temperature of less than or equal to 20 °C prior to introducing the first permeate stream into the third module; cooling the second permeate stream to a temperature of less than or equal to 20 °C prior to recycling the second permeate stream into the first module; or both.

[0147] A tenth aspect may comprise any of the fifth through ninth aspects, and may further comprise introducing the second retentate stream, the first gas product stream, or both to a heat exchanger, wherein the heat exchanger is in thermal communication with the gas mixture; and introducing the gas mixture to the heat exchanger prior to introducing the gas mixture into the first module, thereby cooling the gas mixture.

[0148] An eleventh aspect may comprise any of the fifth through tenth aspects, and may further comprise introducing the second retentate stream to a pressure swing absorption unit to form a raffinate stream rich in the second gas; and a third effluent stream rich in the first gas.

[0149] A twelfth aspect may comprise any of the fifth through tenth aspects, and may further comprise introducing the second retentate stream to an amine sweetening process to form a second gas product stream rich in the second gas; and a third effluent stream rich in the first gas.

[0150] A thirteenth aspect may comprise either the eleventh or twelfth aspects, and may further comprise introducing the third effluent stream to the third module; or recycling the third effluent stream to the first module.

[0151] A fourteenth aspect may comprise the twelfth aspect, and may further comprise heating the second retentate stream to greater than or equal to 20 °C prior to introducing the second retentate stream into the amine sweetening process.

[0152] A fifteenth aspect may comprise any of the first through fourth aspects, and may further comprise a process for separating a gas mixture comprising a first gas and a second gas utilizing the laminate CMS membrane, the process comprising flowing the gas mixture through the laminate CMS membrane to produce: a permeate stream having an increased concentration of thefirst gas; and a retentate stream having an increased concentration of the second gas, wherein the second gas has a lesser representative molecular diameter than the first gas.

[0153] It is noted that recitations in the present disclosure of a component of the present disclosure being “operable” or “sufficient” in a particular way, to embody a particular property, or to function in a particular manner, are structural recitations, as opposed to recitations of intended use. More specifically, the references in the present disclosure to the manner in which a component is “operable” or “sufficient” denotes an existing physical condition of the component and, as such, is to be taken as a definite recitation of the structural characteristics of the component.

[0154] It is also noted that recitations herein of “at least one” component, element, etc., should not be used to create an inference that the alternative use of the articles “a” or “an” should be limited to a single component, element, etc. The singular forms “a,” “an” and “the” include plural referents, unless the context clearly dictates otherwise.

[0155] Throughout this disclosure ranges are provided. It is envisioned that each discrete value encompassed by the ranges are also included. Additionally, the ranges which may be formed by each discrete value encompassed by the explicitly disclosed ranges are equally envisioned.

[0156] It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present invention, it is noted that this term is introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.” It is noted that the use of the terms “having” or “including”, or grammatical variations thereof, in this disclosure should also be interpreted in like manner as the more commonly used open-ended preamble term “comprising”.

[0157] As used in this disclosure, terms such as “first” and “second” are arbitrarily assigned and are merely intended to differentiate between two or more instances or components. It is to be understood that the words “first” and “second” serve no other purpose and are not part of the name or description of the component, nor do they necessarily define a relative location, position, or order of the component. Furthermore, it is to be understood that the mere use of the term “first” and “second” does not require that there be any “third” component, although that possibility is contemplated under the scope of the present disclosure.

[0158] Having described the subject matter of the present embodiments herein in detail and by reference to specific embodiments thereof, it is noted that the various details disclosed herein should not be taken to imply that these details relate to elements that are essential components ofthe various embodiments described herein, even in cases where a particular element is illustrated in each of the drawings that accompany the present description. Further, it will be apparent that modifications and variations are possible without departing from the scope of the present embodiments including, but not limited to, embodiments defined in the appended claims. More specifically, although some aspects of the present embodiments are identified herein as preferred or particularly advantageous, it is contemplated that the present embodiments is not necessarily limited to these aspects.

Claims

CLAIMS1. A laminate carbon molecular sieve (CMS) membrane, the membrane comprising a microcapillary laminate comprising: two or more microcapillary films, each microcapillary film comprising a first lengthwise face, a second lengthwise face, a first widthwise face, and a second widthwise face; one or more widthwise spacers; and two or more lengthwise spacers, wherein: the one or more widthwise spacers and the two or more lengthwise spacers are interposed between each of the two or more microcapillary films, at least one widthwise spacer is positioned proximal to the first widthwise face of the two or more microcapillary films; at least one lengthwise spacer is positioned proximal to the first lengthwise face of the two or more microcapillary films; at least one lengthwise spacer is positioned proximal to the second lengthwise face of the two or more microcapillary films, and the two or more microcapillary films comprise a polyvinylidene chloride (PVDC) copolymer.

2. The CMS membrane of claim 1, wherein: the microcapillary laminate comprises two or more widthwise spacers interposed between each of the two or more microcapillary films; and at least one widthwise spacer of the two or more widthwise spacers is positioned proximal to the second widthwise face of the two or more microcapillary films.

3. The CMS membrane of claim 1, wherein the at least one widthwise spacer, the two or more lengthwise spacers, or both comprise PVDC copolymer.

4. The CMS membrane of any previous claim, further comprising an adhesive: on an interface between the two or more microcapillary films and the at least one widthwise spacer, on an interface between the two or more microcapillary films and the two or more lengthwise spacers, orboth.

5. A process for separating a gas mixture comprising a first gas and a second gas utilizing laminate CMS membranes of any of the previous claims, the process comprising: introducing the gas mixture to a first module comprising a first laminate CMS membrane, the first laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming: a first permeate stream rich in the first gas, and a first retentate stream rich in the second gas, wherein the second gas has a lesser representative molecular diameter than the first gas; introducing the first retentate stream to a second module comprising a second laminate CMS membrane, the second laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming: a second permeate stream rich in the first gas, and a second retentate stream rich in the second gas, wherein the second retentate stream has a greater percentage of the second gas than the first retentate stream; introducing the first permeate stream to a third module comprising a third laminate CMS membrane, the third laminate CMS membrane having the structure of the laminate CMS membrane of any of the previous claims, thereby forming: a third retentate stream, and a first gas product stream rich in the first gas; and recycling the second permeate stream and the third retentate stream to the first module.

6. The process of claim 5, wherein the first gas is carbon dioxide and the second gas is hydrogen.

7. The process of either claim 5 or 6, further comprising cooling the gas mixture to less than 20 °C prior to introduction to the first module.

8. The process of any of claims 5-7, further comprising introducing the gas mixture to a H2O scavenger bed prior to introduction to the first module.

9. The process of any of claims 5-8, further comprising: cooling the first permeate stream to a temperature of less than or equal to 20 °C prior to introducing the first permeate stream into the third module; cooling the second permeate stream to a temperature of less than or equal to 20 °C prior to recycling the second permeate stream into the first module; or both.

10. The process of any of claims 5-9, further comprising: introducing the second retentate stream, the first gas product stream, or both to a heat exchanger, wherein the heat exchanger is in thermal communication with the gas mixture; and introducing the gas mixture to the heat exchanger prior to introducing the gas mixture into the first module, thereby cooling the gas mixture.

11. The process of any of claims 5-10, further comprising introducing the second retentate stream to a pressure swing absorption unit to form: a raffinate stream rich in the second gas; and a third effluent stream rich in the first gas.

12. The process of any of claims 5-10, further comprising introducing the second retentate stream to an amine sweetening process to form: a second gas product stream rich in the second gas; and a third effluent stream rich in the first gas.

13. The process of either claim 11 or 12, further comprising: introducing the third effluent stream to the third module; or recycling the third effluent stream to the first module.

14. The process of claim 12, further comprising heating the second retentate stream to greater than or equal to 20 °C prior to introducing the second retentate stream into the amine sweetening process.

15. A process for separating a gas mixture comprising a first gas and a second gas utilizing the laminate CMS membrane of any of claims 1-4, the process comprising flowing the gas mixture through the laminate CMS membrane to produce: a permeate stream having an increased concentration of the first gas; and a retentate stream having an increased concentration of the second gas, wherein the second gas has a lesser representative molecular diameter than the first gas.

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