Membrane separation device, membrane separation system, and method for operating membrane separation device

Abstract

Provided is a membrane separation device suitable for suppressing deterioration of the sanitary state inside the membrane separation device. The membrane separation device is provided with a spiral membrane element. The membrane element comprises a central tube having a through-hole, and a membrane leaf wound around the central tube, the membrane leaf having a pervaporation membrane for separating a fermentation broth containing a volatile organic compound into a permeable fluid and a non-permeable fluid. During operation of the membrane separation device, inflow of a non-permeable fluid into a space adjacent to the outer peripheral surface of the membrane element is prevented.

Description

Technical Field

[0001] The present invention relates to a membrane separation device, a membrane separation system and an operation method of the membrane separation device. Background Art

[0002] A method for producing volatile organic compounds (fermented products) such as alcohols by fermenting carbon sources such as glucose using microorganisms has been developed. The fermentation of the carbon source is carried out, for example, in an aqueous solution. In this method, if the content of the fermented product in the aqueous solution increases, the fermentation based on the microorganism is sometimes stopped. In order to continuously produce the fermented product based on the microorganism, it is necessary to separate the fermented product from the aqueous solution.

[0003] As an example of a method for separating volatile organic compounds from an aqueous solution containing the organic compounds, a pervaporation method (pervaporation method) using a separation membrane can be cited. The pervaporation method is suitable for separating volatile organic compounds from aqueous solutions containing various substances. Compared with the distillation method, the pervaporation method also tends to suppress energy consumption and carbon dioxide emissions. By combining a membrane separation device for performing the pervaporation method with a fermentation tank for producing fermented products, fermented products can be continuously produced. For example, Patent Document 1 discloses a membrane separation system that combines a membrane separation device and a fermentation tank.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2010-161987 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the above-mentioned pervaporation method, a membrane separation device having a spiral membrane element having a pervaporation membrane is sometimes used. As such a membrane separation device, for example, Fig.14 As shown in FIG. 1 , there is a membrane separation device having a spiral membrane element and a housing for accommodating the membrane element. Fig.14 In the membrane separation device 200 shown, the non-permeable fluid s2 can flow into the space adjacent to the outer peripheral surface 35s of the spiral membrane element 35, specifically, into the space 45 formed between the outer peripheral surface 35s and the inner peripheral surface 32s of the housing 32. If the non-permeable fluid s2 is retained in the space 45, the sanitary condition deteriorates, and therefore it is required to suppress the retention as much as possible.

[0009] Therefore, an object of the present invention is to provide a membrane separation device suitable for suppressing deterioration of the sanitary condition inside the membrane separation device.

[0010] Means for solving problems

[0011] The present invention provides a membrane separation device, which is a membrane separation device having a spiral membrane element, wherein:

[0012] The membrane element includes a central tube having a through hole, and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0013] During operation, the non-permeated fluid is prevented from flowing into the space adjacent to the outer peripheral surface of the membrane element.

[0014] In another aspect, the present invention provides a membrane separation device comprising a spiral membrane element, wherein:

[0015] The membrane element includes a central tube having a through hole, and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0016] The following conditions (1) or (2) are met.

[0017] (1) The space adjacent to the outer peripheral surface of the membrane element is sealed.

[0018] (2) The space adjacent to the outer peripheral surface of the membrane element constitutes a flow path for a fluid other than the non-permeated fluid.

[0019] In another aspect, the present invention provides a membrane separation system including the membrane separation apparatus of the present invention.

[0020] In still another aspect, the present invention provides a method for operating a membrane separation device, which is a method for operating a membrane separation device having a spiral membrane element, wherein:

[0021] The membrane element comprises a central tube having a through hole, and a membrane leaf having a pervaporation membrane and wound around the central tube.

[0022] The operation method comprises:

[0023] supplying a fermentation liquid containing volatile organic compounds to the membrane separation device;

[0024] Separating the fermentation broth into permeated fluid and non-permeated fluid by the pervaporation membrane;

[0025] The non-permeated fluid is discharged from the membrane separation device while preventing the non-permeated fluid from flowing into a space adjacent to the outer peripheral surface of the membrane element.

[0026] Effects of the Invention

[0027] According to the present invention, it is possible to provide a membrane separation apparatus suitable for suppressing deterioration of the sanitary condition inside the membrane separation apparatus. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] [ Figure 1 ] is a schematic cross-sectional view showing the membrane separation device according to embodiment 1.

[0029] [ Figure 2 ] is a perspective view schematically showing the development of the spiral membrane element provided in the membrane separation device of the present embodiment.

[0030] [ Figure 3 ]yes Figure 2 Schematic cross-sectional view of a spiral membrane element.

[0031] [ Figure 4 ] is a schematic cross-sectional view of the permeation vaporization membrane included in the membrane separation device of the present embodiment.

[0032] [ Figure 5 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 2.

[0033] [ Figure 6 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 3.

[0034] [ Figure 7 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 4.

[0035] [ Figure 8 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 5.

[0036] [ Fig. 9 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 6.

[0037] [ Fig.10 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 7.

[0038] [ Fig.11 ] is a schematic cross-sectional view showing a membrane separation device according to embodiment 8.

[0039] [ Fig.12 ] is a schematic diagram showing the structure of the membrane separation system of this embodiment.

[0040] [ Fig.13A ] is a schematic configuration diagram showing a modified example 1 of the membrane separation system of the present embodiment.

[0041] [ Fig. 13B ] is a schematic configuration diagram showing a second modification of the membrane separation system of the present embodiment.

[0042] [ Fig.14] is a schematic cross-sectional view showing a conventional membrane separation device having a spiral membrane element. DETAILED DESCRIPTION

[0043] A membrane separation device according to a first aspect of the present invention is a membrane separation device including a spiral membrane element, wherein:

[0044] The membrane element includes a central tube having a through hole and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0045] During operation, the non-permeated fluid is prevented from flowing into the space adjacent to the outer peripheral surface of the membrane element.

[0046] A membrane separation device according to a second aspect of the present invention is a membrane separation device including a spiral membrane element, wherein:

[0047] The membrane element includes a central tube having a through hole and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0048] The following conditions (1) or (2) are met.

[0049] (1) The space adjacent to the outer peripheral surface of the membrane element is sealed.

[0050] (2) The space adjacent to the outer peripheral surface of the membrane element constitutes a flow path for a fluid other than the non-permeated fluid.

[0051] In a third aspect of the present invention, for example, in the membrane separation device of the first or second aspect,

[0052] The outer peripheral surface of the membrane element is formed of a flow path material.

[0053] In a fourth aspect of the present invention, for example, the membrane separation apparatus according to any one of the first to third aspects further includes a sealing portion disposed around the membrane element.

[0054] In a fifth aspect of the present invention, for example, in the membrane separation device of the fourth aspect, the sealing portion has a through hole for allowing the fermentation liquid to flow into the space.

[0055] In a sixth aspect of the present invention, for example, in the membrane separation device of the fourth aspect,

[0056] The space is sealed by the two sealing parts.

[0057] In a seventh aspect of the present invention, for example, in the membrane separation device of the sixth aspect,

[0058] The sealing portion includes a molding compound.

[0059] In an eighth aspect of the present invention, for example, in the membrane separation device of the first or second aspect,

[0060] The space is sealed by filling the filler in the space.

[0061] In a ninth aspect of the present invention, for example, in the membrane separation device of the first or second aspect,

[0062] The above space is filled with a material having a thermal conductivity of 0.1 W / m·K or more.

[0063] In a tenth aspect of the present invention, for example, in the membrane separation device according to any one of the first to ninth aspects,

[0064] The membrane element is configured to be attachable to and detachable from the housing.

[0065] A membrane separation system according to an eleventh aspect of the present invention includes the membrane separation apparatus according to any one of the first to tenth aspects.

[0066] In a twelfth aspect of the present invention, for example, the membrane separation system according to the eleventh aspect further includes a tank for storing the fermentation liquid to be supplied to the membrane separation device.

[0067] In the 13th aspect of the present invention, for example, in the membrane separation system of the 11th or 12th aspect,

[0068] The membrane separation system comprises a plurality of the membrane separation devices.

[0069] The plurality of membrane separation devices are connected in series or in parallel with each other.

[0070] A method for operating a membrane separation device according to a fourteenth aspect of the present invention is a method for operating a membrane separation device having a spiral membrane element, wherein:

[0071] The membrane element comprises a central tube having a through hole, and a membrane leaf having a pervaporation membrane and wound around the central tube.

[0072] The above-mentioned operation method comprises:

[0073] supplying a fermentation liquid containing volatile organic compounds to the membrane separation device;

[0074] Separating the fermentation liquid into permeated fluid and non-permeated fluid by the pervaporation membrane; and

[0075] The non-permeated fluid is discharged from the membrane separation device while preventing the non-permeated fluid from flowing into a space adjacent to the outer peripheral surface of the membrane element.

[0076] A membrane separation device according to a fifteenth aspect of the present invention is a membrane separation device comprising a spiral membrane element and a housing for housing the membrane element, wherein:

[0077] The membrane element includes a central tube having a through hole and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0078] During operation, the non-permeated fluid does not flow into the space between the outer peripheral surface of the membrane element and the inner peripheral surface of the housing.

[0079] A membrane separation device according to a sixteenth aspect of the present invention is a membrane separation device comprising a spiral membrane element and a housing for housing the membrane element, wherein:

[0080] The membrane element includes a central tube having a through hole and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid.

[0081] The following conditions (1) or (2) are met.

[0082] (1) The space between the outer peripheral surface of the membrane element and the inner peripheral surface of the housing is sealed.

[0083] (2) The space between the outer peripheral surface of the membrane element and the inner peripheral surface of the housing constitutes a flow path of at least one selected from the group consisting of the fermentation liquid and an effluent generated by the fermentation liquid flowing out of the outer peripheral surface of the membrane element.

[0084] A method for operating a membrane separation device according to a seventeenth aspect of the present invention is a method for operating a membrane separation device comprising a spiral membrane element and a housing for housing the membrane element, wherein:

[0085] The membrane element comprises a central tube having a through hole, and a membrane leaf having a pervaporation membrane and wound around the central tube.

[0086] The above-mentioned operation method comprises:

[0087] supplying a fermentation liquid containing volatile organic compounds to the membrane separation device;

[0088] Separating the fermentation liquid into permeated fluid and non-permeated fluid by the pervaporation membrane; and

[0089] The non-permeated fluid is discharged from the membrane separation device in such a manner that the non-permeated fluid does not flow into a space between an outer peripheral surface of the membrane element and an inner peripheral surface of the housing.

[0090] Hereinafter, the present invention will be described in detail, but the following description is not intended to limit the present invention to specific embodiments.

[0091] <Embodiment of membrane separation device>

[0092] The membrane separation device of this embodiment is equipped with a spiral membrane element. The membrane element includes a central tube having a through hole and a membrane leaf wound around the central tube, and the membrane leaf has a pervaporation membrane that separates the fermentation liquid containing volatile organic compounds into a permeable fluid and a non-permeable fluid. The membrane separation device of this embodiment is a device that performs membrane separation on the fermentation liquid containing volatile organic compounds using the pervaporation membrane when it is in operation.

[0093] In the membrane separation device of this embodiment, during operation, the inflow of the non-permeated fluid into the space adjacent to the outer peripheral surface of the membrane element is blocked. According to another aspect, with respect to the membrane separation device of this embodiment, the following condition (1) or (2) is satisfied.

[0094] (1) The space adjacent to the outer peripheral surface of the membrane element is sealed.

[0095] (2) The space adjacent to the outer peripheral surface of the membrane element constitutes a flow path for a fluid other than the non-permeable fluid. The fluid other than the non-permeable fluid is at least one selected from the group consisting of a fermentation liquid, an effluent produced by the fermentation liquid flowing out of the outer peripheral surface of the membrane element, and a heat medium for heating the membrane element.

[0096] Below, use Figures 1 to 11 Embodiments 1 to 8 are described as preferred examples of the present embodiment. The same reference numerals are used for the common elements in Embodiments 1 to 8, and their descriptions are sometimes omitted. The descriptions of Embodiments 1 to 8 are applicable to each other as long as they are not technically contradictory. Moreover, Embodiments 1 to 8 can also be combined with each other as long as they are not technically contradictory.

[0097] [Implementation Method 1]

[0098] Figure 1 2 is a schematic cross-sectional view showing the membrane separation device 100 according to Embodiment 1. Figure 1 As shown, the membrane separation device 100 of Embodiment 1 includes a spiral membrane element 15 and a housing 12 for housing the membrane element 15. In the membrane separation device 100, the space 25 adjacent to the outer peripheral surface 15s of the membrane element 15 is a space formed between the outer peripheral surface 15s of the membrane element 15 and the inner peripheral surface 12s of the housing 12. In the membrane separation device 100 of Embodiment 1, the space 25 constitutes a flow path of the effluent S3 generated by the fermentation liquid S flowing out from the outer peripheral surface 15s of the membrane element 15.

[0099] Figure 2It is a developed perspective view schematically showing a membrane element 15 included in the membrane separation device of the present embodiment. Figure 3 yes Figure 2 Schematic cross-sectional view of a membrane element 15. The membrane element 15 includes a central tube 15 having a through hole 16h, and a membrane leaf 17a having a permeation vaporization membrane 11 for separating a fermentation liquid S into a permeated fluid S1 and a non-permeated fluid S2 and wound around the central tube 15.

[0100] like Figure 2 and Figure 3 As shown, the membrane element 15 includes a stacked body 17. The stacked body 17 is wound around the central tube 15 and arranged around the central tube 15. A supply space and a permeation space are formed inside the stacked body 17.

[0101] The fermentation liquid S is supplied to the inside of the membrane element 15 from one end face of the stack 17, and flows in the supply space in parallel with the length direction of the central tube 16. That is, the fermentation liquid S is a fluid supplied from the end face of the upstream side of the stack 17 provided to the membrane element 15. The fluid flowing out from the outer peripheral surface 15s of the membrane element 15 among the fluids flowing in the supply space in parallel with the length direction of the central tube 16 corresponds to the effluent liquid S3. In the membrane element 15, the fermentation liquid S is separated to generate a permeable fluid S1 and a non-permeable fluid S2. The permeable fluid S1 is guided to the outside through the central tube 16. The non-permeable fluid S2 is discharged from the other end face of the stack 17 to the outside of the membrane element 15. That is, the non-permeable fluid S2 is a fluid discharged from the end face of the downstream side of the stack 17 provided to the membrane element 15.

[0102] like Figure 3 As shown in FIG. 1 , the stack 17 has a plurality of membrane leaves 17a. Each membrane leaf 17a has a pervaporation membrane 11 and a permeation side flow path material 19. Figure 3 In the figure, the permeable side flow path material 19 is indicated by a dotted line. In detail, the membrane leaf 17a has two pervaporation membranes 11. The two pervaporation membranes 11 overlap each other and are sealed on three sides in a bag-like structure. The two pervaporation membranes 11 are sealed by, for example, an adhesive layer 11a containing an adhesive. The permeable side flow path material 19 is arranged between the two pervaporation membranes 11 so as to be located inside the bag-like structure. The permeable side flow path material 19 ensures a space (permeable space) between the two pervaporation membranes 11 as a flow path for the permeating fluid S1. In this way, the permeable side flow path material 19 is used in combination with the pervaporation membrane 11. The number of membrane leaves 17a is not particularly limited, and is, for example, 2 to 30.

[0103] The stacked body 17 further includes a supply side flow path material 18. Figure 3In the figure, the supply side flow path material 18 is indicated by a dotted line. The supply side flow path material 18 is located outside the bag-like structure and is stacked on the membrane leaf 17a. In detail, the stacked body 17 has a plurality of supply side flow path materials 18, and the plurality of supply side flow path materials 18 and the plurality of membrane leaves 17a are alternately stacked. The supply side flow path material 18 ensures a space (supply space) as a flow path for the fermentation liquid S between the membrane leaves 17a and the membrane leaves 17a.

[0104] like Figure 2 and Figure 3 As shown, the shape of the center tube 16 is typically cylindrical, particularly cylindrical. The center tube 16 is responsible for collecting the permeated fluid S1 that has permeated each pervaporation membrane 11 and guiding it to the outside of the membrane element 15. The center tube 16 is provided with a through hole 16h that connects the internal space of the center tube 16 with the external space. The through hole 16h is formed, for example, on the wall surface of the center tube 16. The number of through holes 16h is not particularly limited, and may be one, or may be two or more. It is also possible to provide a plurality of through holes 16h at a predetermined interval on the center tube 16 along the direction in which the center tube 16 extends. The number of rows of the plurality of through holes 16h provided along the direction in which the center tube 16 extends is not particularly limited, and may be one, or may be two or more. On the center tube 16, two rows of the plurality of through holes 16h may also be provided in a manner that is opposite to each other in a cross-sectional view. The outer diameter of the center tube 16 is, for example, 10 to 100 mm, preferably 12 to 50 mm.

[0105] Examples of the material of the central tube 16 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.

[0106] The membrane element 15 may further include a flow path material 19c. Figure 3 In the figure, the flow path material 19c is shown by a dotted line. The flow path material 19c is located between the central tube 16 and the stack 17, and is wound around the central tube 16 on the central tube 16 side of the stack 17. The flow path material 19c ensures a space as a flow path for the permeable fluid S1 between the stack 17 and the central tube 16. The flow path material 19c is connected to the open end of the membrane leaf 17a described above. Thus, the permeable side flow path material 19 of the membrane leaf 17a is connected to the flow path material 19c. The flow path material 19c is connected to the through hole 16h of the central tube 16. Thus, the permeable fluid S1 can pass through the through hole 16h and flow from the flow path material 19c into the interior of the central tube 16.

[0107] As the supply side flow path material 18, the permeation side flow path material 19 and the flow path material 19c, a net, a woven fabric or a knitted fabric made of a resin, for example, formed from polyethylene, polypropylene, polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polysulfone (PSU) or ethylene-chlorotrifluoroethylene copolymer (ECTFE) can be used.

[0108] like Figure 1 As shown, in the membrane separation device 100 of the first embodiment, the outer peripheral surface 15s of the membrane element 15 is composed of the flow path material 26. In other words, the membrane element 15 includes the flow path material 26 surrounding the stack 17. With such a configuration, Figure 1 As shown, the effluent S3 generated by the outflow of the fermentation liquid S from the outer peripheral surface 15s of the membrane element 15 flows into the space 25. The effluent S3 flowing into the space 25 flows along the space 25. That is, in the membrane separation device 100, the above-mentioned condition (2) is satisfied. More specifically, in the membrane separation device 100, the space 25 constitutes a flow path for the effluent S3. The effluent S3 flowing in the space 25 is discharged to the outside of the membrane separation device 100 together with the fermentation liquid S (non-permeable fluid S2) that has not permeated the permeation vaporization membrane 11 of the membrane element 15. Therefore, in the membrane separation device 100, the inflow of the non-permeable fluid S2 into the space 25 is blocked.

[0109] As the channel material 26, the materials listed as the feed-side channel material 18, the permeate-side channel material 19, the channel material 19c, and the channel material 26 can be used. The channel material 26 may be the same as the feed-side channel material 18.

[0110] The membrane separation device 100 of Embodiment 1 further includes a sealing portion 24 disposed around the membrane element 15. One end of the space 25 is sealed by the sealing portion 24. For example, as the sealing portion 24, a seal having a U-shaped cross section, an O-ring seal, or the like can be used.

[0111] In the membrane separation device 100 of Embodiment 1, the sealing portion 24 is disposed at one location. In other words, one end of the space 25 is sealed by one sealing portion 24. That is, in the membrane separation device 100, one sealing portion 24 is used as the sealing portion 24.

[0112] like Figure 1 As shown, the seal portion 24 is preferably disposed at the upstream end 15a of the membrane element 15. The seal portion 24 may be disposed slightly downstream of the upstream end 15a of the membrane element 15. Even with such a structure, the same effect can be expected.

[0113] In the membrane separation device 100 of the first embodiment, the sealing portion 24 has a ring shape and surrounds the membrane element 15 in the circumferential direction. Fig.11The sealing member 44 used in the conventional membrane separation apparatus 200 shown is the same.

[0114] In the present embodiment, the shape of the housing 12 is not particularly limited as long as it can accommodate the membrane element 15. The shape of the housing 12 may be, for example, a cylindrical shape or a square cylindrical shape. Figure 1 The case where the shape of the housing 12 is cylindrical is exemplified.

[0115] like Figure 1 As illustrated, in this embodiment, the shell 12 has a shell body 12a, a first end plate 12b and a second end plate 12c. The shell body 12a has a cylindrical shape and is made of a material having sufficient pressure resistance. The shell 12 can be a high-pressure container for a reverse osmosis membrane. The first end plate 12b is installed at the end 23a on the upstream side of the shell 12. The end 23a of the shell 12 is closed by the first end plate 12b. The second end plate 12c is installed at the end 23b on the downstream side of the shell 12. The end 23b of the shell 12 is closed by the second end plate 12c.

[0116] The housing 12 has a port 21a, a port 21b, and a port 22b. These ports are used to communicate the inside and the outside of the housing 12. The port 21a is provided at an end 23a on the upstream side of the housing 12. The ports 21b and the port 22b are provided at an end 23b on the downstream side of the housing 12.

[0117] like Figure 1 As shown, the port 21a may be provided on the first end plate 12b, and the port 22b may be provided on the second end plate 12c. The port 21b and the port 22b may be provided on the second end plate 12c.

[0118] The port 22b may be provided on the first end plate 12b. That is, the port 21a and the port 22b may be provided on the first end plate 12b.

[0119] like Figure 1 As shown in the example, in the present embodiment, an upstream space 25a is formed between the inner side surface 12bs of the first end plate 12b and the end surface 15as on the upstream side of the membrane element 15. A downstream space 25b is formed between the inner side surface 12cs of the second end plate 12c and the end surface 15bs on the downstream side of the membrane element 15. The space 25 is separated from the upstream space 25a by the sealing portion 24.

[0120] Although not shown in the figure, in the membrane separation device 100, an end part may be installed at one or both ends of the axial direction of the membrane element 15. The end part is also called an anti-telescoping part, an anti-telescoping material, etc. In this case, the sealing portion 24 seals one end of the space 25 via the end part 15a disposed at the upstream side of the membrane element 15. It should be noted that when an end part is installed at one or both ends of the axial direction of the membrane element 15, the outer peripheral surface 15s of the membrane element 15 refers to the outer peripheral surface including the end part.

[0121] In this embodiment, the membrane element 15 is disposed transversely in such a manner that the length direction is along the horizontal direction. In the case where the membrane element 15 is disposed transversely, the port 21b may also be located above the second end plate 12c. In this case, the port 21a may also be located below the first end plate 12b. The membrane element 15 may be disposed longitudinally in such a manner that the length direction is along the vertical direction, or may be disposed obliquely in such a manner that the length direction has an angle greater than 0° and less than 90° relative to the horizontal direction.

[0122] The fermentation liquid inlet 13a is an opening for supplying the fermentation liquid S to the membrane separation device 100. The permeated fluid outlet 14b is an opening for discharging the permeated fluid S1 from the membrane separation device 100. The non-permeated fluid outlet 13b is an opening for discharging the fermentation liquid S (non-permeated fluid S2) that has not passed through the permeation vaporization membrane 11 from the membrane separation device 100. The fermentation liquid inlet 13a is connected to the port 21a, and the port 21a is used as the inlet of the fermentation liquid S. The central tube 16 is connected to the port 22b at the permeated fluid outlet 14b. In other words, the port 22b is used as the outlet of the permeated fluid S1. The non-permeated fluid outlet 13b is connected to the port 21b, and the port 21b is used as the outlet of the non-permeated fluid S2. Each port may be a simple opening or may be a port such as Figure 1 The nozzle-shaped opening shown.

[0123] In this embodiment, the membrane element 15 may be detachably mounted on the housing 12. In other words, the membrane element 15 may be cassetted and replaced with respect to the housing 12. With such a configuration, the time required for replacement of the membrane element 15 can be shortened.

[0124] In the present embodiment, the diameter of the membrane element 15 may be 8 inches (about 201 mm) or less. A membrane separation apparatus including a membrane element 15 of such a size has excellent transportability.

[0125] The membrane separation device of the present embodiment can also separate the fermentation liquid S into the permeated fluid S1 and the non-permeated fluid S2 in a state where the supply space of the membrane element 15 is filled with the fermentation liquid S.

[0126] The membrane separation apparatus of this embodiment is suitable for a flow-through (continuous) membrane separation method. However, the membrane separation apparatus can also be used for a batch-type membrane separation method.

[0127] (Pervaporation membrane)

[0128] The pervaporation membrane 11 is a separation membrane that generates a permeated fluid S1 containing a gas of volatile organic compounds by pervaporation. In other words, the pervaporation membrane 11 is a membrane that preferentially permeates the organic compounds contained in the fermentation liquid S. Therefore, the content of organic compounds in the permeated fluid S1 is higher than the content of organic compounds in the fermentation liquid S. On the other hand, the content of organic compounds in the non-permeated fluid S2 is lower than the content of organic compounds in the fermentation liquid S.

[0129] Figure 4 1 is a schematic cross-sectional view of a pervaporation membrane 11 included in the membrane separation device of the present embodiment. Figure 4 As shown, the pervaporation membrane 11 includes, for example, a separation functional layer 1 and a porous support 2 supporting the separation functional layer 1. The pervaporation membrane 11 may further include a protective layer (not shown) for protecting the separation functional layer 1. The separation functional layer 1 is, for example, directly in contact with the porous support 2. For example, the main surface 11a of the pervaporation membrane 11 on the separation functional layer side is exposed to the supply space, and the main surface 11b on the porous support side is exposed to the permeation space.

[0130] (Separation Functional Layer)

[0131] The separation functional layer 1 is a layer that allows the organic compounds contained in the fermentation liquid S to preferentially pass through. The separation functional layer 1, for example, contains a hydrophobic material. In this specification, "hydrophobic material" refers to, for example, a material whose static contact angle of water exceeds 90° when a 10 μL water droplet (temperature 25° C.) is dropped on the surface of a test piece composed of the material. It should be noted that the static contact angle of water can be measured using a commercially available contact angle meter.

[0132] As a hydrophobic material, for example, compounds having a siloxane bond (Si-O-Si bond), olefin polymers, oils, fluorine compounds, etc. can be cited. The separation functional layer 1 preferably contains a compound having a siloxane bond as a hydrophobic material. The compound having a siloxane bond is typically an organosilicon polymer. The organosilicon polymer can be solid or liquid at 25°C. As a specific example of an organosilicon polymer, polydimethylsiloxane (PDMS) and the like can be cited. As a specific example of an olefin polymer, polyethylene, polypropylene, etc. can be cited. As an oil, for example, hydrocarbon oils such as liquid paraffin can be cited. As a fluorine compound, polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), etc. can be cited. The hydrophobic material can be used alone or in combination of two or more.

[0133] The separation functional layer 1 may contain a hydrophobic material as a main component, or may be substantially composed of only a hydrophobic material. The "main component" refers to the component that is contained in the largest amount by weight in the separation functional layer 1 .

[0134] The separation function layer 1 may include: a matrix including a hydrophobic material, and fillers dispersed in the matrix. The fillers are embedded in the matrix. In the matrix, all fillers may be separated from each other or partially aggregated.

[0135] The filler includes, for example, inorganic materials such as zeolite, silica, and bentonite. The zeolite contained in the filler is preferably a high-silicon zeolite having a high ratio of silica to alumina. High-silicon zeolite is suitable for separating aqueous solution S1 due to its excellent hydrolysis resistance. As high-silicon zeolite, HSZ (registered trademark) manufactured by Tosoh Corporation, HiSiv (registered trademark) manufactured by United Showa Corporation, USKY manufactured by United Showa Corporation, and Zeoal (registered trademark) manufactured by Nakamura Superhard Co., Ltd. can be used.

[0136] The filler may include a metal-organic framework (MOF). The metal-organic framework is also called a porous coordination polymer (PCP). The metal-organic framework is preferably hydrophobic. The metal-organic framework includes, for example, metal ions and organic ligands. Examples of metal ions include Zn ions. Organic ligands include, for example, aromatic rings. Examples of aromatic rings contained in organic ligands include imidazole rings. Examples of organic ligands include 2-methylimidazole. Specific examples of metal-organic frameworks include ZIF-8.

[0137] The shape of the filler is, for example, particulate. In this specification, "particulate" includes spherical, ellipsoidal, scaly and fibrous. The average particle size of the filler is not particularly limited, for example, it is less than 50 μm, preferably less than 20 μm, and more preferably less than 10 μm. The lower limit of the average particle size of the filler is, for example, 0.01 μm. The average particle size of the filler can be determined, for example, by the following method. First, observe the cross section of the separation functional layer 1 with a transmission electron microscope. In the obtained electron microscope image, the area of ​​a specific filler is calculated by image processing. The diameter of a circle having the same area as the calculated area is regarded as the particle size (diameter of the particle) of the specific filler. The particle sizes of any number (at least 50) of fillers are calculated separately, and the average value of the calculated values ​​is regarded as the average particle size of the filler.

[0138] The content of the filler in the separation functional layer 1 is, for example, 10 wt% or more, preferably 30 wt% or more, and more preferably 40 wt% or more. The upper limit of the content of the filler in the separation functional layer 1 is not particularly limited, and is, for example, 70 wt%. The content of the matrix in the separation functional layer 1 is not particularly limited, and is, for example, 30 wt% to 90 wt%.

[0139] The thickness of the separation functional layer 1 is, for example, 200 μm or less, preferably 100 μm or less, and more preferably 80 μm or less. The thickness of the separation functional layer 1 may be 1.0 μm or more, 10 μm or more, or 30 μm or more.

[0140] The separation functional layer 1 may have a microporous structure with an average pore diameter of less than 0.01 μm, or may be a dense layer with no pores on the surface.

[0141] (Porous Support)

[0142] Examples of the porous support 2 include: nonwoven fabrics; porous polytetrafluoroethylene; aromatic polyamide fibers; porous metals; sintered metals; porous ceramics; porous polyesters; porous nylons; activated carbon fibers; latex; silicone; silicone rubber; a permeable (porous) polymer comprising at least one selected from polyvinyl fluoride, polyvinylidene fluoride, polyurethane, polypropylene, polyethylene, polystyrene, polycarbonate, polysulfone, polyetheretherketone, polyacrylonitrile, polyimide, and polyphenylene ether; a metal foam having open or closed cells; a polymer foam having open or closed cells; silicon dioxide; porous glass; a mesh, and the like. The porous support 2 may be a combination of two or more of these.

[0143] The porous support 2 has an average pore size of, for example, 0.01 to 0.4 μm. The thickness of the porous support 2 is not particularly limited, and is, for example, 10 μm or more, preferably 50 μm or more, and more preferably 100 μm or more. The thickness of the porous support 2 is, for example, 300 μm or less, and preferably 200 μm or less.

[0144] (Protective layer)

[0145] The protective layer, for example, covers the surface of the separation functional layer 1. The material of the protective layer is not particularly limited, and for example, a silicone resin can be cited. The material of the protective layer can be the same as or different from the material of the matrix of the separation functional layer 1. The thickness of the protective layer is not particularly limited, and for example, it is 0.5 μm or more, preferably 1 μm or more, more preferably 5 μm or more, and further preferably 10 μm or more. The thickness of the protective layer is, for example, 100 μm or less, preferably 50 μm or less, and more preferably 30 μm or less.

[0146] (Method for manufacturing pervaporation membrane)

[0147] The pervaporation membrane 11 can be produced, for example, by forming a separation functional layer 1 on a porous support 2. In detail, first, a coating liquid containing a material for the separation functional layer 1 is prepared. The coating liquid may contain a filler and a dispersant for dispersing the filler in the coating liquid. For example, in the case where the coating liquid contains a compound having a siloxane bond, the coating liquid may further contain a catalyst for curing the compound. Next, a coating membrane is obtained by applying the coating liquid on the porous support 2. The separation functional layer 1 is formed by drying the coating membrane. In this way, the pervaporation membrane 11 is obtained.

[0148] <Embodiment of the method for operating the membrane separation device>

[0149] The operating method of the membrane separation device of this embodiment includes: supplying a fermentation liquid S containing volatile organic compounds to the membrane separation device; separating the fermentation liquid S into a permeable fluid S1 and a non-permeable fluid S2 through a permeation vaporization membrane 11; and discharging the non-permeable fluid S2 from the membrane separation device while preventing the non-permeable fluid S2 from flowing into a space 25 adjacent to an outer peripheral surface 15s of a membrane element 15.

[0150] The operating method of the membrane separation device of this embodiment is implemented, for example, as follows for the membrane separation device 100 of Embodiment 1. Figure 1As shown, first, the fermentation liquid S is supplied to the inside of the membrane separation device 100 through the port 21a (fermentation liquid inlet 13a). Then, the fermentation liquid S is supplied to the inside of the membrane element 15 through the upstream space 25a, and contacts one surface of the pervaporation membrane 11 while flowing through the supply space in parallel with the longitudinal direction of the central tube 16. In a state where the fermentation liquid S contacts one surface of the pervaporation membrane 11, the permeation space adjacent to the other surface of the pervaporation membrane 11 is depressurized. Specifically, the permeation space is depressurized through the permeation fluid outlet 14b. By depressurizing the permeation space, a permeation fluid S1 with a high content of organic compounds can be obtained on the other side of the pervaporation membrane 11. In other words, the permeation fluid S1 that permeates the pervaporation membrane 11 is supplied to the permeation space. The permeation fluid S1 moves to the inside of the central tube 16, and is discharged to the outside of the membrane separation device 100 through the port 22b (permeation fluid outlet 14b). The gas permeation fluid S1 is cooled, for example, in a condensation section. Thus, the permeated fluid S1 is liquefied to obtain a liquid permeated fluid S1. On the other hand, the fermented liquid S (non-permeated fluid S2) that has not passed through the permeation vaporization membrane 11 is discharged to the outside of the membrane element 15. Thereafter, the non-permeated fluid S2 is discharged to the outside of the membrane separation device 100 through the port 21b (non-permeated fluid outlet 13b). The non-permeated fluid S2 is typically a liquid. At this time, Figure 1 As shown, the effluent S3 generated by the outflow of the fermentation liquid S from the outer peripheral surface 15s of the membrane element 15 flows into the space 25. The effluent S3 flowing into the space 25 flows along the space 25. The effluent S3 flowing in the space 25 suppresses the non-permeable fluid S2 from flowing into the space 25 and staying inside the space 25. The effluent S3 flowing in the space 25 passes through the downstream side space 25b together with the non-permeable fluid S2 and passes through the port 21b (non-permeable fluid outlet 13b), thereby being discharged to the outside of the membrane separation device 100.

[0151] Fig.14 1 is a schematic cross-sectional view showing a membrane separation device 200 having a conventional spiral membrane element 35. In the conventional membrane separation device 200, the outer peripheral surface 35s of the membrane element 35 is formed by a shell (not shown) made of a material through which the aqueous solution s cannot pass, and one end of the space 45 is sealed by a sealing member 44 disposed in the space 45 between the membrane element 35 and the housing 32. The sealing member 44 has a ring shape and surrounds the membrane element 35 in the circumferential direction. The sealing member 44 is generally disposed on the downstream side ( Fig.14 left side).

[0152] for Fig.14The conventional membrane separation device 200 shown in FIG. 1 has the following problem: during operation, the non-permeated fluid s2 discharged from the downstream end surface of the membrane element 35 flows back to the space 45 and stays inside the space 45. If the non-permeated fluid s2 stays in the space 45, undesirable microorganisms may proliferate, thereby sometimes deteriorating the sanitary condition inside the membrane separation device 200. The deterioration of the sanitary condition inside the membrane separation device 200 is particularly problematic when a fermentation liquid containing volatile organic compounds is used as the aqueous solution s supplied to the membrane separation device 200.

[0153] In contrast, in the operating method of the membrane separation device of the present embodiment, the non-permeable fluid S2 is discharged from the membrane separation device in such a manner that the non-permeable fluid S2 does not flow into the space 25 adjacent to the outer peripheral surface 15s of the spiral membrane element 15. Figure 1 As shown, in the membrane separation device 100 of Embodiment 1, during operation, the effluent S3 flows into the space 25 and flows along the space 25. That is, the space 25 constitutes the flow path of the effluent S3. As a result, in the membrane separation device 100, the non-permeable fluid S2 is suppressed from flowing into the space 25 and staying inside the space 25. Therefore, the growth of undesirable microorganisms inside the membrane separation device 100 is suppressed, and thus the deterioration of the sanitary state inside the membrane separation device 100 is suppressed.

[0154] In addition, in the membrane separation device 100 of Embodiment 1, during operation, the effluent S3 flows in the space 25, thereby easily transferring heat from the outside of the housing 12 to the membrane element 15, so that the temperature of the membrane element 15 is not easily reduced. As a result, it is possible to suppress the temperature reduction of the membrane element 15 during operation and the performance reduction of the permeation vaporization membrane 11. The temperature of the effluent S3 is about the same as the temperature of the fermentation liquid S supplied to the supply space. As an example, the temperature of the fermentation liquid S supplied to the supply space is 15°C to 75°C.

[0155] The fermentation liquid S contains, for example, an organic compound as a fermentation product, and water. The organic compound contained in the fermentation liquid S is not particularly limited as long as it is volatile. In this specification, "volatile organic compound" refers to an organic compound having a boiling point of 20°C to 260°C, preferably 50°C to 260°C under atmospheric pressure (101.325 kPa). It should be noted that, when the concentration of the organic compound is high, for example, in an aqueous solution, an aqueous phase containing water as the main component and an organic phase having a higher content of the organic compound than the aqueous phase are generated.

[0156] The number of carbon atoms in the organic compound is not particularly limited, and may be, for example, 10 or less, 8 or less, 6 or less, or 4 or less. The lower limit of the number of carbon atoms in the organic compound may be 1 or 2. The organic compound may have, for example, a functional group containing an oxygen atom such as a hydroxyl group, a carbonyl group, an ether group, or an ester group. In the organic compound, the number of functional groups containing an oxygen atom is typically 1.

[0157] As organic compounds, for example, alcohols, ketones, esters, etc. can be cited. In the case where the organic compound is an alcohol, the organic compound is easily miscible with water, and the environment in the system is not easy to deviate. The alcohol can be an alkyl alcohol consisting only of an alkyl group and a hydroxyl group, or an aryl alcohol containing an aryl group and a hydroxyl group. The alkyl alcohol can be any of a straight chain, a branched chain, and a ring. Among organic compounds, as an alkyl alcohol, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol (BuOH), 2-butanol, isobutanol, tert-butanol, n-pentanol, etc. can be cited, preferably n-butanol. n-Butanol is a compound that generates two phases (aqueous phase and organic phase) in an aqueous solution when the content rate in the aqueous solution is about 8wt% or more. Therefore, in the case where the organic compound is n-butanol, for example, by adjusting the content rate of the organic compound in the permeated fluid to about 8wt% or more, an aqueous phase and an organic phase can be generated in the permeated fluid after liquefaction. In this case, by separating the aqueous phase and the organic phase, the permeated fluid can be easily purified. As aryl alcohols, for example, phenol can be cited.

[0158] The ketone may be a dialkyl ketone consisting only of an alkyl group and a carbonyl group. Examples of the dialkyl ketone include methyl ethyl ketone (MEK) and acetone among organic compounds.

[0159] The ester may be a fatty acid alkyl ester consisting only of an alkyl group and an ester group. Examples of the fatty acid alkyl ester include ethyl acetate and the like.

[0160] It should be noted that the organic compound is not limited to the above compounds and may be an aromatic hydrocarbon such as benzene, toluene, or xylene.

[0161] The fermentation liquid S may contain one organic compound or two or more organic compounds. The content of the organic compound in the fermentation liquid S is, for example, 50 wt% or less, or 30 wt% or less, 10 wt% or less, 5 wt% or less, 2 wt% or less, or even 1 wt% or less. The lower limit of the content of the organic compound is not particularly limited, and is, for example, 0.01 wt%.

[0162] In the present embodiment, the organic compound is a fermentation product produced by fermenting a carbon source by a microorganism. That is, in the present embodiment, the fermentation liquid S is a fermentation liquid containing the organic compound as the fermentation product.

[0163] The fermentation liquid S may also contain other components such as microorganisms involved in the production of the fermented product, carbon sources, nitrogen sources, inorganic ions, etc. in addition to water and organic compounds. The microorganisms involved in the production of the fermented product are typically bacteria. As carbon sources, polysaccharides such as starch and monosaccharides such as glucose can be cited.

[0164] The amount of the fermentation liquid S supplied to the membrane separation device of this embodiment is not particularly limited and is determined according to the processing capacity of the membrane separation device. The fermentation liquid S supplied to the supply space may be preheated. As described above, the temperature of the fermentation liquid S supplied to the supply space is 15°C to 75°C.

[0165] The decompression in the permeation space can be performed, for example, by a decompression device such as a vacuum pump. The pressure in the permeation space is, for example, 50 kPa or less, and may also be 20 kPa or less, 10 kPa or less, 5 kPa or less, 3 kPa or less, or even 2 kPa or less. It should be noted that, in this specification, "pressure" refers to absolute pressure unless otherwise specified.

[0166] As described above, the pervaporation membrane provided in the membrane separation device of this embodiment can preferentially permeate organic compounds contained in the fermentation liquid S. Therefore, the content of organic compounds in the permeated fluid S1 obtained by operating the membrane separation device is higher than that in the fermentation liquid S supplied to the membrane separation device.

[0167] After the membrane separation operation is performed for a certain period of time according to the above-mentioned membrane separation device operation method, the membrane separation device cleaning operation may be performed. The membrane separation device cleaning operation may also be performed regularly.

[0168] According to the operating method of the membrane separation device of the present embodiment, for example, a permeated fluid S1 having a high content of organic compounds can be produced. In other words, according to the operating method of the membrane separation device of the present embodiment, an organic compound can be produced in the form of the permeated fluid S1.

[0169] <Embodiment of the method for producing an organic compound>

[0170] The method for producing an organic compound of the present embodiment includes: supplying a fermentation liquid S to a membrane separation device; separating the fermentation liquid S into a permeated fluid S1 and a non-permeated fluid S2 through the permeation vaporization membrane 11 of the spiral membrane element 15; discharging the non-permeated fluid S2 from the membrane separation device while preventing the non-permeated fluid S2 from flowing into the space 25 adjacent to the outer peripheral surface 15s of the membrane element 15; and recovering the permeated fluid S1. In the method for producing an organic compound of the present embodiment, the content of the organic compound in the permeated fluid S1 is higher than the content of the organic compound in the fermentation liquid S.

[0171] In the method for producing an organic compound of the present embodiment, the organic compound may be an alcohol. According to the method for producing an organic compound of the present embodiment, the alcohol can be efficiently separated from the fermentation liquid S containing volatile alcohol.

[0172] [Implementation Method 2]

[0173] Figure 5 1 is a schematic cross-sectional view showing a membrane separation device 101 according to Embodiment 2. In the membrane separation device 101 according to Embodiment 2, the space 25 between the outer peripheral surface 15s of the membrane element 15 and the inner peripheral surface 12s of the housing 12 is sealed. That is, in the membrane separation device 101, the above-mentioned condition (1) is satisfied. Therefore, in the membrane separation device 101, the inflow of the non-permeable fluid S2 into the space 25 is blocked. Therefore, the situation where the non-permeable fluid S2 flows into the space 25 and stays inside the space 25 is suppressed. As a result, the proliferation of undesirable microorganisms inside the membrane separation device 101 is suppressed, and thus the deterioration of the sanitary state inside the membrane separation device 101 is suppressed.

[0174] It should be noted that, in this specification, “the space 25 is sealed” means that the space 25 is filled or the entrance and exit of the space 25 are blocked.

[0175] In the membrane separation device 101 of the second embodiment, the outer peripheral surface 15s of the membrane element 15 is composed of a shell (not shown) made of a material that does not allow the fermentation liquid S to pass. The shell can be made of FRP (fiber reinforced plastic). Therefore, in the membrane separation device 101, the effluent S3 does not flow out from the outer peripheral surface 15s of the membrane element 15 during operation, as in the membrane separation device 100 of the first embodiment described above.

[0176] The membrane separation device 101 of the second embodiment includes a sealing portion 24 disposed around the membrane element 15 . The space 25 is sealed by the sealing portion 24 .

[0177] In the membrane separation device 101 of the second embodiment, the sealing part 24 is arranged at two locations. That is, in the membrane separation device 101, two sealing parts 24 are used as the sealing parts 24. One end and the other end of the space 25, in other words, the inlet and outlet of the space 25 are sealed by the two sealing parts 24. That is, the space 25 is separated from the upstream space 25a and the downstream space 25b by the two sealing parts 24.

[0178] like Figure 5As shown in the figure, the two sealing parts 24 are preferably respectively arranged at the end 15a on the upstream side and the end 15b on the downstream side of the membrane element 15. With such a structure, it is easier to prevent the non-permeable fluid S2 from flowing into the space 25 and staying inside the space 25. The two sealing parts 24 can also be arranged slightly downstream of the end 15a on the upstream side of the membrane element 15, and slightly upstream of the end 15b on the downstream side of the membrane element 15. Even with such a structure, the same effect can be expected.

[0179] The sealing portion 24 has a ring shape and surrounds the membrane element 15 in the circumferential direction. Fig.11 The sealing member 44 used in the conventional membrane separation apparatus 200 shown is the same.

[0180] Although not shown in the figure, in the membrane separation device 101, an end member may be installed at one or both ends in the axial direction of the membrane element 15. In this case, the two sealing portions 24 seal one end of the space 25 via an end member disposed at the end 15a on the upstream side of the membrane element 15 and an end member disposed at the end 15b on the downstream side of the membrane element 15.

[0181] Although not shown in the figure, in the membrane separation device 101, the space 25 can also be filled with a material with high thermal conductivity. According to such a structure, it is easy to conduct heat from the outside of the shell 12 to the membrane element 15, so the temperature of the membrane element 15 is not easy to decrease. As a result, it is possible to suppress the temperature drop of the membrane element 15 during operation and the performance reduction of the permeation vaporization membrane 11. As a material with high thermal conductivity, for example, thermal pastes such as water, ethylene glycol, ethanol, CPU grease, etc. can be cited. The thermal paste may include, for example, a matrix and thermally conductive particles dispersed in the matrix. The matrix may include, for example, silicone. The conductive particles may include, for example, metals such as aluminum. The material with high thermal conductivity may also be water. The thermal conductivity of the material with high thermal conductivity is preferably above 0.1W / m·K. The upper limit of the thermal conductivity of the material with high thermal conductivity is not particularly limited. The upper limit is, for example, 20.0W / m·K.

[0182] Regarding the operating method of the membrane separation device of this embodiment, the membrane separation device 101 of Embodiment 2 is implemented as follows, for example. Figure 5 As shown, first, fermentation liquid S is supplied to the interior of the membrane separation device 101 through the port 21a (fermentation liquid inlet 13a). Then, the fermentation liquid S is supplied to the interior of the membrane element 15 from the upstream space 25a, and contacts one surface of the permeation vaporization membrane 11. While the fermentation liquid S is in contact with one surface of the permeation vaporization membrane 11, the permeation space adjacent to the other surface of the permeation vaporization membrane 11 is depressurized. Thus, the permeated fluid S1 is obtained. The permeated fluid S1 moves to the interior of the central tube 16, and is discharged to the outside of the membrane separation device 101 through the port 22b (permeated fluid outlet 14b). At this time, as shown in FIG. Figure 5 As shown, in the membrane separation device 101, since the space 25 is sealed by the sealing portion 24, it is possible to prevent the non-permeable fluid S2 from flowing into the space 25 and staying inside the space 25. On the other hand, the fermentation liquid S (non-permeable fluid S2) that has not permeated the pervaporation membrane 11 is discharged to the outside of the membrane element 15. Thereafter, the non-permeable fluid S2 passes through the downstream space 25b and is discharged to the outside of the membrane separation device 101 through the port 21b (non-permeable fluid outlet 13b).

[0183] [Implementation method 3]

[0184] Figure 6 2 is a schematic cross-sectional view showing a membrane separation device 102 according to Embodiment 3. In the membrane separation device 102 according to Embodiment 3, the filler 27 is filled in the space 25, whereby the space 25 is sealed. That is, in the membrane separation device 102, the above-mentioned condition (1) is satisfied. In other words, the space 25 is filled with the filler 27. That is, the space 25 is separated from the upstream space 25a and the downstream space 25b by the filler 27. Therefore, in the membrane separation device 102, the inflow of the non-permeable fluid S2 into the space 25 is blocked.

[0185] like Figure 6 As shown in FIG. 1 , the filler 27 is preferably filled from the end 15a on the upstream side to the end 15b on the downstream side of the membrane element 15. With such a configuration, it is easier to prevent the non-permeable fluid S2 from flowing into the space 25 and stagnating inside the space 25. The filler 27 may also be filled from the end 15a on the upstream side of the membrane element 15 slightly downstream to the end 15b on the downstream side of the membrane element 15 slightly upstream. Even with such a configuration, the same effect can be expected.

[0186] The filler 27 has a ring shape and surrounds the membrane element 15 in the circumferential direction. The membrane element 15 is fixed to the inner circumferential surface 12s of the housing 12 by the filler 27. As the filler 27, the material cited as a material with high thermal conductivity in Embodiment 2 can also be used. According to such a structure, it is easy to conduct heat from the outside of the housing 12 to the membrane element 15, so the temperature of the membrane element 15 is not easy to decrease. As a result, it is possible to suppress the temperature drop of the membrane element 15 during operation and the performance drop of the permeation vaporization membrane 11. As the filler 27, a commercially available filler can also be used.

[0187] Although not shown in the figure, in the membrane separation device 102, end members may be installed at one or both axial ends of the membrane element 15. In this case, the space 25 adjacent to the outer peripheral surface 15s of the membrane element 15 including the outer peripheral surface of the end member may be filled with the filler 27.

[0188] The operating method of the membrane separation apparatus 102 according to the third embodiment is implemented in the same manner as the operating method of the membrane separation apparatus 101 according to the second embodiment described above.

[0189] [Implementation Method 4]

[0190] Figure 7 1 is a schematic cross-sectional view showing a membrane separation device 103 according to Embodiment 4. In the membrane separation device 103 according to Embodiment 4, the sealing portion 24 is an injection molding agent 24a. The membrane separation device 103 has the same structure as the membrane separation device 101 except that the injection molding agent 24a is used as the sealing portion 24. That is, in the membrane separation device 103, the above-mentioned condition (1) is satisfied. In other words, the space 25 is separated from the upstream space 25a and the downstream space 25b by the injection molding agent 24a. Therefore, in the membrane separation device 103, the inflow of the non-permeable fluid S2 into the space 25 is blocked.

[0191] In the membrane separation device 103, the housing 12 and the membrane element 15 are integrated by the injection molding agent 24a. In this specification, the so-called "integrated" means that the parts cannot be separated from each other in a non-destructive manner.

[0192] like Figure 7 As shown, the molding agent 24a is preferably disposed at the upstream end 15a and the downstream end 15b of the membrane element 15. With such a configuration, it is easier to prevent the non-permeable fluid S2 from flowing into the space 25 and stagnating inside the space 25. As the molding agent 24a, for example, urethane resin, epoxy resin, etc. can be used.

[0193] Although not shown in the figure, in the membrane separation device 103, end parts may be installed at one or both ends of the axial direction of the membrane element 15. In this case, the injection molding agent 24a on the upstream side and the downstream side seals one end of the space 25 by the end part arranged at the end 15a on the upstream side of the membrane element 15 and the end part arranged at the end 15b on the downstream side of the membrane element 15.

[0194] The operating method of the membrane separation apparatus 103 according to the fourth embodiment is implemented in the same manner as the operating method of the membrane separation apparatus 101 according to the second embodiment described above.

[0195] [Implementation method 5]

[0196] Figure 8 : is a schematic cross-sectional view showing a membrane separation device 104 according to Embodiment 5. In the membrane separation device 104 according to Embodiment 5, the sealing portion 24 has a through hole 24h for allowing the fermentation liquid S to flow into the space 35. That is, the membrane separation device 104 has a structure in which the space 25 is not sealed by the sealing portion 24.

[0197] like Figure 8As shown, in the membrane separation device 104 of the fifth embodiment, a part of the fermentation liquid S to be supplied to the membrane element 15 flows into the space 25 through the through hole 24h of the sealing portion 24. The fermentation liquid S flowing into the space 25 flows along the space 25. That is, in the membrane separation device 104, the above-mentioned condition (2) is satisfied. More specifically, in the membrane separation device 104, the space 25 constitutes a flow path for the fermentation liquid S. The fermentation liquid S flowing in the space 25 is discharged from the non-permeable fluid outlet 13b together with the fermentation liquid S (non-permeable fluid S2) that has not passed through the permeation vaporization membrane 11 of the membrane element 15. Therefore, in the membrane separation device 104, the situation in which the non-permeable fluid S2 flows into the space 25 and stays inside the space 25 is suppressed.

[0198] In addition, if Figure 8 As shown, in the membrane separation device 104 of the fifth embodiment, during operation, the fermentation liquid S flows in the space 25, thereby easily transferring heat from the outside of the housing 12 to the membrane element 15, so that the temperature of the membrane element 15 is not easily reduced. As a result, it is possible to suppress the temperature reduction of the membrane element 15 during operation and the performance reduction of the pervaporation membrane 11. As described above, the temperature of the fermentation liquid S is 15°C to 75°C.

[0199] The through hole 24h is provided in a manner that penetrates the sealing portion 24 in the thickness direction. The number of the through holes 24h is not particularly limited, and may be one, or may be two or more. In the sealing portion 24, a plurality of through holes 24h may also be provided at prescribed intervals along the circumference of the sealing portion 24. The number of rows of the plurality of through holes 24h provided along the circumference of the sealing portion 24 is not particularly limited, and may be one, or may be two or more. In the case where a plurality of through holes 24h are provided, the sum of the cross-sectional areas of the plurality of through holes 24h is preferably less than 50% of the cross-sectional area of ​​the sealing portion 24. According to such a configuration, the loss of the fermentation liquid S caused by the excessive flow of the fermentation liquid S into the space 25 can be suppressed.

[0200] In the membrane separation device 104 of embodiment 5, the sealing portion 24 having the through hole 24h is arranged at the end 15a on the upstream side of the membrane element 15. The arrangement position of the sealing portion 24 having the through hole 24h is not particularly limited. The sealing portion 24 having the through hole 24h can be arranged at the end 15a on the upstream side of the membrane element 15, or at the end 15b on the downstream side. The sealing portion 24 having the through hole 24h can also be arranged at any position between the end 15a on the upstream side and the end 15b on the downstream side of the membrane element 15.

[0201] The sealing portion 24 having the through hole 24h may be arranged at two locations. As the sealing portion 24, two sealing portions 24 having the through hole 24h may be used. The two sealing portions 24 having the through hole 24h may be arranged at the end 15a on the upstream side and the end 15b on the downstream side of the membrane element 15, respectively.

[0202] Although not shown in the figure, in the membrane separation device 104, an end member may be installed at one or both ends in the axial direction of the membrane element 15. In this case, the sealing portion 24 having the through hole 24h forms a flow path via the end member disposed at the end 15a on the upstream side of the membrane element 15 without sealing one end of the space 25.

[0203] For the membrane separation device 104 of Embodiment 5, the operation method of the membrane separation device of this embodiment is implemented as follows. Figure 8 As shown, the fermentation liquid S is supplied to the interior of the membrane separation device 104 through the port 21a (fermentation liquid inlet 13a). Then, the fermentation liquid S passes through the upstream space 25a and is supplied to the interior of the membrane element 15, and contacts one surface of the permeation vaporization membrane 11. While the fermentation liquid S is in contact with one surface of the permeation vaporization membrane 11, the permeation space adjacent to the other surface of the permeation vaporization membrane 11 is depressurized. Thus, a permeated fluid S1 is obtained. The permeated fluid S1 moves toward the interior of the central tube 16, passes through the port 22b (permeated fluid outlet 14b) and is discharged to the outside of the membrane separation device 104. On the other hand, the fermentation liquid S (non-permeable fluid S2) that has not passed through the permeation vaporization membrane 11 is discharged to the outside of the membrane element 15. Thereafter, the non-permeable fluid S2 passes through the port 21b (non-permeable fluid outlet 13b) and is discharged to the outside of the membrane separation device 104. At this time, as shown in FIG. Figure 8 As shown in FIG. 1 , a part of the fermentation liquid S to be supplied to the membrane element 15 flows into the space 25 through the through hole 24h of the sealing portion 24, and flows along the space 25. That is, the space 25 constitutes a flow path of the fermentation liquid S. By the fermentation liquid S flowing in the space 25, the non-permeable fluid S2 is suppressed from flowing into the space 25 and staying inside the space 25. The fermentation liquid S flowing in the space 25 passes through the downstream side space 25b together with the non-permeable fluid S2 and is discharged to the outside of the membrane separation device 104 through the port 21b (non-permeable fluid outlet 13b).

[0204] [Implementation Method 6]

[0205] Fig. 91 is a schematic cross-sectional view showing a membrane separation device 105 according to Embodiment 6. In the membrane separation device 105 according to Embodiment 6, the housing 12 has an opening 12i and an opening 12o that communicate the space 25 with the outside of the membrane separation device 105. The membrane separation device 105 has the same structure as the membrane separation device 101 except that the housing 12 has the opening 12i and the opening 12o.

[0206] The opening 12 i and the opening 12 o are formed at positions facing the space 25 in the housing 12 .

[0207] The opening 12i functions as an inlet of the heat medium M. That is, in the membrane separation device 105, the above-mentioned condition (2) is satisfied. More specifically, in the membrane separation device 105, the space 25 constitutes a flow path of the heat medium M. Therefore, in the membrane separation device 105, the inflow of the non-permeable fluid S2 into the space 25 is blocked. The opening 12i may also be connected to a heat medium supply path (not shown) for supplying the heat medium M to the space 25. The opening 12о functions as an outlet of the heat medium M. The opening 12о may also be connected to a heat medium discharge path (not shown) for discharging the heat medium M from the space 25. According to such a structure, the membrane element 15 can be easily heated by the heat medium M flowing in the space 25. Thus, the temperature drop of the membrane element 15 during operation and the performance drop of the permeation vaporization membrane 11 can be suppressed.

[0208] exist Fig. 9 In the example shown, the heat medium M is introduced into the space 25 through the opening 12i. The heat medium M introduced into the space 25 exchanges heat with the membrane element 15 via the outer peripheral surface 15s of the membrane element 15, and heats the membrane element 15. The heat medium M that has exchanged heat with the membrane element 15 is discharged from the space 25 through the opening 12o. It is also possible to configure that the heat medium discharge path is connected to the heat medium supply path, and the heat medium M circulates in the heat medium supply path, the space 25, and the heat medium discharge path.

[0209] The heat medium M is typically warm water. However, the heat medium M may also be steam (e.g., water vapor). Steam may be utilized at a pressure above the atmospheric pressure of the surrounding environment, or may be utilized at a pressure lower than the atmospheric pressure of the surrounding environment. In this specification, steam used at a pressure lower than the atmospheric pressure of the surrounding environment is sometimes referred to as vacuum steam. The temperature of the heat medium M may be the same as the temperature of the fermentation liquid S supplied to the membrane separation device 105.

[0210] [Implementation method 7]

[0211] Fig.101 is a schematic cross-sectional view showing a membrane separation device 106 according to Embodiment 7. In the membrane separation device 106 according to Embodiment 7, the housing 12 has a plurality of openings 12i and a plurality of openings 12o. The membrane separation device 106 has the same structure as the membrane separation device 105 except that the housing 12 has a plurality of openings 12i and a plurality of openings 12o. That is, in the membrane separation device 106, the above-mentioned condition (2) is satisfied. More specifically, in the membrane separation device 106, the space 25 constitutes a flow path of the heat medium M. Therefore, in the membrane separation device 106, the inflow of the non-permeable fluid S2 into the space 25 is blocked.

[0212] According to the membrane separation device 106 of the seventh embodiment, the heat medium M can be introduced into the space 25 more evenly, and the heat medium M can be discharged from the space 25 more evenly. Therefore, the membrane elements 15 can be heated evenly.

[0213] There is no particular limitation on the arrangement of the plurality of openings 12i and the plurality of openings 12o. Fig.10 As shown, a plurality of openings 12i and a plurality of openings 12о may be formed evenly at positions in the housing 12 facing the space 25. The number of the openings 12i and the number of the openings 12о are not particularly limited. For example, the housing 12 may have a mesh structure at a position facing the space 25, thereby being configured to have a plurality of openings 12i and a plurality of openings 12о.

[0214] [Embodiment 8]

[0215] Fig.11 1 is a schematic cross-sectional view showing a membrane separation device 107 according to Embodiment 8. The membrane separation device 107 according to Embodiment 8 has an end member 18 mounted at least on 15a of the membrane element 15, and the end member 18 has a through hole 18h for allowing the fermentation liquid S to flow into the space 35. As described above, the membrane separation device 107 has the same structure as the membrane separation device 104 except that the end member 18 has a through hole 18h instead of the sealing portion 24. That is, in the membrane separation device 107, the above condition (2) is satisfied. More specifically, in the membrane separation device 107, the space 25 constitutes a flow path for the fermentation liquid S.

[0216] like Fig.11As shown, in the membrane separation device 107 of the eighth embodiment, a part of the fermentation liquid S to be supplied to the membrane element 15 flows into the space 25 through the through hole 18h of the end member 18. The fermentation liquid S flowing into the space 25 flows along the space 25. That is, the space 25 constitutes a flow path of the fermentation liquid S. The fermentation liquid S flowing in the space 25 is discharged from the non-permeable fluid outlet 13b together with the fermentation liquid S (non-permeable fluid S2) that has not passed through the permeation vaporization membrane 11 of the membrane element 15. Therefore, in the membrane separation device 107, the situation in which the non-permeable fluid S2 flows into the space 25 and stays inside the space 25 is suppressed.

[0217] In addition, if Fig.11 As shown, in the membrane separation device 107 of Embodiment 8, during operation, the fermentation liquid S flows in the space 25, thereby easily transferring heat from the outside of the housing 12 to the membrane element 15, so that the temperature of the membrane element 15 is not easily reduced. As described above, the temperature of the fermentation liquid S is 15°C to 75°C.

[0218] [Other embodiments]

[0219] like Figure 1 , Figure 5 to Figure 11 As shown, in the membrane separation devices of embodiments 1 to 8, the fermentation liquid inlet 13a, the non-permeated fluid outlet 13b, and the permeated fluid outlet 14b are provided in a direction parallel to the axis of the central tube 16. Therefore, the membrane separation devices of embodiments 1 to 8 can be easily connected in series for use individually or in combination.

[0220] <Embodiment of membrane separation system>

[0221] Fig.12 1 is a schematic diagram showing an example of the membrane separation system 1000 according to the present embodiment. Fig.12 As shown, the membrane separation system 1000 of this embodiment includes the membrane separation device of the above-mentioned present embodiment as a membrane separation device. Fig.12 In the present invention, for convenience, the membrane separation device of the present embodiment is described as a membrane separation device 100. The membrane separation system 1000 can perform the above-mentioned operation method on the membrane separation device 100.

[0222] The membrane separation system 1000 includes a membrane separation device 100 and a tank 30. The tank 30 stores a fermentation liquid S to be supplied to the membrane separation device 100. The tank 30 is typically a fermentation tank for producing an organic compound by fermentation of a carbon source by microorganisms.

[0223] The membrane separation system 1000 may also include a decompression device 40. The decompression device 40 can decompress the permeation space 14 of the membrane separation device 100. The decompression device 40 is preferably a vacuum device such as a vacuum pump. The vacuum pump is typically a gas-transporting vacuum pump, and examples include a reciprocating vacuum pump, a rotary vacuum pump, and the like. As a reciprocating vacuum pump, a diaphragm type and a swing piston type vacuum pump may be mentioned. As a rotary vacuum pump, examples include: a liquid seal pump; an oil rotary pump (rotary pump); a mechanical booster pump; various dry pumps such as Roots type, claw type, screw type, turbine type, and vortex type. The pump as the decompression device 40 may also include a variable speed mechanism for changing the rotation speed, etc. An example of a variable speed mechanism is an inverter that drives the motor of the pump. By controlling the rotation speed of the pump, etc. using a variable speed mechanism, the pressure of the supply space 13 of the membrane separation device 100 can be appropriately adjusted.

[0224] The membrane separation system 1000 may further include a recovery unit 50 for recovering the permeated fluid S1. The recovery unit 50 recovers the permeated fluid S1 sent from the membrane separation device 100 and can, for example, store the permeated fluid S1. The recovery unit 50 is, for example, a tank for storing the permeated fluid S1.

[0225] The membrane separation system 1000 further includes a fermentation liquid supply path 71 , a permeated fluid discharge path 72 , and a non-permeated fluid discharge path 73 .

[0226] The fermentation liquid supply path 71 is connected to the fermentation liquid outlet (outlet 31) of the tank 30 and the fermentation liquid inlet (inlet 13a) of the membrane separation device 100, and is a path for supplying the fermentation liquid S from the tank 30 to the membrane separation device 100. In the fermentation liquid supply path 71, a pump for controlling the flow rate of the fermentation liquid S may be arranged, and a sensor for measuring the content rate of the organic compound in the fermentation liquid S may also be arranged.

[0227] The permeated fluid discharge path 72 is connected to the permeated fluid outlet (outlet 14b) of the membrane separation device 100 and the permeated fluid inlet (inlet 51) of the recovery unit 50, and is a path for conveying the permeated fluid S1 from the membrane separation device 100 to the recovery unit 50. A sensor for measuring the content of organic compounds in the permeated fluid S1 may be disposed in the permeated fluid discharge path 72.

[0228] The non-permeated fluid discharge path 73 is connected to the non-permeated fluid outlet (outlet 13b) of the membrane separation device 100, and is a path for discharging the non-permeated fluid S2 from the membrane separation device 100. A sensor for measuring the content of organic compounds in the non-permeated fluid S2 may be disposed in the non-permeated fluid discharge path 73.

[0229] The non-permeable fluid discharge path 73 may be connected to the non-permeable fluid inlet (inlet 32) of the tank 30, and configured to convey the non-permeable fluid S2 to the tank 30. That is, in the membrane separation system 1000, the non-permeable fluid S2 may be mixed with the fermentation liquid S in the tank 30 and circulate in the fermentation liquid supply path 71 and the non-permeable fluid discharge path 73. When the non-permeable fluid S2 is conveyed to the tank 30, the fermentation liquid S and the non-permeable fluid S2 are mixed in the tank 30, and the content of organic compounds in the fermentation liquid S is reduced. When the tank 30 is a fermentation tank, by reducing the content of organic compounds in the fermentation liquid S, it is possible to suppress the stop of fermentation by microorganisms, thereby continuously producing fermented products. In addition, since the retention of the non-permeable fluid S2 is suppressed in the membrane separation device 100, the mixing of impurities into the tank 30 caused by the retention can be suppressed. In addition, it is also possible to suppress the accumulation of air in the space 25 of the membrane separation device 100, and thus the cavitation of the membrane separation device 100 can be suppressed.

[0230] A condensation section for condensing the permeated fluid S1 may also be disposed in the permeated fluid discharge path 72. The condensation section is, for example, a heat exchanger for cooling the permeated fluid S1. The gas permeated fluid S1 can be cooled and condensed by the heat exchanger. The heat exchanger is, for example, a gas-liquid heat exchanger that generates heat exchange between a cooling medium such as an antifreeze liquid and the gas permeated fluid S1. The condensation section may be located between the membrane separation device 10 and the pressure reducing device 40 (on the upstream side of the pressure reducing device 40), or between the pressure reducing device 40 and the recovery section 50 (on the downstream side of the pressure reducing device 40).

[0231] The membrane separation system 1000 may further include a controller 60 for controlling the various components of the membrane separation system 1000. The controller 60 is, for example, a DSP (Digital Signal Processor) including an A / D conversion circuit, an input / output circuit, an operation circuit, a storage device, etc. A program for properly operating the membrane separation system 1000 is stored in the controller 60. For example, the controller 60 can control the operation of the decompression device 40, etc., and switch between membrane separation operation and cleaning operation.

[0232] Unless otherwise specified, each path of the membrane separation system 1000 is constituted by, for example, a pipe made of metal or resin.

[0233] <Modification of membrane separation device included in membrane separation system>

[0234] The membrane separation system 1000 of the present embodiment may include a plurality of membrane separation devices 100, and the plurality of membrane separation devices 100 may be connected in series or in parallel. In the present specification, “a plurality of membrane separation devices 10 are connected in series” refers to a configuration in which a plurality of membrane separation devices 100 are connected to each other in such a manner that the fermentation liquid S (non-permeable fluid S2) discharged from the supply space 13 of the membrane element 15 of the membrane separation device 100 at the front section is supplied to the supply space 13 of the membrane element 15 of the membrane separation device 100 at the rear section. “A plurality of membrane separation devices 100 are connected in parallel” refers to a configuration in which a plurality of membrane separation devices 100 are connected to each other in such a manner that the fermentation liquid S sent from the tank 30 is supplied to the supply space 13 of the membrane element 15 of each of the plurality of membrane separation devices 100. The number of membrane separation devices 100 in the membrane separation system 1000 is not particularly limited, and is, for example, 2 to 5. Hereinafter, refer to Fig.13A and 13B A modified example of the membrane separation system 1000 will be described in detail.

[0235] (Variant 1)

[0236] Fig.13A 1 is a schematic diagram showing a modification example 1 of the membrane separation system 1000 of the present embodiment. The membrane separation system 1001 of the modification example 1 is provided with two membrane separation devices 100A and 100B connected in series with each other. The membrane separation devices 100A and 100B are connected by piping. The membrane separation system 1001 has the same structure as the membrane separation system 1000 except that it is provided with two membrane separation devices 100A and 100B, etc. Therefore, sometimes the same reference numerals are marked on the common elements in the above-mentioned membrane separation system 1000 and the membrane separation system 1001 of the modification example 1, and their description is omitted. That is, the description of each embodiment can be applied to each other as long as it is not technically contradictory. Moreover, the various embodiments can also be combined with each other as long as it is not technically contradictory.

[0237] As described above, in the membrane separation system 1001, the membrane separation devices 100A and 100B are connected in series. In detail, the membrane separation system 1001 further includes a connection path 74 that connects the membrane separation devices 100A and 100B to each other. The connection path 74 is connected to the non-permeable fluid outlet 13b of the membrane separation device 100A and the fermentation liquid inlet 13a of the membrane separation device 100B. It should be noted that the fermentation liquid supply path 71 is connected to the fermentation liquid inlet 13a of the membrane separation device 100A, and the non-permeable fluid discharge path 73 is connected to the non-permeable fluid outlet 13b of the membrane separation device 100B.

[0238] The permeated fluid discharge path 72 includes a first portion 72A and a second portion 72B. The first portion 72A is connected to the permeated fluid outlet 14b of the membrane separation device 100A, and the second portion 72B is connected to the permeated fluid outlet 14b of the membrane separation device 100B. The first portion 72A and the second portion 72B merge at a merging position 75.

[0239] For example, two pressure reducing devices 40A and 40B are arranged on the permeated fluid discharge path 72. The pressure reducing device 40A is located between the membrane separation device 100A and the confluence position 70, and can reduce the pressure in the permeation space 14 of the membrane element 15 provided in the membrane separation device 100A. The pressure reducing device 40B is located between the membrane separation device 100B and the confluence position 70, and can reduce the pressure in the permeation space 14 of the membrane element 15 provided in the membrane separation device 100B. However, one pressure reducing device may be arranged on the permeated fluid discharge path 72, and the pressure reducing device may be located between the confluence position 70 and the recovery unit 50. That is, one pressure reducing device may be shared by the membrane separation devices 100A and 100B.

[0240] It should be noted that in the membrane separation system 1001, the pervaporation membrane 11A of the membrane element 15 of the membrane separation device 100A may be the same as or different from the pervaporation membrane 11B of the membrane element 15 of the membrane separation device 100B except for the membrane area. The membrane area (m 2 ) relative to the total value of the membrane area of ​​the pervaporation membrane 11A and the membrane area of ​​the pervaporation membrane 11B (m 2 ) is not particularly limited.

[0241] As an example, the membrane separation system 1001 can be operated by the following method. First, a pump (not shown) is operated to supply the fermentation liquid S from the tank 30 to the membrane separation device 100A, and then the fermentation liquid S is supplied from the membrane separation device 100A to the membrane separation device 100B. In this way, the fermentation liquid S can be brought into contact with the pervaporation membrane 11A of the membrane element 15 provided in the membrane separation device 100A and the pervaporation membrane 11B of the membrane element 15 provided in the membrane separation device 100B.

[0242] Next, the permeate fluid passes through the permeate fluid outlet 14b to reduce the pressure of the permeate space 14 of the membrane element 15 of the membrane separation device 100A, and the permeate fluid passes through the permeate fluid outlet 14b to reduce the pressure of the permeate space 14 of the membrane element 15 of the membrane separation device 100B. Thus, the membrane separation operation can be performed in both the membrane separation devices 100A and 100B, and the permeate fluid S1 can be obtained from the membrane separation devices 100A and 100B, respectively. It should be noted that the fermentation liquid S (non-permeate fluid S2) processed in the membrane separation device 100A is sent to the membrane separation device 100B through the connection path 74, and is further processed in the membrane separation device 100B.

[0243] Next, the pressure of the permeation space 14 of at least one of the membrane element 15 included in the membrane separation apparatus 100A and the membrane element 15 included in the membrane separation apparatus 100B is increased, and the membrane separation operation is terminated.

[0244] (Variant 2)

[0245] Fig. 13B 1 is a schematic diagram showing a second modification of the membrane separation system 1000 of the present embodiment. The membrane separation system 1002 of the second modification includes two membrane separation devices 100A and 100B connected in parallel to each other. The membrane separation devices 100A and 100B are connected by piping. The membrane separation system 1002 has the same configuration as the membrane separation system 100 except that it includes two membrane separation devices 100A and 100B.

[0246] As described above, in the membrane separation system 1002, the membrane separation devices 100A and 100B are connected in parallel with each other. Specifically, the fermentation liquid supply path 71 includes a first portion 71A and a second portion 71B. The first portion 71A of the fermentation liquid supply path 71 is connected to the fermentation liquid inlet 13a of the membrane separation device 100A, and the second portion 71B is connected to the fermentation liquid inlet 13a of the membrane separation device 100B. The second portion 71B branches from the first portion 71A at a branch position 76. The branch position 76 is located between the tank 30 and the membrane separation device 100A.

[0247] In addition, the non-permeated fluid discharge path 73 has a first portion 73A and a second portion 73B. The first portion 73A of the non-permeated fluid discharge path 73 is connected to the non-permeated fluid outlet 13b of the membrane separation device 100A, and the second portion 73B is connected to the non-permeated fluid outlet 13b of the membrane separation device 100B. The first portion 73A and the second portion 73B merge at a merging position 77. The merging position 77 is located, for example, between the tank 30 and the membrane separation device 100A.

[0248] Similar to the membrane separation system 1001 of Modification 1, the permeated fluid discharge path 72 includes a first portion 72A and a second portion 72B. The first portion 72A is connected to the permeated fluid outlet 14b of the membrane separation device 100A, and the second portion 72B is connected to the permeated fluid outlet 14b of the membrane separation device 100B. The first portion 72A and the second portion 72B merge at a merging position 75.

[0249] In the permeated fluid discharge path 72, for example, two decompression devices 40A and 40B are arranged. The decompression device 40A is located between the membrane separation device 100A and the confluence position 75, and can decompress the permeation space 14 of the membrane element 15 provided in the membrane separation device 100A. The decompression device 40B is located between the membrane separation device 100B and the confluence position 75, and can decompress the permeation space 14 of the membrane element 15 provided in the membrane separation device 100B. However, one decompression device may be arranged on the permeated fluid discharge path 72, and the decompression device may be located between the confluence position 75 and the recovery unit 50. That is, one decompression device may be shared by the membrane separation devices 100A and 100B.

[0250] It should be noted that in the membrane separation system 1002, the pervaporation membrane 11A of the membrane element 15 of the membrane separation device 100A may be the same as or different from the pervaporation membrane 11B of the membrane element 15 of the membrane separation device 100B. The membrane area (m 2 ) relative to the total value of the membrane area of ​​the pervaporation membrane 11A and the membrane area of ​​the pervaporation membrane 11B (m 2 ) is not particularly limited.

[0251] As an example, the membrane separation system 1002 can be operated by the following method. First, a pump (not shown) is operated to supply the fermentation liquid S from the tank 30 to the membrane separation devices 100A and 100B, respectively. Thus, the fermentation liquid S can be brought into contact with the pervaporation membrane 11A of the membrane element 15 of the membrane separation device 100A and the pervaporation membrane 11B of the membrane element 15 of the membrane separation device 100B, respectively.

[0252] Next, the permeate fluid passes through the permeate outlet 14b to reduce the pressure in the permeate space 14 of the membrane element 15 of the membrane separation device 100A, and the permeate fluid passes through the permeate outlet 14b to reduce the pressure in the permeate space 14 of the membrane element 15 of the membrane separation device 100B. Thus, the membrane separation operation can be performed in both the membrane separation devices 100A and 100B, and the permeate fluid S1 can be obtained from each of the membrane separation devices 100A and 100B.

[0253] Next, the pressure of the permeation space 14 of at least one of the membrane element 15 included in the membrane separation apparatus 10A and the membrane element 15 included in the membrane separation apparatus 10B is increased, and the membrane separation operation is terminated.

[0254] Industrial Applicability

[0255] The membrane separation system of the present embodiment is suitable for efficiently separating volatile organic compounds from a fermentation liquid containing the organic compounds.

Claims

1. A membrane separation device comprising a spiral membrane element, wherein: The membrane element includes a central tube having a through hole, and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid. During operation, the non-permeated fluid is prevented from flowing into the space adjacent to the outer peripheral surface of the membrane element.

2. A membrane separation device comprising a spiral membrane element, wherein: The membrane element includes a central tube having a through hole, and a membrane leaf wound around the central tube, wherein the membrane leaf has a permeation vaporization membrane for separating a fermentation liquid containing volatile organic compounds into a permeated fluid and a non-permeated fluid. If the following conditions (1) or (2) are met, (1) The space adjacent to the outer peripheral surface of the membrane element is sealed; (2) The space adjacent to the outer peripheral surface of the membrane element constitutes a flow path for a fluid other than the non-permeated fluid.

3. The membrane separation device according to claim 1 or 2, wherein: The outer peripheral surface of the membrane element is formed of a flow path material. 4 . The membrane separation device according to claim 1 , further comprising a sealing portion disposed around the membrane element.

5. The membrane separation device according to claim 4, wherein: The sealing portion has a through hole for allowing the fermentation liquid to flow into the space.

6. The membrane separation device according to claim 4, wherein: The space is sealed by the two sealing parts.

7. The membrane separation device according to claim 6, wherein: The seal includes a molding compound.

8. The membrane separation device according to claim 1 or 2, wherein: The space is sealed by filling the space with a filler.

9. The membrane separation device according to claim 1 or 2, wherein: The space is filled with a material having a thermal conductivity of 0.1 W / m·K or more.

10. The membrane separation device according to claim 1 or 2, wherein: The membrane element is configured to be attachable to and detachable from the housing.

11. A membrane separation system comprising the membrane separation device according to claim 1 or 2. 12 . The membrane separation system according to claim 11 , further comprising a tank for storing the fermentation liquid to be supplied to the membrane separation device.

13. The membrane separation system according to claim 11, wherein: The membrane separation system comprises a plurality of membrane separation devices, A plurality of the membrane separation devices are connected in series or in parallel.

14. A method for operating a membrane separation device, which is a method for operating a membrane separation device having a spiral membrane element, wherein: The membrane element comprises a central tube having a through hole, and a membrane leaf having a pervaporation membrane and wound around the central tube. The operation method comprises: supplying a fermentation liquid containing volatile organic compounds to the membrane separation device; Separating the fermentation broth into a permeated fluid and a non-permeated fluid by the pervaporation membrane; and The non-permeated fluid is discharged from the membrane separation device while preventing the non-permeated fluid from flowing into a space adjacent to the outer peripheral surface of the membrane element.

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