Pervaporation membrane

Abstract

A pervaporation membrane 100 comprises a separation functional layer 10 that contains porous particles 11. The ratio of the average particle size D (μm) of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 is 0.03 or more and less than 1.0. The porous particles 11 have an average pore diameter P of, for example, not less than 0.35 nm. The porous particles 11 contain at least one selected from the group consisting of, for example, metal-organic frameworks, silicas, and zeolites.

Description

Permeation vaporization membrane

[0001] The present invention relates to a pervaporation membrane.

[0002] As a method for obtaining non-petroleum-derived valuable substances, a method using fermentation by microorganisms is known. For example, a method for producing volatile organic compounds (fermentation products) such as alcohol by fermenting a carbon source such as glucose using microorganisms has been developed. Fermentation of the carbon source is carried out, for example, in an aqueous solution. In this method, when the content rate of the fermentation product in the aqueous solution increases, fermentation by microorganisms may stop. In order to continuously produce a fermentation product by microorganisms, it is necessary to separate the fermentation product from the aqueous solution.

[0003] As an example of a method for separating a volatile organic compound from an aqueous solution containing the same, there is a pervaporation method (Pervaporation; PV method) using a pervaporation membrane. The pervaporation method is suitable for separating volatile organic compounds from an aqueous solution containing various substances. The pervaporation method also tends to be able to suppress the energy consumption and the amount of carbon dioxide emissions as compared with the distillation method. Patent Document 1 discloses an example of a pervaporation membrane used in the pervaporation method.

[0004] Japanese Patent Application Laid-Open No. 10-147546

[0005] When separating a volatile organic compound from an aqueous solution containing the same using a pervaporation membrane, an improvement in separation performance is required.

[0006] An object of the present invention is to provide a pervaporation membrane suitable for improving separation performance.

[0007] The present invention provides a pervaporation membrane including a separation functional layer containing porous particles, wherein the ratio of the average particle diameter (μm) of the porous particles to the thickness (μm) of the separation functional layer is 0.

[0008] According to the present invention, a pervaporation membrane suitable for improving separation performance can be provided.

[0009] It is a schematic cross-sectional view schematically showing a pervaporation membrane according to an embodiment of the present invention. It is a diagram for explaining the permeation mechanism in the separation functional layer included in the pervaporation membrane of FIG. 1. It is a diagram for explaining the permeation mechanism in the separation functional layer included in the pervaporation membrane of the reference example. It is a SEM photograph (2000 times) of an example of the cross section of the separation functional layer. It is a binary image of the SEM photograph of FIG. 4A. It is a schematic cross-sectional view schematically showing a membrane separation device. It is a schematic perspective view schematically showing a modified example of the membrane separation device. It is a schematic configuration diagram schematically showing a membrane separation system.

[0010] The pervaporation membrane according to the first aspect of the present invention includes a separation functional layer containing porous particles, and the ratio of the average particle diameter (μm) of the porous particles to the thickness (μm) of the separation functional layer is 0.03 or more and less than 1.0.

[0011] In the second aspect of the present invention, for example, in the pervaporation membrane according to the first aspect, the porous particles have an average pore diameter of 0.35 nm or more.

[0012] In the third aspect of the present invention, for example, in the pervaporation membrane according to the first or second aspect, the content rate of the porous particles in the separation functional layer is 20 to 70 wt%.

[0013] In the fourth aspect of the present invention, for example, in the pervaporation membrane according to any one of the first to third aspects, the separation functional layer has a thickness of 1 μm or more and 30 μm or less.

[0014] In the fifth aspect of the present invention, for example, the pervaporation membrane according to any one of the first to fourth aspects has an adsorption amount of water (cm 3 / g) by the porous particles under water vapor at 25°C and 3.2 kPa, and an adsorption amount of ethanol (cm 3 / g) by the porous particles in an ethanol atmosphere at 25°C and 7.4 kPa, and the ratio is 10 or more.

[0015] In the sixth aspect of the present invention, for example, in the pervaporation membrane according to any one of the first to fifth aspects, the porous particles have an average particle diameter exceeding 1 μm.

[0016] In a seventh aspect of the present invention, for example, in a permeable vaporization membrane according to any one of the first to sixth aspects, the porous particles include at least one selected from the group consisting of metal-organic structures, silica, and zeolites.

[0017] In the eighth aspect of the present invention, for example, in the permeable vaporization membrane according to the seventh aspect, the metal-organic structure has a metal ion as a core and an organic ligand coordinated to the core.

[0018] In the ninth aspect of the present invention, for example, in the permeable vaporization membrane according to the eighth aspect, the metal ion is Zn 2+ It contains, and the organic ligand contains an imidazole ring.

[0019] In the tenth embodiment of the present invention, for example, in a permeable vaporization membrane according to any one of the first to ninth embodiments, the separation functional layer further includes a matrix in which the porous particles are dispersed.

[0020] In the eleventh embodiment of the present invention, for example, in the permeable vaporization membrane according to the tenth embodiment, the matrix includes a silicone resin.

[0021] In a twelfth aspect of the present invention, for example, a permeable vaporization membrane according to any one of the first to eleventh aspects further comprises a porous support that supports the separation functional layer.

[0022] In a thirteenth aspect of the present invention, for example, in the permeable vaporization membrane according to the twelfth aspect, the porous support comprises an organic material.

[0023] In a fourteenth aspect of the present invention, for example, a permeable vaporization membrane according to any one of the first to thirteenth aspects is used to separate an organic compound from an aqueous solution containing a volatile organic compound.

[0024] In a 15th aspect of the present invention, for example, in the permeable vaporization membrane according to the 14th aspect, the organic compound is an alcohol.

[0025] The details of the present invention will be described below, but the following description is not intended to limit the present invention to any particular embodiment.

[0026] <Permeation Vaporization Membrane> Figure 1 is a schematic cross-sectional view showing a permeation vaporization membrane according to one embodiment of the present invention. The permeation vaporization membrane 100 of this embodiment includes a separation functional layer 10 containing porous particles 11. In the permeation vaporization membrane 100, the ratio R1 of the average particle size D of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 is 0.03 or more and less than 1.0.

[0027] The permeation vaporization membrane 100 is typically a membrane (separation membrane) that preferentially allows organic compound C to permeate from an aqueous solution S containing volatile organic compound C. The permeation vaporization membrane 100 having the above configuration is suitable for improving the separation performance of separating organic compound C from aqueous solution S, and in particular for improving the flux (permeation velocity) of the permeating fluid that permeates through the permeation vaporization membrane 100 under low temperature and reduced pressure conditions.

[0028] As shown in Figure 1, the permeable vaporization membrane 100 may further include a porous support 20 that supports the separation functional layer 10. The separation functional layer 10 has, for example, a surface that is in direct contact with the porous support 20 and a surface that is exposed to the outside of the permeable vaporization membrane 100. The permeable vaporization membrane 100 is composed of, for example, only the separation functional layer 10 and the porous support 20.

[0029] [Separation Functional Layer] The separation functional layer 10 is a layer that can preferentially allow organic compound C to pass through from an aqueous solution S containing a volatile organic compound C. The organic compound C may be an alcohol. Typically, the separation functional layer 10 is a so-called non-porous layer that has a dense structure in which no pores can be observed when viewed with a scanning electron microscope (SEM) at a magnification of 5000x.

[0030] The separation functional layer 10 may contain multiple porous particles 11. Within the separation functional layer 10, secondary particles formed by the aggregation of multiple porous particles 11 may exist. In this embodiment, "porous particles 11" refers to primary particles.

[0031] Figure 2 is a diagram illustrating the permeation mechanism in the separation functional layer 10. The dashed arrows in Figure 2 represent an example of the path of the target substance M permeating through the separation functional layer 10. As described above, in the permeation vaporization membrane 100 of this embodiment, the ratio R1 of the average particle size D (μm) of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 is 0.03 or more and less than 1.0. With this configuration, the number of porous particles 11 present in the thickness direction of the separation functional layer 10 is suppressed. As a result, as shown in Figure 2, the number of times the target substance M permeating through the separation functional layer 10 enters and exits the pores 11p of the porous particles 11 is suppressed, so the path of the target substance M becomes shorter and the permeation flow velocity increases. As a result, the separation performance of the permeation vaporization membrane 100 is improved.

[0032] Figure 3 illustrates the permeation mechanism in the separation functional layer 50 of the reference example permeation vaporization membrane. The dashed arrows in Figure 3 represent an example of the path of the object M permeating through the separation functional layer 50. The separation functional layer 50 contains porous particles 51. In the reference example permeation vaporization membrane, the ratio of the average particle size d of the porous particles 51 to the thickness T 50 of the separation functional layer 50 is less than 0.03 and does not satisfy the condition of 0.03 or more and less than 1.0. When the porous particle content is similar, the separation functional layer 50 in Figure 3 may have an increased number of porous particles 51 present in the thickness direction compared to the separation functional layer 10 in Figure 2. In this case, as shown in Figure 3, the number of times the object M permeating through the separation functional layer 10 enters and exits the pores 51p of the porous particles 51 increases, which can lengthen the path of the object M and decrease the permeation velocity.

[0033] The lower limit of the ratio R1 of the average particle size D (μm) of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 may be 0.04, or even 0.05. The upper limit of the ratio R1 may be 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.15, or even 0.1.

[0034] The ratio R1 may be 0.05 or more and 0.5 or less, 0.05 or more and 0.2 or less, or 0.05 or more and 0.15 or less.

[0035] The thickness T of the separation functional layer 10 can be determined, for example, based on an SEM image of a cross-section of the permeable vaporization membrane 100 parallel to the thickness direction of the separation functional layer 10. The thickness of the separation functional layer 10 is measured at arbitrary locations (e.g., five locations) in the SEM image. The thickness T of the separation functional layer 10 is the average of these measurements.

[0036] The separation functional layer 10 may have a thickness T of 1 μm or more and 30 μm or less. With such a configuration, it is easier to realize a separation functional layer 10 in which the ratio R1 of the average particle size D (μm) of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 satisfies the above numerical range.

[0037] The lower limit of the thickness T of the separation functional layer 10 may be 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, or even 10 μm. The upper limit of the thickness T of the separation functional layer 10 may be 29 μm, 28 μm, 27 μm, 26 μm, or even 25 μm.

[0038] The thickness T may be 5 μm or more and 30 μm or less, or 10 μm or more and 30 μm or less.

[0039] The average particle size D of the porous particles 11 contained in the separation functional layer 10 can be determined, for example, based on an SEM image of a cross-section of the separation functional layer 10 parallel to the thickness direction. Figure 4A is an SEM image (2000x magnification) of an example of a cross-section of the separation functional layer 10. Figure 4B is a binarized image of the SEM image in Figure 4A. First, the separation functional layer 10 containing the porous particles 11 is subjected to ion polishing in a cooling environment to expose the cross-section of the separation functional layer 10 in the thickness direction. The exposed cross-section is imaged using a field emission scanning electron microscope (FE-SEM) to obtain a backscattered electron image as image data (see Figure 4A). The imaging conditions are an acceleration voltage of 5kV and a magnification of, for example, 2000x for the SEM image. The obtained image data is subjected to automatic binarization processing using the image analysis software ImageJ to obtain a binarized image (see Figure 4B). The particle size of all porous particles 11 contained in the binarized image is measured. However, porous particles 11 that are only partially visible in the binarized image are not included. In addition, areas where porous particles 11 were detached during the fabrication of the separation functional layer 10 (the black, recessed areas circled in Figure 4A) are removed during binarization and are not included in the porous particles 11. The particle size of the porous particles 11 is defined as the maximum distance between two parallel lines circumscribing the particle's contour (maximum Ferret diameter). The two parallel lines are set in arbitrary directions, and the Ferret diameter is measured in each direction while rotating the particle. The maximum Ferret diameter is the largest value among the measured Ferret diameters. The average particle size D of the porous particles 11 contained in the separation functional layer 10 is the average of the measured maximum Ferret diameters.

[0040] The porous particles 11 contained in the separation functional layer 10 may have an average particle size D greater than 1 μm. With such a configuration, it is easier to realize a separation functional layer 10 in which the ratio R1 of the average particle size D (μm) of the porous particles 11 to the thickness T (μm) of the separation functional layer 10 satisfies the above numerical range.

[0041] The lower limit of the average particle size D of the porous particles 11 contained in the separation functional layer 10 may be 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, or even 1.5 μm. The upper limit of the average particle size D of the porous particles 11 contained in the separation functional layer 10 is, for example, 10 μm. The upper limit of the average particle size D of the porous particles 11 contained in the separation functional layer 10 may be 9 μm, 8 μm, 7 μm, 6 μm, 5 μm, or even 4 μm.

[0042] The average particle size D may be greater than 1 μm and less than or equal to 5 μm, or greater than 1 μm and less than or equal to 4 μm.

[0043] The shape of the porous particles 11 is not particularly limited. The shape of the porous particles 11 may be, for example, spherical, ellipsoidal, flaky, rod-shaped, etc. The shape of the porous particles 11 is preferably spherical or ellipsoidal.

[0044] The porous particle 11 has a plurality of pores 11p. The pores 11p open to the surface of the porous particle 11. The pores 11p include interconnecting pores. Porous particles 11 having pores 11p with interconnecting pores make it easier to improve the permeate flow velocity of the separation functional layer 10. However, the pores 11p may include independent pores in addition to interconnecting pores. In the example in Figure 2, the pores 11p of the porous particle 11 are simplified for convenience.

[0045] It is preferable that the porous particles 11 can preferentially or selectively incorporate alcohol molecules compared to water molecules. For example, it is preferable that the porous particles 11 have an average pore diameter P that is larger than the molecular diameter of the alcohol molecule. Porous particles 11 having such a configuration make it easier to improve the permeate flow rate of the separation functional layer 10. For example, the molecular diameter of ethanol molecules is 0.43 nm, and the molecular diameter of n-butanol molecules is 0.5 nm.

[0046] The porous particles 11 may have an average pore size P of 0.35 nm or more. Porous particles 11 having such a configuration make it easier to improve the permeate flow velocity of the separation functional layer 10.

[0047] The lower limit of the average pore size P of the porous particles 11 may be 0.36 nm, 0.37 nm, 0.38 nm, 0.39 nm, or even 0.4 nm. The upper limit of the average pore size P of the porous particles 11 may be, for example, less than 10 nm. The upper limit of the average pore size P of the porous particles 11 may be 7.5 nm, 5 nm, 2.5 nm, 1 nm, or even 0.75 nm.

[0048] The average pore size P may be between 0.35 nm and 1 nm, or between 0.35 nm and 0.75 nm.

[0049] The average pore diameter P of the porous particles 11 can be determined, for example, by the gas adsorption method using nitrogen gas, using the following method. First, data of the adsorption isotherm of the porous particles 11 is obtained using a pore distribution measuring device that uses nitrogen gas. For example, the Autopore IV manufactured by Shimadzu Micromerities can be used as the pore distribution measuring device. By converting the obtained adsorption isotherm data using the BJH (Barrett-Joyner-Halenda) method, a pore distribution can be obtained in which the volume of pores 11p is specified for each pore diameter. The pore distribution is, for example, a graph showing the relationship between the pore diameter of pores 11p and the log differential pore volume. From the obtained pore distribution, the mode diameter of pores 11p, that is, the pore diameter at which the distribution density is maximum in the pore distribution, can be determined. The obtained mode diameter can be considered as the average pore diameter P of the porous particles 11 contained in the separation functional layer 10.

[0050] The content CR of porous particles 11 in the separation functional layer 10 is preferably 20 wt% or more and 70 wt% or less. With such a configuration, it is easy to realize a separation functional layer 10 in which the ratio of the average particle size D of the porous particles 11 to the thickness T of the separation functional layer 10 satisfies the above numerical range.

[0051] The lower limit of the content CR of porous particles 11 in the separation functional layer 10 may be 21 wt%, 22 wt%, 23 wt%, 24 wt%, or even 25 wt%. The upper limit of the content CR may be 65 wt%, 60 wt%, 55 wt%, or even 50 wt%.

[0052] The CR content may be 20 wt% or more and 60 wt% or less, or 20 wt% or more and 55 wt% or less.

[0053] The content CR of porous particles 11 in the separation functional layer 10 can be determined, for example, from the weight of the separation functional layer 10 and the weight of porous particles 11 removed from the separation functional layer 10 by the method described above. The content CR of porous particles 11 in the separation functional layer 10 can also be determined from the amount of material added.

[0054] The separation functional layer 10 measures the amount of water adsorbed by porous particles 11 Q1 (cm³) under water vapor pressure of 25°C and 3.2 kPa. 3 Q2 (cm³) of ethanol adsorption by porous particles 11 at 25°C and 7.4 kPa ethanol atmosphere relative to g 3 The ratio R2 (per g) is, for example, 1 or greater. In this specification, "adsorption amount" means the value obtained by converting the volume of gas adsorbed by 1 g of porous particles 11 to standard conditions (298 K, 1 atm).

[0055] The ratio R2 is preferably 5 or greater, and more preferably 10 or greater.

[0056] The lower limit of the ratio R2 may be 11, 12, 13, 14, 15, 16, 17, 18, 19, or even 20. The upper limit of the ratio R2 is, for example, 30. The upper limit of the ratio R2 may also be 29, 28, 27, 26, or even 25.

[0057] The ratio R2 may be between 1 and 25, or between 10 and 25.

[0058] The amount of water adsorbed onto the porous particles 11, Q1, can be determined by the following method. First, the porous particles 11 are prepared. The porous particles 11 are pre-treated by heating them under a reduced pressure atmosphere. The pre-treatment may be performed under a vacuum atmosphere. The pre-treatment temperature is, for example, 100°C or higher. The pre-treatment time is not particularly limited, but is, for example, 1 hour or more. Next, the porous particles 11 are set in a known vapor adsorption amount measuring device such as the BELSORP-maxII manufactured by Microtrac-Bel. Next, water vapor is introduced into the measuring device at a measurement temperature of 25°C. The introduction of water vapor is continued until the water vapor pressure inside the measuring device reaches 3.2 kPa. 3.2 kPa corresponds to the equilibrium vapor pressure of water at 25°C. It can be determined that the water adsorption by the porous particles 11 has reached equilibrium by the change in the water pressure inside the measuring device. For example, it can be determined that the water adsorption by the porous particles 11 has reached equilibrium when the change in water pressure inside the measuring device is 40 Pa or less over 500 seconds. After confirming that water adsorption has reached equilibrium, the amount of water adsorbed by the porous particles 11 is determined. The determined amount of water adsorbed can be considered as the adsorption amount Q1.

[0059] The adsorption amount Q2 of ethanol on the porous particles 11 can be specified by the following method. First, the above-described pretreatment is performed on the porous particles 11. The pretreated porous particles 11 are set in a vapor adsorption amount measuring device. Next, at a measurement temperature of 25°C, gaseous ethanol is introduced into the measuring device. The introduced gaseous ethanol is adsorbed by the porous particles 11. The introduction of gaseous ethanol is carried out until the pressure of ethanol in the measuring device reaches 7.4 kPa. 7.4 kPa corresponds to the equilibrium vapor pressure (saturated vapor pressure) of ethanol at 25°C. After confirming that the adsorption of ethanol by the porous particles 11 has reached an equilibrium state, the adsorption amount of ethanol by the porous particles 11 is specified. Whether the adsorption of ethanol by the porous particles 11 has reached an equilibrium state can be judged by the change in the pressure of ethanol in the measuring device. For example, when the change in the pressure of ethanol in the measuring device is 40 Pa or less within 500 seconds, it can be judged that the adsorption of ethanol by the porous particles 11 has reached an equilibrium state. The adsorption amount of ethanol specified by the above method can be regarded as the adsorption amount Q2.

[0060] The adsorption amount Q1 of water on the porous particles 11 is, for example, 5 cm 3 / g or more and 80 cm 3 / g or less. The upper limit of the adsorption amount Q1 is 50 cm 3 / g, 30 cm 3 / g, and further may be 10 cm 3 / g.

[0061] The adsorption amount Q2 of ethanol on the porous particles 11 is, for example, 50 cm 3 / g or more and 300 cm 3 / g or less. The lower limit of the adsorption amount Q2 is 60 cm 3 / g, 70 cm 3 / g, 80 cm 3 / g, 90 cm 3 / g, and further may be 100 cm 3 / g.

[0062] (Porous particles) The porous particles 11 are used, for example, to separate an organic compound C from an aqueous solution S containing a volatile organic compound C. The organic compound C may be an alcohol. As described above, it is preferable that the porous particles 11 can preferentially or selectively incorporate alcohol molecules compared to water molecules.

[0063] As the porous particles 11, for example, metal-organic structures, silicon materials containing silicon atoms, zeolites, etc., can be used. Silica is an example of a silicon material.

[0064] The porous particles 11 may contain at least one selected from the group consisting of metal-organic structures, silica, and zeolites. With such a configuration, porous particles 11 having an average particle size D of more than 1 μm and an average pore diameter P of 0.35 nm or more can be easily realized.

[0065] The porous particles 11 may contain at least one selected from the group consisting of metal-organic structures and silica.

[0066] The porous particles 11 may contain silica. Silica usually refers to silicon dioxide. The porous particles 11 may also be porous silica particles containing silicon dioxide as the main component. Porous silica particles do not have a crystalline structure, for example. Porous silica particles can be produced, for example, by reacting metallic silicon with oxygen. Porous silica particles can also be produced by the sol-gel method, sedimentation method, aqueous solution wet method, etc. Porous silica particles may be mesoporous silica having pores of 2 to 50 nm. Porous silica particles may be composed substantially of silicon dioxide only.

[0067] The porous particles 11 may contain zeolite. The porous particles 11 may consist solely of zeolite. Examples of zeolite include high-silica zeolite, which has a high silica-to-alumina ratio, and silicaite, which does not contain alumina. Examples of porous particles 11 containing high-silica zeolite include HSZ (registered trademark) from Tosoh Corporation, HiSiv (registered trademark) from Resonaq Universal Corporation, USKY from Resonaq Universal Corporation, and Zeoal (registered trademark) from Nakamura Choko Co., Ltd.

[0068] The porous particles 11 may contain a metal-organic framework (MOF). The porous particles 11 may also consist solely of a metal-organic framework. The metal-organic framework is also called a porous coordination polymer (PCP) or nanoporous metal complex, and can incorporate low-molecular-weight compounds inside.

[0069] A metal-organic structure has a metal ion, metal cluster, or metal oxide cluster as a core, and an organic ligand coordinated to the core. A metal-organic structure may also have a metal ion as a core and an organic ligand coordinated to the core.

[0070] Examples of metals included in the core include Zn, Co, Al, Cu, Pd, Mg, Fe, Cr, Zr, and Ni.

[0071] The metal ion that forms the core is Zn. 2+ Co 2+ Al 3+ ,Cd 2+ Preferably, the metal ions are such as Zn. 2+ Or Co 2+ It is more preferable that Zn 2+ It is even more preferable that the core be Zn. 2+ A metal-organic structure having Co as its core 2+ Compared to metal-organic structures with [specific properties], it is easier to design with a larger average particle size.

[0072] Zn as the core 2+Examples of metal-organic structures having this include ZIF-8; ZIF-71; ZIF-90, ZIF-91, ZIF-92; ZIF-6 (MAF-6), etc. Co as the core 2+ Examples of metal-organic structures having this property include ZIF-67.

[0073] The metal cluster serving as the core may be a Zn cluster. Examples of metal-organic structures having a Zn cluster include MOF-5.

[0074] The metal oxide cluster serving as the core may be a Zr oxide cluster. Examples of metal-organic structures having a Zr oxide cluster include UiO-66.

[0075] The organic ligand contains a functional group for coordinating to the core. In the organic ligand, the number of these functional groups is, for example, two or more. The upper limit of the number of these functional groups is, for example, six or less. It is preferable that the organic ligand has one functional group for coordinating to the core. That is, it is preferable that the metal-organic structure has a metal ion, metal cluster, or metal oxide cluster as the core and a single-position organic ligand. An example of such an organic ligand is one having one amino group as a functional group.

[0076] The organic ligand does not necessarily have to have a functional group containing an oxygen atom, such as a carboxyl group or a hydroxyl group.

[0077] The organic ligand may contain a ring structure. The number of ring structures in the organic ligand is, for example, one or more. The upper limit of the number of ring structures is, for example, three or less. The ring structure is preferably an aromatic ring. The aromatic ring may consist only of carbon atoms, or it may be a heteroaromatic ring containing heteroatoms. The aromatic ring may be monocyclic or polycyclic. The number of carbon atoms in the aromatic ring is not particularly limited, and is, for example, 4 to 14. Specific examples of aromatic rings include imidazole rings, benzene rings, naphthalene rings, etc. The aromatic ring may be an imidazole ring. In the organic ligand, a functional group for coordinating to the core may be included in the ring structure.

[0078] Organic ligands may also be represented by the following formula (a).

[0079]

[0080] In the above formula (a), R 1 From R 3 These are, independently of each other, a hydrogen atom or any substituent. Any substituent may include one selected from the group consisting of halogen groups, alkyl groups, and aldehyde groups. Examples of halogen groups include chloro groups and fluoro groups. Examples of alkyl groups include methyl groups and ethyl groups.

[0081] In the above formula (a), R 1 is a hydrogen atom, R 2 and R 3 The ligand may be a chloro group. An example of a ZIF having such an organic ligand is ZIF-71.

[0082] In the above formula (a), R 1 is a methyl group, R 2 and R 3 This could be a hydrogen atom. Examples of ZIFs having such organic ligands include ZIF-8 and ZIF-67.

[0083] In the above formula (a), R 1 is an ethyl group, R 2 and R 3 This could be a hydrogen atom. An example of a ZIF having such an organic ligand is ZIF-6 (MAF-6).

[0084] In the above formula (a), R 1 is an aldehyde group, R 2 and R 3 This could be a hydrogen atom. An example of a ZIF having such an organic ligand is ZIF-90.

[0085] Examples of metal-organic structures having an organic ligand with the structure represented by formula (a) above include the Zeolitic Imidazolate Framework (ZIF). The metal-organic structure may also contain a ZIF. The metal-organic structure may also be a ZIF. ZIF is a general term for metal-organic structures having a three-dimensional crystalline structure similar to that of a zeolite. A ZIF has a metal ion as a core with tetrahedral (Td) four-coordinate structure and an organic ligand containing an imidazole ring, and is constructed by a metal-imidazolate-metal coordination bond. Examples of metal ions include Zn. 2+ Co 2+ Examples of such ZIFs include ZIF-8, ZIF-71, ZIF-90, ZIF-91, ZIF-92, ZIF-6 (MAF-6), and ZIF-67.

[0086] Metal-organic structures are metal ions such as Zn. 2+ The ZIF may contain the imidazole ring as an organic ligand. Examples of such ZIFs include ZIF-8, ZIF-71, and ZIF-6 (MAF-6).

[0087] ZIF may also be ZIF-71. ZIF-71 is a metal ion, Zn, as the core. 2+ It has a crystalline structure in which the organic ligand 4,5-dichloroimidazolate is coordinated.

[0088] (Matrix) As shown in Figure 1, the separation functional layer 10 further includes a matrix 12. Porous particles 11 are dispersed in the matrix 12. All or part of the porous particles 11 are embedded in the matrix 12. All of the porous particles 11 may be spaced apart from each other in the matrix 12. The porous particles 11 may be partially aggregated in the matrix 12, forming secondary particles.

[0089] The matrix 12 preferably contains a silicone resin. With such a configuration, it is easier to disperse the porous particles 11 in the matrix 12.

[0090] The silicone resin is formed, for example, from a silicone resin composition. The silicone resin composition includes, for example, a silicone base and a curing agent. The silicone base is, for example, a mixture of polyorganosiloxanes. The curing agent includes, for example, a curing catalyst. The curing agent may optionally further contain polyorganosiloxanes.

[0091] The weight-average molecular weight of the silicone main component may be between 10,000 and 1,000,000, between 10,000 and 500,000, or even between 10,000 and 200,000. The weight-average molecular weight of the curing agent may be between 10,000 and 500,000.

[0092] The silicone resin is not particularly limited and may be formed from, for example, a condensation-type silicone resin composition, an addition-type silicone resin composition, or a UV-curable silicone resin composition. However, when mixed with a metal-organic structure, a condensation-type silicone resin composition is preferred in consideration of the effect of ligand-induced curing inhibition.

[0093] (Addition-type silicone resin composition) An addition-type silicone resin composition is a type of silicone resin composition that hardens by an addition reaction. An addition-type silicone resin composition includes, for example, a polyorganosiloxane P1 having an alkenyl group and a polyorganosiloxane P2 having a hydrosilyl (SiH) group. Preferably, the addition-type silicone resin composition further contains a curing catalyst (hydrosilylation catalyst). The addition-type silicone resin composition may also be a commercially available silicone resin composition to which a curing catalyst has been added. However, the addition-type silicone resin composition does not necessarily have to contain a curing catalyst.

[0094] Addition-type silicone resin compositions can be formed by, for example, heat treatment, which causes a reaction (hydrosilylation reaction) between the alkenyl group of polyorganosiloxane P1 and the hydrosilyl group of polyorganosiloxane P2 to form a silicone resin. In this hydrosilylation reaction, polyorganosiloxane P2 functions as a crosslinking agent.

[0095] Examples of alkenyl groups in polyorganosiloxane P1 include vinyl groups and hexenyl groups. The number of alkenyl groups in polyorganosiloxane P1 is, for example, two or more. The alkenyl groups are located, for example, at the ends of polyorganosiloxane P1.

[0096] Polyorganosiloxane P1 is obtained by introducing an alkenyl group to polyalkylsiloxanes such as polydimethylsiloxane (PDMS), polydiethylsiloxane, and polymethylethylsiloxane; polyalkylarylsiloxanes; or poly(dimethylsiloxane-diethylsiloxane). Polyorganosiloxane P1 is preferably PDMS.

[0097] The weight-average molecular weight of polyorganosiloxane P1 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The larger the weight-average molecular weight of polyorganosiloxane P1, the more the separation characteristics of the permeation vaporization membrane 100 tend to improve. The upper limit of the weight-average molecular weight of polyorganosiloxane P1 is not particularly limited, and may be, for example, 1,000,000, and may be 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of polyorganosiloxane P1 may be 10,000 to 500,000, 10,000 to 200,000, or 15,000 to 100,000.

[0098] The number of hydrosilyl groups in polyorganosiloxane P2 is, for example, two or more. The hydrosilyl groups may be located at the ends of polyorganosiloxane P2, or they may be included in the main chain of polyorganosiloxane P2.

[0099] Examples of polyorganosiloxane P2 include polymethylhydrogensiloxane, poly(dimethylsiloxane-methylhydrogensiloxane), and hydrosilyl-terminated polydimethylsiloxane.

[0100] The weight-average molecular weight of polyorganosiloxane P2 is, for example, 100 or more, but may be 1,000 or more, 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of polyorganosiloxane P2 is not particularly limited, and may be, for example, 1,000,000, but may be 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of polyorganosiloxane P2 may be 10,000 to 500,000, 10,000 to 200,000, or 15,000 to 100,000.

[0101] The addition-type silicone resin composition comprises polyorganosiloxane P1 and polyorganosiloxane P2, and the weight-average molecular weight of at least one selected from the group consisting of polyorganosiloxane P1 and polyorganosiloxane P2 may be 10,000 or more and 200,000 or less.

[0102] The weight ratio of polyorganosiloxane P2 to polyorganosiloxane P1, P2 / P1, is, for example, 500 wt% or less, and may be 100 wt% or less, 50 wt% or less, 20 wt% or less, 10 wt% or less, or even 5 wt% or less. The lower limit of the weight ratio P2 / P1 is, for example, 0.01 wt% or more.

[0103] Examples of curing catalysts include platinum-based catalysts. In other words, addition-type silicone resin compositions may contain a platinum-containing curing catalyst. Specific examples of platinum-based catalysts include chloroplatinic acid, platinum olefin complexes, and chloroplatinic acid olefin complexes. As mentioned above, addition-type silicone resin compositions do not necessarily need to contain a curing catalyst.

[0104] Addition-type silicone resin compositions may contain compounds that generate catalytically active species that catalyze addition reactions when irradiated with active energy rays such as ultraviolet (UV) light. According to an addition-type silicone resin composition containing such compounds, the addition reaction can be carried out, for example, by UV irradiation.

[0105] The addition-type silicone resin composition may further contain organic solvents in addition to the components described above. Examples of organic solvents include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. The organic solvent may be used alone or in combination of two or more. The addition-type silicone resin composition may have a solvent content of 5 wt% or less, and may be a solvent-free type that substantially does not contain organic solvents.

[0106] (Condensation-type silicone resin composition) A condensation-type silicone resin composition is a type of silicone resin composition that hardens by a condensation reaction. For example, a condensation-type silicone resin composition includes a polyorganosiloxane P3 having a silanol (SiOH) group and a silane compound P4 having functional groups such as an alkoxy group, an alkenyloxy group, an acyloxy group, an amino group, a ketoxime group, or an amide group. The condensation-type silicone resin composition may or may not further contain a curing catalyst. Note that the condensation-type silicone resin composition may also be a commercially available silicone resin composition to which a curing catalyst has been added.

[0107] A condensation-type silicone resin composition can be formed by, for example, heat treatment, which causes a reaction (condensation reaction) between the silanol group of polyorganosiloxane P3 and the above-mentioned functional group of silane compound P4 to form a silicone resin. In this condensation reaction, silane compound P4 functions as a crosslinking agent.

[0108] The number of silanol groups in polyorganosiloxane P3 is, for example, two or more. The silanol groups are located, for example, at the terminal ends of polyorganosiloxane P3. Polyorganosiloxane P3 may also have alkyl groups such as methyl or ethyl groups, or phenyl groups, introduced as substituents on its side chains.

[0109] Polyorganosiloxane P3 is, for example, a polyorganosiloxane P1, to which a silanol group has been introduced.

[0110] The weight-average molecular weight of polyorganosiloxane P3 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of polyorganosiloxane P1 is not particularly limited, and may be, for example, 1,000,000, and may be 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of polyorganosiloxane P3 may be 10,000 to 500,000, 10,000 to 200,000, or 15,000 to 100,000.

[0111] As described above, silane compound P4 has functional groups such as alkoxy groups, alkenyloxy groups, acyloxy groups, amino groups, ketoxime groups, and amide groups. Examples of alkoxy groups include methoxy groups and ethoxy groups. Examples of alkenyloxy groups include isopropenyloxy groups. Examples of acyloxy groups include acetoxy groups. Examples of amino groups include dimethylamino groups, diethylamino groups, and ethylmethylamino groups. Examples of ketoxime groups include acetoxime groups and methylethylketoxime groups. Examples of amide groups include acetamide groups, N-methylacetamide groups, and N-ethylacetamide groups. The number of functional groups in silane compound P4 is, for example, two or more. More specifically, silane compound P4 preferably contains an alkoxysilyl group as an alkoxy group.

[0112] The silane compound P4 may be a low molecular weight compound with a molecular weight of about 1000 or less, or it may be a high molecular weight compound having a polysiloxane skeleton.

[0113] Examples of curing catalysts include tin-based catalysts. Examples of tin-based catalysts include organotin catalysts such as dibutyltin dilaurate, dibutyltin diacetate, and dibutyltin dioctate.

[0114] The condensation-type silicone resin composition may further contain an organic solvent in addition to the components described above. Examples of organic solvents include those described above for the addition-type silicone resin composition. The condensation-type silicone resin composition may also be a solvent-free type that does not contain solvents such as organic solvents.

[0115] (UV-curable silicone resin composition) A UV-curable silicone resin composition is a type of silicone resin composition that hardens upon irradiation with ultraviolet (UV) light. The curing reaction of a UV-curable silicone resin composition proceeds, for example, by radical polymerization, radical addition, or ionic polymerization. A UV-curable silicone resin composition in which the curing reaction proceeds by radical polymerization includes, for example, a polyorganosiloxane P5 having a double bond (specifically a carbon-carbon double bond) derived from an alkenyl group or an acryloyl group. A UV-curable silicone resin composition in which the curing reaction proceeds by radical addition includes, for example, a polyorganosiloxane P5 having a double bond (specifically a carbon-carbon double bond) derived from an alkenyl group or an acryloyl group, and a compound P6 having a functional group that can undergo radical addition, such as a thiol group. A UV-curable silicone resin composition in which the curing reaction proceeds by ionic polymerization includes, for example, a polyorganosiloxane P7 having a functional group that can undergo ionic polymerization, such as an epoxy group, and a compound that generates a catalytically active species that catalyzes ionic polymerization upon UV irradiation.

[0116] In a UV-curable silicone resin composition in which the curing reaction proceeds by radical polymerization, for example, UV irradiation causes a radical polymerization reaction to proceed between the double bonds contained in the alkenyl groups and acryloyl groups of polyorganosiloxane P5, thereby forming a silicone resin.

[0117] Examples of alkenyl groups in polyorganosiloxane P5 include vinyl groups and hexenyl groups. The number of alkenyl groups in polyorganosiloxane P5 is, for example, two or more. The alkenyl groups are located, for example, at the ends of polyorganosiloxane P5. Polyorganosiloxane P5 may also have alkyl groups such as methyl groups and ethyl groups, or phenyl groups, introduced as substituents on its side chains.

[0118] Polyorganosiloxane P5 is, for example, obtained by introducing substituents having double bonds, such as alkenyl groups or acryloyl groups, into the polyorganosiloxane P1 described above.

[0119] The weight-average molecular weight of polyorganosiloxane P5 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of polyorganosiloxane P5 is not particularly limited, and may be, for example, 1,000,000, and may be 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of polyorganosiloxane P5 may be between 10,000 and 500,000, between 10,000 and 200,000, or between 15,000 and 100,000.

[0120] In a UV-curable silicone resin composition in which the curing reaction proceeds by radical addition, for example, UV irradiation causes a radical addition of a functional group in compound P6 to the double bond in the alkenyl group or acryloyl group of polyorganosiloxane P5. This allows the radical addition reaction to proceed, and a silicone resin can be formed.

[0121] In compound P6, functional groups that can undergo radical addition include, for example, thiol groups and alkylthiol groups. Examples of alkylthiol groups include mercaptomethyl groups and mercaptoethyl groups. The number of functional groups in compound P6 that can undergo radical addition is, for example, two or more.

[0122] Compound P6 may be a polyorganosiloxane containing a functional group that can be radical-added. This functional group is, for example, located at the terminal end of the polyorganosiloxane. The polyorganosiloxane may also have alkyl groups such as methyl or ethyl groups, or phenyl groups, introduced as substituents on its side chains.

[0123] Compound P6 is, for example, obtained by introducing a functional group capable of radical addition, such as a thiol group, to the polyorganosiloxane P1 described above.

[0124] The weight-average molecular weight of compound P6 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of compound P6 is not particularly limited, and may be, for example, 1,000,000, 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of compound P6 may be between 10,000 and 500,000, between 10,000 and 200,000, or between 15,000 and 100,000.

[0125] In a UV-curable silicone resin composition in which the curing reaction proceeds by ionic polymerization, for example, UV irradiation generates catalytically active species that catalyze ionic polymerization, and an ionic polymerization reaction proceeds between the ionically polymerizable functional groups contained in polyorganosiloxane P7. This allows for the formation of a silicone resin.

[0126] In polyorganosiloxane P7, functional groups that can undergo ionic polymerization include, for example, epoxy groups. Substituents containing epoxy groups include the epoxy group itself, glycidyl groups, glycidyloxypropyl groups, etc. The number of functional groups that can undergo ionic polymerization in polyorganosiloxane P7 is, for example, two or more. Functional groups that can undergo ionic polymerization are located, for example, at the ends of polyorganosiloxane P7. Polyorganosiloxane P7 may also have alkyl groups such as methyl groups and ethyl groups, phenyl groups, etc., introduced as substituents on the side chains.

[0127] Polyorganosiloxane P7 is, for example, a polyorganosiloxane P1, in which a functional group capable of ionic polymerization, such as an epoxy group, is introduced to the polyorganosiloxane described above.

[0128] The weight-average molecular weight of polyorganosiloxane P7 is, for example, 1,000 or more, and may be 10,000 or more, 15,000 or more, 100,000 or more, 200,000 or more, 300,000 or more, or even 400,000 or more. The upper limit of the weight-average molecular weight of polyorganosiloxane P7 is not particularly limited, and may be, for example, 1,000,000, and may be 500,000 or less, 200,000 or less, or even 100,000 or less. The weight-average molecular weight of polyorganosiloxane P7 may be between 10,000 and 500,000, between 10,000 and 200,000, or between 15,000 and 100,000.

[0129] The UV-curable silicone resin composition may further contain organic solvents in addition to the components described above. Examples of organic solvents include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; ketone solvents such as acetone and methyl ethyl ketone; and alcohol solvents such as methanol, ethanol, and butanol. The organic solvent may be used alone or in combination of two or more. The UV-curable silicone resin composition may also be solvent-free, substantially free of solvents such as organic solvents.

[0130] The separation functional layer 10 may contain silicone resin as its main component, or it may be composed substantially of silicone resin alone. "Main component" means the component that is present in the largest amount by weight in the separation functional layer 10.

[0131] [Porous support] The porous support 20 supports the separation functional layer 10. The porous support 20 preferably contains an organic material, more preferably consists substantially of an organic material, and even more preferably consists solely of an organic material.

[0132] The porous support 20 comprises, for example, a main body 21 and a microporous layer 22 disposed on the main body 21. In the permeation vaporization membrane 100, the microporous layer 22 is located between the main body 21 and the separation function layer 10 and is in direct contact with both the main body 21 and the separation function layer 10. The porous support 20 is typically an ultrafiltration membrane.

[0133] The main body 21 is preferably a fibrous structure. Examples of fibrous structures include woven fabrics, nonwoven fabrics, and stretched porous membranes containing fibrils. Typically, the fibrous structure is a nonwoven fabric or a stretched porous membrane. According to the above, the flux of the permeate fluid passing through the permeation vaporization membrane 100 can be improved.

[0134] When the fiber structure is a woven or nonwoven fabric, the fibers included in the fiber structure may include, for example, natural fibers such as wood pulp, cotton, and hemp (e.g., Manila hemp); and chemical fibers (synthetic fibers) such as polyester fibers, rayon, vinylon, acetate fibers, polyvinyl alcohol (PVA) fibers, polyamide fibers, polyolefin fibers, and polyurethane fibers. The main body 21 is, for example, a nonwoven fabric made of polyester fibers. The nonwoven fabric is preferably a polyethylene terephthalate (PET) nonwoven fabric.

[0135] When the fibrous structure is a stretched porous membrane, it is preferable that the fibrous structure contains a fluororesin. Examples of fluororesins include polytetrafluoroethylene (PTFE), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), perfluoroalkoxy fluororesin (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FEP), with PTFE being preferred.

[0136] As an example, stretched PTFE porous membranes are formed by stretching a paste extruded or cast membrane containing PTFE particles. Stretched PTFE porous membranes are composed of fine PTFE fibrils and may have nodes where the PTFE is more aggregated compared to the fibrils.

[0137] The main body 21 has, for example, an average pore diameter of 1 μm to 100 μm. The lower limit of the average pore diameter of the main body 21 may be 5 μm or more. The upper limit of the average pore diameter of the main body 21 may be 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, 50 μm or less, 40 μm or less, 30 μm or less, or even 20 μm or less.

[0138] Examples of materials for the microporous layer 22 include fluororesins such as polyvinylidene fluoride and polytetrafluoroethylene; polyaryl ethersulfones such as polysulfone and polyethersulfone; and polyimides. The microporous layer 22 preferably contains polysulfone. The microporous layer 22 has an average pore size of, for example, 0.01 μm to 0.4 μm.

[0139] The thickness of the porous support 20 is not particularly limited and may be, for example, 10 μm or more, 50 μm or more, or even 100 μm or more. The thickness of the porous support 20 may also be, for example, 300 μm or less, or 200 μm or less.

[0140] The average diameter of the openings on the surface of the porous support 20 facing the separation functional layer 10 (the surface of the porous support 20 in contact with the separation functional layer 10) is, for example, 1 nm to 100 nm, and preferably 5 nm to 20 nm.

[0141] The porosity of the porous support 20 is, for example, 30% to 80%, preferably 50% to 70%.

[0142] In some cases, the porous support 20 may consist only of the main body portion 21 and may not have a microporous layer 22.

[0143] The surface of the porous support 20 in contact with the separation functional layer 10 may be treated with an easy-adhesion treatment. Examples of easy-adhesion treatments include surface treatments such as corona discharge treatment and plasma treatment.

[0144] The permeable vaporization membrane 100 may further comprise an intermediate layer disposed between the separation functional layer 10 and the porous support 20. The intermediate layer is typically formed from an adhesive composition. The adhesive composition may be a composition containing a silicone polymer (silicone adhesive).

[0145] The permeable vaporization membrane 100 according to this embodiment does not necessarily have to include a porous support 20.

[0146] <Method for Manufacturing a Permeable Vapor-Evaporating Membrane> The permeable vapor-evaporating membrane 100 can be manufactured, for example, by forming a separation functional layer 10 on a microporous layer 22 of a porous support 20. Specifically, first, a coating solution containing the material for the matrix 12 and porous particles 11 is prepared. The material for the matrix 12 is, for example, a silicone resin composition. Next, a coating film is obtained by applying the coating solution onto the porous support 20. The separation functional layer 10 is formed by curing the coating film. The curing of the coating film can be carried out at room temperature or in a heated environment. The curing of the coating film can also be carried out by irradiation with active energy rays such as UV.

[0147] When curing a coating film by heating, the heating conditions for the coating film are not particularly limited. For example, the heating temperature of the coating film may be 80°C or higher, 90°C or higher, 100°C or higher, or even 120°C or higher. The higher the heating temperature of the coating film, the more sufficiently the curing reaction of the components in the silicone resin composition proceeds. The upper limit of the heating temperature of the coating film is not particularly limited, for example, 200°C. The heating time of the coating film can be appropriately adjusted depending on the composition of the silicone resin composition used, etc.

[0148] <Applications of the Permeation Vaporization Membrane> The permeation vaporization membrane 100 of this embodiment is suitable for, for example, separating an organic compound C from an aqueous solution S containing a volatile organic compound C. The organic compound C is not particularly limited as long as it is volatile. In this specification, "volatile organic compound" means, for example, an organic compound whose boiling point at atmospheric pressure (101.325 kPa) is 20°C to 260°C. The organic compound C, for example, when its concentration in an aqueous solution is high, produces an aqueous phase mainly composed of water and an organic phase in which the content of the organic compound C is higher than that of the aqueous phase. However, the organic compound C may not produce an aqueous phase or an organic phase.

[0149] The number of carbon atoms in organic compound C is not particularly limited and may be, for example, 10 or less, 8 or less, 6 or less, or even 4 or less. The lower limit of the number of carbon atoms in organic compound C may be 1 or 2. Organic compound C has functional groups containing oxygen atoms, such as hydroxyl groups, carbonyl groups, ether groups, and ester groups. In organic compound C, the number of functional groups containing oxygen atoms is typically one.

[0150] Examples of organic compound C include alcohols, ketones, and esters, and are typically alcohols. The alcohol may be an alkyl alcohol composed only of an alkyl group and a hydroxyl group, or an aryl alcohol containing an aryl group and a hydroxyl group. The alkyl alcohol may be linear, branched, or cyclic. Examples of alkyl alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, isobutanol, t-butanol, and n-pentanol, preferably ethanol, n-butanol, 2-butanol, and isopropanol, and more preferably ethanol, n-butanol, and isopropanol. Examples of aryl alcohols include phenol.

[0151] The ketone may be a dialkylketone composed solely of an alkyl group and a carbonyl group. Examples of dialkylketones include methyl ethyl ketone (MEK) and acetone.

[0152] The ester may be a fatty acid alkyl ester composed solely of an alkyl group and an ester group. Examples of fatty acid alkyl esters include ethyl acetate.

[0153] The organic compound C is not limited to those described above. The organic compound C may be an aromatic hydrocarbon such as benzene, toluene, or xylene, or an amide solvent such as N,N-dimethylformamide (DMF) and N-methyl-2-pyrrolidone (NMP).

[0154] The aqueous solution S may contain one type of organic compound C, or it may contain two or more types of organic compound C. The content of organic compound C in the aqueous solution S is, for example, 0.1 wt% or more, and may be 0.5 wt% or more, 1 wt% or more, 2 wt% or more, and even 5 wt% or more. The upper limit of the content of organic compound C is not particularly limited, and is, for example, 50 wt% or less. The upper limit of the content of organic compound C may be 40 wt% or less, 30 wt% or less, and even 20 wt% or less.

[0155] Organic compound C may be a fermented product produced by microorganisms fermenting a carbon source, or it may be an alcohol (bio-alcohol) produced by microorganisms. In other words, aqueous solution S may be a fermentation liquid containing organic compound C as a fermented product. However, aqueous solution S is not limited to fermentation liquid, but may also be waste liquid or wastewater discharged from a chemical plant, etc.

[0156] The aqueous solution S may further contain other components besides water and organic compound C, such as microorganisms that produce fermentation products, a carbon source, a nitrogen source, and inorganic ions. The microorganisms that produce fermentation products are typically bacteria. Examples of carbon sources include polysaccharides such as starch and monosaccharides such as glucose.

[0157] For example, if organic compound C is a fermentation product, that is, if aqueous solution S containing volatile organic compound C is the fermentation liquid, the temperature of aqueous solution S is 15°C to 75°C. The temperature of aqueous solution S may also be 30°C to 60°C.

[0158] <Characteristics of the Permeation Vaporization Membrane> In the permeation vaporization membrane 100, the separation coefficient of organic compound C with respect to water is not particularly limited. As an example, the separation coefficient α of ethanol (EtOH) with respect to water in the permeation vaporization membrane 100 is EtOH For example, it may be 7 or more, and may also be 7.5 or more, 8 or more, or even 8.5 or more. Separation coefficient α EtOH The upper limit is, for example, 100.

[0159] Separation coefficient α EtOHThe separation coefficient α can be measured by the following method. A mixed liquid consisting of EtOH and water is brought into contact with one surface of the permeable vaporization membrane 100 (for example, the main surface of the permeable vaporization membrane 100 on the separation functional layer 10 side), and the space adjacent to the other surface of the permeable vaporization membrane 100 (for example, the main surface of the permeable vaporization membrane 100 on the porous support 20 side) is depressurized. This yields a permeate fluid that has permeated through the permeable vaporization membrane 100. The weight ratio of water and the weight ratio of EtOH in the permeate fluid are measured. In the above operation, the EtOH content in the mixed liquid is 5.0 wt%. The mixed liquid brought into contact with the permeable vaporization membrane 100 is at a temperature of 40°C. The space adjacent to the other surface of the permeable vaporization membrane 100 is depressurized to 1.5 kPa. Separation coefficient α EtOH It can be calculated from the following formula. However, in the formula below, X A and X B These represent the weight ratio of EtOH and the weight ratio of water in the mixed liquid, respectively. A and Y B These are the weight ratios of EtOH and water in the permeate fluid that has permeated through the permeation vaporization membrane 100, respectively. Separation coefficient α EtOH = (Y A / Y B ) / (X A / X B )

[0160] The above separation coefficient α EtOH Under these measurement conditions, the flux of EtOH permeating the permeable vaporization membrane 100 is not particularly limited, for example, 0.001 kg / m 2 It may be greater than or equal to 0.010 kg / m 2 / hr or more, 0.020kg / m 2 / hr or more, 0.030kg / m 2 / hr or more, 0.040kg / m 2 / hr or more, and even 0.050 kg / m 2 It may be greater than / hr. The flux of EtOH permeating through the permeable vaporization membrane 100 is 10 kg / m 2 It may be less than or equal to / hr, and 8.0 kg / m 2 Less than / hr, and even less than 6.0 kg / m 2 It may be less than / hr.

[0161] <Membrane Separation Apparatus> Figure 5 is a schematic cross-sectional view of a membrane separation apparatus 1000 equipped with the permeation vaporization membrane 100 described above. As shown in Figure 5, the membrane separation apparatus 1000 comprises a permeation vaporization membrane 100 and a container 200. The container 200 has a first chamber 201 and a second chamber 202. The first chamber 201 functions as a supply space to which a supply fluid (specifically, the aqueous solution S described above) is supplied. The second chamber 202 functions as a permeation space to which a permeate fluid S1 is supplied. The permeate fluid S1 is obtained by the aqueous solution S permeating through the permeation vaporization membrane 100.

[0162] The permeable vaporization membrane 100 is located inside the container 200. Inside the container 200, the permeable vaporization membrane 100 separates the first chamber 201 and the second chamber 202. The permeable vaporization membrane 100 extends from one of a pair of walls of the container 200 to the other.

[0163] The first chamber 201 has an inlet 201a and an outlet 201b. The second chamber 202 has an outlet 202a. The inlet 201a is an opening for supplying the aqueous solution S to the supply space (first chamber 201). The outlet 202a is an opening for discharging the permeate fluid S1 from the permeate space (second chamber 202). The outlet 201b is an opening for discharging the aqueous solution S (non-permeable fluid S2) that did not permeate the permeation vaporization membrane 100 from the supply space (first chamber 201). Each of the inlet 201a, outlet 201b, and outlet 202a is formed, for example, on the wall surface of the container 200.

[0164] The membrane separation apparatus 1000 is suitable for continuous flow membrane separation methods. However, the membrane separation apparatus 1000 may also be used for batch membrane separation methods.

[0165] <Operation Method of the Membrane Separation Device> The membrane separation device 1000 is operated, for example, as follows. First, an aqueous solution S is supplied to the first chamber 201 of the membrane separation device 1000 through the inlet 201a. This allows the aqueous solution S to come into contact with one side of the permeation vaporization membrane 100 (for example, the main surface on the separation function layer 10 side).

[0166] Next, with the aqueous solution S in contact with one surface of the permeable vaporization membrane 100, the space adjacent to the other surface of the permeable vaporization membrane 100 (for example, the main surface on the porous support 20 side) is depressurized. More specifically, the second chamber 202 is depressurized through the outlet 202a. The depressurization of the second chamber 202 can be performed, for example, by a depressurization device such as a vacuum pump. The pressure in the second chamber 202 is, for example, 50 kPa or less, and may be 20 kPa or less, 10 kPa or less, 5 kPa or less, 3 kPa or less, or even 2 kPa or less. In this specification, unless otherwise specified, "pressure" means absolute pressure.

[0167] By reducing the pressure inside the second chamber 202, a permeate fluid S1 with a high content of organic compound C can be obtained on the other side of the permeate vaporization membrane 100. In other words, the permeate fluid S1 is supplied to the second chamber 202. Inside the second chamber 202, the permeate fluid S1 is typically a gas. The permeate fluid S1 is discharged to the outside of the membrane separation device 1000 through the outlet 202a.

[0168] On the other hand, the content of organic compound C in the aqueous solution S gradually decreases from the inlet 201a to the outlet 201b of the first chamber 201. The aqueous solution S (impermeable fluid S2) treated in the first chamber 201 is discharged to the outside of the membrane separation device 1000 through the outlet 201b. The impermeable fluid S2 is typically a liquid.

[0169] As described above, the permeation vaporization membrane 100 can preferentially permeate organic compound C contained in the aqueous solution S. Therefore, the permeate fluid S1 obtained by operating the membrane separation device 1000 has a higher content of organic compound C compared to the aqueous solution S supplied to the membrane separation device 1000.

[0170] (Modification) The membrane separation device 1000 is not limited to one equipped with a flat membrane permeation vaporization membrane 100 as illustrated in Figure 5. The membrane separation device 1000 may be a spiral membrane element, a hollow fiber membrane element, a disc tube type membrane element in which a plurality of permeation vaporization membranes 100 are laminated, a plate and frame type membrane element, etc. Figure 6 shows a spiral membrane element. The membrane separation device 1001 in Figure 6 is equipped with a central tube 301 and a laminate 302. The laminate 302 contains the permeation vaporization membrane 100.

[0171] The central tube 301 has a cylindrical shape. Multiple holes or slits are formed on the surface of the central tube 301 to allow the permeable fluid S1 to flow into the interior of the central tube 301. Examples of materials for the central tube 301 include resins such as acrylonitrile butadiene styrene copolymer resin (ABS resin), polyphenylene ether resin (PPE resin), and polysulfone resin (PSF resin); and metals such as stainless steel and titanium. The inner diameter of the central tube 301 is, for example, in the range of 20 to 100 mm.

[0172] The laminate 302 further includes a supply-side channel material 303 and a permeate-side channel material 304 in addition to the permeate vaporization membrane 100. The laminate 302 is wound around the central tube 301. The membrane separation device 1001 may further include an outer covering material (not shown).

[0173] For the supply-side channel material 303 and the permeate-side channel material 304, for example, a net, woven fabric, or knitted fabric made of a resin such as polyethylene, polypropylene, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), or ethylene-chlorotrifluoroethylene copolymer (ECTFE) can be used.

[0174] The membrane separation device 1001 can be operated, for example, in the following way. First, an aqueous solution S is supplied to one end of the wound laminate 302. The space inside the central tube 301 is depressurized. As a result, the permeate fluid S1 that has permeated through the permeation vaporization membrane 100 of the laminate 302 moves into the central tube 301. The permeate fluid S1 is discharged to the outside through the central tube 301. The aqueous solution S (impermeable fluid S2) processed by the membrane separation device 1001 is discharged to the outside from the other end of the wound laminate 302.

[0175] <Membrane Separation System> Figure 7 is a schematic diagram showing an example of a membrane separation system 2000 equipped with the membrane separation devices 1000 and 1001 described above. In the example of Figure 7, the membrane separation system 2000 is equipped with the membrane separation device 1000 shown in Figure 5. However, the membrane separation system 2000 may be equipped with the membrane separation device 1001 shown in Figure 6 instead of the membrane separation device 1000.

[0176] The membrane separation system 2000 further comprises a storage unit 400 along with the membrane separation device 1000. The storage unit 400 stores an aqueous solution S to be supplied to the membrane separation device 1000. The storage unit 400 is, for example, a tank for storing the aqueous solution S. The storage unit 400 may also be a fermentation tank for producing organic compounds C by fermentation of a carbon source by microorganisms.

[0177] The membrane separation system 2000 further comprises an aqueous solution supply path 71, a non-permeable fluid discharge path 72, and a permeable fluid discharge path 73. The aqueous solution supply path 71 is a path for supplying aqueous solution S from the storage unit 400 to the membrane separation device 1000 during operation, and is connected to the outlet 401 of the storage unit 400 and the inlet 201a of the membrane separation device 1000. For example, a pump 501 for controlling the flow rate of the aqueous solution S is located in the aqueous solution supply path 71.

[0178] The impermeable fluid discharge path 72 is a path for discharging the impermeable fluid S2 from the membrane separator 1000 during operation, and is connected to the outlet 201b of the membrane separator 1000. For example, a pump 502 for controlling the flow rate of the impermeable fluid S2 is located in the impermeable fluid discharge path 72. However, the pump 502 is not required to be located in the impermeable fluid discharge path 72. The impermeable fluid discharge path 72 is connected to the inlet 402 of the storage unit 400 and may be configured to send the impermeable fluid S2 to the storage unit 400 during operation. That is, during operation, the impermeable fluid S2 may be mixed with the aqueous solution S in the storage unit 400 and circulate through the aqueous solution supply path 71 and the impermeable fluid discharge path 72. When the impermeable fluid S2 is sent to the storage unit 400, the aqueous solution S and the impermeable fluid S2 are mixed in the storage unit 400, and the content of organic compound C in the aqueous solution S decreases. If the storage unit 400 is a fermentation tank, the decrease in the content of organic compound C in the aqueous solution S can suppress the cessation of fermentation by microorganisms, thereby enabling the continuous production of fermented products.

[0179] The permeate fluid discharge path 73 is a path for discharging the permeate fluid S1 from the membrane separator 1000 during operation and is connected to the outlet 202a of the membrane separator 1000. For example, a pressure reducing device 505 is located in the permeate fluid discharge path 73. The pressure reducing device 505 can reduce the pressure inside the permeate space of the membrane separator 1000. The pressure reducing device 505 is preferably a vacuum device such as a vacuum pump. The vacuum pump is typically a gas transport type vacuum pump, and examples include reciprocating vacuum pumps and rotary vacuum pumps. Examples of reciprocating vacuum pumps include diaphragm type and oscillating piston type vacuum pumps. Examples of rotary vacuum pumps include liquid-sealed pumps; oil rotary pumps (rotary pumps); mechanical booster pumps; and various dry pumps such as Roots type, claw type, screw type, turbo type, and scroll type. The pump as the pressure reducing device 505 may be equipped with a variable speed mechanism for changing the rotational speed, etc. An example of a variable speed mechanism is an inverter that drives the motor of the pump. By controlling the pump's rotation speed and other parameters using a variable speed mechanism, the pressure in the permeate space of the membrane separation device 1000 can be appropriately adjusted.

[0180] Although not shown in the diagram, a heat exchanger for cooling the permeate fluid S1 may be further arranged in the permeate fluid discharge path 73. The heat exchanger can condense the gaseous permeate fluid S1. The heat exchanger is, for example, a gas-liquid heat exchanger that generates heat exchange between a cooling medium such as antifreeze and the gaseous permeate fluid S1. The heat exchanger may be located between the membrane separation device 1000 and the depressurization device 505 (upstream of the depressurization device 505), or between the depressurization device 505 and the recovery unit 600, which will be described later (downstream of the depressurization device 505).

[0181] The membrane separation system 2000 further comprises a recovery unit 600. The recovery unit 600 can recover the permeate fluid S1 sent from the membrane separation device 1000 and, for example, store the permeate fluid S1. The recovery unit 600 is, for example, a tank for storing the permeate fluid S1. A permeate fluid discharge path 73 is connected to the inlet 601 of the recovery unit 600.

[0182] The membrane separation system 2000 may further include a controller 700 that controls each component of the membrane separation system 2000. The controller 700 is, for example, a DSP (Digital Signal Processor) that includes an A / D conversion circuit, input / output circuits, arithmetic circuits, a memory device, etc. The controller 700 stores a program for properly operating the membrane separation system 2000.

[0183] Each of the pathways in the membrane separation system 2000 consists of, for example, metal or resin piping, unless otherwise specified.

[0184] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0185] <Preparation of Permeable Vapor-Removing Film> (Example 1) ZIF-71 (average particle size: 2 μm, average pore size: 0.42 nm) was used as the porous particle. 1.3 parts by weight of ZIF-71 was added to 14 parts by weight of diluent (toluene), and the mixture was ultrasonically stirred at 25°C for 5 minutes to disperse the ZIF-71 particles in the diluent and obtain the first dispersion. Then, 10 parts by weight of silicone main agent (YSR3022, manufactured by Momentive Performance Materials) was added to the first dispersion, stirred with a stirrer for 5 minutes, and then ultrasonically stirred at 25°C for 60 minutes to obtain the second dispersion. Then, 0.3 parts by weight of curing agent (YC6831, manufactured by Momentive Performance Materials) was added to the second dispersion. The coating solution was prepared in this manner. A coating film (wet thickness: 100 μm) was obtained by applying the coating solution onto a porous support. As the porous support, a laminate of a PTFE microporous layer and a PET nonwoven fabric (thickness: 170 μm, average pore size: 44 nm) was used. The coated film was formed on the RS50 PTFE microporous layer.

[0186] Next, the coated film was heated at 90°C for 30 minutes to cure it. This resulted in a separation functional layer with a thickness of 25 μm. In this manner, the permeable vaporization film of Example 1 was prepared.

[0187] (Example 2) Except for changing the amount of ZIF-71 added to 2.2 parts by weight, a permeable vaporization film of Example 2 with a thickness of 25 μm was prepared in the same manner as in Example 1.

[0188] (Example 3) Except for changing the amount of ZIF-71 added to 1.8 parts by weight, a permeable vaporization film of Example 3 with a thickness of 25 μm was prepared in the same manner as in Example 1.

[0189] (Example 4) Except for changing the amount of ZIF-71 added to 0.9 parts by weight, a permeable vaporization film of Example 4 with a thickness of 25 μm was prepared in the same manner as in Example 1.

[0190] (Comparative Example 1) A permeable vaporization membrane of Comparative Example 1 with a thickness of 25 μm was prepared in the same manner as in Example 1, except that ZIF-67 (average particle size: 0.5 μm, average pore size: 0.34 nm) was used instead of ZIF-71.

[0191] (Comparative Example 2) A permeable vaporization membrane of Comparative Example 2 with a thickness of 25 μm was prepared in the same manner as in Example 1, except that UiO-66 (average particle size: 0.5 μm, average pore size: 0.6 nm) was used instead of ZIF-71.

[0192] (Comparative Example 3) A permeable vaporization membrane of Comparative Example 3 with a thickness of 25 μm was prepared in the same manner as in Example 4, except that ZIF-6 (MAF-6) (average particle size: 1 μm, average pore size: 0.68 nm) was used instead of ZIF-71.

[0193] (Comparative Example 4) A permeable vaporization membrane with a thickness of 25 μm was prepared in the same manner as in Example 1, except that porous particles were not added to the coating solution. In other words, the separation functional layer of Comparative Example 4 did not contain porous particles.

[0194] (Example 5) High silica zeolite (Hisiv3000, manufactured by Resonaq Universal Co., Ltd.) was used as the porous particles. 21 parts by weight of diluent (toluene) was diluted with 10 parts by weight of silicone main agent (addition crosslinked silicone KS-847T, manufactured by Shin-Etsu Chemical Co., Ltd.), then 3.0 parts by weight of high silica zeolite was added, and the mixture was stirred for 5 minutes using a rotation / revolution mixer (Awatori Rentaro, manufactured by Shin-Kee Co., Ltd.) to obtain a dispersion. Then, 0.1 parts by weight of curing agent (CAT-PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the dispersion, and the mixture was stirred for 1 minute using a rotation / revolution mixer. The coating solution was prepared in this way. A coating film (wet thickness: 100 μm) was obtained by applying the coating solution onto a porous support. A polysulfone porous support (thickness: 130 μm, average pore size: 9 nm) was used as the porous support.

[0195] Next, the coated film was heated at 90°C for 30 minutes to cure it. This resulted in a separation functional layer with a thickness of 25 μm. In this manner, the permeable vaporization film of Example 5 was prepared.

[0196] (Comparative Example 5) A permeable vaporization film of Comparative Example 5 with a thickness of 25 μm was prepared in the same manner as in Example 5, except that porous particles were not added to the coating solution. In other words, the separation functional layer of Comparative Example 5 did not contain porous particles.

[0197] Table 1 shows the composition of the coating solution for the permeable vaporization film in Examples 1-4, Comparative Examples 1-4, Example 5, and Comparative Example 5.

[0198]

[0199] For the permeable vaporization membranes of Examples 1-4, Comparative Examples 1-4, Example 5, and Comparative Example 5, the thickness T of the separation functional layer and the average particle size D of the porous particles were determined using the method described above. From the thickness T of the separation functional layer and the average particle size D of the porous particles, the ratio R1 of the average particle size D to the thickness T was calculated. In addition, the content CR of porous particles in the separation functional layer was determined using the method described above. The results are shown in Table 2. A field emission scanning electron microscope (SU-8220, Hitachi High-Tech Corporation) was used to measure the average particle size D of the porous particles, etc.

[0200] For the porous particles used in the permeable vaporization membranes of Examples 1-4 and Comparative Examples 1-4, Example 5 and Comparative Example 5, the amount of water adsorbed by the porous particles Q1 and the amount of ethanol adsorbed by the porous particles Q2 were determined using the method described above. From the amount of water adsorbed by the porous particles Q1 and the amount of ethanol adsorbed by the porous particles Q2, the ratio of the adsorbed amount Q2 to the adsorbed amount Q1, R2 (Q2 / Q1), was determined. The results are shown in Table 2.

[0201]

[0202] <PV Performance> (Separation performance of EtOH) For the permeable vaporization membranes of Examples 1-4 and Comparative Examples 1-4, Example 5 and Comparative Example 5, the separation coefficient α of ethanol (EtOH) relative to water was determined by the following method. EtOH The following measurements were taken. First, a permeable vaporization membrane was cut to a size of 74 mm in diameter to form a flat membrane test piece. This test piece was set in a batch-type membrane separation device (cell). A mixed liquid consisting of EtOH and water was supplied to the supply space of this cell. The EtOH content in the mixed liquid was 5.0 wt%.

[0203] Next, the cell was immersed in a water bath to adjust the temperature of the mixed liquid to 40°C. Then, using a stirring bar placed inside the cell, the pressure in the permeation space was reduced to 1.5 kPa while stirring the mixed liquid. As a result, the mixed liquid permeated through the permeation vaporization membrane, and a gaseous permeate was obtained. The gaseous permeate was cooled and condensed using a cooling trap utilizing liquid nitrogen. The composition of the liquid permeate was analyzed using gas chromatography, and based on the results obtained, the separation coefficient α was determined. EtOH , and the flux of EtOH permeating the permeable vapor membrane [kg / m 2 The value of [ / hr] was calculated. The results are shown in Table 3.

[0204]

[0205] The permeable vaporization membranes of Examples 1 to 4 exhibited a superior separation coefficient α compared to the permeable vaporization membranes of Comparative Examples 1 to 4. EtOH It possessed and exhibited a permeation flow rate that posed no practical problems. The permeation vaporization membrane of Example 5 had a superior separation coefficient α compared to the permeation vaporization membrane of Comparative Example 5. EtOH The membranes exhibited the characteristics of [specific characteristic] and showed a permeation flow rate that posed no practical problems. Based on these results, the permeation vaporization membranes of Examples 1 to 5 are considered suitable for improving separation performance.

[0206] The permeable vaporization membrane of this embodiment is suitable, for example, for separating volatile organic compounds from an aqueous solution containing such compounds.

Claims

1. A permeable vaporization membrane comprising a separation functional layer containing porous particles, wherein the ratio of the average particle size (μm) of the porous particles to the thickness (μm) of the separation functional layer is 0.03 or more and less than 1.

0.

2. The permeable vaporization membrane according to claim 1, wherein the porous particles have an average pore diameter of 0.35 nm or more.

3. The permeable vaporization membrane according to claim 1, wherein the content of the porous particles in the separation functional layer is 20 to 70 wt%.

4. The permeable vaporization membrane according to claim 1, wherein the separation functional layer has a thickness of 1 μm or more and 30 μm or less.

5. Amount of water adsorbed by the porous particles under 25°C and 3.2 kPa of water vapor (cm³) 3 The amount of ethanol adsorbed by the porous particles (cm³) at 25°C and 7.4 kPa in an ethanol atmosphere relative to the amount per g 3 The permeable vapor membrane according to claim 1, wherein the ratio of ( / g) is 10 or more.

6. The permeable vaporization membrane according to claim 1, wherein the porous particles have an average particle size of more than 1 μm.

7. The permeable vaporization membrane according to claim 1, wherein the porous particles include at least one selected from the group consisting of metal-organic structures, silica, and zeolites.

8. The permeable vaporization membrane according to claim 7, wherein the metal-organic structure comprises a metal ion as a core and an organic ligand coordinated to the core.

9. The metal ion is Zn 2+ The permeable vaporization membrane according to claim 8, comprising, wherein the organic ligand comprises an imidazole ring.

10. The permeable vaporization membrane according to claim 1, wherein the separation functional layer further comprises a matrix, and the porous particles are dispersed in the matrix.

11. The permeable vaporization membrane according to claim 10, wherein the matrix comprises a silicone resin.

12. The permeable vaporization membrane according to claim 1, further comprising a porous support for supporting the separation functional layer.

13. The permeable vaporization membrane according to claim 12, wherein the porous support comprises an organic material.

14. The permeable vaporization membrane according to claim 1, used for separating an organic compound from an aqueous solution containing a volatile organic compound.

15. The permeable vaporization membrane according to claim 14, wherein the organic compound is an alcohol.

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