JP2015134310A - Acidic gas separation module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably provide an acidic gas separation module in which the occurrence of a defect caused by rubbing between a facilitated transport membrane and a supply gas flow path member is suppressed and which therefore can be stably obtained while having a desired performance.SOLUTION: The acidic gas separation module includes an acidic gas separation layer which separates acidic gas from a gaseous starting material and comprises: a facilitated transport membrane containing a carrier reacting with an acidic gas and a hydrophilic compound for carrying the carrier; and a protection layer laminated on a surface of the facilitated transport membrane. The protection layer is formed as the uppermost layer of the acidic gas separation layer, and the gas permeation coefficient of the protection layer is 500 Barrer or more. The facilitated transport membrane contains at least one selected from the group consisting of hydroxyl groups and carboxyl groups, and the protection layer has a functional group which reacts with at least one selected from the group consisting of the hydroxyl groups and carboxyl groups contained in the facilitated transport membrane.

Description

  The present invention relates to an acid gas separation module that selectively separates an acid gas from a raw material gas.

  In recent years, development of a technique for selectively separating an acidic gas such as carbon dioxide from a raw material gas (a gas to be treated) has been advanced. For example, an acid gas separation membrane that separates an acid gas from a raw material gas using an acid gas separation membrane that selectively permeates the acid gas has been developed.

For example, in Patent Document 1, a multilayer body including an acidic gas separation membrane is wound around a central cylinder (a central permeate collecting pipe) for collecting separated acidic gas, in which through holes are formed in a tube wall. An acid gas separation module is described.
The acidic gas separation module disclosed in Patent Document 1 uses a so-called dissolution diffusion membrane as the acidic gas separation membrane. The dissolution diffusion membrane separates the acid gas from the raw material gas by utilizing the difference in solubility between the acidic gas and the substance to be separated in the membrane and the diffusivity in the membrane.

Patent Document 2 discloses an aqueous solution containing a carbon dioxide carrier on a carbon dioxide permeable support as an acidic gas separation membrane (carbon dioxide separation gel membrane) for separating carbon dioxide (carbon dioxide) from a raw material gas. Describes an acid gas separation membrane in which a hydrogel membrane is formed by absorbing a bisphenol into a vinyl alcohol-acrylate copolymer having a crosslinked structure.
This acid gas separation membrane is an acid gas separation membrane using a so-called facilitated transport membrane. The facilitated transport film has a carrier that reacts with an acidic gas such as a carbon dioxide carrier in the film, and the acidic gas is separated from the source gas by transporting the acidic gas to the opposite side of the film with this carrier.

  In such an acidic gas separation module, a so-called laminated body having an acidic gas separation membrane is wound around a central cylinder having a through-hole on a wall surface (wrapped around the central cylinder). The spiral acid gas separation module can greatly increase the area of the acid gas separation membrane. Therefore, the spiral acid gas separation module can be efficiently processed and is very effective.

As an example, the spiral type acidic gas separation module is separated by an acidic gas separation membrane and a central tube, a supply gas flow path member that is a raw material gas flow path for separating acidic gas, and an acidic gas separation membrane. A permeated gas flow path member serving as a flow path for the acidic gas thus formed is configured.
A spiral acidic gas separation module made of such a member is formed by laminating one or a plurality of laminated bodies in which an acidic gas separation membrane, a supply gas flow path member, and a permeate gas flow path member are laminated, It has the structure wound around the center tube.

Japanese Patent Laid-Open No. 4-215824 Japanese Patent Publication No. 7-102310

By the way, the facilitated transport film as shown in Patent Document 2 needs to retain a large amount of moisture in the film in order to sufficiently function the carrier. Therefore, a polymer having extremely high water absorption and water retention is used for the facilitated transport film. In addition, moisture is supplied to the facilitated transport film by adding moisture to the source gas. In the facilitated transport membrane, as the content of a carrier such as a metal carbonate increases, the amount of water absorption increases and the acid gas separation performance is improved. That is, the facilitated transport film is often a very soft (low viscosity), gel film.
In addition, in an acidic gas separation membrane using a facilitated transport membrane, a raw material gas having a temperature of about 100 to 130 ° C. is supplied at a pressure of 1 MPa or more when the acidic gas is separated. Therefore, in an acidic gas separation membrane that uses a facilitated transport membrane, the facilitated transport membrane is rubbed between the facilitated transport membrane and a member that is in contact with the facilitated transport membrane, resulting in a defect in the facilitated transport membrane. For example, in the case of a spiral type acidic gas separation module, rubbing occurs between the facilitated transport film and the supply gas flow path member, resulting in a defect in the facilitated transport film.

Therefore, a protective layer is formed on the surface of the facilitated transport film so that the facilitated transport film and the supply gas flow path member are not in direct sliding contact with each other, thereby suppressing the occurrence of defects due to friction of the facilitated transport film. It is possible.
However, according to the study by the present inventor, when the acidic gas is separated, moisture is supplied to the facilitated transport membrane and the facilitated transport membrane swells, so that the facilitated transport membrane has fluidity. Since the facilitated transport film has fluidity, it is not possible to ensure sufficient adhesion between the protective layer and the facilitated transport film simply by providing a protective layer on the surface of the facilitated transport film. As a result, the protective layer cracks or flows, so that the facilitated transport film cannot be sufficiently protected, and it has been found that there is a problem in that the generation of defects in the facilitated transport film cannot be suppressed.

  Therefore, the present invention provides an acidic gas separation module that can suppress the occurrence of defects due to rubbing between the facilitated transport membrane and other members and can stably obtain a module having the intended performance. Let it be an issue.

As a result of earnest research to achieve the above-mentioned problems, the present inventors have separated the acidic gas from the raw material gas, the carrier that reacts with the acidic gas, and the facilitated transport film containing the hydrophilic compound for supporting the carrier, and the accelerated An acidic gas separation layer having a protective layer laminated on the surface of the transport membrane, and the protective layer is formed as the uppermost layer in the acidic gas separation layer, and the gas permeability coefficient of the protective layer is 500 Barrer or more. The facilitated transport film has at least one selected from the group consisting of hydroxyl groups and carboxyl groups, and the protective layer is selected from the group consisting of hydroxyl groups and carboxyl groups contained in the facilitated transport film By having a functional group that reacts with at least one kind, the adhesion between the protective layer and the facilitated transport film is improved, resulting in friction between the facilitated transport film and the supply gas flow path member. It found to be able to suppress the occurrence of defects, thereby completing the present invention.
That is, this invention provides the module for acidic gas separation of the following structures.

(1) An acidic gas separation module that selectively separates an acidic gas from a raw material gas containing 0.1 mol% or more of moisture, the carrier reacting with the acidic gas and the carrier for separating the acidic gas from the raw material gas And an acidic gas separation layer comprising a facilitated transport film containing a hydrophilic compound for supporting a gas and a protective layer laminated on the surface of the facilitated transport film, the protective layer being the uppermost layer in the acidic gas separated layer And the protective layer has a gas permeability coefficient of 500 Barrer or more, the facilitated transport film has at least one selected from the group consisting of a hydroxyl group and a carboxyl group, and the protective layer comprises the above-mentioned An acidic gas separation module having a functional group that reacts with at least one selected from the group consisting of a hydroxyl group and a carboxyl group contained in a facilitated transport membrane.
(2) The acidic gas separation according to (1), wherein the functional group of the protective layer is at least one selected from the group consisting of an epoxy group, an amino group, a methoxy group, an ethoxy group, a hydroxyl group, and a carboxyl group. Module.
(3) The acid gas separation module according to (1) or (2), wherein the water absorption of the facilitated transport membrane is 5% or more.
(4) The acid gas separation module according to any one of (1) to (3), wherein the thickness of the protective layer is 0.1 μm or more and 5 μm or less.
(5) The acidic gas separation module according to any one of (1) to (4), wherein the protective layer is a polydimethylsiloxane derivative.
(6) Further, a central tube having a through-hole formed in the tube wall, a supply gas flow channel member serving as a raw material gas flow channel, and a flow channel through which acidic gas that has permeated the facilitated transport film flows to the central tube. A permeate gas channel member, and the supply gas channel member is laminated on the protective layer side of the acidic gas separation layer, and the permeate gas channel member is opposite to the protective layer of the acidic gas separation layer. A spiral-type module in which one or more laminates laminated on the side and laminated with a supply gas flow path member, an acidic gas separation layer, and a permeate gas flow path member are wound around a central cylinder (1) to (5) The acid gas separation module according to any one of (5).

  According to the present invention, there is provided an acid gas separation module that can suppress the occurrence of defects due to rubbing between the facilitated transport membrane and other members and can stably obtain a module having a target performance. Can do.

It is a schematic perspective view which cuts off an example of the module for acidic gas separation of this invention, and is shown partially. It is a schematic sectional drawing of the laminated body of the module for acidic gas separation shown in FIG. It is a schematic sectional drawing of an acidic gas separation layer. (A) And (B) is a conceptual diagram for demonstrating the preparation methods of the module for acidic gas separation shown in FIG. It is a conceptual diagram for demonstrating the preparation methods of the module for acidic gas separation shown in FIG. (A) And (B) is a conceptual diagram for demonstrating the preparation methods of the module for acidic gas separation shown in FIG. It is a conceptual diagram for demonstrating the preparation methods of the module for acidic gas separation shown in FIG. It is a conceptual diagram for demonstrating the preparation methods of the module for acidic gas separation shown in FIG.

  Hereinafter, the acidic gas separation module of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic perspective view of a partly cutout of an example of the acid gas separation module of the present invention.
As shown in FIG. 1, the acid gas separation module 10 basically includes a center tube 12, a laminate 14 having an acid gas separation membrane (facilitated transport membrane 21), and a telescope prevention plate 16. Configured. In the following description, the acid gas separation module is also simply referred to as a separation module.
The separation module 10 separates the acidic gas Gc from the raw material gas G containing 1% mol or more of moisture. For example, the carbon dioxide gas is separated as the acidic gas Gc from the raw material gas G containing carbon monoxide, carbon dioxide gas (CO ₂ ), water (water vapor) and hydrogen.

  The separation module 10 of the present invention is a so-called spiral type separation module. That is, in the separation module 10, one or a plurality of sheet-like laminates 14 are laminated and wound around the center tube 12, and the center tube 12 is inserted into both end surfaces of the wound product of the laminate 14. Thus, the telescope prevention plate 16 is provided. The outermost peripheral surface of the wound laminate 14 is covered with a gas impermeable coating layer 18.

  In the following description, a wound product of a product obtained by laminating a plurality of laminates 14 wound around the central cylinder 12 (that is, a substantially cylindrical product by the laminate 14 wound by being laminated) For convenience, it is also referred to as a spiral laminate 14a.

In such a separation module 10, the source gas G from which the acidic gas is separated is supplied to the end face of the spiral laminate 14a through, for example, the telescope prevention plate 16 (the opening portion 16d) on the far side in FIG. The acid gas Gc is separated while flowing into the laminated body 14 from the end face and flowing through the laminated body 14.
Further, the acidic gas Gc separated from the raw material gas G by the stacked body 14 is discharged from the central cylinder 12. On the other hand, the source gas G from which the acidic gas has been separated (hereinafter referred to as the residual gas Gr for convenience) is discharged from the end face on the opposite side to the supply side of the spiral laminated body 14a (laminated body 14) to prevent telescoping. It is discharged out of the separation module 10 through the plate 16 (same as above).

The central cylinder (permeate gas collecting pipe) 12 is a cylindrical pipe whose end face on the source gas G supply side is closed, and a plurality of through holes 12a are formed on the peripheral surface (tube wall).
The acidic gas Gc separated from the raw material gas G passes through a permeating gas passage member 26 described later, reaches the inside of the central cylinder 12 from the through hole 12a, and is discharged from the open end 12b of the central cylinder 12.

In the central cylinder 12, the aperture ratio (area ratio of the through-hole 12a in the outer peripheral surface of the central cylinder 12) in the region sealed with the adhesive layer 30 described later is preferably 1.5 to 80%, and preferably 3 to 75. % Is more preferable, and 5 to 70% is more preferable. Among these, from the practical viewpoint, the opening ratio of the center tube 12 is particularly preferably 5 to 25%.
By setting the aperture ratio of the center tube 12 within the above range, the acid gas Gc can be efficiently collected, and the strength of the center tube 12 can be increased to ensure sufficient processability.

  The through hole 12a is preferably a circular hole having a diameter of 0.5 to 20 mm. Furthermore, it is preferable that the through holes 12 a are formed uniformly on the peripheral wall of the central cylinder 12.

  The center tube 12 may be provided with a supply port (supply unit) for supplying a gas (sweep gas) for flowing the separated acidic gas Gc to the open end 12b side as necessary.

The laminate 14 is formed by laminating an acid gas separation layer 20, a supply gas flow path member 24, and a permeate gas flow path member 26.
In FIG. 1, reference numeral 30 denotes an acid gas Gc in the permeate gas flow path member 26 while the acid gas separation layer 20 and the permeate gas flow path member 26 are bonded together and the laminates 14 are bonded together. This is an adhesive layer 30 in which the flow path is formed in an envelope shape opened on the center tube 12 side.

As described above, the separation module 10 in the illustrated example is formed by laminating a plurality of the laminates 14 and winding (wrapping) them around the central cylinder 12 to form a substantially cylindrical spiral laminate 14a. It has a configuration.
Hereinafter, for convenience, a direction corresponding to the winding of the laminate 14 is a circumferential direction (arrow y direction), and a direction orthogonal to the circumferential direction is a width direction (arrow x direction). The laminated body 14 is generally a rectangular sheet, but the circumferential direction is usually the laminated body 14 (acid gas separation layer 20, supply gas flow path member 24, and permeate gas flow path member. 26) in the longitudinal direction.

In the separation module 10, the laminate 14 may be a single layer. However, as shown in the illustrated example, by laminating a plurality of laminated bodies 14, the membrane area of the acidic gas separation layer 20 can be increased, and the amount of the acidic gas Gc separated by one module can be improved. The film area of the acidic gas separation layer 20 can be improved by increasing the length of the stacked body 14 in the width direction.
The number of stacked layers 14 may be set as appropriate according to the processing speed and processing amount required for the separation module 10, the size of the separation module 10, and the like. Here, the number of laminated bodies 14 to be laminated is preferably 50 or less, more preferably 45 or less, and particularly preferably 40 or less. By setting the number of laminated bodies 14 to be this number, winding of the laminated body 14 around the central cylinder 12 becomes easy, and workability can be improved.

In FIG. 2, the fragmentary sectional view of the laminated body 14 is shown. As described above, the arrow x is the width direction and the arrow y is the circumferential direction.
In the illustrated example, the laminated body 14 has a supply gas flow path member 24 sandwiched between two folded acid gas separation layers 20 to form a sandwiching body 36 (see FIG. 5). The road member 26 is laminated. This configuration will be described in detail later.

As described above, in the separation module 10, the source gas G is supplied from one end face of the spiral laminate 14 a through the telescope prevention plate 16 (its opening 16 d). That is, the source gas G is supplied to the end portion (end surface) in the width direction (arrow x direction) of each stacked body 14.
As conceptually shown in FIG. 2, the source gas G supplied to the end surface in the width direction of the stacked body 14 flows in the width direction in the supply gas flow path member 24. In this flow, the acidic gas Gc in contact with the acidic gas separation layer 20 (facilitated transport film 21) is separated from the source gas G and passes through the acidic gas separation layer 20 in the stacking direction of the laminate 14 ( It is transported in the stacking direction by the carrier of the facilitated transport film 21) and flows into the permeating gas channel member 26.

The acidic gas Gc that has flowed into the permeate gas flow path member 26 flows in the permeate gas flow path member 26 in the circumferential direction (the direction of the arrow y), reaches the central cylinder 12, and passes through the through hole 12 a of the central cylinder 12. 12 flows in.
The flow of the acid gas Gc is regulated by the adhesive layer 30. That is, in the separation module 10, the two acidic gas separation layers 20 (facilitated transport membrane 21) sandwiching the permeate gas flow path member 26, the permeate gas flow path member 26 and the acidic gas separation layer 20 (porous support) 22) and the adhesive layer 30 penetrating into the inner surface of the adhesive layer 30 in the surface direction forms an envelope-like flow path (space) that encloses the permeate gas flow path member 26 and that is open on the central tube 12 side. (See FIGS. 5 and 6). Thereby, the separation module 10 prevents the acidic gas Gc that has passed through the acidic gas separation layer 20 from flowing out.
The adhesive layer 30 will be described in detail later.

The acidic gas Gc that has flowed into the center tube 12 flows through the center tube 12 in the width direction and is discharged from the open end 12b.
Further, the remaining gas Gr from which the acid gas Gc has been removed flows in the supply gas flow path member 24 in the width direction, and is discharged from the opposite end face of the spiral laminated body 14a. It is discharged to the outside of the separation module 10 through the part 16d).

The supply gas flow path member 24 is supplied with the source gas G from the end in the width direction, and brings the source gas G flowing in the member into contact with the acidic gas separation layer 20.
Here, in the separation module 10 of the present invention, the supply gas flow path member 24 is disposed to face the protective layer 28 formed on the surface of the facilitated transport film 21 of the acidic gas separation layer 20. That is, the supply gas flow path member 24 is provided in contact with the protective layer 28. The protective layer 28 will be described in detail later.

  The supply gas flow path member 24 functions as a spacer of the acid gas separation layer 20 folded in half as described above, and constitutes a flow path for the source gas G. Further, the supply gas flow path member 24 preferably makes the source gas G turbulent. In consideration of this point, the supply gas flow path member 24 is preferably a member having a mesh structure (net shape / mesh shape). Especially, the network structure formed with the thread | yarn containing 1 or more of the resin material mentioned later is preferable.

As a material for forming the supply gas flow path member 24, various materials can be used as long as they have sufficient heat resistance and moisture resistance.
Examples include paper materials such as paper, fine 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 metal, glass, and ceramics. A material etc. are illustrated suitably.
Among these, a resin material or a material containing a resin material) is preferably exemplified. Specific examples of the resin material include polyethylene, polystyrene, polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyphenylene sulfide (PPS), polysulfone (PSF), and polypropylene (PP). , Polyimide, polyetherimide, polyetheretherketone, polyvinylidene fluoride and the like are preferably exemplified. A plurality of such resin materials may be used in combination.

The thickness of the supply gas flow path member 24 may be appropriately determined according to the supply amount of the source gas G, the required processing capacity, and the like.
Specifically, 100 to 1000 μm is preferable, 150 to 950 μm is more preferable, and 200 to 900 μm is particularly preferable.

Further, when the supply gas flow path member 24 is a woven or non-woven fabric having a network structure formed of resin threads or the like, the fiber diameter is preferably 100 to 900 μm. The fiber density is preferably ² to 30 mg / cm ² .
As will be described in detail later, in the separation module, damage to the facilitated transport film 21 caused by the sliding contact between the facilitated transport film 21 that is a gel film and the supply gas flow path member 24 is exemplified as a cause of performance degradation. .
On the other hand, the separation module 10 of the present invention has the protective layer 28 on the surface of the facilitated transport film 21 so that the facilitated transport film is caused by the sliding contact between the facilitated transport film 21 and the supply gas flow path member 24. 21 damage is prevented.

However, when the fiber diameter of the yarn (fiber) constituting the supply gas flow path member 24 is less than 100 μm, the porosity of the supply gas flow path member 24 is lowered and the pressure loss is increased. , Processing efficiency may be reduced. Therefore, the fiber diameter is preferably 100 μm or more.
In addition, when the fiber diameter exceeds 900 μm, the amount of fibers pushed into the membrane surface increases, so even if the protective layer 28 is formed on the surface, damage to the facilitated transport membrane 21 due to the sliding contact between the two is caused. There is a risk that it cannot be prevented. Therefore, the fiber diameter is preferably 900 μm or less.

Similarly, when the fiber density of the yarn (fiber) constituting the supply gas flow path member 24 is less than 2 mg / cm ² , the supply gas flow path member 24 (protective layer 28) and the facilitated transport film 21 Since the contact area is not sufficiently large and the amount of fibers pushed into the membrane surface becomes large, there is a possibility that damage to the facilitated transport membrane 21 due to the sliding contact between the two cannot be prevented. Therefore, the fiber diameter is preferably ² mg / cm ² or more.
Further, when the fiber density is more than 30 mg / cm ² , the porosity of the supply gas flow path member 24 becomes low, the resistance to the flowing raw material gas G increases, and the processing efficiency may be lowered. . Accordingly, the fiber density is preferably 30 mg / cm ² or less.

Further, the tensile elastic modulus of the supply gas flow path member 24 is preferably 1 to 500 MPa.
When the tensile elastic modulus exceeds 500 MPa, that is, when the supply gas flow path member 24 is hard, when the laminate 14 is wound around the central cylinder 12, the amount of fibers pushed into the membrane surface increases. The facilitated transport film 21 may be damaged. Therefore, the tensile elastic modulus is preferably 500 MPa or less.
Further, when the tensile elastic modulus is less than 1 MPa, the supply gas flow path member 24 is soft, so that it may not function as a spacer between the acidic gas separation layers 20, that is, the flow path of the source gas may not be secured. There is. Accordingly, the tensile elastic modulus is preferably 1 MPa or more.
In this way, by controlling the fiber diameter, fiber density, and tensile modulus of the supply gas flow path member 24, it is possible to improve manufacturing stability and processing performance.

  The tensile elastic modulus of the supply gas channel member 24 is obtained from the relationship between the tensile stress and the strain amount as a structure such as a network structure.

The separation module 10 of the present invention is a facilitated transport type. Therefore, the acidic gas separation layer 20 has a facilitated transport membrane 21.
FIG. 3 shows a schematic cross-sectional view of the acidic gas separation layer 20.
As shown in FIG. 3, the acidic gas separation layer 20 includes a facilitated transport film 21, a porous support 22 including a porous film 22 a and an auxiliary support film 22 b that support the facilitated transport film 21, and a facilitated transport film 21. And a protective layer 28 laminated on the surface of the substrate.

The facilitated transport film 21 contains at least a carrier that reacts with the acidic gas Gc contained in the source gas G flowing through the supply gas flow path member 24, and a hydrophilic compound that supports the carrier. Such a facilitated transport film 21 has a function of selectively transmitting the acidic gas Gc from the raw material gas G (a function of selectively transporting the acidic gas Gc).
The facilitated transport type separation module is required to be used at high temperature and high humidity. Therefore, the facilitated transport film 21 has a function of selectively permeating the acidic gas Gc even at high temperatures (for example, 100 to 200 ° C.). Moreover, since the source gas G contains 1% mol or more of moisture (water vapor), the carrier transports the acidic gas Gc when the hydrophilic compound absorbs moisture and the facilitated transport film 21 retains moisture. Therefore, the separation efficiency is increased as compared with the case of using a dissolution diffusion membrane.

The membrane area of the facilitated transport membrane 21 may be appropriately set according to the size of the separation module 10, the processing capacity required for the separation module 10, and the like. Specifically, preferably 0.01～1000M ^2, more preferably 0.02～750M ^2, more preferably 0.025m~500m ^2. Among these, the membrane area of the facilitated transport film 21 is particularly preferably 1 to 100 m ² from a practical viewpoint.
By setting the membrane area of the facilitated transport membrane 21 in the above range, the acidic gas Gc can be efficiently separated with respect to the membrane area, and the processability is also improved.

The circumferential length of the facilitated transport film 21 (the total length before folding in half) may be appropriately set according to the size of the separation module 10, the processing capacity required for the separation module 10, and the like. Specifically, 100 to 10000 mm is preferable, 150 to 9000 mm is more preferable, and 200 to 8000 mm is even more preferable. Among them, the length of the facilitated transport film 21 is particularly preferably 800 to 4000 mm from a practical viewpoint.
By setting the circumferential length of the facilitated transport film 21 in the above range, the acidic gas Gc can be efficiently separated with respect to the film area, and further, the winding slippage when the laminate 14 is wound can be reduced. Occurrence is suppressed and workability is facilitated.
The width of the facilitated transport film may be set as appropriate according to the size of the separation module 10 in the width direction.

  What is necessary is just to set the thickness of the facilitated-transport film | membrane 21 suitably according to the magnitude | size of the separation module 10, the processing capability requested | required of the separation module 10, etc. FIG.

Here, as will be described in detail later, in the separation module, damage to the facilitated transport film 21 due to the sliding contact between the facilitated transport film 21 that has absorbed water and swelled and the supply gas flow path member 24 is a cause of performance degradation. Is exemplified.
A decrease in performance due to damage to the facilitated transport film 21 can be suppressed by increasing the thickness of the facilitated transport film 21. However, when the facilitated transport membrane 21 becomes thicker, the permeation performance is lowered, so that the separation performance of the acid gas Gc is lowered accordingly.
On the other hand, since the separation module of the present invention has the protective layer 28 on the surface of the facilitated transport film 21, it is facilitated by sliding contact between the facilitated transport film 21 swollen by water absorption and the supply gas flow path member 24. Damage to the transport film 21 can be prevented. That is, even if the facilitated transport film 21 is made thinner in order to improve the permeation performance, it is possible to prevent the performance degradation due to the damage of the facilitated transport film 21.

Considering the above points, the thickness of the facilitated transport film 21 is preferably 5 to 150 μm, and more preferably 10 to 120 μm.
By setting the thickness of the facilitated transport membrane 21 within the above range, high gas permeability and separation selectivity can be realized.

The water absorption rate of the facilitated transport film 21 is preferably 5% or more. By setting the water absorption rate of the facilitated transport film 21 to 5% or more, the hydrophilic compound absorbs water vapor and the facilitated transport film 21 retains moisture, so that the carrier easily transports the acidic gas Gc and the separation efficiency is improved. Rise.
Here, since the facilitated transport film becomes softer when the hydrophilic compound retains more water, the facilitated transport film 21 is damaged due to the sliding contact between the facilitated transport film 21 and the supply gas flow path member 24. It becomes easy.
On the other hand, since the separation module of the present invention has the protective layer 28 on the surface of the facilitated transport membrane 21, even when the amount of water absorption increases and the facilitated transport membrane becomes softer, the facilitated transport membrane 21 and the supply gas channel The facilitated transport film 21 can be suitably prevented from being damaged due to the sliding contact with the member 24 for use.
In the present invention, the water absorption was measured by the following method.
The sample dried by vacuum heating for 16 hours in an environment of temperature 80 ° C and humidity 4% or less is left in an environment of temperature 85 ° C and humidity 85% for 6 hours, and the mass of the sample before and after water absorption is measured. The amount of change in mass was calculated as the water absorption rate.

In the present invention, the facilitated transport film 21 has at least one selected from the group consisting of a hydroxyl group (—OH group) and a carboxyl group (—COOH group). That is, the facilitated transport film 21 contains a hydrophilic compound having a hydroxyl group or a carboxyl group.
In the separation module of the present invention, a protective layer 28 is provided on the surface of the facilitated transport film 21 in order to prevent damage to the facilitated transport film 21 due to sliding contact between the facilitated transport film 21 and the supply gas flow path member 24. . Here, in the present invention, the facilitated transport film 21 has at least one selected from the group consisting of hydroxyl groups and carboxyl groups, and the protective layer 28 is selected from the group consisting of hydroxyl groups and carboxyl groups. It has a functional group that reacts with at least one species. Therefore, the adhesion between the facilitated transport film 21 and the protective layer 28 can be improved, and damage to the facilitated transport film 21 due to the sliding contact between the facilitated transport film 21 and the supply gas flow path member 24 can be prevented.
This will be described in detail later.

The hydrophilic compound contained in the facilitated transport film 21 functions as a binder. In the facilitated transport film 21, moisture is retained and a function of separating a gas such as carbon dioxide by a carrier is exhibited. Moreover, it is preferable that a hydrophilic compound has a crosslinked structure from a heat resistant viewpoint.
As described above, the hydrophilic compound has at least one selected from the group consisting of a hydroxyl group and a carboxyl group.
Examples of such hydrophilic compounds include hydrophilic polymers.

What is necessary is just to select the weight average molecular weight of a hydrophilic compound suitably in the range which can form a stable film | membrane. Specifically, 20,000 to 2,000,000 is preferable, 25,000 to 2,000,000 is more preferable, and 30,000 to 2,000,000 is particularly preferable.
By setting the weight average molecular weight of the hydrophilic compound to 20,000 or more, the facilitated transport film 21 having a sufficient film strength can be obtained stably.
In particular, when the hydrophilic compound has —OH as a crosslinkable group, the hydrophilic compound preferably has a weight average molecular weight of 30,000 or more. In this case, the weight average molecular weight is more preferably 40,000 or more, and more preferably 50,000 or more. When the hydrophilic compound has —OH as a crosslinkable group, the weight average molecular weight is preferably 6,000,000 or less from the viewpoint of production suitability.
For example, when PVA is used as the hydrophilic compound, the weight average molecular weight of the hydrophilic compound may be a value measured according to JIS K 6726. Moreover, when using a commercial item, what is necessary is just to use the molecular weight nominally mentioned in a catalog, a specification, etc.

  The hydroxyl group (—OH group) and carboxyl group (—COOH group) of the hydrophilic compound are crosslinkable groups that form the hydrophilic compound, and can form a hydrolysis-resistant crosslinked structure.

Specific examples of the hydrophilic compound include those having a hydroxyl group, such as polyvinyl alcohol, polyethylene oxide, water-soluble cellulose, starch, polyhydroxy methacrylate, polyhydroxyethyl methacrylate, and the like. Examples of those having a carboxyl group include polyacrylic acid, alginic acid, and carboxymethylcellulose.
Most preferred is polyvinyl alcohol. Moreover, as a hydrophilic compound, these copolymers are also illustrated.

Moreover, as a hydrophilic compound having a hydroxyl group and a carboxyl group, a polyvinyl alcohol-polyacrylic acid copolymer is exemplified. A polyvinyl alcohol-polyacrylic salt copolymer is preferable because of its high water absorption ability and high hydrogel strength even at high water absorption.
The content of polyacrylic acid in the polyvinyl alcohol-polyacrylic acid copolymer is, for example, 1 to 95 mol%, preferably 2 to 70 mol%, more preferably 3 to 60 mol%, and particularly preferably 5 to 50 mol%. It is.
In the polyvinyl alcohol-polyacrylic acid copolymer, the polyacrylic acid may be a salt. Examples of the polyacrylic acid salt in this case include ammonium salts and organic ammonium salts in addition to alkali metal salts such as sodium salts and potassium salts.

  Polyvinyl alcohol is also available as a commercial product. Specific examples include PVA117 (manufactured by Kuraray Co., Ltd.), poval (manufactured by Kuraray), polyvinyl alcohol (manufactured by Aldrich), J-poval (manufactured by Nippon Vinegarten Poval). A polyvinyl alcohol-polyacrylate copolymer (sodium salt) is also available as a commercial product. For example, Crustomer AP20 (made by Kuraray Co., Ltd.) is exemplified.

In the facilitated transport membrane 21 of the separation module 10 of the present invention, two or more hydrophilic compounds may be mixed and used.
Moreover, you may contain the hydrophilic compound which has crosslinkable groups other than a hydroxyl group and a carboxyl group. As the crosslinkable group other than the hydroxyl group and the carboxyl group, those capable of forming a hydrolysis-resistant crosslinked structure are preferably selected.
Examples include amino groups (—NH ₂ ) and epoxy groups.
Specific examples include polyallylamine, polyvinylpyrrolidone, polyethyleneimine, polyvinylamine, polyornithine, polylysine, chitin and the like.

The content of the hydrophilic compound in the facilitated transport film 21 functions as a binder for forming the facilitated transport film 21, and the amount capable of sufficiently retaining moisture depends on the type of the hydrophilic composition, the carrier, and the like. It can be set as appropriate.
Specifically, 0.5-50 mass% is preferable, 0.75-30 mass% is more preferable, and 1-15 mass% is especially preferable. By setting the content of the hydrophilic compound within this range, the above-mentioned function as a binder and the moisture retention function can be stably and suitably expressed.

The crosslinked structure in the hydrophilic compound can be formed by a conventionally known method such as thermal crosslinking, ultraviolet crosslinking, electron beam crosslinking, radiation crosslinking, or photocrosslinking.
Photocrosslinking or thermal crosslinking is preferred, and thermal crosslinking is most preferred.

In order to form the facilitated transport film 21, it is preferable to use a crosslinking agent together with the hydrophilic compound. That is, when forming the facilitated-transport film | membrane 21 by the apply | coating method, it is preferable to use the coating composition containing a crosslinking agent.
As the cross-linking agent, one containing a cross-linking agent having two or more functional groups capable of reacting with a hydrophilic compound and capable of cross-linking such as thermal cross-linking or photo-crosslinking is selected. The formed crosslinked structure is preferably a hydrolysis-resistant crosslinked structure.
From such a viewpoint, the crosslinking agent used for forming the facilitated transport film 21 includes an epoxy crosslinking agent, a polyvalent glycidyl ether, a polyhydric alcohol, a polyvalent isocyanate, a polyvalent aziridine, a haloepoxy compound, a polyvalent aldehyde, Preferred examples include valent amines and organometallic crosslinking agents. More preferred are polyvalent aldehydes, organometallic crosslinking agents and epoxy crosslinking agents, and among them, polyvalent aldehydes such as glutaraldehyde and formaldehyde having two or more aldehyde groups are preferred.

As an epoxy crosslinking agent, it is a compound which has 2 or more of epoxy groups, and the compound which has 4 or more is also preferable. Epoxy crosslinking agents are also available as commercial products, for example, trimethylolpropane triglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., Epolite 100MF, etc.), Nagase ChemteX Corporation EX-411, EX-313, EX-614B, Examples include EX-810, EX-811, EX-821, EX-830, NOF Corporation Epiol E400, and the like.
Moreover, the oxetane compound which has cyclic ether as a compound similar to an epoxy crosslinking agent is also used preferably. The oxetane compound is preferably a polyvalent glycidyl ether having two or more functional groups, and commercially available products include, for example, EX-411, EX-313, EX-614B, EX-810, EX-811, EX manufactured by Nagase ChemteX Corporation. -821, EX-830, and the like.

  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 Examples include 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, and oxyethylene oxypropylene block copolymer. Examples include coalescence, pentaerythritol, and sobitol.

Examples of the polyvalent isocyanate include 2,4-toluylene diisocyanate and hexamethylene diisocyanate.
Examples of the polyvalent aziridines include 2,2-bishydroxymethylbutanol-tris [3- (1-acylidinyl) propionate], 1,6-hexamethylenediethyleneurea, diphenylmethane-bis-4,4′-N, N. Examples include '-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.
Furthermore, examples of the organometallic crosslinking agent include organic titanium crosslinking agents and organic zirconia crosslinking agents.

For example, when polyvinyl alcohol having a weight average molecular weight of 130,000 or more is used as the hydrophilic compound, it is possible to form a crosslinked structure having good reactivity with this hydrophilic compound and excellent hydrolysis resistance. Therefore, an epoxy crosslinking agent and glutaraldehyde are preferably used.
Moreover, when using a polyvinyl alcohol-polyacrylic acid copolymer as a hydrophilic compound, an epoxy crosslinking agent and glutaraldehyde are preferably utilized.

What is necessary is just to set the quantity of a crosslinking agent suitably according to the kind of hydrophilic compound used for formation of the facilitated-transport film | membrane 21 or a crosslinking agent.
Specifically, the amount is preferably 0.001 to 80 parts by weight, more preferably 0.01 to 60 parts by weight, and particularly preferably 0.1 to 50 parts by weight with respect to 100 parts by weight of the crosslinkable group possessed by the hydrophilic compound. preferable. By setting the content of the cross-linking agent in the above range, a facilitated transport film having good cross-linking structure formation and excellent shape maintainability can be obtained.
Further, when focusing on the crosslinkable group possessed by the hydrophilic compound, the crosslinked structure is formed by reacting 0.001 to 80 mol of a crosslinking agent with respect to 100 mol of the crosslinkable group possessed by the hydrophilic compound. preferable.

As described above, in the acidic gas separation layer 20 of the separation module 10, the facilitated transport film 21 contains a carrier in addition to such a hydrophilic compound.
The carrier is various water-soluble compounds having affinity with an acidic gas (for example, carbon dioxide gas) and showing basicity. Specific examples include alkali metal compounds, nitrogen-containing compounds, and sulfur oxides.
The carrier may react indirectly with the acid gas, or the carrier itself may react directly with the acid gas.
The former reacts with other gas contained in the supply gas, shows basicity, and the basic compound reacts with acidic gas. More specifically, OH react with steam (water) ^- was released, the OH ^- that reacts with CO _2, a compound can be incorporated selectively CO ₂ in facilitated transport membrane 21 For example, an alkali metal compound.
The latter is such that the carrier itself is basic, for example, a nitrogen-containing compound or a sulfur oxide.

  Examples of the alkali metal compound include alkali metal carbonates, alkali metal bicarbonates, and alkali metal hydroxides. Here, as the alkali metal, an alkali metal element selected from cesium, rubidium, potassium, lithium, and sodium is preferably used. In addition, in this invention, an alkali metal compound contains the salt and its ion other than alkali metal itself.

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 hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, and cesium hydrogen carbonate.
Furthermore, 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 having high solubility in water is preferable from the viewpoint of good affinity with acidic gas.

Moreover, when using an alkali metal compound as a carrier, two or more kinds of carriers may be used in combination.
When two or more kinds of carriers are present in the facilitated transport film 21, different carriers can be separated from each other in the film. Thereby, due to the difference in deliquescence of a plurality of carriers, due to the hygroscopicity of the facilitated transport film 21, the facilitated transport films 21 and the facilitated transport film 21 and other members are adhered to each other at the time of manufacture. (Blocking) can be suitably suppressed.
Moreover, when using 2 or more types of alkali metal compounds as a carrier by the point of being able to obtain the blocking inhibitory effect more suitably, the deliquescence property is more excellent than the first compound having deliquescence and the first compound. It is preferable to include a second compound having a low specific gravity. As an example, the first compound is exemplified by cesium carbonate, and the second compound is exemplified by potassium carbonate.

Nitrogen-containing compounds include amino acids such as glycine, alanine, serine, proline, histidine, taurine, diaminopropionic acid, hetero compounds such as pyridine, histidine, piperazine, imidazole, triazine, monoethanolamine, diethanolamine, triethanolamine , Alkanolamines such as monopropanolamine, dipropanolamine and tripropanolamine, cyclic polyetheramines such as cryptand [2.1] and cryptand [2.2], cryptand [2.2.1] and cryptand [ And bicyclic polyetheramines such as 2.2.2], porphyrin, phthalocyanine, ethylenediaminetetraacetic acid and the like.
Further, examples of the sulfur compound include amino acids such as cystine and cysteine, polythiophene, dodecylthiol and the like.

What is necessary is just to set content of the carrier in the facilitated-transport film | membrane 21 suitably according to the kind etc. of a carrier or a hydrophilic compound. Specifically, 0.3-30 mass% is preferable, 0.5-25 mass% is more preferable, and 1-20 mass% is especially preferable.
By setting the content of the carrier in the facilitated transport film 21 within the above range, in the composition (paint) for forming the facilitated transport film 21, salting out before coating can be suitably prevented, and further, The transport membrane 21 can reliably exhibit the acid gas separation function.

  The facilitated transport film 21 (composition for forming the facilitated transport film 21) may contain various components as necessary in addition to such a hydrophilic compound, a crosslinking agent and a carrier.

Examples of such components include an antioxidant such as dibutylhydroxytoluene (BHT), a compound having 3 to 20 carbon atoms or a fluorinated alkyl group having 3 to 20 carbon atoms and a hydrophilic group, and a siloxane structure. Specific compounds such as compounds having a surfactant, surfactants such as sodium octoate and sodium 1-hexasulfonate, polymer particles such as polyolefin particles and polymethyl methacrylate particles, and the like.
In addition, a catalyst, a moisturizing (moisture absorbing) agent, an auxiliary solvent, a film strength adjusting agent, a defect detecting agent and the like may be used as necessary.

The porous support 22 has acid gas permeability and can be coated with a coating composition for forming the facilitated transport film 21 (supports the coating film). The transport membrane 21 is supported.
As the material for forming the porous support 22, various known materials can be used as long as they can exhibit the above functions.

Here, in the separation module 10 of the present invention, the porous support 22 constituting the acidic gas separation layer 20 may be a single layer, but as shown in FIG. 3, the porous membrane 22a and the auxiliary support membrane A two-layer structure consisting of 22b is preferred. By having such two configurations, the porous support 22 more reliably expresses the functions of acid gas permeability, application of the coating composition to be the facilitated transport film 21 and support of the facilitated transport film 21. .
When the porous support 22 is a single layer, various materials exemplified below as the porous film 22a and the auxiliary support film 22b can be used as the forming material.

In this two-layered porous support 22, the porous membrane 22a is on the facilitated transport membrane 21 side.
The porous membrane 22a is preferably made of a material having heat resistance and low hydrolyzability. Specific examples of such porous membrane 22a include membrane filter membranes such as polysulfone, polyethersulfone, polypropylene and cellulose, interfacial polymerized thin films of polyamide and polyimide, polytetrafluoroethylene (PTFE) and high molecular weight polyethylene. The stretched porous membrane is exemplified.
Among them, a stretched porous membrane of PTFE or high molecular weight polyethylene has a high porosity, is small in inhibition of diffusion of acidic gas (especially carbon dioxide gas), and is preferable from the viewpoints of strength and manufacturing suitability. Among them, a stretched porous membrane of PTFE is preferably used in terms of heat resistance and low hydrolyzability.

The porous membrane 22a is hydrophobic so that the facilitated transport membrane 21 containing moisture can easily penetrate into the porous portion under the usage environment and does not cause deterioration in film thickness distribution or performance over time. Is preferred.
The porous membrane 22a preferably has a maximum pore diameter of 1 μm or less.
Furthermore, the average pore diameter of the pores of the porous membrane 22a is preferably 0.001 to 10 μm, more preferably 0.002 to 5 μm, and particularly preferably 0.005 to 1 μm. By setting the average pore diameter of the porous membrane within this range, the adhesive application region described later is sufficiently impregnated with the adhesive, and the porous membrane 22a is preferably prevented from obstructing the passage of acidic gas. it can.

The auxiliary support film 22b is provided to reinforce the porous film 22a.
Various materials can be used for the auxiliary support film 22b as long as it satisfies the required strength, stretch resistance and gas permeability. For example, a nonwoven fabric, a woven fabric, a net, and a mesh having an average pore diameter of 0.001 to 10 μm can be appropriately selected and used.

The auxiliary support film 22b is also preferably made of a material having heat resistance and low hydrolyzability, similar to the porous film 22a described above.
Non-woven fabrics, woven fabrics, and knitted fabrics that have excellent durability and heat resistance include polyolefins such as polypropylene (PP), modified polyamides such as aramid (trade name), polytetrafluoroethylene, polyvinylidene fluoride, etc. A fiber made of a fluorine-containing resin is preferable. It is preferable to use the same material as the resin material constituting the mesh. Among these materials, a non-woven fabric made of PP that is inexpensive and has high mechanical strength is particularly preferably exemplified.

  When the porous support 22 has the auxiliary support film 22b, the mechanical strength can be improved. Therefore, for example, even when handled in a coating apparatus using a roll-to-roll (hereinafter also referred to as RtoR) described later, the porous support 22 can be prevented from wrinkling, and productivity can be increased. .

If the porous support 22 is too thin, the strength is difficult. Considering this point, the thickness of the porous membrane 22a is preferably 5 to 100 μm, and the thickness of the auxiliary support membrane 22b is preferably 50 to 300 μm.
Moreover, when making the porous support body 22 into a single layer, as for the thickness of the porous support body 22, 30-500 micrometers is preferable.

Such an acidic gas separation layer 20 is prepared by preparing a liquid coating composition (coating / coating liquid) containing a component that becomes the facilitated transport film 21, applying it to the porous support 22, and drying it. It can be produced by a coating method.
That is, first, the hydrophilic compound, the carrier, and other components to be added as necessary are respectively added to water (room temperature water or warm water) in appropriate amounts, and sufficiently stirred to facilitate transport film 21. A coating composition is prepared.
In the preparation of the coating composition, if necessary, dissolution of each component may be promoted by heating with stirring. Moreover, after adding a hydrophilic compound to water and melt | dissolving, precipitation (salting out) of a hydrophilic compound can be effectively prevented by adding a carrier gradually and stirring.

The facilitated transport film 21 is formed by applying this composition to the porous support 22 and drying it.
Here, the application and drying of the composition may be performed on a cut sheet-like porous support 22 cut into a predetermined size by a so-called single wafer type.
Preferably, the facilitated transport film 21 is formed by so-called RtoR. That is, the prepared coating composition is applied while the porous support 22 is fed out from a feed roll formed by winding the long porous support 22 and conveyed in the longitudinal direction, and then the coated coating composition is applied. The product (coating film) is dried to produce a laminate in which the facilitated transport film 21 is formed on the surface of the porous support 22, and the produced laminate is wound up.

What is necessary is just to set the conveyance speed of the porous support body 22 in RtoR suitably according to the kind of porous support body 22, the viscosity of a coating liquid, etc.
Here, when the conveyance speed of the porous support 22 is too fast, the film thickness uniformity of the coating film of the coating composition may be lowered, and when it is too slow, the productivity is lowered. Considering this point, the conveyance speed of the porous support 22 is preferably 0.5 m / min or more, more preferably 0.75 to 200 m / min, and particularly preferably 1 to 200 m / min.

Various known methods can be used for applying the coating composition.
Specific examples include curtain flow coaters, extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, bar coaters, and the like.

The coating film of the coating composition may be dried by a known method. As an example, drying with warm air is exemplified.
The speed of the warm air may be set as appropriate so that the gel film can be quickly dried and the gel film is not broken. Specifically, 0.5 to 200 m / min is preferable, 0.75 to 200 m / min is more preferable, and 1 to 200 m / min is particularly preferable.
The temperature of the hot air may be set as appropriate so that the porous support 22 is not deformed and the gel membrane can be quickly dried. Specifically, the film surface temperature is preferably 1 to 120 ° C, more preferably 2 to 115 ° C, and particularly preferably 3 to 110 ° C.
Moreover, you may use together the heating of the porous support body 22 for drying of a coating film as needed.

As described above, in the separation module 10 of the present invention, the protective layer 28 is formed on the surface of the facilitated transport film 21 of the acidic gas separation layer 20. That is, the protective layer 28 is formed as the uppermost layer of the acid gas separation layer 20.
The protective layer 28 is a layer that protects the facilitated transport film 21 from sliding contact with the supply gas flow path member 24, has a gas permeability coefficient of 500 Barr or more, and contains hydroxyl groups or It has a functional group that reacts with a carboxyl group.

As described above, the spiral type separation module is formed by stacking the acid gas separation layer 20, the supply gas flow path member 24, and the permeate gas flow path member 26, or by stacking this stack. The laminate is formed by winding (wrapping) around the central tube 12.
The separation module 10 in the illustrated example forms an sandwiching body 36 in which the acidic gas separation layer 20 is folded in two with the facilitated transport membrane 21 inside, and the supply gas flow path member 24 is sandwiched by the acidic gas separation layer 20. 5 (see FIG. 5), the laminated body 14 in which the permeating gas flow path member 26 is laminated on the sandwiching body 36 is laminated, and the laminated body of the laminated body 14 is wound around the central cylinder 12.

Here, the acidic gas separation layer 20 and the permeating gas channel member 26 are fixed by the adhesive layer 30. On the other hand, the acidic gas separation layer 20 and the supply gas flow path member 24 are simply sandwiched between the acidic gas separation layer 20 and the supply gas flow path member 24.
In addition, as described above, the supply gas flow path member 24 preferably has a mesh structure formed of resin threads or the like.
On the other hand, the facilitated transport film 21 has a configuration in which a hydrophilic compound such as a superabsorbent resin is used as a binder and carriers are dispersed in the binder. The facilitated transport film 21 needs to retain a large amount of moisture in the film in order for the carrier to function sufficiently. Further, the facilitated transport membrane 21 increases the water absorption amount as the content of a carrier such as a metal carbonate increases, and the acid gas separation performance is improved. Therefore, the facilitated transport film 21 is a very soft gel film.
In addition, when the acidic gas is separated, a raw material gas having a temperature of about 100 to 130 ° C. is supplied at a pressure of 1 MPa or more. For this reason, the facilitated transport film and the supply gas flow path member move relatively, and the two come into sliding contact with each other, and the facilitated transport film may be rubbed by the sliding contact to cause a defect.

Therefore, a protective layer is formed on the surface of the facilitated transport film so that the facilitated transport film and the supply gas flow path member do not directly come into sliding contact with each other, thereby suppressing the occurrence of defects due to friction of the facilitated transport film. It is possible.
However, according to the study by the present inventor, when the acidic gas is separated, moisture is supplied to the facilitated transport membrane and the facilitated transport membrane swells, so that the facilitated transport membrane has fluidity. Since the facilitated transport film has fluidity, it is not possible to ensure sufficient adhesion between the protective layer and the facilitated transport film simply by providing a protective layer on the surface of the facilitated transport film. As a result, the protective layer cracks or flows, so that the facilitated transport film cannot be sufficiently protected, and it has been found that there is a problem in that the generation of defects in the facilitated transport film cannot be suppressed.

On the other hand, in the separation module 10 of the present invention, the facilitated transport membrane 21 has at least one selected from the group consisting of hydroxyl groups and carboxyl groups, and the protective layer 28 is a group consisting of hydroxyl groups and carboxyl groups. It has a functional group that reacts with at least one selected from
The present invention chemically bonds the facilitated transport film 21 and the protective layer 28 with such a configuration. Therefore, even if the facilitated transport film 21 is a soft gel film and has fluidity, the adhesion between the facilitated transport film 21 and the protective layer 28 can be improved. Therefore, damage to the facilitated transport film 21 due to the sliding contact between the facilitated transport film 21 and the supply gas flow path member 24 can be prevented.
Therefore, according to the present invention, high production stability, high confidentiality, performance degradation due to damage to the facilitated transport film 21, no leakage of the raw material gas G, no pressure loss, and the like are achieved. A separation module 10 can be obtained.

As described above, the protective layer 28 has a gas permeability coefficient of 500 Barr or more and has a functional group that reacts with a hydroxyl group and / or a carboxyl group contained in the facilitated transport film 21.
In the present invention, when the gas permeability of the protective layer 28 is less than 500 Barrer (1 Barrer = 1 × 10 −10 cm ³ (STP) · cm / (sec · cm ² · cmHg)), the permeability of the acidic gas is lowered and desired. Inconveniences such as inability to obtain the separation performance are caused.

The protective layer 28 can be formed of various materials.
Specifically, the protective layer 28 has a functional group that reacts with a hydroxyl group and / or a carboxyl group. More specifically, the protective layer 28 is preferably a compound having at least one of an epoxy group, an amino group, a methoxy group, an ethoxy group, a hydroxyl group, and a carboxyl group.
The material of the protective layer 28 is a polymer (polymer) or a copolymer (copolymer) including a compound having at least one of an epoxy group, an amino group, a methoxy group, an ethoxy group, a hydroxyl group, and a carboxyl group. Preferably there is.

Examples of the protective layer 28 include a layer made of a compound having a silicone bond or a silicone-containing compound. Specifically, silicone-containing polyacetylene such as organopolysiloxane (silicone resin) and polytrimethylsilylpropyne can be used. Specific examples of the organopolysiloxane include those represented by the following general formula.
In the above general formula, n represents an integer of 1 or more. Here, from the viewpoint of availability, volatility, viscosity, and the like, the average value of n is preferably in the range of 10 to 1000000, and more preferably in the range of 100 to 100000.
R _1n , R _2n , R ₃ and R ₄ are each a hydrogen atom, alkyl group, vinyl group, aralkyl group, aryl group, hydroxyl group, amino group, carboxyl group, epoxy group, methoxy group or ethoxy group. Any one selected from the group consisting of: Here, as described above, at least one of R _1n , R _2n , R _3, and R ₄ is any one of an epoxy group, an amino group, a methoxy group, an ethoxy group, a hydroxyl group, and a carboxyl group. preferable.
Note that n R _1n and R _2n may be the same or different. Further, at least a part of the epoxy group, alkyl group, aralkyl group, and aryl group may have a ring structure. Further, the alkyl group, vinyl group, aralkyl group and aryl group may have a substituent, and the substituent in this case is, for example, an alkyl group, a vinyl group, an aryl group, a hydroxyl group, an amino group, a carboxyl group. Selected from a group, an epoxy group and a fluorine atom. These substituents may further have a substituent, if possible.
The alkyl group, vinyl group, aralkyl group and aryl group selected from R _1n , R _2n , R ₃ and R ₄ are each an alkyl group having 1 to 20 carbon atoms, a vinyl group, or a carbon number from the viewpoint of availability. A 7-20 aralkyl group and a C6-C20 aryl group are more preferable.

R _1n , R _2n , R ₃ and R ₄ are preferably methyl groups or epoxy-substituted alkyl groups. For example, PDMS derivatives such as epoxy-modified polydimethylsiloxane (PDMS) can be suitably used.

  As the protective layer 28, in addition to the above organopolysiloxane, silicone materials such as poly [1- (trimethylsilyl) -1-propyne] (PTMSP), butadiene / isoprene rubber materials, low-density polymethyl A layer made of pentene or the like can also be used.

  Here, the protective layer 28 may be formed on at least a part of the surface of the facilitated transport film 21 as long as the facilitated transport film 21 and the supply gas flow path member 24 can be prevented from being in direct sliding contact. Preferably, the protective layer 28 is formed over the entire surface of the facilitated transport film 21.

In the formation portion of the protective layer 28, the thickness of the protective layer 28 depends on the material for forming the protective layer 28, the surface coverage of the facilitated transport film 21 by the protective layer 28, the type of the supply gas flow path member 24 (formation material or mesh). The thickness capable of reliably protecting the facilitated transport film 21 may be appropriately set according to the type of the facilitated transport film 21 (including components and the ratio of the content of each contained component).
Specifically, the thickness of the protective layer 28 is preferably 0.1 μm to 5 μm, and more preferably 0.15 μm to 4 μm.
By setting the thickness of the protective layer 28 within the above range, it is preferable in that damage to the facilitated transport film 21 by the supply gas flow path member 24 can be more suitably prevented.

The acidic gas separation layer 20 shown in FIG. 3 is configured to include the porous support 22, the facilitated transport film 21, and the protective layer 28, but is not limited thereto. Between the facilitated transport film 21, an intermediate layer for preventing the facilitated transport film 21 (carrier) from permeating the porous support 22 may be provided.
Such an intermediate layer can be formed of the same material as that of the protective layer 28 described above.

Such an acidic gas separation layer 20 may be produced by various known methods. Preferably, it is produced by a coating method using RtoR.
As is well known, RtoR means that a substrate is delivered from a roll formed by winding a long substrate (object to be processed) and conveyed in the longitudinal direction, and the coating composition is applied and dried. It is a manufacturing method which winds up the board | substrate in roll shape.

When producing the acidic gas separation layer 20, a roll formed by winding a long porous support (hereinafter also simply referred to as “support”) 22 is loaded into the apparatus for forming the facilitated transport film 21. Then, the support is sent out from this roll, and the coating composition to be the facilitated transport film 21 is applied while the support 22 is conveyed in the longitudinal direction.
What is necessary is just to set suitably the conveyance speed of the support body 22 at the time of forming the facilitated-transport film | membrane 21 according to a composition, a viscosity, etc. of a coating composition.
Here, when the conveyance speed of the support 22 is too fast, there is a fear that the coating film thickness uniformity of the coating composition is lowered and drying of the coating composition is insufficient, and when too slow, the productivity is lowered. . Considering this point, the conveyance speed of the support 22 is preferably 0.5 m / min or more, more preferably 0.75 to 200 m / min, and particularly preferably 1 to 200 m / min.

As described above, the facilitated transport film 21 contains a hydrophilic compound such as a hydrophilic polymer, a carrier that reacts with an acidic gas, water, and the like.
Therefore, the coating composition (coating liquid / paint) for forming such a facilitated transport film 21 requires the above-mentioned hydrophilic compound, carrier and water (room temperature water or warm water), or a crosslinking agent or the like. It is a coating composition containing the component used as this. The hydrophilic compound may be crosslinked, partially crosslinked, or uncrosslinked, or a mixture of these. This coating composition may also be prepared by a known method.

Here, the coating composition to be the facilitated transport film 21 preferably has a viscosity at 25 ° C. of 100 cp or more.
By setting the viscosity at 25 ° C. of the coating composition to 100 cp or more, it is preferable from the standpoint that repelling at the time of coating the coating composition can be suppressed, and uniformity of coating of the coating composition can be improved.
In addition, what is necessary is just to measure the viscosity of the coating composition used as the facilitated-transport film | membrane 21 at 25 degreeC in the rotation speed of 60 rpm by a B type viscometer according to JISZ8803.

  Various known materials can be used to apply the coating composition to be the facilitated transport film 21. In particular, a roll coater, a bar coater, a positive rotation roll coater, a knife coater, etc. are preferably used in consideration of the preferred viscosity of the coating composition to be the facilitated transport film 21 and the coating amount of the coating composition.

If the coating composition used as the facilitated-transport film | membrane 21 is apply | coated, then this coated composition is dried and the facilitated-transport film | membrane 21 is formed.
Various known methods for drying by removing water, such as hot air drying or drying by heating the support 22, can be used as the drying method.
When performing warm air drying, the speed of the warm air may be set as appropriate so that the coating composition can be dried quickly and the coating film (gel film) of the coating composition does not collapse. Specifically, 0.5 to 200 m / min is preferable, 0.75 to 200 m / min is more preferable, and 1 to 200 m / min is particularly preferable.
Further, the temperature of the warm air may be appropriately set to a temperature at which the support 22 is not deformed and the coating composition can be dried quickly. Specifically, the film surface temperature is preferably 1 to 120 ° C, more preferably 2 to 115 ° C, and particularly preferably 3 to 110 ° C.

When drying the support 22 by heating, the temperature at which the support 22 is not deformed and the coating composition can be dried quickly may be appropriately set. Moreover, you may use blowing of a dry wind for heating of the support body 22 together.
Specifically, the temperature of the support 22 is preferably 60 to 120 ° C, more preferably 60 to 90 ° C, and particularly preferably 70 to 80 ° C. In this case, the film surface temperature is preferably 15 to 80 ° C, and more preferably 30 to 70 ° C.

  When the facilitated transport film 21 is formed on the support 22 in this manner, the support 22 on which the facilitated transport film is formed is wound into a roll.

Next, a roll of the support 22 (hereinafter also referred to as a composite) on which the facilitated transport film 21 is formed is loaded into a forming device for the protective layer 28, and the composite is sent out from the roll and conveyed in the longitudinal direction. A coating composition to be the protective layer 28 is applied.
Here, the conveyance speed of the composite is preferably faster from the viewpoint of productivity. However, in order to apply | coat a coating composition uniformly, 3-200 m / min is preferable, 5-150 m / min is more preferable, and 10-120 m / min is especially preferable.

  The coating composition to be the protective layer 28 includes monomers, dimers, trimers, oligomers, prepolymers, and mixtures of the compounds to be the protective layer 28 such as the above-described PDMS derivatives, curing agents, curing accelerators, and crosslinking agents. A general coating composition used when a resin layer (resin film) or the like is formed by a coating method, in which a thickener, a reinforcing agent, a filler or the like is dissolved (dispersed) in an organic solvent. (Coating liquid / paint). Such a coating composition may be prepared by a known method.

Here, the coating composition to be the protective layer 28 preferably has a viscosity at 25 ° C. of 100 cp or more.
By setting the viscosity at 25 ° C. of the coating composition to be the protective layer 28 to 100 cp or more, the protective layer 28 having a desired thickness can be stably formed. In consideration of this point, the viscosity at 25 ° C. of the coating composition to be the protective layer 28 is more preferably 400 cp or more, and particularly preferably 500 cp or more.
Therefore, it is preferable to apply the coating composition to be the protective layer 28 at room temperature, or it is preferable to apply the coating composition at a temperature at which the viscosity is 100 cp or more.

On the other hand, the upper limit of the viscosity at 25 ° C. of the coating composition to be the protective layer 28 may be in accordance with the limit viscosity in the coating apparatus to be used, but the thickness of the protective layer 28 can be suitably controlled. 1,000,000 cp or less is preferable.
In addition, what is necessary is just to measure a viscosity similarly to the coating composition used as the facilitated-transport film | membrane 21. FIG.

  Various known coating devices for the silicone coating composition can be used as the coating composition coating device to be the protective layer 28. In particular, a roll coater, a direct gravure coater, an offset gravure coater, a 1 roll kiss coater, a 3 reverse roll coater, a forward rotation roll coater, a squeeze coater, a reverse roll coater and the like are preferably exemplified.

  If the coating composition used as the protective layer 28 is applied, this coating composition is then dried. The drying may be performed by a known method such as hot air drying or drying with a heater.

After the coating composition to be the protective layer 28 is dried, the coating composition is then cured to form the protective layer 28.
For curing, a method capable of curing, such as heat curing, ultraviolet irradiation, electron beam irradiation, or the like, may be appropriately selected according to the material for forming the protective layer 28. Here, for the reason that curling (deformation) of the support 22 can be suppressed and deterioration of the resin constituting the support 22 can be prevented, curing of the coating composition by ultraviolet irradiation or short heating is preferably performed. In particular, curing by ultraviolet irradiation is most preferably used. That is, in the present invention, the protective layer 28 is preferably formed by a coating composition using a monomer or the like that can be cured by ultraviolet irradiation.

Note that, depending on the composition of the coating composition (protective layer 28) to be the protective layer 28, the coating composition may be dried and cured simultaneously.
Moreover, you may perform drying and / or hardening of a coating composition in inert atmosphere, such as nitrogen atmosphere, as needed.

  When the coating composition is dried to produce the protective layer 28, that is, the acidic gas separation layer 20, the acidic gas separation layer 20 is wound into a roll.

  The intermediate layer formed on the support 22 can be basically formed in the same manner as the protective layer 28.

In the above example, the support 22 on which the facilitated transport film 21 is formed is temporarily wound, and the support 22 on which the facilitated transport film 21 is formed is sent out from this roll to form the protective layer 28. .
However, the support 22 on which the facilitated transport film 21 is formed is not wound up, but is transported in the longitudinal direction as it is, and the protective layer 28 is formed to produce the acidic gas separation layer 20. Good.

The laminated body 14 is further laminated with a permeating gas flow path member 26.
The permeating gas channel member 26 is a member for allowing the acidic gas Gc that has reacted with the carrier and permeated the acidic gas separation layer 20 to flow through the through hole 12a of the central cylinder 12.
As described above, in the illustrated example, the laminated body 14 has the sandwiching body 36 in which the acidic gas separation layer 20 is folded in two with the facilitated transport film 21 inside, and the supply gas flow path member 24 is sandwiched. By laminating the permeating gas flow path member 26 on the sandwiching body 36 and bonding them with the adhesive layer 30, one laminated body 14 is configured.
The permeating gas flow path member 26 functions as a spacer between the stacked bodies 14, and the acidic gas separated from the source gas G reaches the through hole 12 a of the central cylinder 12 toward the winding center (inner side) of the stacked body 14. A flow path for the gas Gc is formed. Further, in order to properly form the flow path of the acidic gas Gc, the adhesive layer 30 described later needs to penetrate. Considering this point, the permeating gas channel member 26 is preferably a member having a mesh structure (net / mesh), like the supply gas channel member 24.

  Various materials can be used as the material for forming the permeating gas channel member 26 as long as it has sufficient strength and heat resistance. Specifically, polyester materials such as epoxy-impregnated polyester, polyolefin materials such as polypropylene, and fluorine materials such as polytetrafluoroethylene are preferably exemplified.

The thickness of the permeating gas channel member 26 may be appropriately determined according to the supply amount of the raw material gas G, the required processing capacity, and the like.
Specifically, 100 to 1000 μm is preferable, 125 to 950 μm is more preferable, and 150 to 900 μm is particularly preferable.

As described above, the permeating gas flow path member 26 is a flow path of the acidic gas Gc that is separated from the source gas G and permeates the acidic gas separation layer 20.
Therefore, it is preferable that the permeating gas channel member 26 has a low resistance to flowing gas. Specifically, it is preferable that the porosity is high, the deformation is small when pressure is applied, and the pressure loss is small.

The porosity of the permeating gas channel member 26 is preferably 30 to 99%, more preferably 35 to 97.5%, and particularly preferably 40 to 95%.
Further, deformation when pressure is applied can be approximated by elongation when a tensile test is performed. Specifically, the elongation when a load of 10 N / 10 mm width is applied is preferably within 5%, more preferably within 4%.
Furthermore, the pressure loss can be approximated by a flow rate loss of compressed air that flows at a constant flow rate. Specifically, when 15 L / min of air is passed through the 15 cm square permeate gas channel member 26 at room temperature, the flow rate loss is preferably within 7.5 L / min, and within 7 L / min. More preferably.

  Hereinafter, the lamination method of the laminated body 14, and the winding method of the laminated body 14, ie, the preparation method of the spiral laminated body 14a, are demonstrated. 4 to 7 used in the following description, the supply gas flow path member 24 and the permeate gas flow path member 26 are only end surfaces (end portions) in order to simplify the drawings and clearly show the configuration. Is shown as a net.

  First, as conceptually shown in FIGS. 4 (A) and 4 (B), the extending direction of the central cylinder 12 and the short direction coincide with each other, and a fixing means such as an instantaneous adhesive is attached to the central cylinder 12. 34 is used to fix the end of the permeating gas channel member 26.

Next, as conceptually shown in FIG. 5, the acidic gas separation layer 20 produced as described above is folded in half with the facilitated transport membrane 21 side (protective layer 28 side) inside, and the supply gas is sandwiched therebetween. The channel member 24 is sandwiched. That is, a sandwiching body 36 is produced in which the supply gas flow path member 24 is sandwiched between the acidic gas separation layers 20 folded in half. In this case, the acidic gas separation layer 20 is not equally folded in half, but is folded in half so that one is slightly longer as shown in FIG.
Further, in order to prevent the facilitated transport film 21 from being damaged by the supply gas flow path member 24, a sheet-shaped protective member (for example, Kapton tape) folded in half at the trough portion where the acidic gas separation layer 20 is folded in half. Etc.) are preferably arranged.

Further, an adhesive 30 a to be the adhesive layer 30 is applied to the shorter surface of the acid gas separation layer 20 folded in half (the surface of the porous support 22).
Here, as shown in FIG. 5, the adhesive 30 a (that is, the adhesive layer 30) extends in the vicinity of both ends in the width direction (arrow x direction) and extends in the entire circumferential direction (arrow y direction). It is applied in the form of a strip, and is further applied in the form of a strip extending in the entire width direction in the vicinity of the end opposite to the folded portion.

  Next, as conceptually shown in FIGS. 6 (A) and 6 (B), the surface coated with the adhesive 30a is directed to the permeating gas flow path member 26, and the folded side is directed to the central cylinder 12. The sandwiching body 36 is laminated on the permeate gas channel member 26 fixed to the central cylinder 12, and the permeate gas channel member 26 and the acidic gas separation layer 20 (porous support 22) are bonded.

Further, as shown in FIG. 6A, an adhesive 30a to be the adhesive layer 30 is applied to the upper surface of the laminated sandwiching body 36 (the surface of the long porous support 22). In the following description, the direction opposite to the permeating gas flow path member 26 first fixed to the central cylinder 12 by the fixing means 34 is also referred to as the upper side.
As shown in FIG. 6A, the adhesive 30a on this surface is also applied in the form of a belt extending in the entire circumferential direction in the vicinity of both end portions in the width direction, and the reverse of the folded portion. It is applied in the form of a strip extending in the entire width direction in the vicinity of the end on the side.

  Next, as conceptually shown in FIG. 7, a permeating gas flow path member 26 is laminated on the sandwiching body 36 coated with the adhesive 30a, and the permeation with the acidic gas separation layer 20 (porous support 22). The gas flow path member 26 is bonded to form the laminate 14.

Next, as shown in FIG. 5, as shown in FIG. 5, a sandwiching body 36 is produced in which the supply gas flow path member 24 is sandwiched by the acidic gas separation layer 20 in which the protective layer 28 is formed on the surface of the facilitated transport film 21. Then, the adhesive layer 30a to be the adhesive layer 30 is applied, the side to which the adhesive is applied is directed downward, and the last laminated permeated gas channel member 26 and the sandwiching body 36 are laminated and bonded. .
Further, similarly to the above, an adhesive 30a is applied to the upper surface of the laminated sandwiching body 36 as shown in FIG. 6A, and then, as shown in FIG. The member 26 is laminated and bonded, and the second layered laminate 14 is laminated.

Thereafter, the steps shown in FIGS. 5 to 7 are repeated, and a predetermined number of laminated bodies 14 are laminated as conceptually shown in FIG.
In this case, as shown in FIG. 8, it is preferable that the laminated body 14 is laminated so as to be gradually separated from the central tube 12 in the circumferential direction as it goes upward. Thereby, winding (wrapping) of the laminated body 14 around the center tube 12 is easily performed, and the end portion or the vicinity of the end portion of each permeate gas flow path member 26 on the center tube 12 side is preferably the center tube. 12 can be contacted.

  When the predetermined number of the laminated bodies 14 are laminated, as shown in FIG. The adhesive 38b is applied between the sandwiching body 36 and the adhesive 36b.

  Next, as shown by an arrow yx in FIG. 8, the laminated body 14 is wound (wrapped) around the central cylinder 12 so as to wind the laminated body 14.

After winding, the permeate gas passage member 26 on the outermost periphery (that is, the lowermost layer first fixed to the center tube 12) is maintained for a predetermined time in a state where tension is applied in the pulling-out direction (winding and squeezing direction). Then, the adhesive 30a and the like are dried.
When a predetermined time has elapsed, the outermost permeate gas channel member 26 is fixed by ultrasonic welding or the like at a position where it has made one round, and the excess permeate gas channel member 26 outside the fixed position is cut. Thus, the spiral laminated body 14a formed by winding the laminated body 14 around the central cylinder is completed.

  As described above, the raw material gas G is supplied from the end of the supply gas flow path member 24, and the acidic gas Gc passes (transports) in the stacking direction through the acidic gas separation layer 20 to transmit the permeated gas flow. It flows into the road member 26, flows through the permeate gas flow path member 26, and reaches the central cylinder 12.

Here, the adhesive 30a is applied to the porous support 22, and the adhesive 30a is bonded to the permeated gas flow path member 26 having a network structure. Therefore, the adhesive 30a permeates (impregnates) into the porous support 22 and the permeating gas flow path member 26, and the adhesive layer 30 is formed inside both.
In addition, as described above, the adhesive layer 30 (adhesive 30a) is formed in a strip shape extending in the entire circumferential direction in the vicinity of both ends in the width direction. Further, the adhesive layer 30 extends across the entire width direction in the vicinity of the end portion on the side opposite to the folded portion on the central tube 12 side so as to cross the adhesive layer 30 in the vicinity of both ends in the width direction in the width direction. Then, it is formed in a band shape. That is, the adhesive layer 30 is formed so as to surround the outer peripheries of the permeating gas flow path member 26 and the porous support 22 by opening the central tube 12 side. Further, the permeating gas channel member 26 is sandwiched between the facilitated transport films 21.
As a result, an envelope-like flow path is formed in the permeate gas flow path member 26 of the laminate 14 so that the central tube 12 side is open. Therefore, the acidic gas Gc that has passed through the acidic gas separation layer 20 and has flowed into the permeate gas flow path member 26 flows toward the central cylinder 12 in the permeate gas flow path member 26 without flowing out, It flows into the center tube 12 from the through hole 12a.

In the separation module 10 of the present invention, various known adhesives can be used as the adhesive layer 30 (adhesive 30a) as long as it has sufficient adhesive strength, heat resistance, and moisture resistance.
Examples include epoxy resins, vinyl chloride copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylonitrile copolymers, butadiene-acrylonitrile copolymers, polyamide resins, polyvinyl butyral. Suitable examples include polyesters, cellulose derivatives (nitrocellulose, etc.), styrene-butadiene copolymers, various synthetic rubber resins, phenol resins, urea resins, melamine resins, phenoxy resins, silicone resins, urea formamide resins, and the like. .

The adhesive 30a to be the adhesive layer 30 may be applied once, but preferably, an adhesive diluted with an organic solvent such as acetone is applied first, and only the adhesive is applied thereon. preferable. In this case, the adhesive diluted with an organic solvent is preferably applied in a wide width, and the adhesive is preferably applied in a narrower width.
Thereby, the adhesive layer 30 (adhesive 30a) can be suitably infiltrated into the porous support 22 and the permeating gas channel member 26.

In the separation module 10 of the present invention, telescope prevention plates (telescope prevention members) 16 are disposed at both ends of the spiral laminate 14a produced in this way.
As described above, the telescope prevention plate 16 is a so-called telescope in which the spiral laminated body 14a is pressed by the source gas G, the supply-side end surface is pushed in a nested manner, and the opposite end surface protrudes in a nested manner. This is a member for preventing the phenomenon.

In the present invention, as the telescoping prevention plate 16, various known types used for spiral type separation modules can be used.
In the illustrated example, the telescope prevention plate includes an annular outer ring portion 16a, an annular inner ring portion 16b arranged in the outer ring portion 16a so as to coincide with the center, an outer ring portion 16a and an inner ring. And a rib (spoke) 16c for connecting and fixing the portion 16b. As described above, the center tube 12 around which the stacked body 14 is wound passes through the inner ring portion 16b.
In the illustrated example, the ribs 16c are provided radially at equal angular intervals from the center of the outer ring part 16a and the inner ring part 16b, and between the outer ring part 16a and the inner ring part 16b and each rib 16c. Is an opening 16d through which the source gas G or the residual gas Gr passes.

  Further, the telescope prevention plate 16 may be disposed in contact with the end face of the spiral laminate 14a. However, in general, in order to use the entire end face of the spiral laminate 14a for supplying the source gas and discharging the residual gas Gr, there is a slight gap between the telescope prevention plate 16 and the end face of the spiral laminate 14a. It is arranged.

Various materials having sufficient strength, heat resistance and moisture resistance can be used as the material for forming the telescope prevention plate 16.
Specifically, metal materials (for example, stainless steel (SUS), aluminum, aluminum alloy, tin, tin alloy, etc.), resin materials (for example, polyethylene resin, polypropylene resin, aromatic polyamide resin, nylon 12, nylon 66, polysulfin resin) , Polytetrafluoroethylene resin, polycarbonate resin, acrylic / butadiene / styrene resin, acrylic / ethylene / styrene resin, epoxy resin, nitrile resin, polyetheretherketone resin (PEEK), polyacetal resin (POM), polyphenylene sulfide (PPS) Etc.), and fiber reinforced plastics of these resins (for example, as the fiber, glass fiber, carbon fiber, stainless steel fiber, aramid fiber, etc.) are particularly preferable long fibers. Fiber-reinforced polypropylene, long glass fiber-reinforced polyphenylene sulfide), as well as ceramics (such as zeolite, alumina, etc.) and the like are preferably exemplified.
In addition, when using resin, you may use resin reinforced with glass fiber etc.

  The covering layer 18 covers the peripheral surface of the spiral laminated body 14a and blocks the discharge of the source gas G and the residual gas Gr from the peripheral surface other than the end face of the spiral laminated body 14a to the outside.

As the coating layer 18, various materials that can shield the raw material gas G and the like can be used. The covering layer 18 may be a cylindrical member or may be configured by winding a wire or a sheet-like member.
As an example, a wire made of FRP is impregnated with the adhesive used for the adhesive layer 30 described above, and the wire impregnated with the adhesive is wound around the spiral laminated body 14a in multiple layers without a gap as necessary. The covering layer 18 is illustrated.
In this case, if necessary, a sheet-like member such as Kapton tape is provided between the coating layer 18 and the spiral laminate 14a to prevent the adhesive from penetrating into the spiral laminate 14a. Also good.

  Although the separation module (acid gas separation module) of the present invention has been described in detail above, the present invention is not limited to the above-described examples, and various improvements and modifications are made without departing from the scope of the present invention. Of course, you may.

For example, in the above embodiment, the spiral type acidic gas separation module is used, but the present invention is not limited to this, and a flat membrane type acidic gas separation module may be used.
Since the spiral type separation module is likely to rub between the facilitated transport film and the supply gas flow path member, the present invention that can suppress the rub between the facilitated transport film and the supply gas flow path member is preferably applied. can do.

  Hereinafter, the specific example of this invention is given and the module for acidic gas separation of this invention is demonstrated in detail. The present invention is not limited to these examples.

[Example 1]
<Production of acid gas separation layer>
3.3% by mass of polyvinyl alcohol-polyacrylic acid copolymer (Kuraray Co., Ltd., Crustomer AP-20), 0.016% by mass of a crosslinking agent (25% by mass of a glutaraldehyde aqueous solution manufactured by Wako Pure Chemical Industries, Ltd.), An aqueous solution containing was prepared. To this aqueous solution, 1M hydrochloric acid was added until the pH reached 1.5 to cause crosslinking.
After crosslinking, a 40% aqueous cesium carbonate solution (manufactured by Rare Metal Co., Ltd.) as a carrier was added so that the concentration of cesium carbonate was 6.0% by weight to prepare a coating composition A. That is, in this example, cesium carbonate serves as a carrier for the facilitated transport film 21.

The coating composition A is applied to a porous support (a laminate (manufactured by GE) obtained by laminating porous PTFE on the surface of a PP nonwoven fabric) and dried, whereby the porous support 22 is coated. Then, the facilitated transport film 21 was formed. The facilitated transport film 21 has a hydroxyl group and a carboxyl group.
The thickness of the facilitated transport film 21 was 30 μm.

Next, as coating composition B1 to be the protective layer 28, 20% by mass of polymerizable polydimethylsiloxane (UV9300, manufactured by Momentive Performance Materials Japan), 4-isopropyl-4'-methyldiphenyliodonium tetrakis ( A heptane solution containing 0.1% of pentafluorophenyl) borate (I0591, manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared.
By applying this coating composition B1 on the surface of the facilitated transport film 21 formed on the porous support 22 and performing a drying / UV irradiation treatment, the porous support 22, the facilitated transport film 21, and the protective layer are applied. An acidic gas separation layer 20 composed of 28 was prepared.
The protective layer 28 was polydimethylsiloxane (PDMS), and the thickness was 0.9 μm. The protective layer 28 has an epoxy group that is a functional group that reacts with a hydroxyl group or a carboxyl group.
Moreover, when the gas permeability coefficient of this protective layer 28 was measured by the method shown below, the gas permeability coefficient was 750 Barrer.

The method for measuring the gas permeability coefficient is as follows.
First, a sample in which the same composition as the protective layer 28 was formed by applying and drying the coating composition B1 to be the protective layer 28 on the porous film Z having a negligible permeability coefficient was produced.
Next, the produced sample was sandwiched between PTFE membrane filters to produce a transmission test sample. A mixed gas of CH ₄ : CO ₂ = 87: 13 was supplied as a test gas to the permeation test sample at a relative humidity of 0% (below the detection limit), a temperature of 25 ° C., and a total pressure of 601.3 kPa. The permeated gas was analyzed with a gas chromatograph, the CO ₂ permeation rate (P (CO ₂ )) was calculated, and the permeation coefficient of the protective layer 28 was calculated.

<Production of separation module>
First, as shown in FIG. 4A, a permeating gas flow path member 26 (tricot knitted epoxy-impregnated polyester) was fixed to the center tube 12 using an adhesive.

On the other hand, the produced acidic gas separation layer 20 was folded in two with the facilitated transport membrane 21 inside. As shown in FIG. 5, the half-folding was performed so that one acidic gas separation layer 20 was slightly longer. Kapton tape was attached to the trough of the acid gas separation layer 20 folded in half, and the end of the supply gas flow path member 24 was reinforced so as not to damage the trough of the facilitated transport film 21. The folds were folded firmly so that the film surface was not damaged, so that there was no curl.
Next, the supply gas flow path member 24 (a polypropylene net having a thickness of 0.5 mm) was sandwiched between the acid gas separation layer 20 folded in half, and a sandwich body 36 was produced.

As shown in FIG. 5, in the vicinity of both ends in the width direction (arrow x direction), the circumferential direction (arrow y direction) is arranged on the porous support 22 side of the sandwich body 36 where the acidic gas separation layer 20 is shorter. An adhesive 30a (extending to the entire region and extending to the entire region in the width direction in the vicinity of the end on the opposite side to the circumferential folded portion, and made of an epoxy resin having a high viscosity (about 40 Pa · s). E120HP manufactured by Henkel Japan KK was applied.
Next, the side to which the adhesive 30a was applied was directed downward, and as shown in FIG. 6A, the sandwiching body 36 and the permeating gas flow path member 26 fixed to the central cylinder 12 were laminated and bonded.
Next, on the upper surface of the acidic gas separation layer 20 of the sandwiching body 36 laminated on the permeating gas flow path member 26, as shown in FIG. In addition, the adhesive 30a was applied in the vicinity of the end portion on the side opposite to the folded portion in the circumferential direction so as to extend over the entire region in the width direction. Further, as shown in FIG. 7, a permeate gas flow path member 26 is laminated on the acidic gas separation layer 20 coated with the adhesive 30a and bonded to form the first layered product 14. did.

In the same manner as described above, another holding member 36 shown in FIG. 5 in which the supply gas flow path member 24 having the protective layer 28 formed on the surface is sandwiched between the acidic gas separation layers 20 is produced. Similarly, the adhesive 30a was applied to the porous support 22 side of the acidic gas separation layer 20 on the short side. Next, in the same manner as in FIG. 6A, the sandwiched body 36 is set to 1 side toward the first layered body 14 (the permeating gas flow path member 26) formed first on the side to which the adhesive 30a is applied. It laminated | stacked on the laminated body 14 (the member 26 for permeate gas flow paths) of the layer, and was adhere | attached. Further, an adhesive 30a is applied to the upper surface of the sandwiching body 36 in the same manner as in FIG. 6A, and a permeating gas flow path member 26 is laminated thereon and adhered in the same manner as in FIG. A second layered laminate 14 was formed.
Further, the third layered product 14 was formed on the second layered product 14 in the same manner as the second layer.

After laminating the three-layer laminate 14 on the permeate gas flow path member 26 fixed to the central cylinder 12, an adhesive 38a is applied to the peripheral surface of the central cylinder 12, as shown in FIG. The adhesive 38b was applied onto the permeating gas flow path member 26 between the central cylinder 12 and the lowermost layered laminate 14. The adhesives 38a and 38b were the same as the adhesive 30a.
Next, the central cylinder 12 is rotated in the direction of the arrow yx in FIG. Thus, the sides were cut to align both ends to form a spiral laminate 14a.

Further, the center tube 12 is inserted into the inner ring portion 16b at both ends of the spiral laminated body 14a, and the telescope prevention plate 16 made of PPS (40% glass-filled) having a thickness of 2 cm as shown in FIG. Attached.
Further, a coating layer 18 is formed by wrapping an FRP resin tape around the peripheral surface of the telescope prevention plate 16 and the peripheral surface of the spiral laminated body 14a, and sealing it. A separation module 10 as shown was created. In addition, the thickness of the coating layer 18 was 5 mm.
The membrane area of the separation module 10 was 1.2 m ² .

[Example 2]
A separation module 10 was produced in the same manner as in Example 1 except that the thickness of the protective layer 28 was 2 μm and the gas permeability coefficient was 570 Barrer.

[Example 3]
A separation module 10 was produced in the same manner as in Example 1 except that the thickness of the protective layer 28 was 0.4 μm and the gas permeability coefficient was 1000 Barrer.

[Example 4]
A separation module 10 was produced in the same manner as in Example 2 except that KF-102 manufactured by Shin-Etsu Chemical Co., Ltd. was used as the polymerizable polydimethylsiloxane.
The formed protective layer 28 is polydimethylsiloxane (PDMS). The gas permeability coefficient was 620 Barrer.

[Example 5]
Using the coating composition to be the protective layer 28, an intermediate layer having a thickness of 2.2 μm is formed on the support 22 in the same manner as the protective layer 28, and a facilitated transport film is formed on the intermediate layer. A separation module was formed in the same manner as in Example 1 except that the thickness of the protective layer 28 was 1.2 μm.
In the intermediate layer, the thickness of the region formed on the support was 2 μm, and the thickness of the region soaked into the support was 0.2 μm.
The gas permeability coefficient was 620 Barrar.

[Comparative Example 1]
A separation module was produced in the same manner as in Example 1 except that a PTFE porous membrane having a thickness of 20 μm was used as the protective layer.
Since this protective layer (PTFE porous membrane) is a porous membrane, the gas permeability coefficient is very large and can be ignored.

[Comparative Example 2]
A separation module was produced in the same manner as in Example 1 except that the protective layer was not formed.

[Evaluation]
The adhesion between the facilitated transport membrane and the protective layer of the produced acidic gas separation layer, the reduction rate of the gas permeation rate of the produced separation module, and the change rate of the separation performance were measured.

<Adhesion>
The produced acidic gas separation layer was allowed to stand in an environment of a temperature of 85 ° C. and a humidity of 85% RH for 5 hours, and then the protective layer was visually evaluated for cracking and peeling. The evaluation is as follows.
A: There was no peeling and cracking.
B: Some peeling and cracking occurred.
C: There was peeling and cracking in an area of 20% or more of the surface.

<Decrease rate>
The rate of decrease in permeation rate due to the formation of the protective layer was evaluated. That is, the ratio of the transmission speed of each separation module to the transmission speed of the separation module of Comparative Example 4 in which no protective layer was formed was evaluated as a reduction rate of the transmission speed.
Specifically, a mixed gas of N ₂ : CO ₂ : H ₂ O = 66: 21: 13 (partial pressure ratio) is used as a test source gas G to each manufactured separation module at a temperature of 130 ° C. and a total pressure. It was supplied under the condition of 2001.3 kPa.
The gas (acid gas Gc and residual gas Gr) permeating through the separation module 10 was analyzed with a gas chromatograph, and the CO ₂ permeation rate (P (CO ₂ )) was calculated. The unit of transmission speed GPC is “1 GPU = [1 × 10 ⁻⁶ cm ³ (STP)] / [s · cm ² · cmHg]”. The evaluation is as follows.
A: Reduction rate is less than 10%.
B: The decrease rate is more than 10% and less than 30%.
C: Reduction rate is over 30%.

<Change rate of separation performance>
The permeation rate and the separation factor at the time when gas separation was started for 1 hour and the time after 200 hours were measured, and the rate of change of the permeation rate and the separation factor with time was evaluated.
Specifically, a mixed gas of N ₂ : CO ₂ : H ₂ O = 66: 21: 13 (partial pressure ratio) is used as a test source gas G to each manufactured separation module at a temperature of 130 ° C. and a total pressure. It was supplied under the condition of 2001.3 kPa. The gas (acid gas Gc and residual gas Gr) that has permeated through the separation module 10 when 1 hour has passed and when 200 hours have passed are analyzed by a gas chromatograph, and the CO ₂ permeation rate (P (CO ₂ )) and The CO ₂ / H ₂ separation factor (α) was calculated.
For each of the permeation rate and the separation factor, the rate of change was determined as follows: rate of change = (value at 1 hour elapsed time−value at 200 hour elapsed time) / value at 1 hour elapsed time × 100. The evaluation is as follows.
A: The rate of change is less than 5% for both the transmission rate and the separation factor.
B: The rate of change of at least one of the transmission rate and the separation factor is more than 5% and less than 10%.
C: The rate of change of at least one of the permeation rate and the separation factor exceeds 10%.

<Comprehensive evaluation>
The performance of the separation module 10 was evaluated according to the following evaluation criteria.
AA: Adhesion and rate of change are both A, and rate of decrease is A or B.
A: Adhesion evaluation is A, change rate evaluation is B, and decrease rate evaluation is A or B.
B: Evaluation of adhesion is B, and evaluation of change rate and reduction rate is A or B.
C: There is at least one C in the evaluation of adhesion, change rate, and reduction rate.
The results of the evaluation are shown in the following table. Note that “-” in the performance evaluation result column indicates that the evaluation is not possible because a defect has occurred in the manufacturing stage of the separation module.

  As shown in the above table, the facilitated transport film has at least one selected from the group consisting of a hydroxyl group and a carboxyl group, and the protective layer formed on the facilitated transport film is in the facilitated transport film. The separation modules of Examples 1 to 6 having functional groups that react with at least one selected from the group consisting of a hydroxyl group and a carboxyl group contained in each have adhesion, change rate, and reduction rate. It is good.

On the other hand, the protective layer has no functional group that reacts with at least one selected from the group consisting of a hydroxyl group and a carboxyl group contained in the facilitated transport film and does not have a protective layer In Comparative Example 2, the rate of change is large. This is considered that the facilitated transport film 21 was greatly damaged by the supply gas flow path member 24 during the gas separation.
From the above results, the effects of the present invention are clear.

DESCRIPTION OF SYMBOLS 10 (Acid gas) separation module 12 Center tube 14 Laminated body 14a Spiral laminated body 16 Telescope prevention board 16a Outer ring part 16b Inner ring part 16c Rib 16d Opening part 18 Covering layer 20 Acid gas separation layer 21 Accelerated transport film 22 Porous Support 22a Porous membrane 22b Auxiliary support membrane 24 Supply gas channel member 26 Permeate gas channel member 28 Protective layer 30 Adhesive layer 30a Adhesive 34 Fixing means 36 Holding body

Claims (6)

An acid gas separation module that selectively separates an acid gas from a source gas containing 0.1 mol% or more of water,
An acidic gas comprising a carrier that reacts with an acidic gas and a hydrophilic compound for supporting the carrier to separate the acidic gas from the source gas, and a protective layer laminated on the surface of the facilitated transport membrane Having a gas separation layer,
The protective layer is formed in the uppermost layer in the acid gas separation layer,
The gas permeability coefficient of the protective layer is 500 Barrer or more,
The facilitated transport membrane has at least one selected from the group consisting of a hydroxyl group and a carboxyl group,
The acidic gas separation module, wherein the protective layer has a functional group that reacts with at least one selected from the group consisting of a hydroxyl group and a carboxyl group contained in the facilitated transport membrane.   2. The acidic gas separation according to claim 1, wherein the functional group of the protective layer is at least one selected from the group consisting of an epoxy group, an amino group, a methoxy group, an ethoxy group, a hydroxyl group, and a carboxyl group. module.   The acid gas separation module according to claim 1, wherein the facilitated transport membrane has a water absorption rate of 5% or more.   The acid gas separation module according to claim 1, wherein the protective layer has a thickness of 0.1 μm or more and 5 μm or less.   The acid gas separation module according to claim 1, wherein the protective layer is a polydimethylsiloxane derivative. Furthermore, a central tube having a through-hole formed in the tube wall;
A supply gas flow path member serving as a flow path for the source gas;
A permeating gas channel member that serves as a channel through which the acidic gas that has permeated the facilitated transport membrane flows to the central cylinder;
The supply gas flow path member is laminated on the protective layer side of the acidic gas separation layer,
The permeating gas channel member is laminated on the opposite side of the acidic gas separation layer from the protective layer,
6. A spiral-type module formed by winding one or more laminates each including the supply gas flow path member, the acid gas separation layer, and the permeate gas flow path member around the central cylinder. The module for acidic gas separation of any one of these.