Patent Application
20160158693
1. Field of the Invention
The present invention relates to a module for acidic-gas separation which selectively separates acidic gas from raw material gas. Specifically, the present invention relates to a spiral-shaped module for acidic-gas separation obtained by winding a laminate including an acidic gas separation film.
2. Description of the Related Art
In recent years, a technique of selectively separating acidic gas such as carbon dioxide from raw material gas (gas to be treated) has been developed. For example, an acidic-gas separation module that separates acidic gas from raw material gas using an acidic gas separation film through which acidic gas selectively permeates has been developed.
For example, JP1992-215824A (JP-H04-215824A) discloses an acidic-gas separation module obtained by winding a laminate containing an acidic gas separation film around a central tube (central permeating material collection tube), in a tube wall of which through-holes are formed and which is used for collecting separated acidic gas, multiple times.
The acidic-gas separation module disclosed in JP1992-215824A (JP-H04-215824A) is a dissolution-diffusion type acidic-gas separation module using a so-called dissolution diffusion film as an acidic gas separation film. The dissolution diffusion film separates acidic gas from raw material gas using differences in solubilities of acidic gas and materials to be separated therefrom in a film and differences in diffusibility in a film.
JP4621295B discloses an acidic-gas separation module (experimental device) that divides a space into a raw material chamber and a permeation chamber using an acidic gas separation film, supplies raw material gas (mixed gas formed of CO2, H2, and H2O) to the raw material chamber, and removes the acidic gas selectively separated out (through permeation) by the acidic gas separation film from the permeation chamber.
The acidic-gas separation module disclosed in JP4621295B is a facilitated transport type acidic-gas separation module using a so-called facilitated transport film as an acidic gas separation film. The facilitated transport film includes a carrier reacting with acidic gas in the film and separates acidic gas from raw material gas by the acidic gas being transported to the opposite side of the film using the carrier.
In such an acidic-gas separation module, with a so-called spiral-shaped module for acidic-gas separation obtained by winding a laminate that includes an acidic gas separation film around a central tube having through-holes on the wall surface (laminate is wrapped around the central tube), as described in JP1992-215824A (JP-H04-215824A), the area of the acidic gas separation film is able to be greatly increased. Accordingly, the spiral-shaped module for acidic-gas separation is capable of performing a treatment with high efficiency.
The spiral-shaped module for acidic-gas separation includes a supply gas channel member which becomes a raw material gas channel from which acidic gas is separated and a permeating gas channel member which becomes a channel of acidic gas separated out by an acidic gas separation film in addition to an acidic-gas separation film and a central tube, as an example.
The spiral-shaped module for acidic-gas separation including such members has a configuration in which one or a plurality of laminates, each of which is obtained by laminating the acidic gas separation film, the supply gas channel member, and the permeating gas channel member, are wound around the central tube.
For example, JP1992-215824A (JP-H04-215824A) discloses a spiral-shaped module for acidic-gas separation obtained by folding an acidic gas separation film into two and interposing a supply gas channel member (feed material spacer) therebetween, preparing a laminate formed by laminating a permeating gas channel member (permeating material spacer) on one surface of the acidic gas separation films folded into two, and winding a laminated product formed by laminating a plurality of the laminates around a central tube (permeating material collecting tube).
Further, a channel regulation member (sealing (adhesive) edge) which regulates a channel of acidic gas having permeated through an acidic gas separation film, and prevents the acidic gas having permeated through the acidic gas separation film from being mixed with raw material gas or the like is formed in the inside of the permeating gas channel member.
Here, raw material gas under the conditions of a high temperature and a high humidity is normally supplied to the acidic-gas separation module using a facilitated transport film at a high pressure. In addition, the acidic-gas separation module using a facilitated transport film is normally operated under a high temperature condition in order to prevent condensation of moisture contained in the raw material gas.
However, according to the examination of the present inventor, when a spiral-shaped module having a configuration of the above-described acidic-gas separation module using a facilitated transport film is configured, the facilitated transport film deteriorates and is damaged so that the performance of the acidic-gas separation module is gradually degraded in some cases due to the high temperature condition and the raw material gas supplied at a high pressure.
The present invention has been made for solving the problems of the related art, and an object thereof is to provide a spiral-shaped module for acidic-gas separation which uses an acidic-gas separation film (acidic-gas separation layer) including a facilitated transport film, prevents deterioration of the facilitated transport film caused by the high temperature condition and the raw material gas supplied at a high pressure, and stably exhibits a predetermined performance for a long period of time.
In order to achieve the above-described purpose, there is provided a spiral-shaped module for acidic-gas separation of the invention including: a central tube in a tube wall of which through-holes are formed; a supply gas channel member which becomes a channel of raw material gas; an acidic gas separation layer which separates acidic gas from raw material gas flowing in the supply gas channel member and includes a facilitated transport film that contains a carrier reacting with the acidic gas and a hydrophilic compound for carrying the carrier, and a porous support that supports the facilitated transport film; and a permeating gas channel member which is a channel in which the acidic gas having permeated through the acidic gas separation layer flows into the central tube, has a net shape formed of a metal wire having a wire diameter of 0.4 mm or less, and is provided with a channel regulation member to regulate the channel in the inside, in which at least one laminate including the supply gas channel member, the acidic gas separation layer, and the permeating gas channel member is wound around the central tube.
In the spiral-shaped module for acidic-gas separation of the present invention, it is preferable that the aperture of the permeating gas channel member is in a range of 0.05 mm to 0.3 mm.
Further, it is preferable that the channel regulation member also serves as an adhesive member that bonds the acidic gas separation layer to the permeating gas channel member.
Further, it is preferable that the viscosity of an adhesive which becomes the adhesive member is in a range of 5 Pa·sec to 60 Pa·sec.
Further, it is preferable that the permeating gas channel member is made of stainless steel.
Further, it is preferable that the channel regulation member is formed to have a rectangular shape in which a side of the central tube is open in the plane direction of the permeating gas channel member.
Further, it is preferable that the temperature of the raw material gas is 100° C. or higher.
Further, it is preferable that the spiral-shaped module for acidic-gas separation further includes a hydrophobic intermediate layer having gas permeability between the porous support and the facilitated transport film.
Further, it is preferable that the intermediate layer is a silicone resin layer.
Further, it is preferable that the facilitated transport film contains at least one metal element selected from a group consisting of Ti, Zr, Al, Si, and Zn.
Further, it is preferable that the content of the metal element in the facilitated transport film is in a range of 0.1% by mass to 50% by mass with respect to the total mass of the hydrophilic compound.
Further, it is preferable that the facilitated transport film contains a structural unit represented by Formula (1):
M-(O-*)m Formula (1)
M represents a metal element selected from the group consisting of Ti, Zr, Al, Si, and Zn. m represents the valence of the metal element represented by M. The symbol “*” represents a binding site.
According to the present invention, the spiral-shaped module for acidic-gas separation that uses a facilitated transport film can suitably prevent deterioration or damage to the facilitated transport film caused by the operation condition at a high temperature and the raw material gas supplied at a high pressure.
For this reason, according to the present invention, it is possible to obtain a spiral-shaped module for acidic-gas separation stably exhibiting a predetermined performance for a long period of time.
Hereinafter, a spiral-shaped module for acidic-gas separation of the present invention will be described in detail with reference to preferred examples illustrated in the accompanying drawings.
As illustrated in
The separation module 10 separates carbon dioxide as acidic gas Gc from raw material gas G containing carbon monoxide, carbon dioxide (CO2), water (water vapor), and hydrogen.
The separation module 10 of the present invention is a so-called spiral-shaped separation module. That is, the separation module 10 has a configuration in which one or a plurality of sheet-like laminates 14 are laminated on each other and wound around the central tube 12 and telescoping prevention plates 16 are provided on both end surfaces of the wound product of the laminate 14 into which the central tube 12 is inserted. Moreover, the outermost peripheral surface of the laminate 14 wound around the tube is covered by a gas-impermeable coating layer 18.
Further, for the sake of convenience of description, the wound product of a laminated product obtained by laminating a plurality of the laminates 14 which are wound around the central tube 12 is referred to as a spiral laminate 14a in the description below. In other words, the spiral laminate 14a is a substantially cylindrical product formed of the laminates 14 which are laminated on each other and wound around the central tube.
In such a separation module 10, the raw material gas G from which the acidic gas is separated passes through the telescoping prevention plate 16 (opening portion 16d) on the far side in
The acidic gas Gc separated from the raw material gas G by the laminate 14 is discharged from the central tube 12. In addition, the raw material gas G (hereinafter, for the sake of convenience of description, referred to as residual gas Gr) from which the acidic gas has been separated is discharged from the end surface on the side opposite to the supply side of the spiral laminate 14a (laminate 14), and is discharged outside of the separation module 10 after passing through the telescoping prevention plate 16 (in the same manner as described above).
The central tube (permeating gas collecting tube) 12 is a cylindrical tube, in which the end surface on the supply side of the raw material gas G is blocked, and in which a plurality of through-holes 12a are formed on the peripheral surface (tube wall) thereof.
The acidic gas Gc separated from the raw material gas G reaches the inside of the central tube 12 from the through-holes 12a after passing through a permeating gas channel member 26 described below and is discharged from an open end 12b of the central tube 12.
In the central tube 12, the opening ratio (the area ratio of the through-holes 12a occupying the outer peripheral surface of the central tube 12) in a region sealed by an adhesive layer 30 described below is preferably in a range of 1.5% to 80%, more preferably in a range of 3% to 75%, and still more preferably in a range of 5% to 70%. In this, from the practical viewpoint, the opening ratio of the central tube 12 is particularly preferably in a range of 5% to 25%.
When the opening ratio of the central tube 12 is in the above-described range, the acidic gas Gc can be efficiently collected, the strength of the central tube 12 is higher, and the processing suitability can be secured.
Further, it is preferable that the through-hole 12a is a circular hole having a diameter of 0.5 mm to 20 mm. Further, it is preferable that the through-holes 12a are uniformly formed on the peripheral wall of the central tube 12.
In addition, the central tube 12 may be provided with a supply port (supply unit) that supplies gas (sweep gas) for allowing the separated acidic gas Gc to flow into the open end 12b side as needed.
The laminate 14 is obtained by laminating the acidic gas separation layer 20, the supply gas channel member 24, and the permeating gas channel member 26 on each other. Here, in the separation module 10 of the present invention, the permeating gas channel member 26 is a net product made of a metal.
Further, in
The separation module 10 in the example of the figure has a configuration in which a plurality of the laminates 14 are laminated on each other, are wound around the central tube 12 (the laminates are wrapped around the central tube), and form a substantially cylindrical spiral laminate 14a.
Hereinafter, for the sake of convenience of description, a direction corresponding to the winding of the laminate 14 is set as a winding direction (arrow y direction) and a direction perpendicular to the winding direction is set as a width direction (arrow x direction).
In the separation module 10, one layer of the laminate 14 may be formed. However, as in the example of the figure, when a plurality of the laminates 14 are laminated on each other, the film area of the acidic gas separation layer 20 is increased and the amount of the acidic gas Gc separated out by one module can be increased. Moreover, the film area of the acidic gas separation layer 20 can be improved by making the length of the laminate 14 in the width direction larger.
The number of sheets of the laminates 14 to be laminated may be appropriately set according to the treatment rate and the treatment amount required for the separation module 10, the size of the separation module 10, and the like. Here, the number of sheets of the laminates 14 to be laminated is preferably 50 or less, more preferably 45 or less, and particularly preferably 40 or less. When the number of sheets of the laminates 14 to be laminated is in the above-described range, the winding of the laminates 14 around the central tube 12 becomes easy and the workability can be improved.
In the example of the figure, the laminate 14 has a configuration in which the supply gas channel member 24 is interposed between the acidic gas separation layers 20 folded into two to form a pinching body 36 (see
In the separation module 10, the raw material gas G passes through the telescoping prevention plate 16 (the opening portion 16d) and is supplied from one end surface of the spiral laminate 14a. That is, the raw material gas G is supplied to the end portion (end surface) of each laminate 14 in the width direction.
As conceptually illustrated in
The acidic gas Gc flowing into the permeating gas channel member 26 flows in the permeating gas channel member 26 in the winding direction (arrow y direction), and reaches the central tube 12. The acidic gas Gc having reached the central tube 12 flows into the central tube 12 from the through-holes 12a of the central tube 12.
The flow of the acidic gas Gc is regulated by the adhesive layer 30. That is, in the separation module 10, an envelope-like channel (space), in which the central tube 12 side is open, incorporating the permeating gas channel member 26 on the inside of the adhesive layer 30 in the plane direction is formed by two acidic gas separation layers 20 (facilitated transport films 20a) between which the permeating gas channel member 26 is interposed and the adhesive layer 30 having infiltrated into the permeating gas channel member 26 and the acidic gas separation layer 20 (porous support 20b) (see
The adhesive layer 30 will be described below in detail.
The acidic gas Gc flowing into the central tube 12 flows in the central tube 12 in the width direction and is discharged from the open end 12b.
Further, the residual gas Gr from which the acidic gas Gc has been removed flows into the supply gas channel member 24 in the width direction, is discharged from the end surface on the opposite side of the spiral laminate 14a, passes through the telescoping prevention plate 16 (the opening portion 16d), and is discharged outside of the separation module 10.
The supply gas channel member 24 supplies the raw material gas G from the end portion in the width direction thereof and brings the raw material gas G flowing in the member into contact with the acidic gas separation layer 20.
Such a supply gas channel member 24 functions as a spacer of the acidic gas separation layers 20 folded into two as described above and constitutes a channel of the raw material gas G. Further, it is preferable that the supply gas channel member 24 causes turbulence in the raw material gas G. In consideration of this point, it is preferable that the supply gas channel member 24 is a member having a net shape (net-like/mesh-like).
As materials for forming such a supply gas channel member 24, various materials can be used as long as the materials have sufficient heat resistance and moisture resistance.
Preferred examples thereof include paper materials such as paper, high-quality paper, coated paper, cast-coated paper, and synthetic paper; resin materials such as cellulose, polyester, polyolefin, polyamide, polyimide, polysulfone, aramid, and polycarbonate; and inorganic materials such as metals, glass, and ceramics.
Specific examples of the resin materials include polyethylene, polystyrene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyphenylene sulfide (PPS), polysulfone (PSF), polypropylene (PP), polyimide, polyetherimide, polyether ether ketone, and polyvinylidene fluoride. Such resin materials may be used in combination of plural kinds thereof.
The thickness of the supply gas channel member 24 may be appropriately determined according to the amount of the raw material gas G to be supplied or treatment performance to be required.
Specifically, the thickness thereof is preferably in a range of 100 μm to 1000 μm, more preferably in a range of 150 μm to 950 μm, and particularly preferably in a range of 200 μm to 900 μm.
The separation module 10 of the present invention is a facilitated transport type module. Accordingly, the acidic gas separation layer 20 is configured of the facilitated transport film 20a and the porous support 20b.
The facilitated transport film 20a includes at least a carrier reacting with the acidic gas Gc contained in the raw material gas G that flows in the supply gas channel member 24 and a hydrophilic compound carrying the carrier. Such a facilitated transport film 20a has a function of allowing the acidic gas Gc to selectively permeate from the raw material gas G (function of selectively transporting the acidic gas Ge).
A property of the facilitated transport type separation module which is required is that the module can be used in a high temperature and high humidity environment. Accordingly, the facilitated transport film 20a has a function of allowing the acidic gas Gc to selectively permeate in a high temperature condition (for example, in a temperature range of 100° C. to 200° C.). Further, when a hydrophilic compound absorbs water vapor so that the facilitated transport film 20a holds moisture even if the raw material gas G contains water vapor, since a carrier more easily transports the acidic gas Gc, the separation efficiency becomes higher than in a case of using a dissolution diffusion film.
The film area of the facilitated transport film 20a may be appropriately set according to the size of the separation module 10, the treatment performance required for the separation module 10, and the like. Specifically, the film area is preferably in a range of 0.01 m2 to 1000 m2, more preferably in a range of 0.02 m2 to 750 m2, and still more preferably in a range of 0.025 m2 to 500 m2. In this, from the practical viewpoint, the film area of the facilitated transport film 20a is particularly preferably in a range of 1 m2 to 100 m2.
When the film area of the facilitated transport film 20a is in the above-described range, the acidic gas Gc can be efficiently separated out with respect to the film area and the workability becomes improved.
The length of the facilitated transport film 20a (total length before folding into two) in the winding direction may be appropriately set according to the size of the separation module 10, the treatment performance required for the separation module 10, and the like. Specifically, the length thereof is preferably in a range of 100 mm to 10,000 mm, more preferably in a range of 150 mm to 9000 mm, and still more preferably in a range of 200 mm to 8000 mm. In this, from the practical viewpoint, the length of the facilitated transport film 20a is particularly preferably in a range of 800 mm to 4000 mm.
When the length of the facilitated transport film 20a in the winding direction is in the above-described range, the acidic gas Gc can be efficiently separated out with respect to the film area. Further, generation of winding deviation at the time of winding the laminate 14 is suppressed, and the workability is improved.
Further, the width of the facilitated transport film may be appropriately set according to the size of the separation module 10 in the width direction.
The thickness of the facilitated transport film 20a may be appropriately set according to the size of the separation module 10, the treatment performance required for the separation module 10, and the like. Specifically, the thickness thereof is preferably in a range of 1 μm to 200 μm and more preferably in a range of 2 μm to 175 μm.
High gas permeability and separation selectivity can be realized by adjusting the thickness of the facilitated transport film 20a to be in the above-described range.
A hydrophilic compound functions as a binder, holds moisture in the facilitated transport film 20a, and exhibits a function of separating out gas such as carbon dioxide using a carrier. Moreover, it is preferable that the hydrophilic compound has a cross-linked structure from a viewpoint of heat resistance.
As such a hydrophilic compound, a hydrophilic polymer is exemplified.
A hydrophilic compound having high hydrophilicity is preferable from viewpoints that the hydrophilic compound is dissolved in water and capable of forming a coating solution and it is preferable that the facilitated transport film 20a has high hydrophilicity (moisture-retaining properties).
Specifically, the hydrophilic compound has a hydrophilicity at which the water absorption amount of physiological saline is preferably 0.5 g/g or greater, more preferably 1 g/g or greater, still more preferably 5 g/g or greater, particularly preferably 10 g/g or greater, and most preferably 20 g/g or greater.
The weight average molecular weight of the hydrophilic compound may be appropriately selected within the range in which a stable film can be formed. Specifically, the weight average molecular weight thereof is preferably 20,000 to 2,000,000, more preferably 25,000 to 2,000,000, and particularly preferably 30,000 to 2,000,000.
By adjusting the weight average molecular weight of the hydrophilic compound to be 20,000 or greater, the facilitated transport film 20a which is stabilized and has sufficient film strength can be obtained.
In a case where the hydrophilic compound includes a hydroxy group (—OH) as a crosslinkable group, the weight average molecular weight of the hydrophilic compound is preferably 30,000 or greater. At this time, the weight average molecular weight thereof is more preferably 40,000 or greater and still more preferably 50,000 or greater. Further, in the case where the hydrophilic compound includes a hydroxy group as a crosslinkable group, the weight average molecular weight thereof is preferably 6,000,000 or less from a viewpoint of production suitability.
In addition, in a case where the hydrophilic compound includes an amino group (—NH2) as a crosslinkable group, the weight average molecular weight of the hydrophilic compound is preferably 10,000 or greater. At this time, the weight average molecular weight of the hydrophilic compound is more preferably 15,000 or greater and particularly preferably 20,000 or greater. Further, in the case where the hydrophilic compound includes an amino group as a crosslinkable group, the weight average molecular weight thereof is preferably 1,000,000 or less from a viewpoint of production suitability.
Further, a value measured in conformity with JIS K6726 may be used as the weight average molecular weight of the hydrophilic compound in a case where PVA is used as the hydrophilic compound. In addition, when a commercially available product is used, the molecular weight known by a catalog or a specification may be used.
As a crosslinkable group that forms a hydrophilic compound, one which can form a hydrolysis-resistant cross-linked structure is preferably selected.
Specific examples thereof include a hydroxy group (—OH), an amino group (—NH2), a chlorine atom (—Cl), a cyano group (—CN), a carboxy group (—COOH), and an epoxy group. Among these, an amino group and a hydroxy group are preferable. Further, from viewpoints of affinity for a carrier and an effect of carrying a carrier, a hydroxy group is most preferable.
Examples of the hydrophilic compound which has a single crosslinkable group include polyallylamine, polyacrylic acid, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, polyethyleneimine, polyvinylamine, polyornithine, polylysine, polyethylene oxide, water-soluble cellulose, starch, alginic acid, chitin, polysulfonic acid, polyhydroxy methacrylate, and poly-N-vinylacetamide. Polyvinyl alcohol is most preferable. In addition, as the hydrophilic compound, a copolymer of these may be exemplified.
Further, examples of the hydrophilic compound having a plurality of crosslinkable groups include a polyvinyl alcohol-polyacrylic acid copolymer. A polyvinyl alcohol-polyacrylic salt copolymer has high water absorption performance and high hydrogel strength at the time of high water absorption, which is preferable.
The percentage content of polyacrylic acid in the polyvinyl alcohol-polyacrylic acid copolymer is in a range of 1% by mole to 95% by mole, preferably in a range of 2% by mole to 70% by mole, still more preferably in a range of 3% by mole to 60% by mole, and particularly preferably in a range of 5% by mole to 50% by mole.
In addition, in the polyvinyl alcohol-polyacrylic acid copolymer, there may be a salt of polyacrylic acid. As the polyacrylate at this time, an ammonium salt or an organic ammonium salt may be exemplified in addition to an alkali metal salt such as a sodium salt or a potassium salt.
The polyvinyl alcohol may be a commercially available product. Specific examples thereof include PVA117 (manufactured by KURARAY CO., LTD.), POVAL (manufactured by KURARAY CO., LTD.), polyvinyl alcohol (manufactured by Sigma-Aldrich Japan K.K.), and J-POVAL (manufactured by JAPAN VAM&POVAL CO., LTD.). The range of the molecular weight varies, but a product having a weight average molecular weight of 130,000 to 300,000 is preferable.
The polyvinyl alcohol-polyacrylate copolymer (sodium salt) may be a commercially available product. For example, KURASTOMER AP20 (manufactured by KURARAY CO., LTD.) is exemplified.
In the facilitated transport film 20a of the separation module 10 of the present invention, hydrophilic compounds may be used in a mixture of two or more kinds thereof.
The content of the hydrophilic compound in the facilitated transport film 20a may be determined by appropriately setting the amount thereof which can function as a binder in order to form the facilitated transport film 20a and can sufficiently hold moisture according to the kind of hydrophilic composition or carrier.
Specifically, the content thereof is preferably in a range of 0.5% by mass to 50% by mass, more preferably in a range of 0.75% by mass to 30% by mass, and particularly preferably in a range of 1% by mass to 15% by mass. When the content of the hydrophilic compound is in the above-described range, the function as a binder and the function of holding moisture described above can be stably and suitably exhibited.
The cross-linked structure of the hydrophilic compound can be formed using a known method of the related art, for example, thermal crosslinking, ultraviolet crosslinking, electron beam crosslinking, radiation crosslinking, or photocrosslinking.
Photocrosslinking or thermal crosslinking is preferable and thermal crosslinking is most preferable.
Further, it is preferable to use a crosslinking agent together with a hydrophilic compound in order to form the facilitated transport film 20a. That is, it is preferable to use a coating composition containing a crosslinking agent when the facilitated transport film 20a is formed by a coating method.
As the crosslinking agent, a crosslinking agent including two or more functional groups which react with a hydrophilic compound and are capable of performing crosslinking such as thermal crosslinking or photocrosslinking is selected. Further, it is preferable that the cross-linked structure to be formed is a hydrolysis-resistant cross-linked structure.
From this viewpoint, preferred examples of the crosslinking agent to be used for forming the facilitated transport film 20a include an epoxy crosslinking agent, a polyvalent glycidyl ether, a polyhydric alcohol, a polyvalent isocyanate, a polyvalent aziridine, a haloepoxy compound, a polyvalent aldehyde, a polyvalent amine, and an organic metal-based crosslinking agent. A polyvalent aldehyde, an organic metal-based crosslinking agent, and an epoxy crosslinking agent are more preferable. Among these, a polyvalent aldehyde such as glutaraldehyde or formaldehyde having two or more aldehyde groups is preferable.
As the epoxy crosslinking agent, a compound including two or more epoxy groups may be exemplified and a compound including four or more epoxy groups is preferable. The epoxy crosslinking agent is also commercially available and examples thereof include trimethylolpropane triglycidyl ether (EPOLIGHT 100MF or the like, manufactured by KYOEISHA CHEMICAL Co., LTD.), EX-411, EX-313, EX-614B, EX-810, EX-811, EX-821, EX-830, (all manufactured by Nagase Chemtex Corporation), and EPIOL E400 (manufactured by NOF CORPORATION).
In addition, as a compound similar to an epoxy crosslinking agent, an oxetane compound having a cyclic ether is preferably used. A polyvalent glycidyl ether having two or more functional groups is preferable as an oxetane compound. A commercially available product can be used for an oxetane compound. Examples of commercially available product for an oxetane compound include EX-411, EX313, EX-614B, EX-810, EX-811, EX-821, and EX-830 (all manufactured by Nagase Chemtex Corporation).
Examples of the polyvalent glycidyl ether include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, pentaerythritol polyglycidyl ether, propylene glycol glycidyl ether, and polypropylene glycol diglycidyl ether.
Examples of the polyhydric alcohol include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, glycerin, polyglycerin, propylene glycol, diethanolamine, triethanolamine, polyoxypropyl, an oxyethylene-oxypropylene block copolymer, pentaerythritol, and sorbitol.
Examples of the polyvalent isocyanate include 2,4-toluylene diisocyanate and hexamethylene diisocyanate.
Examples of the polyvalent aziridine include 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate], 1,6-hexamethylene diethylene urea, and diphenylmethane-bis-4,4′-N,N′-diethylene urea.
Examples of the haloepoxy compound include epichlorohydrin and α-methylchlorohydrin.
Examples of the polyvalent aldehyde include glutaraldehyde and glyoxal.
Examples of the polyvalent amine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, and polyethyleneimine.
Further, examples of the organic metal-based crosslinking agent include an organic titanium crosslinking agent and an organic zirconia crosslinking agent.
For example, in a case where a polyvinyl alcohol having a weight average molecular weight of 130,000 or greater is used as a hydrophilic compound, an epoxy crosslinking agent or glutaraldehyde is preferably used in terms of excellent reactivity with the hydrophilic compound and capability of forming a cross-linked structure having excellent hydrolysis resistance.
In a case where a polyvinyl alcohol-polyacrylic acid copolymer is used as a hydrophilic compound, an epoxy crosslinking agent or glutaraldehyde is preferably used.
In a case where a polyallylamine having a weight average molecular weight of 10,000 or greater is used as a hydrophilic compound, an epoxy crosslinking agent, glutaraldehyde, or an organic metal crosslinking agent is preferably used in terms of excellent reactivity with the hydrophilic compound and capability of forming a cross-linked structure having excellent hydrolysis resistance.
In a case where a polyethyleneimine or polyallylamine is used as a hydrophilic compound, an epoxy crosslinking agent is preferably used.
The amount of a crosslinking agent may be appropriately set according to the kind of hydrophilic compound or crosslinking agent used for forming the facilitated transport film 20a.
Specifically, the amount thereof is preferably in a range of 0.001 parts by mass to 80 parts by mass, more preferably 0.01 parts by mass to 60 parts by mass, and particularly preferably 0.1 parts by mass to 50 parts by mass with respect to 100 parts by mass of a crosslinkable group included in the hydrophilic compound. When the content of the crosslinking agent is adjusted to be in the above-described range, the formation properties of the cross-linked structure become excellent and a facilitated transport film with excellent shape-maintaining properties can be obtained.
In addition, when the crosslinkable group included in the hydrophilic compound is considered, it is preferable that the cross-linked structure is formed by reacting 0.001 mol to 80 mol of a crosslinking agent with 100 mol of the crosslinkable group included in the hydrophilic compound.
It is preferable that the facilitated transport film 20a contains metal elements. As a preferable embodiment of the facilitated transport film 20a, an embodiment in which the facilitated transport film contains at least one metal element selected from a group consisting of Ti, Zr, Al, Si, and Zn is exemplified. When such a metal element is contained, the strength of the facilitated transport film 20a is improved. Particularly, when a crosslinking structure having the above-described metal elements is formed as described below, the strength of the facilitated transport film 20a is further improved and thus deterioration of the facilitated transport film 20a at the time of winding in the form of a spiral is more suppressed.
The form of the facilitated transport film 20a containing such a metal element is not particularly limited, but a facilitated transport film having a structural unit represented by the following Formula (1) is preferable. Further, the symbol “*” in the following Formula (1) represents a binding position.
M-(O-*)m Formula (1)
In the formula, M represents a metal element selected from the group consisting of titanium (Ti), zirconium (Zr), aluminum (Al), silicon (Si), and zinc (Zn).
m represents the valence of the metal element represented by M. For example, as described below, m represents 2 when M represents Zn, m represents 3 when M represents Al, and m represents 4 when M represents Ti, Zr, and Si.
More specifically, structural formulae (Formulae (2) to (4)) are shown below in the case where m represents 2 to 4.
The structural unit represented by Formula (1) can be introduced to the facilitated transport film 20a by combining a hydrolyzable compound with a hydrophilic compound having the above-described crosslinkable group (for example, a hydroxy group) as described below. In this case, the structural unit functions as a so-called crosslinking moiety (crosslinking structure).
Further, as a method of detecting the structural unit represented by Formula (1) in the facilitated transport film 20a, the structural unit thereof can be verified by detecting specific peaks through IR measurement. The IR measurement may be performed on remaining films after carriers in the facilitated transport film 20a are removed if necessary.
The total mass of the metal elements in the facilitated transport film 20a is not particularly limited, but the content of the metal elements is preferably in a range of 0.1% by mass to 50% by mass, more preferably in a range of 0.3% by mass to 20% by mass, and still more preferably in a range of 0.5% by mass to 10% by mass with respect to the total mass of the hydrophilic compound in terms that the facilitated transport film 20a has superior strength.
The method of measuring the content of metal elements is not particularly limited and the content thereof can be measured by fluorescent X-ray spectroscopy.
As described above, when the structural unit represented by Formula (1) is introduced to the facilitated transport film 20a, it is preferable that a hydrolyzable compound containing the above-described metal elements is used, and specific example thereof include a hydrolyzable compound represented by Formula (5) is exemplified. These compounds function as a so-called organic metal crosslinking agent.
M(X)m Formula (5)
In Formula (5), M represents a metal element selected from the group consisting of titanium (Ti), zirconium (Zr), aluminum (Al), silicon (Si), and zinc (Zn).
X represents a hydrolyzable group. Examples of the hydrolyzable group include an alkoxyl group, an isocyanate group, a halogen atom such as a chlorine atom, an oxyhalogen group, an acetylacetonate group, and a hydroxy group. A plurality of X's may be the same as or different from each other.
m represents the valence of the metal element represented by M.
In the acidic gas separation layer 20 of the separation module 10, the facilitated transport film 20a contains a carrier in addition to such a hydrophilic compound.
The carrier may be various kinds of water-soluble compound which have affinity for acidic gas (for example, carbon dioxide) and show basicity. Specific examples thereof include an alkali metal compound, a nitrogen-containing compound, and a sulfur oxide.
In addition, a carrier may indirectly react with acidic gas or the carrier itself may directly react with acidic gas.
Examples of the former include carriers which react with another gas contained in a supply gas and show basicity and in which a basic compound thereof reacts with acidic gas. More specifically, the former is a compound which is capable of selectively taking CO2 into the facilitated transport film 20a, for example, an alkali metal compound by reacting with steam (moisture) to release OH— and allowing OH— to react with CO2.
Examples of the latter include a nitrogen-containing compound and a sulfur oxide in which a carrier has basicity.
Examples of the alkali metal compound include alkali metal carbonates, alkali metal bicarbonates, and an alkali metal hydroxides. Here, an alkali metal element selected from cesium, rubidium, potassium, lithium, and sodium is preferably used as an alkali metal. In addition, in the present invention, the alkali metal compound includes salts and ions thereof in addition to an alkali metal.
Examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.
Examples of the alkali metal bicarbonate include lithium hydrogencarbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, rubidium hydrogencarbonate, and cesium hydrogencarbonate.
Further, examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide.
Among these, an alkali metal carbonate is preferable, and a compound containing potassium, rubidium, and cesium which have high solubility in water are preferable from a viewpoint of excellent affinity for acidic gas.
Moreover, when an alkali metal compound is used as a carrier, two or more kinds of carrier may be used in combination.
When two or more kinds of carrier are present in the facilitated transport film 20a, different kinds of carriers in the film can be separated from each other. In this manner, adhesion (blocking) of the facilitated transport films 20a to each other or adhesion of the facilitated transport film 20a to another member, caused by hygroscopicity of the facilitated transport film 20a, can be suitably suppressed at the time of production or the like due to a difference in deliquescency among a plurality of carriers.
In addition, in a case where two or more kinds of alkali metal compound are used as carriers, it is preferable that a first compound having deliquescency and a second compound having less deliquescency and a smaller specific specific gravity than those of the first compound are included. When a carrier includes a first compound having deliquescency and a second compound having less deliquescency and a smaller specific gravity than those of the first compound, the effect of suppressing blocking can be more suitably obtained. As an example, cesium carbonate is exemplified as the first compound and potassium carbonate is exemplified as the second compound.
As the nitrogen-containing compounds, amino acids such as glycine, alanine, serine, proline, histidine, taurine, and diaminopropionic acid; hetero compounds such as pyridine, histidine, piperazine, imidazole, and triazine; alkanolamines such as monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, dipropanolamine, and tripropanolamine; cyclic polyether amines such as cryptand[2.1] and cryptand[2.2]; bicyclic polyether amines such as cryptand[2.2.1] and cryptand[2.2.2]; porphyrin; phthalocyanine; and ethylenediaminetetraacetic acid can be used.
As sulfur compounds, amino acids such as cystine and cysteine; polythiophene; and dodecylthiol can be used.
The content of carriers in the facilitated transport film 20a may be suitably set according to the kind of carrier and hydrophilic compound. Specifically, the content thereof is preferably in a range of 0.3% by mass to 30% by mass, more preferably in a range of 0.5% by mass to 25% by mass, and particularly preferably in a range of 1% by mass to 20% by mass.
When the content of the carriers in the facilitated transport film 20a is adjusted to be in the above-described range, salting-out before application can be suitably prevented in a composition (coating material) used for forming the facilitated transport film 20a. Further, the facilitated transport film 20a can reliably exhibit the function of separating out acidic gas.
The facilitated transport film 20a (composition used for forming the facilitated transport film 20a) may contain various components as needed in addition to such a hydrophilic compound, a crosslinking agent, and a carrier.
Examples of such a component include an antioxidant such as dibutylhydroxytoluene (BHT); a specific compound such as a compound which includes an alkyl group having 3 to 20 carbon atoms or a fluorinated alkyl compound having 3 to 20 carbon atoms and a hydrophilic group, or a compound having a siloxane structure; a surfactant such as sodium octanate or sodium 1-hexasulfonate; and polymer particles such as polyolefin particles or polymethyl methacrylate particles.
In addition, if necessary, a catalyst, a moisturizing agent (moisture absorbent), a co-solvent, a film strength control agent, or a defect detection agent may be used.
The acidic gas separation layer 20 is configured of such a facilitated transport film 20a and the porous support 20b.
The porous support 20b has acidic gas permeability, allows application of a coating composition (capable of supporting a coating film) for forming the facilitated transport film 20a to be performed thereon, and supports the formed facilitated transport film 20a.
Various kinds of known materials can be used as the materials for forming the porous support 20b when the materials can exhibit the above-described function.
In the separation module 10 of the present invention, the porous support 20b constituting the acidic gas separation layer 20 may be formed of a single layer, but it is preferable that the porous support 20b has a two-layer structure formed of a porous film and an auxiliary support film. When the porous support 20b has such a two-layer structure, the porous support 20b more reliably exhibits the acidic gas permeability and functions of the application of a coating composition which becomes the facilitated transport film 20a and the support of the facilitated transport film 20a.
Moreover, in the case where the porous support 20b is formed of a single layer, examples of various materials for the following porous film and the auxiliary support film can be used as the formation material thereof.
In the porous support 20b having the two-layer structure, the porous film becomes the facilitated transport film 20a side.
It is preferable that the porous film has heat resistance and is formed of a material having low hydrolyzability. Specific examples of such a porous film include a membrane filter film such as those of polysulfone, polyethersulfone, polypropylene, or cellulose; an interfacial polymerization thin film such as those of polyamide or polyimide; and a stretched porous film such as those of polytetrafluoroethylene (PTFE) or high molecular weight polyethylene.
Among these, a stretched porous film such as PTFE or high-molecular-weight polyethylene is preferable from viewpoints of having high porosity, less diffusion inhibition of acidic gas (particularly, carbon dioxide), strength, production suitability, and the like. Among stretched porous films, a stretched porous film of PTFE is preferably used in terms of heat resistance, less hydrolyzability, and the like.
In order for the facilitated transport film 20a containing moisture and a coating composition which becomes a facilitated transport film to easily infiltrate into a porous portion in a use environment and for performance of film thickness distribution or aging not to be degraded, it is preferable that the porous film is hydrophobic.
The maximum pore diameter of the porous film is preferably 1 μm or less.
Further, the average pore diameter of the porous film is preferably in a range of 0.001 μm to 10 μm, more preferably in a range of 0.002 μm to 5 μm, and particularly preferably in a range of 0.005 μm to 1 μm. When the average pore diameter of the porous film is adjusted to be in the above-described range, an adhesive sufficiently permeates into a region to be coated with the adhesive described below, and it is possible to suitably prevent the porous film from inhibiting passing through of acidic gas.
The auxiliary support film is provided for reinforcing the porous film.
Various kinds of material can be used for the porous support film as long as the strength, drawing resistance, and gas permeability to be required for the film are satisfied. For example, non-woven fabric, woven fabric, a net, and a mesh having an average pore diameter of 0.001 μm to 10 μm can be appropriately selected and used.
It is preferable that the auxiliary support film is formed of a material which has heat resistance and low hydrolyzability similar to the porous film described above.
As fibers constituting the non-woven fabric, woven fabric, or knitted fabric, fibers formed of polyolefin such as polypropylene (PP); reforming polyamide such as ARAMID (trade name); and a fluorine-containing resin such as polytetrafluoroethylene or polyvinylidene fluoride which have excellent durability and heat resistance are preferable. It is preferable that the same materials are used for resin materials constituting a mesh. Among these materials, a particularly suitable example is non-woven fabric formed of polypropylene (PP) which is inexpensive and has high mechanical strength.
When the porous support 20b includes the auxiliary support film, the mechanical strength can be improved. For this reason, even though handling is performed by a coating device using a roll-to-roll system (hereinafter, also referred to as RtoR) described below, it is possible to prevent the porous support 20b from becoming wrinkled and the productivity can be improved.
When the porous support 20b is thin, strength is a problem. In consideration of this point, the film thickness of the porous film is preferably in a range of 5 μm to 100 μm and the film thickness of the auxiliary support film is in a range of 50 μm to 300 μm.
In the case where the porous support 20b is formed of a single layer, the thickness of the porous support 20b is preferably in the range of 30 μm to 500 μm.
The acidic gas separation layer 20 can be produced using a so-called coating method in which a liquid coating composition (coating material/coating solution) containing a component which becomes the facilitated transport film 20a is prepared and the porous support 20b is coated with the coating composition and dried.
Moreover, in a case where the acidic gas separation layer 20 includes an intermediate layer described below between the porous support 20b and the facilitated transport film 20a, the intermediate layer is formed on the porous support 20b and then the facilitated transport film 20a may be formed on the intermediate layer as described below.
That is, first, a coating composition which becomes the facilitated transport film 20a can be prepared by adding respectively appropriate amounts of a hydrophilic compound, a carrier, and other components to be added if necessary to water (room temperature water or hot water) and sufficiently stirring the solution.
In the preparation of the coating composition, dissolution of each component may be promoted by stirring and heating the solution if necessary. In addition, after a hydrophilic compound is added to water and dissolved therein, deposition (salting-out) of the hydrophilic compound can be effectively prevented by gradually adding a carrier to the solution and stirring the same.
The acidic gas separation layer 20 is prepared by coating the porous support 20b with the composition and drying the porous support.
Here, the application and the coating of the composition may be performed with a cut sheet-like porous support 20b, a so-called sheet type, which is cut to have a predetermined size.
Preferably, the preparation of the acidic gas separation layer 20 is performed by so-called RtoR. That is, the porous support 20b is sent from a feeding roll formed by being wound around a long porous support 20b, conveyed in the longitudinal direction, and coated with the prepared composition. Next, the coating composition (coating film) which is applied to the support is dried, the acidic gas separation layer 20 is obtained by forming the facilitated transport film 20a on the surface of the porous support 20b, and the prepared acidic gas separation layer 20 is wound.
The conveying speed of the porous support 20b in RtoR may be appropriately set according to the kind of porous support 20b or the viscosity of the coating solution.
Here, when the conveying speed of the porous support 20b is extremely high, the uniformity in film thickness of a coating film of the coating composition may be decreased. Further, when the conveying speed thereof is extremely low, the productivity is decreased. When this point is considered, the conveying speed of the porous support 20b is preferably 0.5 m/min or greater, more preferably 0.75 m/min to 200 m/min, and particularly preferably 1 m/min to 200 m/min.
Various kinds of known method can be used as the method of applying the coating composition.
Specific examples thereof include a curtain flow coater, an extrusion die coater, an air doctor coater, a blade coater, a rod coater, a knife coater, a squeeze coater, a reverse roll coater, and a bar coater.
The coating film of the coating composition may be dried using a known method. As an example, a drying method using hot air is exemplified.
The air speed of the hot air may be appropriately determined by setting a speed thereof which can rapidly dry a gel membrane and at which the gel membrane does not collapse. Specifically, the air speed thereof is preferably in a range of 0.5 m/min to 200 m/min, more preferably in a range of 0.75 m/min to 200 m/min, and particularly preferably in a range of 1 m/min to 200 m/min.
The temperature of the hot air may be determined by appropriately setting a temperature at which deformation or the like of the porous support 20b does not occur and the gel membrane can be rapidly dried. Specifically, the temperature of the film surface is preferably in a range of 1° C. to 120° C., more preferably 2° C. to 115° C., and particularly preferably 3° C. to 110° C.
The porous support 20b may be heated for drying the coating film if necessary.
As described above, in the porous support 20b of the acidic gas separation layer 20, at least the surface on a side in contact with the facilitated transport film 20a has a hydrophobicity from a viewpoint of suppressing permeation of the facilitated transport film 20a or the coating composition which becomes the facilitated transport film 20a.
Further, since the facilitated transport film 20a is required to hold a large amount of moisture in the film in order to make a carrier sufficiently function, a polymer having extremely high water absorption properties and water-retaining properties is used. In addition, the water absorption amount increases in the facilitated transport film 20a and separation performance of the acidic gas improves as the content of a carrier such as a metal carbonate becomes larger. For this reason, the facilitated transport film 20a is likely to be a gel film or a film having low viscosity. Further, at the time of separating out of the acidic gas, the raw material gas, for example, in a temperature range of 100° C. to 130° C. and at a humidity of approximately 90% is supplied at a pressure of approximately 1.5 MPa. Consequently, due to this use, the separation layer gradually permeates into the porous support 20b and separation performance of the acidic gas tends to be degraded with time.
In order to prevent such inconvenience, it is preferable that the acidic gas separation layer 20 includes an intermediate layer, which more effectively suppresses permeation of the facilitated transport film 20a into the porous support 20b, between the porous support 20b and the facilitated transport film 20a.
The intermediate layer is not particularly limited as long as the layer has gas permeability with hydrophobicity, but it is preferable that the intermediate layer has air conductivity and is a layer denser than the porous support 20b. When such an intermediate layer is included, it is possible to prevent the facilitated transport film 20a having high uniformity from infiltrating into the porous support 20b.
The intermediate layer may be formed on the porous support 20b or may have an infiltration region which infiltrates into the porous support 20b. It is preferable that the infiltration region is smaller within a range in which properties of adhesion of the porous support 20b to the intermediate layer are excellent.
As the intermediate layer, a polymer layer (silicone resin layer) having a siloxane bond in a repeating unit is preferable. Examples of the polymer layer include silicone-containing polyacetylene such as organopolysiloxane (a silicone resin) or polytrimethyl silyl propyne. As a specific example of the organopolysiloxane, an organopolysiloxane represented by the following formula is exemplified.
Further, in the formula above, n represents an integer of 1 or greater. Here, from viewpoints of availability, volatility, and viscosity, the average value of n is preferably in a range of 10 to 1,000,000 and more preferably in a range of 100 to 100,000.
In addition, R1n, R2n, R3, and R4 each independently represent any one selected from a group consisting of a hydrogen atom, an alkyl group, a vinyl group, an aralkyl group, an aryl group, a hydroxyl group, an amino group, a carboxyl group, and an epoxy group. Further, n number of R1n's and R2n's may be the same as or different from each other. In addition, an alkyl group, an aralkyl group, and an aryl group may have a ring structure. Further, the alkyl group, the vinyl group, the aralkyl group, and the aryl group may include a substituent and the substituent is selected from an alkyl group, a vinyl group, an aryl group, a hydroxyl group, an amino group, a carboxyl group, an epoxy group, and a fluorine atom. These substituents can further include a substituent if possible.
As an alkyl group, a vinyl group, an aralkyl group, and an aryl group selected for R1n, R2n, R3, and R4, from a viewpoint of availability, an alkyl group having 1 to 20 carbon atoms, a vinyl group, an aralkyl group having 7 to 20 carbon atoms, and an aryl group having 6 to 20 carbon atoms are preferable.
Particularly, it is preferable that R1n, R2n, R3, and R4 represent a methyl group or an epoxy-substituted alkyl group, and epoxy-modified polydimethyl siloxane (PDMS) or the like can be suitably used.
The intermediate layer is a film having gas permeability, but the gas permeability can be significantly degraded when the thickness thereof is large. The intermediate layer may be thin if the intermediate layer entirely covers the surface of the porous support 20b without any space left.
From this viewpoint, the film thickness of the intermediate layer is preferably in a range of 0.01 μm to 30 μm and more preferably in a range of 0.1 μm to 15 μm.
It is preferable that such an intermediate layer is formed by a coating method.
A coating composition (second coating composition) which becomes an intermediate layer may include a monomer, a dimer, a trimer, an oligomer, or a prepolymer of a compound which becomes an intermediate layer of the above-described PDMS derivative, or a normal coating composition (coating solution/coating material) which contains a mixture of these and is used for forming a resin layer (resin film) according to a coating method. The coating composition may be formed by dissolving (dispersing) a monomer or the like in an organic solvent and may further include a curing agent, a curing accelerator, a crosslinking agent, a thickener, a reinforcing agent, or a filler.
The coating composition which becomes such an intermediate layer may be prepared by a known method.
Moreover, various kinds of known coating methods of the coating composition which becomes an intermediate layer can be used similar to the case of the coating composition which becomes the above-described facilitated transport film 20a. The thickness of the coating film of the coating composition may be appropriately set according to the kind of intermediate layer to be formed and the concentration of the coating composition such that the thickness of the intermediate layer is in a range of 0.01 μm to 30 μm as described above.
As a method of curing the coating composition, various kinds of known methods such as UV irradiation, heating and curing, and electron beam irradiation can be used according to a monomer which becomes an intermediate layer. In addition, the coating composition may be dried by evaporating an organic solvent as needed before the curing composition is cured.
In addition, an intermediate layer may be formed using so-called RtoR in the same manner as that of the facilitated transport film 20a.
In a case where the acidic gas separation layer 20 includes such an intermediate layer between the porous support 20b and the facilitated transport film 20a, an intermediate layer is formed on the porous support 20b and then the facilitated transport film 20a is formed on the intermediate layer in the same manner as described above.
The permeating gas channel member 26 is further laminated on the laminate 14.
The permeating gas channel member 26 is a member for allowing the acidic gas Gc having permeated into the acidic gas separation layer 20 by reacting with a carrier to flow into the through-holes 12a of the central tube 12.
In the example illustrated in the figure, the laminate 14 has a pinching body 36 formed by interposing the supply gas channel member 24 between the acidic gas separation layers 20 which are folded into two so that the facilitated transport film 20a is inside. One laminate 14 is configured by laminating the permeating gas channel member 26 on the pinching body 36 and bonding the permeating gas channel member 26 to the pinching body 36 using the adhesive layer 30.
The permeating gas channel member 26 functions as a spacer between the laminates 14 and forms a channel of the acidic gas Gc that reaches the through-holes 12a of the central tube 12 toward the center of the winding (inside) of the laminates 14 and is separated from the raw material gas G.
The adhesive layer 30 is formed in the inside of the permeating gas channel member 26. For the purpose of suitably forming the adhesive layer 30, infiltration of the adhesive layer 30 (adhesive 30a) described below into the permeating gas channel member 26 is required. From this viewpoint, the permeating gas channel member 26 is a member having a net shape (net-like/mesh-like/network structure).
Here, in the separation module 10 of the present invention, the permeating gas channel member 26 is a metal net product (metal net) formed of a metal wire (metal threads) having a wire diameter of 0.4 mm or less.
According to the present invention, with the above-described configuration, the separation module 10 which prevents deterioration or damage to the facilitated transport film 20a caused by the raw material gas G under the conditions of a high temperature and a high humidity being supplied at a high pressure and exhibits a predetermined performance for a long period of time is realized.
As described above, the raw material gas G in the separation module 10 flows into the spiral laminate 14a from the end portion of the supply gas channel member 24 in the width direction (arrow x direction), flows into the supply gas channel member 24 in the width direction, and is brought into contact with the facilitated transport film 20a of the acidic gas separation layer 20 and from which the acidic gas Gc is separated by a carrier.
The separated acidic gas Gc is transported into the facilitated transport film 20a by a carrier, passes through the porous support 20b, flows into the permeating gas channel member 26, flows into the central tube 12 from the permeating gas channel member 26, and is discharged from the open end 12b. In addition, the residual gas Gr remaining after separation of acidic gas Gc is discharged from the end portion on the side opposite to the supply side of the supply gas channel member 24.
In the separation module 10, the permeating gas channel member 26 has a net shape in order to be operated as a spacer and to form a channel of the acidic gas Gc separated from the raw material gas G and having permeated through the acidic gas separation layer 20 as described above.
In addition, the adhesive layer 30 is formed on the permeating gas channel member 26 so that porous support 20b (pinching body 36) of the acidic gas separation layer 20 is bonded thereto and the laminates 14 bond to each other.
The adhesive layer 30 (adhesive 30a which becomes the adhesive layer 30) infiltrates the porous support 20b and the permeating gas channel member 26, thereby forming an envelope-like channel of the acidic gas Gc in the inside of the permeating gas channel member 26. In other words, the adhesive layer 30 is operated as a channel regulation member that regulates channel of the acidic gas Gc.
In this manner, the separation module 10 seals the acidic gas Gc having permeated through the acidic gas separation layer 20 in the permeating gas channel member 26, regulates the direction of a channel towards the central tube 12, and prevents the acidic gas Gc having permeated through the acidic gas separation layer 20 from being mixed with the raw material gas G or the residual gas Gr.
The raw material gas G under the conditions of a high temperature (normally, 100° C. or higher) and a high humidity is supplied to the separation module 10 using the facilitated transport film 20a at a high pressure of approximately 200 kPa to 3000 kPa.
For this reason, when the acidic gas Gc is separated from the raw material gas G, the spiral laminate 14a is in a state of a high temperature and a high humidity. Further, when the acidic gas Gc is separated from the raw material gas G, high pressure is applied to the inside of the spiral laminate 14a (supply gas channel member 24).
Here, in the separation module of the related art, the permeating gas channel member is formed of a resin material, for example, a polyester-based material such as epoxy-impregnated polyester; a polyolefin-based material such as polypropylene; or a fluorine-based material such as polytetrafluoroethylene.
As described above, the facilitated transport film 20a is formed by carrying a carrier to a hydrophilic compound serving as a binder and is frequently soft. Particularly, since the facilitated transport film 20a absorbs moisture (water vapor) contained in the raw material gas G, the facilitated transport film 20a becomes extremely soft during the separation of the acidic gas Gc from the raw material gas G.
Respective members (respective layers) of such a facilitated transport type separation module of the related art are laminated on each other in a contact state as conceptually illustrated in
On the contrary, when the raw material gas G at a high pressure is supplied to the facilitated transport type separation module, the acidic gas separation layer 20 and the permeating gas channel member 26 are pressurized by the pressure of the raw material gas G. As a result, the permeating gas channel member 26 which is a net-like member made of a resin is compressed in the thickness direction as conceptually illustrated in
Moreover, the acidic gas separation layer 20 laminated on the permeating gas channel member 26a is pressed by the pressure of the gas in the same manner as described above and follows the permeating gas channel member 26a.
The compression amount of the permeating gas channel member 26a is different between a region in which the adhesive layer 30 (channel regulation member) is formed and a region other than the region. That is, since the portion in which the adhesive layer 30 resulting from an adhesive is formed is hard in the permeating gas channel member 26a, the compression amount is significantly less than other regions.
As a result, a difference in level is generated between a region where the adhesive layer 30 is formed and a region other than the region in the permeating gas channel member 26a and the acidic gas separation layer 20 as conceptually illustrated in
Deterioration or damage of the facilitated transport film 20a and generation of a defective portion are causes of a decrease in the acidic gas separation efficiency or release of the raw material gas G, and then the performance of the separation module is degraded.
Meanwhile, the separation module 10 of the present invention uses a net product made of a metal (metal net) formed of a metal wire having a wire diameter of 0.4 mm or less as the permeating gas channel member 26.
The permeating gas channel member 26 formed of a metal wire has greatly high rigidity (firm) in contrast to a permeating gas channel member formed of a resin material of the related art. For this reason, according to the separation module 10 of the present invention, when the raw material gas G at a high pressure is supplied and pressurized, the permeating gas channel member 26 is not compressed as illustrated in
Therefore, according to the present invention, it is possible to obtain the separation module 10 which can prevent damage or deterioration of the facilitated transport film 20a and generation of breakage or the like caused by a difference in level due to compression of the permeating gas channel member 26 even when the raw material gas G under the conditions of a high temperature of 100° C. or higher and a high humidity is supplied at a high pressure and exhibits a predetermined performance for a long period of time.
When the wire diameter of the metal wire constituting the permeating gas channel member 26 exceeds 0.4 mm, inconvenience occurs, for example, the rigidity of the permeating gas channel member 26 is extremely strong so that the permeating gas channel member 26 is not able to be properly wound around the laminate 14, the cutting into the shape according to the separation module 10 becomes difficult, or unevenness of the permeating gas channel member 26 (metal net) becomes significant so that a difference in level is generated at the time of pressurization.
When this point is considered, the wire diameter of the metal wire constituting the permeating gas channel member 26 is more preferably 0.3 mm or less and particularly preferably 0.2 mm or less.
Meanwhile, the lower limit of the wire diameter of the metal wire constituting the permeating gas channel member 26 is not limited. However, when the metal wire is extremely thin, inconvenience may occur, for example, the acidic gas Gc barely flows so that the permeating gas channel member 26 is not able to function well.
When this point is considered, the wire diameter of the metal wire constituting the permeating gas channel member 26 is preferably 0.01 mm or greater and more preferably 0.03 mm or greater.
In the separation module 10 of the present invention, the aperture (pitch) of the permeating gas channel member 26 is preferably in a range of 0.05 mm to 0.3 mm.
When the aperture of the permeating gas channel member 26 is set to 0.05 mm or greater, the permeating gas channel member 26 can be more reliably impregnated with the adhesive 30a so that the adhesive layer 30 (channel regulation member of acidic gas Gc) is properly formed therein and the acidic gas Gc can smoothly flow in the central tube 12, which is preferable.
Moreover, when the aperture of the permeating gas channel member 26 is set to 0.3 mm or less, a difference in level of the acidic gas separation layer 20 caused by the aperture of the permeating gas channel member 26 can be suitably prevented and deformation due to the tension of the winding at the time of preparation of a separation module can be reduced, which is preferable.
When the above-described points are considered, the aperture of the permeating gas channel member 26 is more preferably in a range of 0.06 mm to 0.25 mm and particularly preferably in a range of 0.07 mm to 0.2 mm.
In the separation module 10 of the present invention, the pressure loss of the permeating gas channel member 26 can be approximated by a flow rate loss of compressed air flowing at a constant flow rate and, when air is allowed to flow in the permeating gas channel member 26 having a dimension of 15 cm2 at a rate of 15 L (liter)/min at room temperature, the flow rate loss is preferably less than 7.5 L/min and more preferably less than 7 L/min.
In the separation module 10 of the present invention, various kinds of metal can be used for materials of forming the permeating gas channel member 26.
Specific preferred examples thereof include stainless steel, iron, copper, bronze, nickel, aluminum, and brass.
Among these, in terms of corrosion resistance and rigidity, stainless steel is preferably used.
Further, all known methods of weaving a metal wire such as plain weave, twill weave, plain dutch weave, and twilled dutch weave can be used as a method of weaving the metal wire, that is, the permeating gas channel member 26.
Hereinafter, a method of laminating the laminate 14 and a method of winding the laminated laminates 14, that is, a method of preparing the spiral laminate 14a will be described. Further, for the purpose of clearly showing the configuration by simplifying the drawings,
First, as conceptually illustrated in
Here, it is preferable that a slit (not illustrated in the figure) is provided on the tube wall of the central tube 12 along the axial direction. In this case, the tip portion of the permeating gas channel member 26 is put into the slit so as to be fixed to the inner peripheral surface of the central tube 12 using the fixing means. According to this configuration, when a laminate including the permeating gas channel member 26 is wound around the central tube 12, release of the permeating gas channel member 26 from the slit can be prevented due to friction between the inner peripheral surface of the central tube 12 and the permeating gas channel member 26 even if the laminate is wound around the central tube 12 while tension is applied thereto, that is, the fixation of the permeating gas channel member 26 is maintained.
Moreover, as conceptually illustrated in
Further, in order to prevent damage to the facilitated transport film 20a caused by the supply gas channel member 24, it is preferable that a sheet-like protection member folded into two is arranged in a valley portion obtained by folding the acidic gas separation layer 20 into two. As the protection member, a Kapton tape or a PTFE tape is exemplified.
Further, the surface on the shorter side of the acidic gas separation layer 20 folded into two (surface of the porous support 20b) is coated with the adhesive 30a which becomes the adhesive layer 30. The adhesive layer 30 and the adhesive 30a will be described below.
Here, the adhesive 30a (that is, the adhesive layer 30) is applied to the entire region by being extended to have a strip shape in the winding direction (arrow y direction) in the periphery of both end portions in the width direction (arrow x direction) as illustrated in
Next, as conceptually illustrated in
Further, as illustrated in
As illustrated in
Next, as conceptually illustrated in
Subsequently, in the same manner as illustrated in
In addition, as illustrated in
Hereinafter, the processes of
It is preferable that the laminates 14 are laminated in order to become gradually farther away from the central tube 12 in the winding direction toward the upper side as illustrated in
When a predetermined number of laminates 14 are laminated on each other, an adhesive 38a is applied to the outer peripheral surface of the central tube 12 and an adhesive 38b is applied to a space between the pinching body 36 and the central tube 12 on the upper surface of the permeating gas channel member 26 initially fixed to the central tube 12 as illustrated in
Next, as indicated by an arrow yw in
When the winding is finished, the state in which tension is applied to the permeating gas channel member 26 of the outermost periphery (that is, the lowermost layer initially fixed to the central tube 12) in the drawing direction (winding direction) is maintained for a predetermined time and the adhesive 30a or the like is dried.
When the predetermined time has elapsed, the permeating gas channel member 26 of the outermost periphery is fixed to a position, at which the permeating gas channel member has gone round once, by ultrasonic welding or the like, the extra permeating gas channel member 26 outward from the fixation position is cut, and then the spiral laminate 14a obtained by laminating the laminated laminates 14 around the central tube is completed.
As described above, the raw material gas G is supplied from the end portion of the supply gas channel member 24, and the acidic gas Gc passes through (is transported to) the acidic gas separation layer 20 in the lamination direction, flows into the permeating gas channel member 26, flows through the permeating gas channel member 26, and reaches the central tube 12.
Here, the porous support 20b is coated with the adhesive 30a and the permeating gas channel member 26 having a net structure is bonded using the adhesive 30a. Accordingly, the adhesive 30a infiltrates (impregnation) into the porous support 20b and the permeating gas channel member 26 and then the adhesive layers 30 are formed in the inside of the porous support 20b and the permeating gas channel member 26.
Further, as described above, the adhesive layer 30 (adhesive 30a) is formed to have a strip shape by being extended in the entire region in the winding direction in the periphery of both end portions in the width direction. In addition, the adhesive layer 30 is formed to have a strip shape by being extended in the entire region in the width direction in the periphery of the end portion on the side opposite to the folded portion which becomes the central tube 12 side such that the adhesive layer crosses the adhesive layer 30 in the width direction in the periphery of both end portions in the width direction. That is, the adhesive layer 30 is open at the central tube 12 side and is formed so as to enclose the outer periphery of the permeating gas channel member 26 and the porous support 20b. In addition, the permeating gas channel member 26 is brought into a state of being interposed between the facilitated transport films 20a.
In this manner, an envelope-like channel in which the central tube 12 side is open is formed in the permeating gas channel member 26 of the laminate 14.
Accordingly, the acidic gas Gc, which permeates into the acidic gas separation layer 20 and flows into the permeating gas channel member 26, flows through the permeating gas channel member 26 toward the central tube 12 without flowing out, and flows into the central tube 12 from the through-holes 12a. Further, the raw material gas G and the residual gas Gr are not mixed into the inside of the permeating gas channel member 26 (more inside than the adhesive layer 30) because the raw material gas G and the residual gas Gr are obstructed by the adhesive layer 30. That is, the adhesive layer 30 bonds respective members to each other and plays a role of a channel regulation member of the acidic gas Gc and a sealing member that seals each gas in a predetermined region.
In the separation module 10 of the present invention, various kinds of known adhesive can be used as long as the adhesive layer 30 (adhesive 30a) has sufficient adhesive strength, heat resistance, and moisture resistance.
Examples thereof include an epoxy resin, a vinyl chloride copolymer, a vinyl chloride-vinyl acetate copolymer, a vinyl chloride-vinylidene chloride copolymer, a vinyl chloride-acrylonitrile copolymer, a butadiene-acrylonitrile copolymer, a polyamide resin, polyvinyl butyral, polyester, a cellulose derivative (nitrocellulose or the like), a styrene-butadiene copolymer, various synthetic rubber resins, a phenol resin, a urea resin, a melamine resin, a phenoxy resin, a silicon resin, and a urea formamide resin.
The viscosity of the adhesive 30a which becomes the adhesive layer 30 is preferably in a range of 5 Pa·sec to 60 Pa·sec. Further, in the present specification, the viscosity indicates viscosity at a temperature of 25° C.
When the viscosity of the adhesive 30a is in the above-described range, the permeating gas channel member 26 can be more reliably impregnated with the adhesive 30a so that the adhesive layer 30, that is, a channel regulation member of acidic gas Gc is formed therein, which is preferable.
When this point is considered, the viscosity of the adhesive 30a which becomes the adhesive layer 30 is more preferably in a range of 6 Pa·sec to 55 Pa·sec and particularly preferably in a range of 7 Pa·sec to 50 Pa·sec.
Further, it is preferable that an adhesive whose coating properties are improved by containing an organic solvent or a surfactant is applied before the adhesive 30a which becomes the adhesive layer 30 is applied and then the adhesive 30a is applied thereto. At this time, it is preferable that the adhesive 30a is applied in a width narrower than that of the adhesive applied previously.
In this manner, the adhesive layer 30 (adhesive 30a) can suitably infiltrate into the porous support 20b and the permeating gas channel member 26.
In the separation module 10 of the present invention, the telescoping prevention plate (telescoping prevention member) 16 is arranged in both end portions of the spiral laminate 14a prepared in this manner.
As described above, the telescoping prevention plate 16 is a member used for preventing a so-called telescoping phenomenon in which the spiral laminate 14a is pressed by the raw material gas G, the end surface on the supply side is pushed in a nested shape, and the end surface on the opposite side protrudes in a nested shape.
In the present invention, various kinds of known telescoping prevention plate used for a spiral-shaped separation module can be used as the telescoping prevention plate 16.
In the example illustrated in the figure, the telescoping prevention plate includes a circular outer ring portion 16a; a circular inner ring portion 16b arranged such that the center thereof corresponds to the center of the outer ring portion 16a and is incorporated therein; and ribs (spokes) 16c which connect the outer ring portion 16a with the inner ring portion 16b such that they are fixed to each other. As described above, the central tube 12 around which the laminate 14 is wound is inserted into the inner ring portion 16b.
In the example illustrated in the figure, the ribs 16c are radially provided at an equal angle interval from the center of the outer ring portion 16a and the inner ring portion 16b. In the telescoping prevention plate 16, gaps of each rib 16c between the outer ring portion 16a and the inner ring portion 16b become opening portions 16d through which the raw material gas G or the residual gas Gr passes.
The telescoping prevention plate 16 may be arranged such that the telescoping prevention plate 16 is brought into contact with the end surface of the spiral laminate 14a. However, in order for the entire region of the end surface of the spiral laminate 14a to be used for supply of the raw material gas or discharge of the residual gas Gr, the end surfaces of the telescoping prevention plate 16 and the spiral laminate 14a are normally arranged with small gaps therebetween.
Various materials have sufficient strength, heat resistance, and moisture resistance can be used for a material forming the telescoping prevention plate 16.
Preferred specific examples thereof include metal materials (such as stainless steel (SUS), aluminum, an aluminum alloy, tin, and a tin alloy); resin materials (such as a polyethylene resin, a polypropylene resin, an aromatic polyamide resin, nylon 12, nylon 66, a polysulfone resin, a polytetrafluoroethylene resin, a polycarbonate resin, an acrylic-butadiene-styrene resin, an acrylic-ethylene-styrene resin, an epoxy resin, a nitrile resin, a polyether ether ketone resin (PEEK), a polyacetal resin (POM), and a polyphenylene sulfide resin (PPS)); fiber-reinforced plastics of these resins (glass fibers, carbon fibers, stainless steel fibers, and aramid fibers are exemplified as fibers. Among these, long fibers are particularly preferable and specific examples thereof include long glass fiber-reinforced polypropylene and long glass fiber-reinforced polyphenylene sulfide); and ceramics (such as zeolite and alumina).
In addition, when a resin is used, a resin reinforced by glass fibers may be used.
The coating layer 18 is provided by covering the spiral laminate 14a or the peripheral surface of the telescoping prevention plate 16. The coating layer 18 blocks discharge of the raw material gas G or the residual gas Gr outside from the peripheral surface of the spiral laminate 14a. That is, the coating layer 18 blocks discharge of the raw material gas G or the residual gas Gr outside other than from the end surface of the spiral laminate 14a.
Various kinds of material which can shield the raw material gas G or the like from being discharged can be used as the coating layer 18. Further, the coating layer 18 may be a tubular member or may be configured by winding a wire or a sheet-like member.
As an example, a coating layer 18 obtained by impregnating a wire made of FRP with an adhesive used for the above-described adhesive layer 30 and winding the wire impregnated with the adhesive around the spiral laminate 14a multiple times without any space left if necessary is exemplified.
At this time, as needed, a sheet-like member such as a Kapton tape which prevents permeation of an adhesive into the spiral laminate 14a may be provided between the coating layer 18 and the spiral laminate 14a.
Hereinbefore, the acidic-gas separation module (spiral-shaped module for acidic-gas separation) of the present invention has been described in detail, but the present invention is not limited to the examples described above. Further, various improvements or modifications are possible within the range not departing from the scope of the present invention.
Hereinafter, the separation module of the present invention will be described in detail with reference to specific examples of the present invention.
An aqueous solution containing 2.4% by mass of a polyvinyl alcohol-polyacrylic acid copolymer (KURASTOMER AP-20, manufactured by KURARAY CO., LTD.) and 0.01% by mass of a crosslinking agent (a 25 mass % glutaraldehyde aqueous solution, manufactured by Wako Pure Chemical Industries, Ltd.) was prepared. 1 M hydrochloric acid was added to the aqueous solution such that the pH thereof becomes 1 and cross-linking was allowed to occur in the solution.
After cross-linking was allowed to occur in the solution, a 40% cesium carbonate aqueous solution (manufactured by Kisan Kinzoku Chemicals Co., Ltd.) was added thereto such that the concentration of cesium carbonate became 3.66% by weight and a 40% potassium carbonate aqueous solution (manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto such that the concentration of potassium carbonate became 0.61% by weight. That is, in the present example, cesium carbonate and potassium carbonate became a carrier of the facilitated transport film 20a.
Further, 0.003% by mass of a blocking inhibitor (1% RAPISOL A-90, manufactured by NOF CORPORATION) was added thereto, thereby preparing a coating composition (1).
The porous support 20b (porous film made of PTFE, having a thickness of 30 μm, and having a pore diameter of 0.1 μm) was coated with the coating composition and then dried, and the acidic gas separation layer 20 formed of the facilitated transport film 20a and the porous support 20b was prepared.
The thickness of the facilitated transport film 20a was 50 μm.
<Preparation of Separation Module>
First, as illustrated in
A metal net (wire diameter: 0.1 mm, aperture: 0.154 mm) made of stainless steel having 100 meshes was used as the permeating gas channel member 26.
Further, 100 meshes indicate that the number of meshes in one inch is 100. Hereinafter, similarly, 50 meshes, 200 meshes, and 400 meshes respectively indicate that the numbers of meshes in one inch are respectively 50, 200, and 400.
In addition, the prepared acidic gas separation layer 20 was folded into two by putting the facilitated transport film 20a on the inside thereof. The acidic gas separation layer 20 was folded into two such that one side of the acidic gas separation layer 20 became slightly longer than the other as illustrated in
Next, the supply gas channel member 24 (a polypropylene net having a wire diameter of 50 μm and an aperture of 500 μm) was interposed between the acidic gas separation layers 20 folded into two, thereby preparing the pinching body 36.
The adhesive 30a was applied to the entire region by being extended in the winding direction (arrow y direction) in the periphery of both end portions in the width direction (arrow x direction) and applied to the entire region by being extended in the width direction in the periphery of the end portion on the side opposite to the folded portion in the winding direction on the porous support 20b side, in which the acidic gas separation layer 20 of the pinching body 36 was shorter as illustrated in
Next, as illustrated in
Subsequently, as illustrated in
In the same manner as described above, another pinching body 36 formed of the acidic gas separation layer 20, illustrated in
In addition, a third layer of laminate 14 was formed on the second layer of the laminate 14 in the same manner as that of the second layer and then a laminate on which 20 layers of laminates 14 were laminated was formed in the same manner as described above.
After the 20 layers of the laminate 14 was laminated on the permeating gas channel member 26 fixed to the central tube 12, the peripheral surface of the central tube 12 was coated with the adhesive 38a as illustrated in
Next, the laminated 20 layers of the laminates 14 were wound around the central tube 12 multiple times such that the laminates 14 were rolled around the central tube 12 by the central tube 12 being rotated in the arrow yw direction of
In addition, the central tube 12 was inserted into the inner ring portions 16b and telescoping prevention plates 16, made of SUS, having a thickness of 2 cm in the form illustrated in
Moreover, the coating layer 18 having a thickness of 5 mm was formed by winding an FRP resin tape around the peripheral surface of the telescoping prevention plate 16 and the peripheral surface of the spiral laminate 14a and sealing the telescoping prevention plate and the spiral laminate therein, thereby preparing the separation module 10 having a width of 30 cm as illustrated in
The separation module 10 was prepared in the same manner as in Example 1 except that a metal net, made of brass, having 100 meshes (wire diameter: 0.1 mm, aperture: 0.154 mm) was used as the permeating gas channel member 26 (Example 2).
The separation module 10 was prepared in the same manner as in Example 1 except that a metal net, made of titanium, having 100 meshes (wire diameter: 0.1 mm, aperture: 0.154 mm) was used as the permeating gas channel member 26 (Example 3).
The separation module 10 was prepared in the same manner as in Example 1 except that TB2083 (putty-like) (manufactured by ThreeBond Holdings Co., Ltd.) was used as the adhesive 30a (Example 4).
The separation module 10 was prepared in the same manner as in Example 1 except that TB2106G (viscosity of approximately 3 Pa·sec) (manufactured by ThreeBond Holdings Co., Ltd.) was used as the adhesive 30a (Example 5).
The separation module 10 was prepared in the same manner as in Example 1 except that a metal net, made of stainless steel, having 200 meshes (wire diameter: 0.053 mm, aperture: 0.074 mm) was used as the permeating gas channel member 26 (Example 6).
The separation module 10 was prepared in the same manner as in Example 1 except that a metal net, made of stainless steel, having 50 meshes (wire diameter: 0.23 mm, aperture: 0.28 mm) was used as the permeating gas channel member 26 (Example 7).
The separation module 10 was prepared in the same manner as in Example 1 except that a metal net, made of stainless steel, having 400 meshes (wire diameter: 0.16 mm, aperture: 0.48 mm) was used as the permeating gas channel member 26 (Example 8).
The separation module 10 was prepared in the same manner as in Example 8 except that an intermediate layer was formed on the surface of the porous support 20b before the facilitated transport film 20a was formed.
The intermediate layer was formed as follows.
UV9300 (manufactured by Momentive Performance Materials Inc.) was used as a silicone coating solution used for forming a silicone resin layer as an intermediate layer, 0.5% by weight of 4-isopropyl-4′methyldiphenyliodoniumtetrakis(pentafluorophenyl)borate (manufactured by Tokyo Chemical Industry Co., Ltd.), with respect to the content of the silicone resin, was added to the silicone coating solution as a curing agent, thereby preparing a coating composition used for forming an intermediate layer.
The porous support 20b was coated with the coating composition such that the thickness thereof became 10 μm and the porous support was irradiated with ultraviolet rays having an integrated light intensity of 500 mJ/cm2, thereby forming an intermediate layer.
40% by mass of cesium carbonate (manufactured by Kisan Kinzoku Chemicals Co., Ltd.) aqueous solution was added to an aqueous solution (copolymer concentration: 4.3% by mass) containing a copolymer of a polyvinyl alcohol (PVA)-polyacrylic acid copolymer (PAA) (molar ratio: PVA/PAA=3/7), which was synthesized by referencing a method described in “T.Sato, et al. (1993). Synthesis of poly(vinyl alcohol) having a thiol group at one end and new block copolymers containing poly(vinyl alcohol) as one cinsistent. Macromolecular Chemistry and Physics, 194, 175 to 185” such that the concentration of cesium carbonate became 6.0% by mass. In addition, Orgatix TC-100 (manufactured by Matsumoto Fine Chemistry Co., Ltd.) serving as a Ti-based crosslinking agent was added such that the content thereof was 10% by mass with respect to the content of the PVA-PAA copolymer and the mixture was stirred and defoamed, thereby preparing a coating composition (2). The separation module 10 was prepared in the same manner as in Example 1 using the coating composition (2) in place of the coating composition (1).
The facilitated transport film of the separation module 10 contains a structural unit in which M in Formula (1) represents Ti. When the content of Ti in the facilitated transport film was measured using a fluorescent X-ray spectroscopy, the content of Ti was 1.1% by mass with respect to the content of the PVA-PAA copolymer serving as a hydrophilic compound. The content of Ti in the facilitated transport film was measured, according to the fluorescent X-ray spectroscopy, through quantification by performing analysis at a measurement area of 10 mmφ using Primusell (Rh-ray source) (manufactured by Rigaku Corporation).
The separation module 10 was prepared in the same manner as in Example 10 except that Orgatix TC-100 (manufactured by Matsumoto Fine Chemistry Co., Ltd.) was added such that the content thereof became 1% by mass with respect to the content of PVA-PAA copolymer.
The content of Ti in the facilitated transport film was measured in the same manner as in Example 10. As a result, the content of Ti was 0.11% by mass with respect to the content of the PVA-PAA copolymer serving as a hydrophilic compound.
The separation module 10 was prepared in the same manner as in Example 10 except that Orgatix TC-100 (manufactured by Matsumoto Fine Chemistry Co., Ltd.) was added such that the content thereof became 50% by mass with respect to the content of PVA-PAA copolymer.
The content of Ti in the facilitated transport film was measured in the same manner as in Example 10. As a result, the content of Ti was 5.3% by mass with respect to the content of the PVA-PAA copolymer serving as a hydrophilic compound.
The separation module 10 was prepared in the same manner as in Example 10 except that Orgatix TC-401 (manufactured by Matsumoto Fine Chemistry Co., Ltd.) was used in place of Orgatix TC-100 (manufactured by Matsumoto Fine Chemistry Co., Ltd.) and added such that the content thereof became 15% by mass with respect to the content of PVA-PAA copolymer.
The content of Ti in the facilitated transport film was measured in the same manner as in Example 10. As a result, the content of Ti was 1% by mass with respect to the content of the PVA-PAA copolymer serving as a hydrophilic compound.
The separation module 10 was prepared in the same manner as in Example 8 except that the coating composition (2) was used in place of the coating composition (1).
The separation module 10 was prepared in the same manner as in Example 9 except that the coating composition (2) was used in place of the coating composition (1).
A separation module was prepared in the same manner as in Example 1 except that a metal net, made of stainless steel, having 24 meshes (wire diameter: 0.45 mm, aperture: 0.61 mm) was used as the permeating gas channel member (Comparative Example 1).
A separation module was prepared in the same manner as in Example 1 except that tricot-knitted fabric (wire diameter: 0.1 mm, number of courses: 40/in, number of wales: 40/in) formed of polyester was used as the permeating gas channel member (Comparative Example 2).
A separation module was prepared in the same manner as in Example 1 except that a plain-weaved net (wire diameter: 0.071 mm, aperture: 0.211 mm) formed of polyester was used as the permeating gas channel member (Comparative Example 3).
The respective prepared separation modules 10 were accommodated in a closed cylindrical container in a state in which only the open end 12b of the central tube 12 penetrated to the outside, helium gas was introduced to the closed container, and then the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was measured in a state in which a pressure of 0.3 MPa was applied to the container.
Next, the pressure was increased to 1.5 MPa and then the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was measured in the same manner as described above.
In addition, the closed container was heated to 100° C. while the pressure was maintained at 1.5 MPa and then the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was measured in the same manner as described above.
A case where the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was less than 100 mL (milliliter)/min was evaluated as A.
A case where the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was 100 mL/min or greater to less than 200 mL/min was evaluated as B.
A case where the flow rate of the helium gas discharged from the open end 12b of the central tube 12 was 200 mL/min or greater was evaluated as C.
The results are listed in Table below.
Only in Example 9, an intermediate layer is present between the support and the facilitated transport film
As listed in the table, in the separation module 10 of the present invention using a permeating gas channel member formed of a metal wire having a wire diameter of 0.4 mm or less as the permeating gas channel member 26, the flow rates of helium gas discharged from the open end 12b of the central tube 12 are low under the conditions of a pressure of 0.3 MPa at room temperature, a pressure of 1.5 MPa at room temperature, and a pressure of 1.5 MPa at 100° C.
That is, according to the present invention, it is understood that the permeating gas channel member 26 is compressed by the pressure of the separation module 10 so that generation of a difference in level between the permeating gas channel member 26 and the acidic gas separation layer 20 is prevented and thus deterioration or damage to the facilitated transport film 20a caused by the difference in level is not generated.
Moreover, the degree of impregnation of the adhesive 30a into the permeating gas channel member 26 is less in Example 4 in which the viscosity of the adhesive 30a which becomes the adhesive layer 30 is high and the degree of impregnation of the adhesive 30a into the permeating gas channel member 26 is high in Example 5 in which the viscosity of the adhesive 30a which becomes the adhesive layer 30 is low. Accordingly, it is considered that the function of regulating the gas channel becomes inferior compared to other examples, and a slight amount of helium gas leaks and is discharged from the open end 12b of the central tube 12.
Further, in Examples 8 and 9 in which the aperture of the permeating gas channel member 26 is 0.48, which is large, it is considered that a difference in level is slightly generated on the acidic gas separation layer 20 caused by the aperture at a pressure of 1.5 MPa, the facilitated transport film 20a is damaged due to the difference in level, and the helium gas slightly leaks therefrom and is discharged from the open end 12b of the central tube 12. In this case, since the facilitated transport film 20a is supported by an intermediate layer in a case of Example 9 in which an intermediate layer is present between the porous support 20b and the facilitated transport film 20a, the leakage of the helium gas can be prevented at room temperature.
Meanwhile, in Comparative Example 1 in which a permeating gas channel member formed of a thick metal wire having a wire diameter of 0.45 mm, it is considered that unevenness of the permeating gas channel member is large even through the same metal net made of stainless steel as described above was used, the facilitated transport film 20a is damaged because of a difference in level generated due to the unevenness, and the helium gas leaks therefrom and is discharged from the open end 12b of the central tube 12.
Further, in Comparative Example 2 in which a permeating gas channel member formed of polyester which is tricot-knitted is used, it is considered that the permeating gas channel member is softened by heating, the permeating gas channel member is compressed so that a difference in level is generated between the permeating gas channel member and the acidic gas separation layer 20, the facilitated transport film 20a is damaged due to the difference in level, and the helium gas leaks therefrom and is discharged from the open end 12b of the central tube 12.
Moreover, in Comparative Example 3 in which a permeating gas channel member formed of polyester which is plain-weaved is used, it is considered that a difference in level is generated between the permeating gas channel member and the acidic gas separation layer 20 because the opening portion is pushed by pressure under a pressure condition of 1.5 MPa, the facilitated transport film 20a is damaged due to the difference in level, and the helium gas leaks therefrom and is discharged from the open end 12b of the central tube 12.
From the results described above, the effects of the present invention are obvious.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-169545 | Aug 2013 | JP | national |
| 2014-142481 | Jul 2014 | JP | national |
| 2014-165487 | Aug 2014 | JP | national |
This application is a Continuation of PCT International Application No. PCT/JP2014/071548 filed on Aug. 18, 2014, which claims priority under 35 U.S.C. §119(a) to Japanese Patent Application No. 2013-169545 filed on Aug. 19, 2013, Japanese Patent Application No. 2014-142481 filed on Jul. 10, 2014, and Japanese Patent Application No. 2014-165487 filed on Aug. 15, 2014. Each of the above applications is hereby expressly incorporated by reference, in its entirety, into the present application.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2014/071548 | Aug 2014 | US |
| Child | 15046824 | US |
