JP6069944B2 - Gas separation membrane module - Google Patents

Description

  The present invention relates to a gas separation membrane module that performs gas separation using a hollow fiber membrane, and more particularly to a gas separation membrane module that can suppress deformation such as swelling and shrinkage of a tube plate in gas separation.

  Conventionally, as a separation membrane module for performing gas separation (for example, oxygen separation, nitrogen separation, hydrogen separation, water vapor separation, carbon dioxide separation, organic vapor separation, etc.) using a separation membrane having selective permeability, plates and frames are used. Type, tubular type, and hollow fiber membrane type. Among them, the hollow fiber membrane type gas separation membrane module not only has the advantage that the membrane area per unit volume is the largest, but also has excellent pressure resistance and self-supporting properties. It is advantageous and widely used.

  A hollow fiber membrane type gas separation membrane module generally includes a hollow fiber bundle composed of a plurality of hollow fiber membranes having selective permeability and a cylindrical container for accommodating the hollow fiber bundle, and one end or both ends of the hollow fiber bundle are It is the structure fixed by the resin-made hardening board (tube board).

  In Patent Document 1, for organic vapor separation using a gas separation membrane module, an aqueous solution containing an organic compound is heated and vaporized to produce an organic vapor mixture containing vapor of the organic compound (organic vapor) and water vapor, A method is described in which a high purity organic compound is obtained by passing the organic vapor mixture through a separation membrane at a temperature of, for example, 70 ° C. or higher and selectively permeating and separating water vapor.

JP-A 63-267415

  By the way, when performing organic vapor separation as described above, since the deformation such as swelling and shrinkage of the tube sheet is large, the gas-tightness of the gas separation membrane module is impaired, and there is a possibility that good gas separation cannot be continued. is there. The above-mentioned problems are not limited to organic vapor separation, but can also occur in other gas separations that can cause deformation of the tube sheet. For example, even when the tube plate adsorbs hydrocarbon, carbon dioxide, water, or the like, the tube plate may be plasticized or swelled to cause deformation.

  This invention is made | formed in view of the said subject, The objective is to provide the gas separation membrane module which can suppress deformation | transformation, such as swelling and shrinkage | contraction of the tube sheet in gas separation.

In order to achieve the above object, a gas separation membrane module according to an embodiment of the present invention is as follows:
1. A hollow fiber bundle in which a plurality of hollow fiber membranes having selective permeability are converged;
A module container in which the hollow fiber bundle is disposed;
A gas separation membrane module comprising a tube plate for fixing the plurality of hollow fiber membranes at an end of the hollow fiber bundle,
The cross section of the tube sheet includes a hollow fiber membrane embedded portion in which the hollow fiber membrane is embedded, and a solid portion that is located outside the hollow fiber membrane embedded portion and in which the hollow fiber membrane does not exist,
A gas separation membrane module, wherein a reinforcing fiber cloth is wound around at least a part of the plurality of hollow fiber membranes at least in the hollow fiber membrane embedded portion.

2. 1. The reinforcing fiber cloth is an inorganic fiber woven cloth. A gas separation membrane module according to claim 1.

3. 2. The reinforcing fiber cloth is a glass cloth, A gas separation membrane module according to claim 1.

4). The above-mentioned 1-3. Characterized in that the reinforcing fiber cloth is arranged in a spiral shape. The gas separation membrane module according to any one of the above.

5. The above-mentioned 1-3. Characterized in that the reinforcing fiber cloth is arranged in a circle. The gas separation membrane module according to any one of the above.

6). Having one tube sheet at each end of the hollow fiber bundle,
In each tube sheet, a reinforcing fiber cloth is wound around at least a part of the plurality of hollow fiber membranes. The gas separation membrane module according to any one of the above.

7). The above 1-6, wherein the hollow fiber membrane is a gas separation membrane for organic vapor separation. The gas separation membrane module according to any one of the above.

8). A hollow member for supplying a purge gas into the module, further comprising a core tube disposed substantially at the center of the hollow fiber bundle. The gas separation membrane module according to any one of the above.

  ADVANTAGE OF THE INVENTION According to this invention, the gas separation membrane module which can suppress deformation | transformation, such as swelling and shrinkage | contraction of a tube sheet in gas separation, can be provided.

It is sectional drawing which shows typically the structure of the gas separation membrane module of one form of this invention. It is sectional drawing which shows the example of arrangement | positioning of the reinforcing fiber cloth in a tube sheet, (a) shows the reinforcing fiber cloth wound spirally, (b) shows the reinforcing fiber cloth wound circularly. . It is sectional drawing which shows typically the cross section which cut | disconnected the tube sheet in the thickness direction. It is sectional drawing which shows the other example of arrangement | positioning of the reinforcing fiber cloth in a tube sheet. It is sectional drawing which shows the other example of arrangement | positioning of the reinforcing fiber cloth in a tube sheet. It is sectional drawing which illustrates some of the winding methods of a reinforcing fiber cloth. It is sectional drawing which shows the other example of the reinforcing fiber cloth wound by spiral shape.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following, a module of a type in which purge gas is flowed will be described, but the present invention is not limited to this. In the following, an example of performing organic vapor separation will be mainly described. However, the present invention is naturally not limited to this and can be applied to a gas separation membrane module for performing other gas separation.

[Configuration of gas separation membrane module]
A gas separation membrane module (hereinafter also simply referred to as a module) 100 shown in FIG. 1 includes a hollow fiber bundle 115 in which a plurality of hollow fiber membranes 114 are converged, a module container 110 that accommodates the bundle, and both ends of the hollow fiber bundle 115. Tube plates 120-1 and 120-2 (hereinafter, simply referred to as tube plate 120 without being distinguished from each other). As an example, the gas separation membrane module 100 is of a so-called bore feed type in which a mixed gas is supplied to the inside of the hollow fiber membrane 114.

  As the hollow fiber membrane 114, a conventionally known membrane having selective permeability can be used. The structure of the hollow fiber membrane may be homogeneous or non-homogeneous such as a composite membrane or an asymmetric membrane. In gas separation applications, for example, an asymmetric membrane made of aromatic polyimide is suitable because of its excellent selectivity and gas permeation rate. A film having a thickness of 20 to 200 μm and an outer diameter of 50 to 1000 μm can be suitably used. As an example of the material of the hollow fiber membrane 114, a polymer material, particularly polyimide, polysulfone, polyetherimide, polyphenylene oxide, polycarbonate, or the like can be used.

  In this specification, “organic vapor separation” means that a vapor mixture (organic vapor mixture) obtained by heating a liquid mixture containing an organic compound that is liquid at room temperature is introduced into a gas separation membrane module, and the organic vapor mixture is hollow. While circulating in contact with the yarn membrane, the permeated vapor that has permeated through the hollow fiber membrane and the non-permeated vapor that has not permeated through the hollow fiber membrane are separated. It means a method of collecting from the permeate gas outlet. Since the hollow fiber membrane has a selective permeability, the permeate vapor is rich in components that have a high rate of permeation through the hollow fiber membrane (hereinafter sometimes referred to as a high permeation component), and the non-permeate vapor has a low high permeation component. Become. As a result, the organic vapor mixture is separated into a permeate vapor rich in a high permeation component and a non-permeate vapor with a low high permeation component.

  Examples of organic vapor separation include an example of dehydrating ethanol containing water using a polyimide hollow fiber membrane. The rate of permeation through the polyimide hollow fiber membrane is higher because water vapor is a higher permeation component, and is separated and recovered into permeate vapor mainly composed of water vapor and non-permeate vapor mainly composed of ethanol vapor. The As a result, dehydrated ethanol is obtained.

  The hollow fiber bundle 115 may be a bundle of about 100 to 1,000,000 hollow fiber membranes 114, for example. Although there is no restriction | limiting in particular in the shape of the bundled hollow fiber bundle 115, A cylindrical shape is preferable as an example from a viewpoint of the ease of manufacture and the pressure resistance of a module container. Although FIG. 1 illustrates a form in which the hollow fiber membranes are arranged substantially in parallel, a form in which the hollow fiber membranes are arranged in a crossing manner may be used.

  A film member 131 that regulates the flow of the purge gas is wound around the hollow fiber bundle 115 so that the purge gas (detailed below) is counterflowed with respect to the supply direction of the mixed gas. The film member 131 is a gas impermeable material. In the vicinity of the permeate gas outlet 110c, the film member 131 is not wound around the hollow fiber bundle 115, and the hollow fiber membrane 114 is exposed.

  The module container 110 has a substantially cylindrical shape as a whole. In this example, a mixed gas inlet 110a is formed on one end face, and a purge gas inlet 110d for introducing a purge gas is formed on the opposite end face. . In the present specification, the “cylindrical shape” is not limited to a cylindrical shape, and includes a hollow member whose cross-sectional shape is rectangular, polygonal, elliptical or the like. The module container 110 may be composed of, for example, one cylindrical member and cap members attached to both ends thereof.

  The interior of the module container 110 is partitioned by two tube plates 120-1 and 120-2, and three spaces 111, 112, and 113 are formed. The space 111 is formed on the upstream side of the tube plate 120-1, and the mixed gas flows through the mixed gas inlet 110a. The space 112 is formed between the tube plates 120-1 and 120-2, and a permeated gas or the like that has passed through the hollow fiber membrane 114 flows therethrough. The space 113 is formed on the downstream side of the tube plate 120-2, and a non-permeating gas flows there.

  In order to send the permeated gas released into the space 112 to the outside, a permeate gas outlet 110 c is provided on the peripheral wall portion of the module container 110. Further, a non-permeate gas outlet 110 b is provided on the peripheral wall portion of the module container 110 in order to send out the non-permeate gas supplied into the space 113 to the outside.

  A core tube 171 is passed through the center of the hollow fiber bundle 115. The core tube 171 is a member in which one of both ends is closed and the other is opened, and the opening is arranged in a direction that becomes the downstream side (tube plate 120-2 side). The core tube 171 extends through the tube plate 120-2, and the tip portion is embedded in the upstream tube plate 120-1. The core tube 171 has a hole 171a at a position between the two tube plates 120-1 and 120-2. The purge gas supplied from the opening (purge gas inlet 110d) of the core tube 171 is sent into the space 112 through the hole 171a, and the discharge of the permeated gas is promoted by this purge gas.

  As the material of the tube plate 120, conventionally known materials can be used. Examples thereof include thermoplastic resins such as polyethylene and polypropylene, or thermosetting resins made of epoxy resin and urethane resin. The tube sheet 120 basically plays a role of fixing (adhering) the plurality of hollow fiber membranes 114. Moreover, the outer peripheral surface of the tube sheet 120 may be bonded to the inner peripheral surface of the module container.

  2A and 2B, the tube sheet 120 includes a hollow fiber membrane embedded portion 120A in which the hollow fiber membrane 114 is present and a solid portion 120B in which the hollow fiber membrane 114 is not present on the outer side. And have. The hollow fiber buried portion 120A has a structure in which a resin is buried between the hollow fiber membranes 114, and the solid portion 120B basically has a structure composed only of a resin.

  As shown in FIGS. 2A and 2B, in this embodiment, the reinforcing fiber cloth 125 is disposed at least in the hollow fiber embedded portion 120 </ b> A of one or both of the tube plates 120. The reinforcing fiber cloth 125 may be wound in a spiral shape as shown in FIG. 2 (a), or may be wound so as to have a ring-shaped cross section as shown in FIG. 2 (b). A form in which the reinforcing fiber cloth 125 of FIG. 2A is wound longer and extends to the solid portion 125B is also preferable.

  In FIG. 2, the reinforcing fiber cloth 125 is drawn with a smooth curve. However, the present invention is not limited to this, and the reinforcing fiber cloth 125 has a fine corrugation (a shape uneven in the radial direction) and spirals as a whole. It may be wound in the shape or circle. As shown in FIG. 2B, when the reinforcing fiber cloths 125 are arranged in a circular shape, a plurality of reinforcing fiber cloths 125 may be arranged in a substantially concentric shape. Although the core material 171 is not shown in FIG. 2A, the reinforcing fiber cloth 125 may be wound in a spiral shape starting from the core material 171 or its vicinity.

  Other arrangement modes of the reinforcing fiber cloth 125 will be described later with reference to another drawing.

  Examples of the material of the reinforcing fiber cloth 125 include glass fiber cloth such as glass cloth, metal fiber cloth such as metal mesh screen, carbon fiber, alumina fiber, aramid fiber, boron fiber, and zylon fiber. Those having a low coefficient of thermal expansion are preferred. Examples of the type of reinforcing fiber cloth 125 include fiber cloths such as woven cloth and non-woven cloth.

  The thickness of the reinforcing fiber cloth 125 varies depending on the type of yarn used, the weaving density, and the degree of opening, but can range from 10 μm to 2000 μm, for example. When the thickness of the reinforcing fiber cloth 125 is thinner than 10 μm, there is a concern that a sufficient reinforcing effect cannot be obtained. Moreover, when the thickness of the reinforcing fiber cloth 125 is thicker than 2000 μm, the area of the reinforcing fiber cloth occupied in the cross-sectional area of the tube sheet 120 is increased, and there is a concern that the filling amount of the hollow fiber membrane is decreased.

The basis weight of the reinforcing fiber cloth 125 varies depending on the type of yarn to be used, the weaving density, and the degree of opening, but can range from 10 g / m ² to 1500 g / m ² , for example. Examples of the tensile strength of the reinforcing fiber cloth 125 include a range of 10 MPa or more. The preferable lower limit of the tensile elastic modulus of the reinforcing fiber cloth 125 is 1 GPa, the more preferable lower limit is 5 GPa, the preferable upper limit is 500 GPa, and the more preferable upper limit is 200 GPa. If the tensile elastic modulus is too low, there is a concern that a sufficient reinforcing effect cannot be obtained.

As an example of the reinforcing fiber cloth 125 in the present embodiment, glass cloth (manufactured by Tokyo Glass Instrument Co., Ltd., thickness 250 μm, basis weight 211 g / m ² , tensile strength 131 MPa, elastic modulus 6.3 GPa) can be mentioned.

The reinforcing fiber cloth 125 may be wound in a state impregnated with a thermosetting resin such as an epoxy resin. Width _{L 125} (the tubesheet dimensions in the thickness direction, see FIG. 3) of the reinforcing fabric 125 may be a same level as the thickness _{L 120} of the tube plate 120, or 50% of the thickness _{L 120} to 90% It is good also as a grade.

[How to use gas separation membrane module]
The gas separation membrane module 100 of the present embodiment configured as described above is used as follows. In addition, the usage method illustrated below does not limit this invention at all.

  Taking the case of organic vapor separation as an example, first, an organic vapor mixture containing organic vapor and water vapor is heated to a temperature of, for example, 70 ° C. or higher and supplied into the module space 111 from the mixed gas inlet 110a. The gas supply pressure at this time is, for example, 0.1 to 0.3 MPaG.

  The organic vapor mixture is then fed into each hollow fiber membrane 114, and a portion of the organic vapor mixture permeates out of the hollow fiber membrane 114 as it flows through it. The permeated gas that has permeated through the hollow fiber membrane 114 is discharged into the space 112, and is discharged to the outside through the permeated gas discharge port 110c by the purge gas supplied via the core tube 171. On the other hand, the non-permeating gas that has not permeated through the hollow fiber membrane 114 flows downstream through the hollow fiber membrane 114, is sent out of the membrane from the downstream opening end, and is supplied into the space 113. Then, the non-permeate gas is discharged to the outside through the non-permeate gas outlet 110b. Since the hollow fiber membrane 114 has selective permeability, the permeated gas that has permeated through the membrane is rich in water vapor, which is a highly permeable component, and the non-permeated gas discharged from the non-permeate gas outlet is high. The concentration of water vapor, which is a permeating component, is decreasing.

  Moreover, as carbon dioxide separation, the example which processes the natural gas of 4-8 MPaG and 40-70 degreeC using a polyimide hollow fiber membrane is mentioned, for example. The speed of the gas that permeates through the hollow fiber membrane made of polyimide is larger in carbon dioxide than hydrocarbons such as methane, so that the permeated gas enriched in carbon dioxide and the non-permeated gas enriched in hydrocarbons such as methane Separated and recovered.

[Example of manufacturing method]
The gas separation membrane module of the present embodiment can be manufactured basically using the same process as that of the prior art except for the process of winding the reinforcing fiber cloth.

  In order to wrap the reinforcing fiber cloth 125 in a spiral shape as shown in FIG. 2A, for example, the reinforcing fiber cloth 125 is continuously wound while the hollow fiber membrane 141 is arranged little by little around the core tube 171. The way to go is mentioned.

  In order to wrap the reinforcing fiber cloth 125 in a circular shape as shown in FIG. 2B, for example, the reinforcing fiber cloth 125 is wound around the core fiber in a state where a predetermined amount of the hollow fiber membrane 114 is focused around the core tube. A method is mentioned. When a plurality of reinforcing fiber cloths are formed concentrically, the above steps may be repeated. In the case of winding in a circular shape, the seam between the end portions of the reinforcing fiber cloth 125 may be bonded using an adhesive or the like. Alternatively, when the reinforcing fiber cloth 125 is impregnated with an epoxy resin or the like, the end portions may be temporarily fixed with an adhesive tape or the like, and the adhesive tape may be peeled off after the resin is cured. When winding in a circular shape, the ends of the reinforcing fiber cloth 125 may be sewn together with fibers equivalent to the reinforcing fiber cloth. Alternatively, fibers equivalent to the reinforcing fiber cloth may be wound on the reinforcing fiber cloth and tied.

  One of the conventional processes for forming the tube sheet 120 is a process of cutting off a part of the tube sheet and opening a hollow fiber membrane after the tube sheet is cured. In this process, the reinforcing fiber cloth 125 in the tube sheet is used. May be cut off together.

  According to the gas separation membrane module 100 of the present embodiment configured as described above, since the reinforcing fiber cloth 125 is wound inside the tube plate 120, the tube plate swells and contracts when performing organic vapor separation. Thus, the gas separation membrane module is not impaired in airtightness, and good gas separation can be performed.

  In a conventional gas separation membrane module without a reinforcing fiber cloth in the tube sheet, the tube sheet may swell and deform so as to be convex in the axial direction (thickness direction) when performing organic vapor separation.

  On the other hand, according to the configuration of the present embodiment, since the reinforcing fiber cloth 125 is wound in the tube plate 120, such deformation as swelling and shrinkage can be suppressed. As a result, according to the gas separation membrane module 100 of this embodiment, gas separation can be performed satisfactorily.

  In addition, the effect by winding the reinforcing fiber cloth as described above is not limited to the tube plate made of epoxy, but can be similarly achieved even with a tube plate made of other materials such as urethane. That is, in the present invention, the tube sheet is not necessarily limited to a specific material.

(Other embodiments)
The present invention is not limited to the above embodiment, and various modifications can be made.

  As shown in FIG. 4, the reinforcing fiber cloth 125 may be wound so as to form one circle in the hollow fiber embedded portion 120 </ b> A of the tube sheet 120. In this case, the reinforcing fiber cloth 125 may be wound only once around the plurality of hollow fiber membranes, or may be wound a plurality of times.

  As shown in FIG. 5A, the reinforcing fiber cloth 125 may be disposed in the solid portion 120B in addition to the hollow fiber embedded portion 120A. Further, as shown in FIGS. 5B and 5C, the reinforcing fiber cloth 125 may be disposed at the boundary portion between the hollow fiber embedded portion 120A and the solid portion 120B. The cross section of the reinforcing fiber cloth 125 may have a waveform as shown in FIG. 5C, and this waveform may be regular or irregular.

  In this specification, “the reinforcing fiber cloth is wound around at least a part of the plurality of hollow fiber membranes” does not necessarily mean that the reinforcing fiber cloth 125 is wound over 360 degrees or more in the circumferential direction. As illustrated in 6 (a) to (d), it may be one or a plurality of arc shapes or only a part of a spiral shape. In FIG. 6A, two arc-shaped reinforcing fiber cloths 125 are arranged in the tube sheet 120. In FIG. 6B, one arc-shaped reinforcing fiber cloth 125 is arranged. In FIG. 6C, two arc-shaped reinforcing fiber cloths 125 are arranged on each of a plurality of circles having different diameters. In FIG. 6D, a plurality of reinforcing fiber cloths 125 extending in a spiral shape from a predetermined position inside the tube plate to the outer peripheral surface of the tube plate are arranged along the circumferential direction.

  As shown in FIG. 7, the reinforcing fiber cloth 125 may be arranged so as to form only a part of the spiral shape. In FIG. 7, the reinforcing fiber cloth 125 is disposed only in the vicinity of the center portion in the tube sheet 120.

100 Gas separation membrane module 110 Module container 110a Mixed gas inlet 110b Non-permeate gas outlet 110c Permeate gas outlet 110d Purge gas inlet 114 Hollow fiber membrane 115 Hollow fiber bundle 111, 112, 113 Space 120-1, 120-2 (120) Tube sheet 120A Hollow fiber membrane embedded portion 120B Solid portion 125 Reinforcing fiber cloth

Claims (8)

A hollow fiber bundle in which a plurality of hollow fiber membranes having selective permeability are converged;
A module container in which the hollow fiber bundle is disposed;
A gas separation membrane module comprising a tube plate for fixing the plurality of hollow fiber membranes at an end of the hollow fiber bundle,
The cross section of the tube sheet includes a hollow fiber membrane embedded portion in which the hollow fiber membrane is embedded, and a solid portion that is located outside the hollow fiber membrane embedded portion and does not have the hollow fiber membrane, In the hollow fiber membrane embedded portion, a reinforcing fiber cloth is wound around at least a part of the plurality of hollow fiber membranes, the entire reinforcing fiber cloth is embedded in the tube plate, and the tube plate is arranged in the thickness direction. The length of the reinforcing fiber cloth in the cut section is 50% to 90% of the thickness of the tube sheet.   The gas separation membrane module according to claim 1, wherein the reinforcing fiber cloth is an inorganic fiber woven cloth.   The gas separation membrane module according to claim 2, wherein the reinforcing fiber cloth is a glass cloth.   The gas separation membrane module according to any one of claims 1 to 3, wherein the reinforcing fiber cloth is arranged in a spiral shape.   The gas separation membrane module according to any one of claims 1 to 3, wherein the reinforcing fiber cloth is arranged in a circular shape. Having one tube sheet at each end of the hollow fiber bundle,
The gas separation membrane module according to any one of claims 1 to 5, wherein a reinforcing fiber cloth is wound around at least a part of the plurality of hollow fiber membranes in each tube sheet.   The gas separation membrane module according to any one of claims 1 to 6, wherein the hollow fiber membrane is a gas separation membrane for organic vapor separation.   It is a hollow member for supplying purge gas in a module, Comprising: The core pipe arrange | positioned in the approximate center of the said hollow fiber bundle is further provided, The Claim 1 characterized by the above-mentioned. Gas separation membrane module.

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