JP2017136546A - Carbon dioxide separation membrane and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a carbon dioxide separation membrane excellent in the permeation rate and selective permeability of carbon dioxide and to provide a production method of the same.SOLUTION: A carbon dioxide separation membrane has a separation function layer on a porous support layer. The separation function layer includes a hydrophilic polymer layer and a carrier layer and the hydrophilic polymer layer includes at least a polyvinyl alcohol-based polymer. The carrier layer includes at least one kind of carrier substances selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate, an alkali metal hydroxide, amino acids and an amine compound and at least one kind of reaction accelerating substances selected from the group consisting of an acid and an acid salt.SELECTED DRAWING: None

Description

  The present invention relates to a carbon dioxide separation membrane for separating carbon dioxide from a mixed gas containing carbon dioxide, and a method for producing the same.

  In recent years, development of a technique for selectively separating carbon dioxide in a mixed gas using a separation membrane has been studied. This technique can be used when carbon dioxide is separated and recovered from off-gas from oil fields, exhaust gas from garbage incineration or thermal power generation, natural gas, or a mixed gas obtained by gasifying coal.

  As the separation membrane used in the technology, for example, the following has been developed.

Patent Document 1 discloses a gas separation membrane for separating at least one acidic gas from a gas mixture,
A porous first layer;
Alkali metal hydroxide, alkali metal alkoxide, alkali metal carbonate, alkali metal bicarbonate, alkali metal phosphate, alkaline earth metal hydroxide, alkaline earth metal alkoxide, alkaline earth metal carbonate At least one acidic gas carrier having a molecular weight of 150,000 or less selected from a salt, an alkaline earth metal bicarbonate, an alkali metal phosphate, an organic amine, an ionic liquid, and a metal complex; and polyethylene glycol, polypropylene glycol A second layer which is a separation active layer containing a hydrophilic crosslinked polymer having at least one repeating unit selected from polyvinyl alcohol, polyvinyl acetate, polyvinyl pyrrolidone, polyethyleneimine and polyallylamine;
There is disclosed a gas separation membrane comprising a specific crosslinked polymer and a third layer having the acid gas permeability higher than that of the second layer in this order.

  Patent Document 2 discloses a gas separation membrane characterized by having a separation active membrane containing a specific diamine compound having a boiling point or decomposition temperature of 200 ° C. or higher and a crosslinked polymer having a specific repeating unit, Is disclosed.

Patent Document 3 discloses a hydrophobic porous film having heat resistance of 100 ° C. or higher,
Formed on the surface of the porous membrane, comprising at least one carbon dioxide carrier selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates and alkali metal hydroxides and moisture, and the following (A) A polymer compound layer having a crosslink structure including a hydrolysis-resistant bond selected from the following group (B), formed by a single crosslinkable group selected from the group;
A carbon dioxide separation member that selectively permeates carbon dioxide gas from a mixture of carbon dioxide gas and hydrogen gas under a temperature condition of 100 ° C. to 250 ° C. is disclosed.
(A) group: —OH, —NH ₂ , —Cl, —CN, —COOH, epoxy group (B) group: ether bond, acetal bond, —NH—CH ₂ —CH (OH) —, —OM —O— (M represents Ti or Zr), —NH—M—O— (M represents Ti or Zr), urethane bond, —CH ₂ —CH (OH) —, amide bond

In Patent Document 4, a CO ₂ facilitated transport membrane having _CO 2 / _{H 2} selectivity performance at a temperature of above 100 ° C.,
A gel layer comprising an additive made of cesium carbonate, cesium bicarbonate or cesium hydroxide in a gel film containing moisture is supported on a hydrophilic porous film having heat resistance of 100 ° C. or higher. A CO ₂ facilitated transport membrane is disclosed.

Patent Document 5 includes a separation functional layer containing a specific amine compound as a high molecular polymer and a hydrophobic layer laminated on both sides of the separation functional layer,
A separation membrane in which the separation functional layer contains a crack inhibitor is disclosed.

  Patent Document 6 discloses a gas separation membrane comprising a resin composition containing an alkali metal compound (A) and a vinyl alcohol copolymer (B) containing a cationic group, Is disclosed.

  Patent Document 7 is characterized by comprising a resin composition containing an alkali metal compound (A) and a vinyl alcohol copolymer (B) having a sulfonate group and / or a sulfonic acid group. A gas separation membrane is disclosed.

  Patent Document 8 includes a resin composition containing a vinyl alcohol polymer (A), an ionic polymer (B) containing a cation and / or an anion, and an alkali metal compound (C). A gas separation membrane characterized by the above is disclosed.

  A conventional separation membrane has a function of selectively separating carbon dioxide from a mixed gas containing carbon dioxide, but is not satisfactory with respect to the permeation rate and selective permeability of carbon dioxide. However, development of a highly functional carbon dioxide separation membrane has been desired.

Japanese Patent No. 5526055 Japanese Patent No. 5526067 Japanese Patent No. 5687765 Japanese Patent No. 4621295 JP 2014-46305 A JP2015-188865A Japanese Patent Application Laid-Open No. 2015-188866 JP2015-188867A

  An object of this invention is to provide the carbon dioxide separation membrane excellent in the permeation | transmission rate and selective permeability of a carbon dioxide, and its manufacturing method.

  As a result of intensive studies to solve the above problems, the present inventor has found that the above object can be achieved by the carbon dioxide separation membrane shown below, and has completed the present invention.

That is, the present invention is a carbon dioxide separation membrane having a separation functional layer on a porous support layer,
The separation functional layer includes a hydrophilic polymer layer and a carrier layer,
The hydrophilic polymer layer includes at least a polyvinyl alcohol-based polymer,
The carrier layer includes at least one carrier substance selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, and a group consisting of acids and acid salts. The present invention relates to a carbon dioxide separation membrane comprising at least one selected reaction promoting substance.

  The present inventor divides the separation functional layer, which is essentially a layer having a function of separating carbon dioxide, into at least two layers of a hydrophilic polymer layer and a carrier layer to increase the concentration of the carrier substance in the carrier layer. At the same time, it has been found that a carbon dioxide separation membrane excellent in carbon dioxide permeation rate and selective permeability can be obtained by adding a reaction promoting substance that promotes the reaction between carbon dioxide and the carrier substance into the carrier layer.

  The acid is preferably boric acid from the viewpoint of an excellent reaction promoting effect and a function of crosslinking the polyvinyl alcohol-based polymer.

  The polyvinyl alcohol-based polymer of the hydrophilic polymer layer is preferably cross-linked by reaction with the reaction promoting substance at least at the interface with the carrier layer. By crosslinking the polyvinyl alcohol-based polymer at the interface between the hydrophilic polymer layer and the carrier layer, the mechanical strength of the hydrophilic polymer layer can be improved and the holding function of the carrier layer can be improved.

  The carbon dioxide separation membrane of the present invention preferably has a protective layer on the separation functional layer.

  The present invention also relates to a carbon dioxide separation membrane module including the carbon dioxide separation membrane.

Furthermore, the present invention provides, on the porous support layer, at least one carrier material selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, Applying a carrier layer forming solution containing at least one reaction accelerator selected from the group consisting of an acid and an acid salt and curing to form a carrier layer;
It is related with the manufacturing method of the said carbon dioxide separation membrane including the process of apply | coating the hydrophilic polymer layer forming solution containing a polyvinyl alcohol type polymer at least on the formed carrier layer, and making it harden | cure and forming a hydrophilic polymer layer.

  After forming a carrier layer on a porous support layer, a hydrophilic polymer layer having a uniform thickness and no defects can be formed by forming a hydrophilic polymer layer on the carrier layer.

  Unlike the conventional separation membrane, the carbon dioxide separation membrane of the present invention has a multilayer structure in which the separation functional layer includes a hydrophilic polymer layer and a carrier layer. Excellent permselectivity.

<Carbon dioxide separation membrane>
The carbon dioxide separation membrane of the present invention is a carbon dioxide separation membrane having a separation functional layer on a porous support layer,
The separation functional layer includes a hydrophilic polymer layer and a carrier layer,
The hydrophilic polymer layer includes at least a polyvinyl alcohol-based polymer,
The carrier layer includes at least one carrier substance selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, and a group consisting of acids and acid salts. And at least one selected reaction accelerator.

<Porous support layer>
As the porous support layer, those known in the art can be used without particular limitation. The porous support layer can be produced using, for example, a polymer described later, and ceramics or polyethylene terephthalate (PET) film can also be used. Specifically, when producing using a polymer, after dissolving the polymer in a solvent to obtain a raw material solution, the raw material solution is brought into contact with a coagulation liquid (a mixed solution of a solvent and a non-solvent), A porous support layer can be produced by a method of inducing phase separation by increasing the non-solvent concentration (non-solvent induced phase separation method; NIPS method, see Japanese Patent Publication No. 1-2003). Examples of the ceramic include alumina, zirconia, titania, and silica.

  Examples of the polymer used for producing the porous support layer include polysulfone (PSF), polyethersulfone, polyarylethersulfone, polyphenylenesulfone, triacetylcellulose, cellulose acetate, polyacrylonitrile, polyvinylidene fluoride, aromatic nylon, and polyethylene. Examples include terephthalate (PET), polyethylene naphthalate, polyarylate, polyimide, epoxy resin, polyether, cellophane, aromatic polyamide, polyethylene, and polypropylene. Of these, polysulfone, polyarylethersulfone, and epoxy resin are preferably used from the viewpoint of being chemically and mechanically stable.

  The solvent is not particularly limited as long as it is soluble in the coagulation liquid, and examples thereof include N-methylpyrrolidone (NMP), acetone, and dimethylformamide. Examples of the non-solvent include water, monohydric alcohol, polyhydric alcohol, ethylene glycol, and tetraethylene glycol.

  In preparing the raw material solution, it is preferable to add a swelling agent to increase the number of through-holes in the support layer after solidification to improve gas permeability. Examples of the swelling agent include polyethylene glycol, polyvinyl pyrrolidone, hydroxypropyl cellulose, sodium chloride, lithium chloride, and magnesium bromide. These may be used alone or in combination of two or more. Among these swelling agents, polyethylene glycol is preferable, and polyethylene glycol having a weight average molecular weight of 400 to 800 is particularly preferable.

  The method for contacting the raw material solution and the coagulating liquid is not particularly limited, and examples thereof include a method of immersing the raw material solution in the coagulating liquid. The concentration of the solvent in the coagulating liquid is not particularly limited, but in the coagulation of the raw material solution, changing the solvent concentration in the coagulating liquid changes the structure of the support film and can increase pressure resistance.

  The pore size of the pores of the porous support layer is preferably 200 nm or less, more preferably 100 nm or less. The thickness of the porous support layer is not particularly limited as long as the gas permeability of the porous support layer is larger than the gas permeability of the separation functional layer, but is usually about 25 to 125 μm, and preferably 40 to 75 μm.

  As the porous support layer, it is particularly preferable to use an ultrafiltration membrane (UF membrane).

  In order to impart mechanical strength, a woven fabric or a non-woven fabric may be laminated on the porous support layer.

<Separation function layer>
The separation functional layer includes a hydrophilic polymer layer and a carrier layer.

  The carrier layer is selected from the group consisting of at least one carrier substance selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, and acids and acid salts. And at least one reaction accelerator.

  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. Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. Among these, from the viewpoint of good affinity with carbon dioxide, a compound containing potassium, rubidium, and cesium as an alkali metal element is preferable, and cesium is particularly preferable. Examples of amino acids include glycine, alanine, serine, proline, hydroxyproline, arginine, dimethylaminoglycine, 2,3-diaminopropionic acid, and salts thereof. Examples of the amine compound include alkanolamine (monoethanolamine, diethanolamine, triethanolamine, ethylmonoethanolamine, n-butylmonoethanolamine, dimethylethanolamine, ethyldiethanolamine, n-butylethanolamine, di-n-butyl. Such as ethanolamine and triisopropanolamine); polyamidoamine dendrimers; polyallylamine, poly-N-1,2-dimethylpropylallylamine, poly-N-methylallylamine, poly-N, N-dimethylallylamine, poly-2- Examples thereof include amine polymers having structural units such as vinylpiperidine, poly-4-vinylpiperidine, polyvinylamine, and polyethyleneimine. These may be used alone or in combination of two or more.

  Examples of the acid and acid salt include oxo acids such as boric acid, arsenous acid, telluric acid, selenious acid, and salts thereof. Among these, it is preferable to use boric acid or a borate from the viewpoint that the reaction promoting effect and the function of crosslinking the polyvinyl alcohol polymer are excellent.

The reaction promoting substance is preferably added in an amount of 0.005 to 0.2 mol, more preferably 0.01 to 0.1 mol, relative to 1 mol of the carrier substance. When the addition amount of the reaction accelerator is less than 0.005 mol, it becomes difficult to improve the permeation rate and selective permeability of carbon dioxide, or the crosslinking of the polyvinyl alcohol polymer in the hydrophilic polymer layer becomes insufficient. There is a tendency. On the other hand, when the amount exceeds 0.2 mol, the water content of the hydrophilic polymer layer decreases due to an increase in the crosslinking density, and the CO ₂ permeation rate tends to decrease.

  The method for forming the carrier layer is not particularly limited, and examples thereof include a method in which a carrier layer forming solution containing a carrier substance and a reaction promoting substance is applied on the porous support layer and cured. The coating method is not particularly limited, but for example, spin coating method, bar coating, die coating coating, blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, comma roll method, kiss coating method, screen printing, and Ink jet printing and the like can be mentioned. The solvent is not particularly limited as long as it can dissolve the carrier substance and the reaction promoting substance. For example, water, methanol, ethanol, isopropyl alcohol, chloroform, methylene chloride, acetone, dioxane, methyl acetate, cyclohexanone, methyl ethyl ketone, acetonitrile, Examples thereof include tetrachloroethylene, tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These may be used alone or in combination of two or more. The solid concentration of the carrier layer forming solution is usually about 5 to 40% by weight, preferably 10 to 30% by weight.

  The carrier layer may contain, in addition to the carrier substance and the reaction promoting substance, known carrier substances, polymers, additives, and the like as long as the effects of the present invention are not impaired.

  The thickness of the carrier layer is not particularly limited, but is usually 1 to 20 μm, preferably 3 to 10 μm.

  The hydrophilic polymer layer contains at least a polyvinyl alcohol-based polymer.

  The polyvinyl alcohol-based polymer is a polymer containing a polyvinyl alcohol structure in the molecule, and may be a homopolymer or a copolymer. The polyvinyl alcohol polymer may be modified with a carboxy group, an amino group, an epoxy group, or the like.

  The weight average molecular weight of the polyvinyl alcohol polymer is not particularly limited, but is usually about 5,000 to 1,000,000, preferably 40,000 to 400,000.

  The saponification degree of the polyvinyl alcohol-based polymer is preferably 90 mol or more, and more preferably 95 mol or more.

  The hydrophilic polymer layer is made of polyethylene alcohol, polyethylene glycol di (meth) acrylate, polypropylene glycol, polypropylene glycol di (meth) acrylate, polyethyleneimine, polyallylamine, polyamide epichlorohydrin, polyacrylic as well as polyvinyl alcohol polymer. One or more hydrophilic polymers such as acid, polymethacrylic acid, polyvinylpyrrolidone, polyacrylamide, polyvinylamine, polyornithine, and polylysine may be included.

  When the polyvinyl alcohol polymer and the hydrophilic polymer are used in combination, the polyvinyl alcohol polymer is preferably used in an amount of 20% by weight or more, more preferably 40% by weight or more.

  Although the formation method in particular of a hydrophilic polymer layer is not restrict | limited, For example, the method of apply | coating and hardening the hydrophilic polymer layer forming solution containing a polyvinyl alcohol type polymer at least on a carrier layer is mentioned. The coating method is not particularly limited, but for example, spin coating method, bar coating, die coating coating, blade coating, air knife coating, gravure coating, roll coating coating, spray coating, dip coating, comma roll method, kiss coating method, screen printing, and Ink jet printing and the like can be mentioned. The solvent is not particularly limited as long as it can dissolve the polyvinyl alcohol polymer. For example, water, methanol, ethanol, isopropyl alcohol, chloroform, methylene chloride, acetone, dioxane, methyl acetate, cyclohexanone, methyl ethyl ketone, acetonitrile, tetrachloroethylene, Examples include tetrahydrofuran, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. These may be used alone or in combination of two or more. The solid content concentration of the hydrophilic polymer layer forming solution is usually about 1 to 10% by weight, preferably 2 to 6% by weight.

  The polyvinyl alcohol polymer of the hydrophilic polymer layer is preferably cross-linked by reaction with a reaction promoting substance added to the carrier layer at least at the interface with the carrier layer. Thereby, the mechanical strength of the hydrophilic polymer layer can be improved and the holding function of the carrier layer can be improved. The polyvinyl alcohol-based polymer may be crosslinked throughout the layer, but is preferably crosslinked only at the interface with the carrier layer because the carbon dioxide permeability decreases due to crosslinking.

  The hydrophilic polymer layer may contain a known crosslinking agent and additive in addition to the polymer as long as the effects of the present invention are not impaired.

  The thickness of the hydrophilic polymer layer is not particularly limited, but is usually 0.5 to 10 μm, preferably 2 to 8 μm.

<Protective layer>
The carbon dioxide separation membrane of the present invention preferably has a protective layer on the separation functional layer. The protective layer is provided in order to impart flexibility and mechanical strength to the separation membrane or to improve workability (for example, winding property) when producing the separation membrane module.

  The material for forming the protective layer is not particularly limited, and examples thereof include polyalkylene glycol, polysiloxane, polyester, fluororesin, and polyolefin. It is particularly preferable to use polysiloxane.

  The formation method in particular of a protective layer is not restrict | limited, A well-known method is employable.

  The thickness of the protective layer is not particularly limited, but is preferably 0.5 to 20 μm in order to sufficiently impart the function to the separation membrane and to suppress a decrease in gas permeability of the separation membrane. Preferably it is 1-10 micrometers.

<CO2 separation membrane module>
The carbon dioxide separation membrane module of the present invention includes the separation membrane. The type of the carbon dioxide separation membrane module is not particularly limited, and examples thereof include a flat membrane type, a spiral type, a pleat type, and a bowl type.

  The carbon dioxide separation membrane and the carbon dioxide separation membrane module of the present invention can selectively and efficiently separate carbon dioxide from a mixed gas containing carbon dioxide and hydrogen, for example.

  EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

〔Measuring method〕
<Measurement of separation factor α, permeance (transmittance) Q _CO2 and Q _He >
A gas permeation measuring device (manufactured by GL Sciences Inc.) was used. A mixed gas containing CO ₂ gas (80% by volume) and He gas (20% by volume) is supplied to the supply side of the produced carbon dioxide separation membrane at atmospheric pressure or a total pressure of 0.7 MPa, and the permeation side at atmospheric pressure. A humidified Ar gas having a certain humidity of 90% was circulated. A part of the Ar gas on the permeate side was introduced into the gas chromatograph at regular time intervals, and the permeance of CO ₂ and He was determined from the increase in the concentration of CO ₂ gas and He gas over time. The mixed gas was humidified to 90% humidity using a bubbler. Measurement was performed 15 hours after supplying the mixed gas. The setting conditions of the gas permeation measuring device, the analysis conditions of gas chromatography, and the calculation method of gas permeance are as follows.

(Setting conditions of gas permeation measuring device)
Supply gas amount: 250cc / min
Supply gas composition: CO ₂ gas (80% by volume), He gas (20% by volume)
Permeation side circulation gas: Ar gas transmission side circulation gas amount: 10 cc / min
Transmission area: 8.04 cm ²
Measurement temperature: 85 ° C
Bubbler temperature: 72.5 ° C
Humidity: 60%

(Gas chromatography analysis conditions)
Ar carrier gas amount: about 10cc / min
TCD temperature: 150 ° C
Oven temperature: 120 ° C
TCD current: 70 mA
TCD polarity: [-] LOW
TCD LOOP: 1ml silico steel tube 1/16 "x 1.0 x 650mm

(Calculation method of separation factor α, permeance Q _CO2 and Q _He )
The permeance Q _CO2 [m ³ / (m ² · Pa · s)] and Q _He is calculated from the gas concentration in the permeation side flow rate gas determined by gas chromatography, using the following equations 1 and 2. [M ³ / (m ² · Pa · s)] was calculated. Further, the separation coefficient α [−] was calculated by the following formula 3.

( _Where N _CO2 and N _He are the permeation amounts of CO ₂ gas and He gas, P _f and P _P are the total pressure of the feed and permeate gas, A is the membrane area, X _{CO 2} and X _He are the CO in the feed gas. (Mole fraction of ₂ gas and He gas, Y _CO2 and Y _He represent the mole fraction of CO ₂ gas and He gas in the permeate gas.)

Example 1
Cesium carbonate (Wako Pure Chemical Industries, reagent grade 1) 4g, sodium polyacrylate (Wako Pure Chemical Industries, reagent special grade) 0.1g, and sodium tetraborate in an amount of 1wt% in aqueous solution Hydrate (made by Wako Pure Chemical Industries, reagent special grade) was added to pure water and dissolved to prepare a carrier layer forming solution.
Also, PVA aqueous solution (Kuraray, COOH modified: 30 mol%, PVA concentration: 7.4 wt%), polyallylamine aqueous solution (made by Kuraray, polyallylamine concentration: 51.6 wt%), and polyamide epichlorohydrin aqueous solution (starlight) Made from PMC, polyamide epichlorohydrin concentration: 25 wt%) and mixed with a solid polymer concentration of 4.5 wt% (solid content composition: PVA 50 wt%, polyallylamine 40 wt%, polyamide epichlorohydrin 10 wt%) A forming solution was prepared.
And the said carrier layer formation solution was apply | coated on the porous support layer (Nitto Denko KK make, NTU-3175M (UF membrane)), and it dried at 60 degreeC for 1 hour, and formed the carrier layer. Thereafter, the hydrophilic polymer layer forming solution was applied onto the carrier layer and dried at 60 ° C. for 1 hour to form a hydrophilic polymer layer, thereby producing a carbon dioxide separation membrane.

Examples 2 and 3
A carbon dioxide separation membrane was produced in the same manner as in Example 1 except that the formulation shown in Table 1 was changed.

Comparative Example 1
4 g of cesium carbonate (manufactured by Wako Pure Chemical Industries, reagent grade 1) and 0.1 g of sodium polyacrylate (manufactured by Wako Pure Chemical Industries, reagent special grade) were added to pure water and dissolved to prepare a carrier layer forming solution. . A carbon dioxide separation membrane was produced in the same manner as in Example 1 except that the carrier layer forming solution was used.

Comparative Example 2
Mix 5 g of PVA aqueous solution (Kuraray, COOH modified: 30 mol%, PVA concentration: 5 wt%), 1.2 g of cesium carbonate (Wako Pure Chemical Industries, reagent grade 1), and 10 g of pure water until uniform. A mixed solution was obtained by stirring. To the obtained mixed solution, 0.04 g of sodium tetraborate heptahydrate (manufactured by Wako Pure Chemical Industries, Ltd., reagent grade) was added and stirred to prepare a separation functional layer forming solution. However, the separation functional layer forming solution gelled. Therefore, the separation functional layer forming solution could not be applied on the porous support layer.

Comparative Example 3
In Comparative Example 2, the amount of sodium tetraborate heptahydrate added was changed to 0.001 g, but the separation functional layer forming solution gelled as in Comparative Example 2. Therefore, the separation functional layer forming solution could not be applied on the porous support layer.

  The carbon dioxide separation membrane and carbon dioxide separation membrane module of the present invention are used for separating and recovering carbon dioxide from oil field off-gas, waste incineration or thermal power generation exhaust gas, natural gas, or a mixed gas obtained by gasifying coal. It can be suitably used.

Claims (6)

A carbon dioxide separation membrane having a separation functional layer on a porous support layer,
The separation functional layer includes a hydrophilic polymer layer and a carrier layer,
The hydrophilic polymer layer includes at least a polyvinyl alcohol-based polymer,
The carrier layer includes at least one carrier substance selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, and a group consisting of acids and acid salts. A carbon dioxide separation membrane comprising at least one reaction promoting substance selected. The carbon dioxide separation membrane according to claim 1, wherein the acid is boric acid. The carbon dioxide separation membrane according to claim 1 or 2, wherein the polyvinyl alcohol-based polymer of the hydrophilic polymer layer is cross-linked by reaction with the reaction promoting substance at least at the interface with the carrier layer. The carbon dioxide separation membrane according to any one of claims 1 to 3, further comprising a protective layer on the separation functional layer. The carbon dioxide separation membrane module containing the carbon dioxide separation membrane in any one of Claims 1-4. The porous support layer comprises at least one carrier material selected from the group consisting of alkali metal carbonates, alkali metal bicarbonates, alkali metal hydroxides, amino acids and amine compounds, and acids and acid salts. Applying a carrier layer forming solution containing at least one reaction promoting substance selected from the group and curing to form a carrier layer;
4. The process according to claim 1, comprising a step of applying a hydrophilic polymer layer-forming solution containing at least a polyvinyl alcohol-based polymer on the formed carrier layer and curing to form a hydrophilic polymer layer. A method for producing a carbon separation membrane.