JP6392412B2 - Acid gas separation composite membrane manufacturing method and acid gas separation module - Google Patents

Description

  The present invention relates to a method for producing an acidic gas separation composite membrane for selectively separating acidic gas in a gas to be separated using a facilitated transport membrane and an acidic gas separation module.

In recent years, development of technology for selectively separating an acidic gas such as CO _{2 in} a gas to be separated has been advanced.
For example, the CO ₂ gas separation membrane which selectively permeates CO ₂ gas, a gas separation module for separating CO ₂ gas from the separation gas have been developed.

  Gas separation membranes are roughly classified into facilitated transport membranes and dissolved diffusion membranes. The facilitated transport membrane contains a substance (carrier) that selectively and reversibly reacts with one or more specific components in the gas to be separated in the membrane, and is specified using this carrier. The components are transported and separated to the opposite side of the membrane, and the dissolution diffusion membrane uses the difference in solubility between the acidic gas and the substance to be separated in the membrane and the diffusivity in the membrane to separate the components. is there.

  Since the facilitated transport membrane uses transport based on a selective reaction between a specific component and a carrier, separation with high selectivity is possible, and the permeation rate of the separation gas in the membrane is also fast. Therefore, a gas separation module (facilitated transport type gas separation module) using a facilitated transport membrane has attracted attention because of its excellent separation characteristics.

  In the facilitated transport type gas separation module, in general, a supply gas flow path member that is a flow path of a gas to be separated to be supplied, and a gas separation member (gas separation composite membrane) in which a facilitated transport film is held on a porous body ) And a permeate gas channel member serving as a permeate gas channel that permeates through the facilitated transport membrane.

  Gas separation composite membranes responsible for the separation performance of the gas separation module are required to be suitable for manufacturing in addition to high separation performance and durability. As a facilitated transport film having high carrier retention and a production method thereof, a facilitated transport film obtained by impregnating a porous polymer film or a hydrogel film with a carrier is disclosed (Patent Documents 1 to 3).

  Patent Document 1 discloses a porous polymer membrane as a method for producing an facilitated transport membrane that is excellent in carbon dioxide separation performance, excellent in carbon dioxide carrier liquid retention, and does not easily deteriorate in membrane performance when contacted with water. Discloses a method of impregnating and holding a carbon dioxide carrier liquid through a hydrophilic polymer film after forming a hydrophilic polymer film by contacting a hydrophilic vinyl monomer vapor on a plasma-treated support. .

  Patent Document 2 discloses a carbon dioxide separator equipped with a facilitated transport membrane formed by casting a copolymer gel containing a carbon dioxide carrier on a hydrophilic porous membrane as a support. Has been. By using a hydrophilic porous membrane as a support, film formation is facilitated, and the pores of the porous membrane are filled with the copolymer gel, so that a carbon dioxide separation membrane with few defects can be obtained. Have been described.

  In Patent Document 3, a non-crosslinked copolymer liquid is coated on a support, cross-linked and insolubilized in water, and then absorbed with a carbon dioxide carrier aqueous solution, whereby long-term stability and high shape-retaining properties are obtained. It describes that a carbon separation membrane can be manufactured.

Japanese Patent Laid-Open No. 7-60078 Japanese Patent Publication No. 7-102310 JP 2009-195900 A

  When applying a liquid or gel-like facilitated transport film coating solution onto a porous membrane as a support, the coating solution penetrates into the support by capillary force or does not penetrate to the support. The surface tends to be uneven. In order to enable durable gas separation when used in a high-pressure, high-temperature, high-humidity environment, the facilitated transport membrane suppresses penetration into the pores of the porous body and unevenness of the surface as much as possible. It is preferable. Under a high pressure, high temperature and high humidity environment, the viscosity term of the gel membrane is lowered with time due to a high flow rate of water vapor, and permeation of the gas separation membrane into the porous body is likely to occur.

  In the manufacturing methods of Patent Documents 1 and 3, no countermeasure is taken against such penetration of the coating liquid into the support by capillary force. In the method of Patent Document 2, the pores of the support are positively filled with the gel of the facilitated transport film.

  The present invention has been made in view of the above circumstances, and in a method for producing an acidic gas separation composite membrane by applying a coating liquid containing a raw material for a facilitated transport membrane on a porous body, An object of the present invention is to produce an acidic gas separation composite membrane having good durability in a high temperature, high humidity and high pressure environment by suppressing the permeation of the coating liquid into the porous body and the uneven surface of the facilitated transport membrane.

The method for producing an acidic gas separation composite membrane of the present invention comprises an acidic gas that reacts with at least a hydrophilic compound and an acidic gas in a gas to be separated on the surface of a porous body having a hydrophobic porous body on at least one surface. A method for producing an acidic gas separation composite membrane comprising a facilitated transport membrane containing a carrier,
A three-dimensional network structure formed by intersecting, connecting, or branching a plurality of fibrils, and a plurality of pores composed of fine gaps divided by the plurality of fibrils,
The three-dimensional network structure has an average interfibril distance of 0.001 μm to 2 μm in a plane parallel to the surface of the support including the facilitated transport film, and an average fibril length in the plane of 0.01 μm or more. The hydrophobic porous body is 2 μm or less, and the average fibril distance in the direction perpendicular to the surface is 0.001 μm or more and 2 μm or less,
Preparing a hydrogel coating solution containing at least the hydrophilic compound and the acidic gas carrier or the accelerator;
The coating liquid is applied to the surface of the hydrophobic porous body.

  In the method for producing an acidic gas separation composite membrane of the present invention, the average fibril diameter of the plurality of fibrils in the porous body is preferably 0.01 μm or more and 5 μm or less.

In this specification, the average distance between fibrils means the average value of the distance between fibrils existing in the xy plane, and the average fibril length means the average value of the length of filrill also existing in the xy plane. The average distance between fibrils in the vertical direction means the average distance between fibrils in the z direction, and the average fibril diameter means the average value of the diameters per fibril. The measurement of the average interfibril distance, the average fibril length, and the average fibril diameter is judged from an image (surface SEM image) of a scanning electron microscope (SEM). The average inter-fibril distance in the vertical direction is determined from a cross-sectional SEM image, or a surface SEM image is acquired, and is determined by the ratio of the contrast between the fibrils existing on the outermost surface and the fibrils existing on the lower layer.
In the present specification, the term “hydrophobic” means that the contact angle with water at room temperature (25 ° C.) is 80 degrees or more.

  The porous body preferably has a contact angle with water of 100 ° or more at room temperature (25 ° C.) on the surface on which the acidic gas separation promoting transport membrane is arranged. Further, the hydrophobic porous body is preferably made of a fluorine-based resin, and more preferably made of polytetrafluoroethylene.

  Moreover, it is preferable that the manufacturing method of the acidic gas separation composite membrane of this invention has the process of laminating | stacking the nonwoven fabric of a resin fiber on the back surface of a porous body.

  In the method for producing an acidic gas separation composite membrane of the present invention, it is preferable to apply a coating solution to one surface of a hydrophobic porous body through a hydrophobic intermediate layer having gas permeability. As such an intermediate layer, a silicone resin layer is preferable.

  The acidic gas separation module according to the present invention is a facilitated transport type acidic gas separation module that separates a supplied gas to be separated into an acidic gas and a residual gas other than the acidic gas, and discharges the separated gas. A supply gas passage member through which gas and residual gas permeate, an acidic gas separation composite membrane produced by the method for producing an acidic gas separation composite membrane of the present invention, and an acidic gas separation composite membrane by reacting with an acidic gas carrier And a permeate gas channel member through which the permeated acid gas flows.

  In the present invention, the three-dimensional network structure formed by the fibrils has an average interfibril distance of 0.001 μm to 2 μm and an average fibril length of 0.01 μm to 2 μm in a plane parallel to the facilitated transport film forming surface. The coating liquid for the facilitated transport film is applied to the surface of the porous body having at least one hydrophobic porous body having an average distance between fibrils in the direction perpendicular to the surface of 0.001 μm to 2 μm. Thus, an acid gas separation composite membrane is manufactured. By using the hydrophobic porous body having such a configuration, the hydrogel-like coating liquid penetrates into the support by capillary force, and the surface of the coating film is prevented from becoming nonuniform, and facilitated transport with high surface uniformity. A film can be formed. Therefore, according to the present invention, it is possible to produce an acidic gas separation composite membrane having good durability under a high temperature, high humidity and high pressure environment.

The schematic diagram which shows the manufacturing method of the gas separation composite membrane of one Embodiment concerning this invention. The schematic diagram which shows the manufacturing method of the gas separation composite membrane following FIG. 1A. The figure which showed the sealing part in the gas separation composite film of FIG. 1B. The perspective view which shows typically the structure of the porous body of one Embodiment concerning this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutaway schematic configuration diagram showing an embodiment of an acid gas separation module of the present invention. Sectional drawing which shows a part of cylindrical winding body by which the laminated body was wound by the permeation | transmission gas collection pipe. Schematic schematic diagram showing the state before the laminate is wound around the permeate gas collecting pipe It is a figure which shows a spiral type module manufacturing process. It is a figure which shows the spiral type module manufacturing process following FIG. 6A. It is a figure which shows the spiral type module manufacturing process following FIG. 6B. It is a figure which shows a spiral type module manufacturing process. It is a figure which shows the modification of a spiral type module manufacturing process.

"Production method of acid gas separation composite membrane"
With reference to drawings, the manufacturing method of the acidic gas separation composite membrane of one Embodiment concerning this invention is demonstrated. 1A to 1B are schematic cross-sectional views showing a method for producing an acidic gas separation composite membrane according to an embodiment of the present invention by process, and FIG. 1C is a view showing a sealing portion in FIG. 1B.
FIG. 2 is a schematic perspective view showing the configuration of the porous body of the present embodiment. In the drawings of this specification, the scale of each part is appropriately changed and shown for easy visual recognition.

  As shown in FIG. 1B, the acidic gas separation composite membrane 1 has at least a hydrophilic compound (hydrophilic polymer) on the surface of the porous support 2 provided with the auxiliary support 2b on the back surface of the hydrophobic porous body 2a. And a facilitated transport film 3 containing an acidic gas carrier that reacts with the acidic gas in the gas to be separated.

  When the acidic gas separation composite membrane 1 is to be formed into a spiral module, which will be described later, the acidic gas separation composite membrane 1 is folded into two layers with a flow path (flow path material) interposed therebetween, and the stacked body is further stacked with another flow path interposed therebetween. Go. The channel and the laminate, and the laminate and the channel are both sealed in an envelope shape by a sealing portion using an adhesive. FIG. 1C shows a portion (sealing portion) that needs to be sealed when modularized as a reference numeral 4 and is provided with an adhesive such as an epoxy resin having excellent heat resistance and hydrolysis resistance.

  The facilitated transport membrane 3 containing a hydrophilic compound and an acidic gas carrier has an elastic modulus of 0.01 MPa to even in an operating environment as an acidic gas separation module by adding an additive as necessary. It becomes a hydrogel in the range of 100 Mpa. The hydrogel having such an elastic modulus is an elastic modulus calculated from an inclination obtained by performing a tensile test at 10 mm / min in an environment of 80 ° C. and a relative humidity of 60% in consideration of an operating environment of a normal acid gas separation module. Means a hydrogel within the above range.

  The inventor permeates the hydrogel in the above elastic modulus range as much as possible in the high-pressure environment and the environment for separating the gas to be separated containing high-flow water vapor (hereinafter referred to as a high-pressure and high-humidity environment). In other words, it is possible to maintain high gas separation performance by suppressing clogging of pores by acidic gas separation layer material and separation layer defects caused by penetration of acidic gas separation layer material into the porous body. The structure of the hydrophobic porous body 2a was examined. The ability to maintain high gas separation performance means that the selectivity for separating acidic gas in a high-pressure and high-humidity environment and the flow rate of the separated acidic gas show a constant value over a long period of time.

As a result of the study by the present inventor, a three-dimensional network structure 200 formed by crossing, connecting, or branching a plurality of fibrils 201 shown in FIG. 2 as the hydrophobic porous body 2a carrying the facilitated transport film 3 is shown. And a large number of holes 203 composed of fine gaps 203 divided by a plurality of fibrils 201,
In the three-dimensional network structure 200, the average fibril distance x in the plane parallel to the surface of the support 2a having the facilitated transport film 3 is 0.001 μm or more and 2 μm or less, and the average fibril length y in the plane is 0.2. Using a support having an average fibril distance z in the direction perpendicular to the surface thereof of not less than 01 μm and not more than 2 μm is not less than 0.001 μm and not more than 2 μm,
By applying a hydrogel coating solution 3m containing at least a hydrophilic compound and an acidic gas carrier on the surface of the hydrophobic porous body 2a, the hydrogel coating solution penetrates into the support by capillary force. It was also found that the facilitated transport film 3 having high surface uniformity can be formed while suppressing the non-uniformity of the coating film surface (see Examples below).
According to the manufacturing method of the present embodiment, it is possible to manufacture the acidic gas separation composite membrane 1 having good durability under a high temperature, high humidity, and high pressure environment.
Below, the manufacturing method of the acidic gas separation composite membrane which the present inventors discovered is demonstrated in detail.

<Preparation of porous body>
First, a porous support 2 having a hydrophobic porous body 2a on at least one surface is prepared (FIG. 1A). As shown in FIG. 1A, the porous support 2 only needs to include the above-described hydrophobic porous body 2a and the facilitated transport film 3, but the porous support 2 can be used in a high-pressure and high-humidity environment. Higher strength is preferred. Therefore, as shown in FIG. 1A, it is preferable to use a porous support 2 comprising an auxiliary support 2b on the back surface of the hydrophobic porous body 2a.

  The hydrophobic porous body 2a is not particularly limited as long as it has the above-described structure, but as shown in FIGS. 1 (A to C) and FIG. 2, the three-dimensional network structure 200 having a plurality of fibrils is: A mode in which a plurality of fibrils 201 and bundling portions (nodes) 202 are configured is common.

  As described above, the hydrophobic porous body 2a includes a three-dimensional network structure 200 formed by intersecting, connecting, or branching a plurality of fibrils 201, and a fine gap 203 partitioned by the plurality of fibrils 201. The average fibril distance x in the plane parallel to the one surface on which the acidic gas separation layer 3 is arranged is 0.001 μm to 2 μm, and the average fibril length in the plane y is 0.01 μm or more and 2 μm or less, and the average fibril distance z in the direction perpendicular to the surface is 0.001 μm or more and 2 μm or less.

  From the viewpoint of suppressing the hydrogel-like coating liquid 3m containing at least a hydrophilic compound and an acidic gas carrier from penetrating into the hydrophobic porous body 2a by capillary force, the average in the plane on which the acidic gas separation layer 3 is disposed It is preferable that the interfibril distance x and the average interfibril distance z in the direction perpendicular to the surface are shorter. If the average interfibril distances x and z are too long, the surface state of the applied gel film becomes non-uniform, which tends to cause an increase in film defects and a decrease in the film life, and to a gel support at high pressure. There is a tendency that the effect of suppressing the penetration of is reduced.

  Therefore, the average interfibril distance x is preferably 0.001 to 2 μm, more preferably 0.005 to 1.5 μm, and still more preferably 0.01 to 1 μm. The average fibril distance z in the z direction is preferably 0.001 to 2 μm, more preferably 0.005 to 1.5 μm, and still more preferably 0.01 to 1 μm.

  The average fibril length y in the plane where the acid gas separation layer 3 is disposed is preferably shorter from the same viewpoint as the average interfibril distance. Therefore, the average interfibril length y is preferably 0.01 to 2 μm, more preferably 0.02 to 2 μm, and still more preferably 0.02 to 2 μm.

  The shape of the hole formed by the gap 203 is not particularly limited, and the cross section may be various structures such as a circle, an ellipse, a polygon, and an indeterminate shape, but the more uniform the size, the better the permeability. It is preferable.

In the hydrophobic porous body 2a, the average fibril diameter of the plurality of fibrils 201 is preferably 0.01 μm or more and 5 μm or less. Moreover, it is preferable that 80% or more of the fibril diameter is 0.01 μm or more and 5 μm or less.
A thicker fibril diameter within a range that does not impair permeability is preferable because the hydrogel support is high. The porosity of the hydrophobic porous body 2a is preferably 0.01% or more and 90% or less, more preferably 0.1% or more and 85% or less, since sufficient permeability and mechanical strength can be secured.

  The material of the hydrophobic porous body 2a is not limited as long as it has hydrophobicity, but the contact angle with water on the surface on which the acidic gas separation layer 3 is disposed is 100 degrees or more. It is preferable. Examples of such a material include a fluorine-based resin, and polytetrafluoroethylene (PTFE) is preferable.

  Examples of a preferable material of the hydrophobic porous body 2a other than PTFE include inorganic materials such as ceramic, glass, and metal, and organic resin materials having heat resistance of 100 ° C. or higher from the viewpoint of heat and humidity resistance. Polyester, polyolefin, heat resistant polyamide, polyimide, polysulfone, aramid, polycarbonate, polypropylene, metal, glass, ceramics and the like can be suitably used. More specifically, ceramics, polyvinylidene fluoride, polyethersulfone (PES), polyphenylene sulfide (PPS), polysulfone (PSF), polyimide, polypropylene (PP), polyetherimide, polyetheretherketone, and the like can be given. .

  If the hydrophobic porous body 2a is too thick, the gas permeability decreases, and if it is too thin, the strength is difficult. Therefore, the thickness of the support is preferably from 30 μm to 500 μm, more preferably from 50 μm to 450 μm, and further preferably from 50 μm to 400 μm.

  The method for producing the hydrophobic porous body 2a is not particularly limited, but in the case of PTFE, it can be easily produced by biaxial stretching due to the stretching characteristics of PTFE. By optimizing the biaxial stretching conditions, the hydrophobic porous body 2a can be produced so as to have a desired fibril structure.

  Since the hydrogel facilitated transport film 3 has poor affinity with the hydrophobic porous body, it is necessary to perform hydrophilic treatment on the surface of the porous body as shown in International Publication No. 2009093666, etc. It was thought. By making the hydrophobic porous body into the structure of the above-described three-dimensional network structure 200, the present inventors do not require such treatment, and the hydrogel is directly applied on the hydrophobic porous body with good durability. It was the first time to support it. The present inventor makes a hydrogel coating liquid having a viscosity measured by a B-type viscometer of 0.1 Pa · s to 5.0 Pa · s by using the above-described hydrophobic porous body having the three-dimensional network structure 200 ( The material of the facilitated transport membrane) could be held on this porous body in an appropriate contact angle (most preferably 120 to 140 degrees) range, and the hydrogel was directly on the hydrophobic porous body. We believe that this is a factor that makes it possible to support with good durability.

As the auxiliary support 2b, the hydrophobic porous body 2a is restrained to restrain the deformation of the hydrophobic porous body 2a in a high-pressure and high-humidity environment, and the strength, stretch resistance and gas permeability are good. As long as there is no particular limitation, a nonwoven fabric, a woven fabric, a woven fabric, and a mesh having a pore diameter of 0.1 μm or more and 2000 μm or less can be appropriately selected and used, but a resin excellent in durability and heat resistance. A fiber nonwoven is preferred.
Examples of such resin fibers include fibers made of heat-resistant resins such as polypropylene and modified polyamides such as aramid (trade name), fluorine-containing resins such as polytetrafluoroethylene and polyvinylidene fluoride, and the like.

  If the auxiliary support 2b is too thick, the gas permeability decreases, and if it is too thin, there is a concern that sufficient strength is difficult to obtain. For this reason, the thickness of the auxiliary support 2b is preferably 30 μm or more and 500 μm or less, more preferably 50 μm or more and 450 μm or less, and particularly preferably 50 μm or more and 400 μm or less.

  Further, the average pore diameter of the opening of the auxiliary support 2b can sufficiently soak the adhesive of the sealing portion 4 in the adhesive application region to form an effective gas non-permeable region, and does not apply the adhesive. In the region, it is preferably 0.001 μm or more and 200 μm or less, more preferably 0.002 μm or more and 200 μm or less, and particularly preferably 0.005 μm or more and 200 μm or less from the viewpoint of preventing the passage of gas.

  In the present invention, it is desirable that a support is formed in order to impart further mechanical strength to the lower part of the support layer forming the gas separation layer. Examples of the support include woven fabric, non-woven fabric, and net, and the non-woven fabric is preferably used from the viewpoint of film forming property and cost. As the nonwoven fabric, fibers made of polyester, polypropylene, polyacrylonitrile, polyethylene, polyamide or the like may be used alone or in combination. For the purpose of removing fluff and improving mechanical properties, it is also preferable to apply a heat treatment by sandwiching a nonwoven fabric with two rolls.

<Intermediate layer>
As already described, the porous support 2 (hydrophobic porous body 2a) of the acidic gas separation composite membrane 1 is at least promoted from the viewpoint of suppressing the penetration of the facilitated transport material when the facilitated transport membrane is formed. The surface on the side in contact with the transport film 3 is hydrophobic. In addition, since the facilitated transport film 3 needs to retain a large amount of moisture in the film in order for the carrier to function sufficiently, a polymer having extremely high water absorption and water retention is used. In addition, in the facilitated transport membrane, as the content of a carrier such as a metal carbonate increases, the water absorption increases and the separation performance of the acid gas improves. Therefore, the facilitated transport membrane 3 is often a gel membrane or a low-viscosity membrane. Further, when separating the acidic gas, a source gas having a temperature of 100 to 130 ° C. and a humidity of about 90% is used at a pressure of about 1.5 MPa. Therefore, the separation layer gradually enters (soaks) the porous support by use, and the acid gas separation ability tends to decrease with time.

  Therefore, the acidic gas separation composite membrane 1 has a porous support 2 (hydrophobic porous body 2a) of a facilitated transport material (membrane) between the hydrophobic porous body 2a and the facilitated transport membrane 3 more effectively. It is preferable to include the intermediate layer 5 that suppresses the penetration into the surface.

  The intermediate layer 5 is not particularly limited as long as it is a hydrophobic layer having gas permeability, but preferably has a gas permeability and is denser than the hydrophobic porous body 2a. By providing the intermediate layer 5, it is possible to prevent the highly uniform facilitated transport film 3 from entering the porous support.

  The intermediate layer 5 only needs to be formed on the hydrophobic porous body 2a, but may have a soaking area that is soaked in the hydrophobic porous body 2a. The soaking area is preferably as small as possible within a range in which the adhesion between the hydrophobic porous body 2a and the intermediate layer 5 is good.

The intermediate layer 5 is preferably a polymer layer having a siloxane bond in the repeating unit. Examples of such a polymer layer include silicone-containing polyacetylene such as organopolysiloxane (silicone resin) and polytrimethylsilylpropyne.
Polyorganosiloxanes include linear silicones such as polydimethylsiloxane (PDMS), polymethylphenylsiloxane, and polymethylhydrogensiloxane, and modified by introducing amino groups, epoxy groups, halogenated alkyl groups, etc. into the side chains. A silicone etc. are illustrated suitably.

  The silicone resin layer is preferably formed by coating. The coating solution used for film formation (silicone coating solution) contains a monomer, dimer, trimer, oligomer, prepolymer, or mixture of compounds that form a silicone resin layer, and further includes a curing agent, a curing accelerator, and a crosslinking agent. , Thickeners, reinforcing agents and the like may be included. It is preferable that the viscosity at the time of application | coating of a coating liquid is 300 cp or more.

  In addition, it is preferable that a silicone coating liquid does not contain the organic solvent normally used when forming such a resin layer. Since the silicone coating solution does not contain an organic solvent, the drying process of the silicone coating solution is not required, and the monomer and the like can be cured immediately after the silicone coating solution is applied. The manufacturing equipment can be simplified. (It is possible to eliminate the need for static elimination equipment and explosion-proof equipment).

  Further, the surface on the facilitated transport film side of the intermediate layer 5 may be a smooth surface or a fine uneven surface. By having fine irregularities on the surface, the adhesion between the intermediate layer 5 and the facilitated transport film 3 can be improved. By making the silicone coating liquid into a spherical or plate-like inorganic fine particle such as silica, aerosil, titania, alumina, carbon, boron nitride, talc, zeolite, etc. Fine irregularities can be easily formed. The average particle size of the inorganic fine particles is preferably in the range of 0.001 μm to 30 μm.

  The intermediate layer 5 is a film having gas permeability, but if it is too thick, the gas permeability may be significantly reduced. The intermediate layer 5 may be thin as long as it covers the entire surface of the hydrophobic porous body 2a without passing through. Considering this point, the film thickness of the intermediate layer 5 is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 5 μm or less.

<Preparation of facilitated transport film>
Next, on the surface of the porous support 2 obtained as described above on the hydrophobic porous body 2a side, a coating liquid 3m containing a hydrophilic compound, an acidic gas carrier and water is applied to form a coating film, and coating is performed. The membrane is dried as necessary to obtain the acidic gas separation composite membrane 1 comprising the facilitated transport membrane 3 on the hydrophobic porous body 2a (FIG. 1B).

  First, a hydrogel coating solution 3m containing at least a hydrophilic compound (hydrophilic polymer), an acidic gas carrier and water is prepared.

  The hydrophilic compound functions as a binder, and retains water when used in the acidic gas separation layer to exhibit the function of separating the acidic gas by the acidic gas carrier. The hydrophilic compound can be dissolved in water to form a coating solution, and the acidic gas separation layer preferably has high water absorption from the viewpoint of high water absorption (humidity retention), and the mass of the hydrophilic compound itself. On the other hand, what absorbs the water of mass 1.5 times or more and 1000 times or less is preferable.

  The hydrophilic compound is preferably a hydrophilic polymer from the viewpoint of water absorption, film-forming property, strength, and the like. For example, polyvinyl alcohol-polyacrylate and polyvinyl alcohol-polyacrylic acid (PVAPAA) A polymer, polyvinyl alcohol, polyacrylic acid, polyacrylate, polyvinyl butyral, poly-N-vinylpyrrolidone, poly-N-nylacetamide, and polyacrylamide are preferable, and a PVA-PAA copolymer is particularly preferable. The PVA-PAA copolymer has a high water absorption capacity and a high hydrogel strength even at high water absorption. The content of polyacrylate in the PVA-PAA copolymer is, for example, preferably 5 mol% or more and 95 mol% or less, more preferably 30 mol% or more and 70 mol% or less. Examples of polyacrylic acid salts include alkali metal salts such as sodium salt and potassium salt, as well as ammonium salts and organic ammonium salts. Examples of commercially available PVA-PAA copolymers include Clastomer-AP20 (trade name: manufactured by Kuraray Co., Ltd.).

Acidic gas carriers are various water-soluble compounds that have an affinity with acidic gas (for example, carbon dioxide gas) and show basicity, and indirectly react with acidic gas, or themselves are directly acidic gas. Say something that reacts. Examples of the former include those that react with other gases contained in the supply gas, exhibit basicity, and react with the basic compound and acid gas. More specifically react with steam OH ^- to the release, the OH ^- refers to alkali metal compounds can be incorporated selectively acid gases in the film by reacting with the acid gases . The latter are, for example, nitrogen-containing compounds and sulfur oxides that are themselves basic.

Here, examples of the acidic gas include hydrogen halides such as carbon dioxide (CO ₂ ), hydrogen sulfide, carbonyl sulfide, sulfur oxide (SO _x ), nitrogen oxide (NO _x ), and hydrogen chloride.
In the present embodiment, examples of the acidic gas carrier include alkali metal compounds, nitrogen-containing compounds, and sulfur oxides.

Examples of the alkali metal compound include at least one selected from alkali metal carbonates, alkali metal bicarbonates, or 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 specification, an alkali metal compound is used in the meaning containing the salt and its ion other than alkali metal itself.

Preferred examples of the alkali metal carbonate include lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, and cesium carbonate.
Preferred examples of the alkali metal bicarbonate include lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, and cesium hydrogen carbonate.
Preferred examples of the alkali metal hydroxide include cesium hydroxide and rubidium hydroxide.
Among these, alkali metal carbonates are preferable, and compounds containing cesium or rubidium are preferable. Moreover, you may mix and use 2 or more types of acidic gas carriers. For example, what mixed cesium carbonate and potassium carbonate can be mentioned suitably.

  The content of the acidic gas carrier in the coating solution 3 m depends on the ratio to the amount of the hydrophilic compound and the type of the acidic gas carrier. However, the acidic gas carrier functions as an acidic gas carrier and is used in the usage environment. From the viewpoint of excellent stability as the separation layer, it is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.2% by mass or more and 20% by mass or less, and further 0.3 It is particularly preferable that the content is not less than 15% by mass.

  The coating solution 3m is, for example, added to a hydrophilic compound while stirring water, and then an aqueous solution of an acidic gas carrier is added and sufficiently stirred. For example, the hydrophilic compound that is a water-soluble polymer is 2.5% by mass. The carbon dioxide carrier accelerator was obtained by preparing an aqueous solution of 6.0% by mass and degassing it.

  The coating solution 3m may contain other components (additives) other than the hydrophilic compound, the acidic gas carrier, and water as long as the separation characteristics are not adversely affected. As an optional component, for example, an aqueous solution (coating solution) for forming an acidic gas separation layer containing a hydrophilic compound and an acidic gas carrier is coated on the porous body and dried in the course of drying. Gelling agent for controlling so-called set property, viscosity adjusting agent for adjusting viscosity at the time of applying the coating liquid with a coating apparatus, and cross-linking agent for improving the film strength of the acidic gas separation layer , Acid gas absorption promoters, other surfactants, catalysts, auxiliary solvents, membrane strength modifiers, and detection agents for facilitating the inspection of the formed acid gas separation layer for defects. It is done.

  The hydrophobic porous body 2a is a hydrogel having an elastic modulus in the range of 0.01 MPa to 100 MPa even under an operating environment as an acidic gas separation module (as described above for the elastic modulus condition). ), Even in a high-pressure and high-humidity environment, clogging of pores by the facilitated transport membrane material and penetration of the facilitated transport membrane material into the porous support can be suppressed, and high gas separation performance can be maintained. Therefore, the coating liquid is used in such a composition that the facilitated transport film satisfies the above elastic modulus condition, and the hydrogel coating liquid has a viscosity of 0.1 Pa · s to 5.0 Pa · s. It is desirable to prepare by including.

  The coating method on the hydrophobic porous body 2a having the fibril structure described above is not particularly limited, and a conventionally known method can be employed. Examples of conventionally known posting methods include curtain flow coaters, extrusion die coaters, air doctor coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, reverse roll coaters, and bar coaters. In particular, an extrusion join die coater is preferable from the viewpoint of film thickness uniformity, coating amount, and the like. When the facilitated transport film is a laminated film having a plurality of layers, a sequential coating method or a simultaneous multilayer method may be used. By these coating methods, the coating solution 3m is coated on the hydrophobic porous body 2a and facilitated transport film of 5 μm to 200 μm, preferably 10 μm to 150 μm, more preferably 15 μm to 130 μm. A film can be formed.

  The obtained facilitated transport film 3 is a hydrogel-like film, and includes at least a hydrophilic compound and an acidic gas carrier that reacts with an acidic gas in a gas to be separated. The facilitated transport film 3 is capable of separating a gas to be separated containing a high temperature of about 130 ° C. and water vapor, and has heat and humidity resistance.

  As described above, the acidic gas separation composite membrane 1 includes a three-dimensional network structure 200 formed by a plurality of fibrils, and a large number of pores including fine gaps 203 partitioned by the plurality of fibrils. The surface of the hydrophobic porous body 2a can be produced by applying the coating liquid 3m of the facilitated transport film 3 so that the three-dimensional network structure 200 has an average fibril spacing in a plane parallel to the facilitated transport film forming surface. The distance x is 0.001 μm to 2 μm, the average fibril length y is 0.01 μm to 2 μm, and the average fibril distance z in the direction perpendicular to the surface is 0.001 μm to 2 μm. When the hydrophobic porous body 2a having such a configuration is used, it is possible to prevent the hydrogel-like coating liquid 3m from penetrating into the support by capillary force and to prevent the coating film surface from becoming non-uniform, and to have high surface uniformity. The facilitated transport film 3 can be formed. Therefore, according to the manufacturing method of the present embodiment, it is possible to manufacture the acidic gas separation composite membrane 1 having good durability under a high temperature, high humidity and high pressure environment.

  As described above, the facilitated transport membrane 3 can be suitably used for an acidic gas separation module used in a high-pressure and high-humidity environment. The type of the gas separation module 10 is not particularly limited, and a module having a known shape such as a flat membrane type, a spiral type, or a pleat type can be used, but the spiral type shown in FIG. 3 is particularly preferable. The spiral type module has a structure in which a structure having a facilitated transport type gas separation membrane is spirally wound and housed in a perforated hollow central tube, and the separation per module is performed. This is preferable because the area of the film can be made very large. The spiral gas separation module will be described below with reference to FIG.

"Spiral acid gas separation module"
FIG. 3 is a partially cutaway schematic configuration diagram showing an embodiment of a spiral type module among acid gas separation modules to which the acid gas separation composite membrane shown in FIG. 1 can be suitably applied. The acidic gas separation module is a facilitated transport type acidic gas separation module that separates and discharges a supplied gas to be separated into an acidic gas and a residual gas other than the acidic gas.
As shown in FIG. 3, the acidic gas separation module 10 separates and discharges the supplied separated gas 20 into a permeated gas (acid gas) 22 and a residual gas 24 other than the permeated gas. As its basic structure, the outermost periphery of the laminate 14 is covered with a coating layer 16 in a state where one or more laminates 14 are wound around the permeate gas collecting pipe 12, and both ends of these units are prevented from telescopes, respectively. A plate 18 is attached and configured. When the gas to be separated 20 containing acid gas is supplied to the laminated body 14 from the one end portion 10A side, the acidic gas separating module 10 having such a configuration has the structure of the laminated body 14 to be described later. Is separated into the acidic gas 22 and the remaining gas 24 and separately discharged to the other end portion 10B side.

  The permeate gas collecting pipe 12 is a cylindrical pipe having a plurality of through holes 12A formed in the pipe wall. One end side (one end 10A side) of the permeate gas collecting pipe 12 is closed, and the other end side (the other end 10B side) of the permeate gas collecting pipe 12 is opened and passes through the laminate 14 and gathers from the through hole 12A. A discharge port 26 from which acidic gas 22 such as carbon dioxide gas is discharged is provided.

  Although the shape of 12 A of through-holes is not specifically limited, It is preferable that the circular hole of 1-20 mmphi is opened. Moreover, it is preferable that the through holes 12 </ b> A are arranged uniformly with respect to the surface of the permeate gas collecting pipe 12.

  The coating layer 16 is formed of a blocking material that can block the gas to be separated 20 passing through the acidic gas separation module 10. This blocking material preferably further has heat and humidity resistance. Here, “heat resistance” in the heat and humidity resistance means having a heat resistance of 80 ° C. or higher. Specifically, the heat resistance of 80 ° C. or higher means that the shape before storage is maintained even after being stored for 2 hours under a temperature condition of 80 ° C. or higher, and curling that can be visually confirmed by heat shrinkage or heat melting does not occur. Means that. In addition, “moisture resistance” of the heat and humidity resistance is a curl that can be visually confirmed by heat shrinkage or heat melting even after being stored at 40 ° C. and 80% RH for 2 hours. It means not occurring.

  The telescope prevention plate 18 has an outer peripheral annular portion 18A, an inner peripheral annular portion 18B, and a radial spoke portion 18C, and each is preferably formed of a heat and moisture resistant material.

  In the laminated body 14, the supply gas flow path member 30 is sandwiched between the acid gas separation composite membrane 1 folded in half, and the acid gas separation composite membrane 1 is attached to the permeate gas flow path member 36 on the inner side in the radial direction. It is configured to be adhesively sealed through a sealing portion 34 (sealing portion 4 in FIG. 1) that has penetrated these.

  The number of the laminated body 14 wound around the permeate gas collecting pipe 12 is not particularly limited, and may be single or plural. By increasing the number (number of laminated layers), the membrane area of the acid gas separation composite membrane 1 can be improved. it can. Thereby, the quantity which can isolate | separate the acidic gas 22 with one module can be improved. Moreover, in order to improve a film area, you may make the length of the laminated body 14 longer.

  Moreover, when there are a plurality of laminates 14, the number is preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. When the number is less than or equal to these numbers, it is easy to wind the laminate 14 and the workability is improved.

Although the width | variety of the laminated body 14 is not specifically limited, It is preferable that they are 50 mm or more and 100000 mm or less, More preferably, they are 60 mm or more and 50000 mm or less, Furthermore, it is preferable that they are 70 mm or more and 30000 mm or less.
Furthermore, it is preferable that the width | variety of the laminated body 14 is 200 mm or more and 2000 mm or less from a practical viewpoint. By setting each lower limit value or more, even if there is application (sealing) of the resin, the membrane area of the effective acidic gas separation composite membrane 1 can be ensured. Moreover, by setting it as each upper limit value or less, the horizontality of the winding core can be maintained and the occurrence of winding deviation can be suppressed.

  FIG. 4 is a cross-sectional view showing a part of a cylindrical wound body in which a laminated body is wound around a permeating gas collecting pipe. As shown in FIG. 4, the stacked bodies 14 are bonded to each other through a sealing portion 40 that has permeated the acidic gas separation composite membrane 1, and are stacked around the permeate gas collecting pipe 12. Specifically, the laminate 14 is formed by laminating a permeate gas flow path member 36, an acidic gas separation composite membrane 1, a supply gas flow path member 30, and an acidic gas separation composite membrane 1 in order from the permeate gas collecting pipe 12 side. ing. By these laminations, the source gas 20 containing the acid gas 22 is supplied from the end of the supply gas flow path member 30 and is separated through the acidic gas separation composite membrane 1 partitioned by the coating layer 16. The gas 22 is accumulated in the permeate gas collecting pipe 12 via the permeating gas flow path member 6 and the through hole 12A, and is recovered from the discharge port 26 connected to the permeated gas collecting pipe 12. The residual gas 24 separated from the acidic gas 22 that has passed through the gap or the like of the supply gas flow path member 30 is supplied to the supply gas flow path on the side where the discharge port 26 is provided in the acidic gas separation module 10. It is discharged from the end of the member 30 and the acid gas separation composite membrane 1.

  FIG. 7 is a view showing a state before the laminated body is wound around the permeating gas collecting pipe, and is a view showing an embodiment of a formation region of the sealing portion 34 and the sealing portion 40. As shown in FIG. 7, the sealing portion 40 covers the through-hole 12 </ b> A with the permeate gas flow path member 6, and the acidic gas in a state where the laminate 14 is wound around the permeate gas collecting pipe 12 in the direction of arrow R in the figure. The separation composite membrane 1 and the permeating gas channel member 6 are bonded and sealed. On the other hand, the sealing portion 34 adheres and seals the acidic gas separation composite membrane 1 and the permeating gas channel member 6 before the laminate 14 is wound around the permeating gas collecting pipe 12.

  Both of the sealing portion 34 and the sealing portion 40 have a so-called envelope shape in which an end portion in the circumferential direction between the acidic gas separation composite membrane 1 at the start of winding and the permeating gas flow path member 6 is opened. And in the area | region enclosed by the sealing part 34, the flow path P1 into which the acidic gas 22 which permeate | transmitted the acidic gas separation composite film 1 flows to 12 A of through-holes is formed. Similarly, a flow path P2 in which the acidic gas 22 that has passed through the acidic gas separation composite membrane 1 flows to the through hole 12A is formed in the region surrounded by the sealing portion 40.

  Each element of the acid gas separation module is the same as the constituent elements of the acid gas separation laminate described above. The present acidic gas separation module includes a supply gas flow path member 30 as a configuration of the laminate, and the supply gas flow path member 30 may be the same as the permeate gas flow path member. it can.

  In the facilitated transport film 3, the moisture contained in the film oozes out to the porous support 2 to enhance the wettability of the porous support 2 or draw the resin with its surface tension, thereby 34 and the resin of the sealing portion 40 easily permeate into the holes of the porous support 2 through the permeating gas flow path member 36, so that the circumferential sealing portions (34, 40) are not formed by the potting method. The adhesive force between the sealing portion 34 and the sealing portion 40 is strengthened by a normal coating method, and as a result, gas leakage can be suppressed.

In the acid gas separation module 10, the resin of the sealing portions 34 and 40 is not particularly limited as long as the sealing performance does not deteriorate by operation, but the gas to be separated 20 containing water vapor is supplied at a high temperature. Assuming that it has heat and humidity resistance, it is preferable. Preferred resins include, for example, epoxy resins, vinyl chloride copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinylidene chloride copolymers, vinyl chloride-acrylonitrile copolymers, butadiene-acrylonitrile copolymers, polyamides. Resins, polyvinyl butyral, polyester, cellulose derivatives (nitrocellulose, etc.), styrene-butadiene copolymers, various synthetic rubber resins, phenol resins, urea resins, melamine resins, phenoxy resins, silicone resins, urea formamide resins, etc. It is done.
Below, the manufacturing method of the module 10 for acidic gas separation is demonstrated.

  6A to 6C are manufacturing process diagrams of the acid gas separation module. In the method for manufacturing the acidic gas separation module 10, first, as shown in FIG. 6A, the front end of the long permeate gas flow path member 36 is fixed to the permeate gas collecting pipe with a fixing member 55 such as Kapton tape or adhesive. It fixes to 12 tube walls (outer peripheral surface). Here, it is preferable that the tube wall is provided with a slit (not shown) along the axial direction. In this case, the tip of the permeate gas flow path member 36 is inserted into the slit and fixed to the inner peripheral surface of the permeate gas collecting pipe 12 by the fixing member 55. According to this configuration, even when the laminate 14 including the permeate gas flow path member 36 is wound around the permeate gas collecting pipe 12, the inner circumferential surface of the permeate gas collecting pipe 12 can be The permeate gas flow path member 36 does not come out of the slit due to friction with the permeate gas flow path member 36, that is, the permeate gas flow path member 36 is fixed.

  Next, as shown in FIG. 6B, the long supply gas flow path member 30 is sandwiched between the long acidic gas separation composite membrane 1 in which the acidic gas separation promoting transport membrane 3 is folded inward. When the acid gas separation composite membrane 1 is folded in two, the acid gas separation composite membrane 1 may be divided into two as shown in FIG.

  Next, both ends in the width direction and one end in the longitudinal direction of the acid gas separation composite membrane 1 folded in half with respect to one outer surface (the surface of the auxiliary support membrane 2a of the porous support 2) Apply an adhesive to (apply envelope). Thereby, the sealing part 34 is formed. Prior to the application of the adhesive, treatment with an organic solvent is performed as described for the laminate film.

  Next, as shown in FIG. 6C, the acidic gas separation composite in which the supply gas flow path member 30 is sandwiched between the surface of the permeate gas flow path member 36 fixed to the permeate gas collecting pipe 12 via the adhesive 40. The film 1 is pasted. When the acidic gas separation composite membrane 1 is pasted, it is pasted so that one end where the adhesive 40 is not applied is on the gas collecting pipe 12 side. As a result, the sealing part 34 as a whole has a shape in which the circumferential end between the acidic gas separation composite membrane 1 and the permeating gas flow path member 36 at the beginning of the opening is opened, and in the region surrounded by the sealing part 34, A flow path P1 through which the acidic gas 22 that has passed through the acidic gas separation composite membrane 1 flows to the through hole 12A is formed.

  Next, the membrane is applied to the surface of the acidic gas separation composite membrane 1 affixed to the permeating gas channel member 36 (the surface of the auxiliary support membrane 3 of the porous support 4 opposite to the affixed surface). The adhesive 40 is applied to both ends in the width direction and one end in the longitudinal direction. Again, before the adhesive application, treatment with an organic solvent is performed. As a result, the adhesive 40 penetrates the auxiliary support film 2a and the porous film 2b to form the second sealing portion 37, and the laminate 14 is formed.

Next, as schematically shown in FIG. 7, the permeate gas collecting pipe 12 is rotated in the direction of arrow C, so that the laminate 14 covers the through hole 12 </ b> A with the permeate gas flow path member 6. The tube 12 is wrapped around multiple times. At this time, it is preferable to wind the laminate 14 while applying tension.
The supply gas flow path member 30 sandwiched between the two folded acidic gas separation composite membranes 1 is defined as one unit, and this unit and the permeate gas flow path member 6 are alternately stacked. As shown in FIG. 8, a plurality of the laminated bodies 14 may be stacked (in this example, three layers) and wrapped around the permeating gas collecting pipe in multiple layers.

A cylindrical winding body is obtained through the above steps, and after trimming both end portions of the obtained cylindrical winding body (end face correction processing), the outermost periphery of the cylindrical winding body is covered with a coating layer 16. The acid gas separation module 10 shown in FIG. 3 is obtained by covering and attaching the telescope prevention plates 18 to both ends.
Hereinafter, the detail of each structure of the module 10 for acidic gas separation is demonstrated.

<Permeate gas passage member>
The permeate gas channel member 36 has a function as a spacer, has a function of flowing the permeated acidic gas to the inside of the permeate gas channel member, and has a function of infiltrating the resin. A shaped member is preferred. The material of the permeating gas channel member 36 can be the same as that of the porous body. Further, assuming that the separation target gas 20 containing water vapor is flowed at a high temperature, it is preferable that the permeated gas flow path member 36 also has heat and humidity resistance.

Specific materials for the permeating gas flow path member 36 are more preferably polyesters such as epoxy-impregnated polyester, polyolefins such as polypropylene, and fluorines such as polytetrafluoroethylene.
The thickness of the permeating gas channel member 36 is not particularly limited, but is preferably 100 μm or more and 1000 μm or less, more preferably 150 μm or more and 950 μm or less, and further preferably 200 μm or more and 900 μm or less.

  The permeated gas flow path member 36 is a flow path for the acidic gas that has permeated the acidic gas separation composite membrane 1 and therefore preferably has low resistance. Specifically, the permeation gas flow path member 36 has a high porosity and is pressurized. It is desirable that the deformation is small and the pressure loss is small. The porosity is preferably 30% or more and 95% or less, more preferably 35% or more and 92.5% or less, and further preferably 40% or more and 90% or less. In addition, the measurement of a porosity can be performed as follows. First, water is sufficiently infiltrated into the gap portion of the permeating gas channel member by using ultrasonic waves or the like, and after removing excess moisture on the surface, the mass per unit area is measured. The value obtained by subtracting this mass from the dry mass is the volume of water that has entered the gap of the permeating gas flow path member, and can be measured by the density of water to measure the void volume and thus the void ratio. At this time, if water is not sufficiently infiltrated, the measurement can be performed using a solvent having a low surface tension such as an alcohol.

The deformation when the pressure is applied can be approximated by the elongation when the tensile test is performed, and the elongation when a load of 10 N / 10 mm width is applied is preferably within 5%, and is within 4%. It is more preferable.
In addition, the pressure loss can be approximated to the flow loss of the compressed air that flows at a constant flow rate, and the loss within 7.5 L / min when flowing through the 15 cm square permeating gas channel member 36 at room temperature for 15 L / min. It is preferable that the loss is within 7 L / min.

<Supply gas flow path member>
The supply gas flow path member 30 is a member to which the gas to be separated 20 containing an acid gas is supplied, has a function as a spacer, and preferably generates a turbulent flow in the gas to be separated 20. These members are preferably used. Since the gas flow path changes depending on the shape of the net, the shape of the unit cell of the net is selected from shapes such as rhombus and parallelogram according to the purpose. The material for the supply gas flow path member 30 may be the same as that of the porous body. In addition, assuming that the separation target gas 20 containing water vapor is flowed at a high temperature, the supply gas flow path member 30 also preferably has heat and humidity resistance.

  Although the thickness of the member 30 for supply gas flow paths is not specifically limited, 100 micrometers or more and 1000 micrometers or less are preferable, More preferably, they are 150 micrometers or more and 950 micrometers or less, More preferably, they are 200 micrometers or more and 900 micrometers or less.

Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor.

Hereinafter, the present invention will be described in more detail based on examples.
Example 1
<Preparation of coating solution composition for carbon dioxide separation layer>
Water was added to a polyvinyl alcohol-polyacrylic acid copolymer (Clastomer AP-20: trade name, manufactured by Kuraray Co., Ltd.) with stirring. Next, an aqueous cesium carbonate solution (solid content concentration: 40% by mass) was added, and the mixture was sufficiently stirred at a temperature of 25 ° C., so that the concentration of polyvinyl alcohol-polyacrylic acid copolymer as a water-soluble polymer was 2. An aqueous solution with 5% by mass and a cesium carbonate concentration of 6.0% by mass as a carbon dioxide carrier was prepared and defoamed to obtain a coating liquid composition (1) for forming a carbon dioxide separation layer.

<Production of support>
A porous body was prepared in which each average fibril distance x listed in Table 1 had an average fibril length y, a film thickness direction average fibril distance z, and an average fibril diameter r. Fibrils distance and fibril length of the support, and analyzed using surface SE M with respect to the fibril diameter was performed. At that time, each interfibril distance x, fibril length y, and fibril diameter r were measured, and an average value was calculated. Moreover, regarding the fibril distance z in the z direction, the cross-sectional SEM was measured, and the average value was calculated by the same method as described above. The thickness of the porous body including the reinforcing material was 200 μm.

<Formation of carbon dioxide separation layer>
The prepared coating liquid composition for forming a carbon dioxide separation layer is applied to the surface of the porous body using a roll coater and dried by passing through a drying zone maintained at 60 ° C. Was made. The coating speed was 10 m / min, and the drying temperature (hot air temperature in the drying zone) was 60 ° C.

The uniformity of the produced composite film was evaluated using a laser microscope. The outermost gel film was photographed at 0.1 mm ² , and when a hole-like object was not observed, the film surface evaluation was A. In addition, when 1 to 5 defects such as holes are observed within the above range, B is indicated, C is indicated when 6 to 10 are observed, and D is indicated when 11 to 99 are observed. It was set to E at the above time.

<Preparation of spiral carbon dioxide separation membrane module>
The obtained gas separation composite membrane (1) for carbon dioxide separation was folded in two with the carbon dioxide separation layer inside. Kapton tape was applied to the valley part folded in half, and the end part of the supply gas channel material was reinforced so as not to damage the surface shape of the valley part of the composite. And the polypropylene net | network of thickness 0.5mm was inserted | pinched as the flow-path material 16 of supply gas between the carbon dioxide separation layers folded in half. An adhesive (Henkel Japan, E120HP: trade name) made of epoxy resin with high viscosity (about 40 Pa · s) is applied to the auxiliary support side of this laminate so that it is enveloped, and made of epoxy impregnated polyester with tricot knitting The permeate gas channel material was stacked and wound around the perforated hollow central tube in a multiple manner to produce a spiral carbon dioxide separation membrane module.

<Evaluation of coating film life>
A source gas (flow rate: 2.2 L / min) of H ₂ : CO ₂ : H ₂ O = 45: 5: 50 as a test gas is supplied to each acid gas separation module at a temperature of 130 ° C. and a total pressure of 301.3 kPa, Ar gas (flow rate 0.6 L / min) was flowed to the permeate side. The permeated gas was analyzed with a gas chromatograph, and the initial values of the CO ₂ permeation rate (P (CO ₂ )) and the CO ₂ / H ₂ separation factor (α) were calculated. Further, the measurement was continued under the same conditions for 50 hours, and the rate of change of P (CO ₂ ) and α was calculated.
At that time, when the rate of change of both P (CO ₂ ) and α is less than 10%, A is 10% to less than 15% B, 15% to less than 20% C, 20% to less than 40% D, E when more than 40%.

<Module performance evaluation>
Performance evaluation of each produced acid gas separation module was performed by filling the supply side with He gas and sealing it, and measuring the time for pressure to decrease from 0.34 MPa to 0.3 MPa. A decrease time of 1000 seconds or more was judged good and less than 1000 seconds was judged as bad.

<Comprehensive evaluation criteria>
The above three types of evaluation experiments were performed, and A to E were determined based on the following criteria as a comprehensive evaluation. A to C are evaluations that can solve the problems of the present invention, and D and E are evaluations that cannot be solved.
Specifically, it was as follows.
Film defect A, life A, module performance: comprehensive evaluation A
Defect A or B, Life A or B, Good module performance: Comprehensive evaluation B
Film defect C, life C, good module performance: Comprehensive evaluation C
Either film defect or lifetime is D, module performance failure: Comprehensive evaluation D
Film defect D or E, lifetime D or E, module performance failure: Overall evaluation E
The results are shown in Table 1. As shown in Table 1, the effectiveness of the present invention was shown.

1 acidic gas separation composite membrane 2 porous support, support 2a hydrophobic porous body 2b auxiliary support 3 facilitated transport membrane (acid gas separation layer)
4, 34, 40 Sealing section 5 Intermediate layer 32A Acid gas separation layer 36 Permeate gas flow path member 30 Supply gas flow path member 10 Acid gas separation module 12 Permeate gas collecting pipe 12A Through hole 14 Laminate 20 Separation target Gas 22 Permeated gas (specific component)
26 Discharge port x Average fibril distance in a plane parallel to one surface (acid gas separation layer formation surface) y Average fibril length in a plane parallel to one surface (acid gas separation layer formation surface) z One surface (acid gas) Separation layer formation surface) Vertical distance between average fibrils r Average fibril diameter

Claims (13)

An acidic gas separation composite membrane comprising a facilitated transport membrane comprising at least a hydrophilic compound and an acidic gas carrier that reacts with an acidic gas in a gas to be separated on a support having a hydrophobic porous body on at least one surface A manufacturing method comprising:
A three-dimensional network structure composed of a plurality of connected or branched fibrils and bundling portions, and a plurality of pores composed of fine gaps divided by the plurality of fibrils,
In the three-dimensional network structure, an average interfibril distance in a plane parallel to the surface including the facilitated transport film of the support is 0.01 μm or more and 1 μm or less, and an average fibril length in a plane parallel to the surface is 0.01 μm or more and 1.50 μm or less, the distance between the average fibrils in the direction perpendicular to the surface is 0.01 μm or more and 1 μm or less, and the average fibril diameter per one fibril is 0.01 μm or more and 0.30 μm or less. And
The porosity is 0.1% or more and 85% or less,
Preparing the hydrophobic porous body;
A step of preparing a hydrogel coating solution containing at least the hydrophilic compound and the acidic gas carrier, and a step of applying the coating solution to one surface of the hydrophobic porous body,
The thickness of the support is 30 μm or more and 500 μm or less,
A method for producing an acidic gas separation composite membrane. The hydrophobic porous body the one surface and a manufacturing method of claim 1 Symbol placement of acid gas separation composite membrane contact angle of at least 100 ° with water. The method for producing an acidic gas separation composite membrane according to claim 1 or 2, wherein the hydrophobic porous body is made of a fluororesin. The method for producing an acidic gas separation composite membrane according to claim 3 , wherein the fluororesin is polytetrafluoroethylene. The acidic gas separation according to any one of claims 1 to 4 , wherein the coating liquid is applied to the one surface of the hydrophobic porous body through a hydrophobic intermediate layer having gas permeability. A method for producing a composite membrane. The method for producing an acidic gas separation composite membrane according to claim 5 , wherein the intermediate layer is a silicone resin layer. A separation module for promoting transporting acidic gas for separating and discharging the supplied gas to be separated into acidic gas and residual gas other than the acidic gas,
The acid gas separation module is:
A supply gas passage member through which the gas to be separated and the residual gas permeate;
An acidic gas separation composite membrane comprising a facilitated transport membrane containing at least a hydrophilic compound and an acidic gas carrier that reacts with an acidic gas in a gas to be separated on a support having a hydrophobic porous body on at least one surface; ,
A permeate gas flow path member through which the acid gas that has reacted with the acid gas carrier and permeated the acid gas separation composite membrane flows ,
The hydrophobic porous body is
A three-dimensional network structure composed of a plurality of connected or branched fibrils and bundling portions, and a plurality of pores composed of fine gaps divided by the plurality of fibrils,
In the three-dimensional network structure, an average interfibril distance in a plane parallel to the surface including the facilitated transport film of the support is 0.01 μm or more and 1 μm or less, and an average fibril length in a plane parallel to the surface is 0.01 μm or more and 1.50 μm or less, the distance between the average fibrils in the direction perpendicular to the surface is 0.01 μm or more and 1 μm or less, and the average fibril diameter per one fibril is 0.01 μm or more and 0.30 μm or less. And
The porosity is 0.1% or more and 85% or less,
Acid gas separation module. The acid gas separation module according to claim 7 , wherein the permeating gas channel member has an elongation of 5% or less in a tensile test with a load of 10 N / 10 mm. The acid gas separation module according to claim 7 or 8 , wherein the permeation gas channel member has a porosity of 30% or more and 95% or less. The support further includes an auxiliary support laminated on the hydrophobic porous body, and both ends of the hydrophobic porous body and the auxiliary support in the width direction and one end in the longitudinal direction are made of an epoxy resin. sealing portions are provided, the acid gas separation module of any one of claims 7 to claim 9. The permeate gas flow path member is laminated on the support, and an end portion of the permeate gas flow path member corresponding to the sealing portion in the hydrophobic porous body and the auxiliary support is also made of epoxy resin. The module for acidic gas separation of Claim 10 in which the sealing part is provided. Facilitated transport comprising a support having a hydrophobic porous body on at least one surface, at least a hydrophilic compound provided on one surface A of the support, and an acidic gas carrier that reacts with an acidic gas in a gas to be separated A method for producing a laminate comprising a membrane and a permeate gas flow path member provided on the other surface B of the support,
A three-dimensional network structure composed of a plurality of connected or branched fibrils and bundling portions, and a plurality of pores composed of fine gaps divided by the plurality of fibrils,
In the three-dimensional network structure, an average interfibril distance in a plane parallel to the surface including the facilitated transport film of the support is 0.01 μm or more and 1 μm or less, and an average fibril length in a plane parallel to the surface is 0.01 μm or more and 1.50 μm or less, the distance between the average fibrils in the direction perpendicular to the surface is 0.01 μm or more and 1 μm or less, and the average fibril diameter per one fibril is 0.01 μm or more and 0.30 μm or less. And
The porosity is 0.1% or more and 85% or less,
Preparing the hydrophobic porous body;
Preparing a hydrogel-like coating liquid containing at least the hydrophilic compound and the acidic gas carrier;
The step of applying the coating liquid on one surface of the hydrophobic porous body, and the permeate gas flow path member disposed on the other surface B of the support and the other surface B of the support, A step of adhering by applying an epoxy resin adhesive at both ends in the width direction and one end in the longitudinal direction of the support and sealing each of the permeate gas flow path member and the hydrophobic porous body;
The thickness of the support is 30 μm or more and 500 μm or less,
A manufacturing method of a layered product. The support further includes an auxiliary support laminated with the hydrophobic porous body, and the epoxy resin adhesive penetrates the hydrophobic porous body through the auxiliary support by applying the epoxy resin adhesive. The manufacturing method according to claim 12 , wherein the auxiliary support and the hydrophobic porous body are sealed at both ends in the width direction and one end in the longitudinal direction of the support.