WO2015030148A1

WO2015030148A1 - Multi-tube separation membrane module

Info

Publication number: WO2015030148A1
Application number: PCT/JP2014/072658
Authority: WO
Inventors: 林　幹夫; 恭石羽; 武脇　隆彦
Original assignee: 三菱化学株式会社
Priority date: 2013-08-30
Filing date: 2014-08-28
Publication date: 2015-03-05
Also published as: JP6409776B2; JPWO2015030148A1

Abstract

Provided is a multi-tube separation membrane module with which a fluid to be treated has a high flow speed along tubular separation membranes within the multi-tube separation membrane module, thereby achieving superior membrane separation efficiency, and yet avoiding an increase in weight of the multi-tube separation membrane module. The multi-tube separation membrane module having a cylindrical housing (2), a plurality of tubular separation membranes (3) arranged in a longitudinal direction of the housing (2), support plates (4, 5) that are fixed to the housing (2) and support the tubular separation membranes (3), and one or more baffles (8) that are arranged in parallel with the support plates (4, 5) and have insertion holes (8a) into which the tubular separation membranes are inserted, wherein the multi-tube separation membrane module is characterized in that a gap (S) is opened between an inner peripheral surface of the insertion holes (8a) and an outer peripheral surface of the tubular separation membranes (3), and a ratio A/(B-C) between a hole length (A) of the insertion holes and the difference between an inner diameter B of the insertion holes (8a) and an outer diameter C of the tubular separation membranes (3) is 0.67 to 50.

Description

Multi-tube separation membrane module

The present invention relates to a multi-tubular separation membrane module used for separating a part of components from a fluid such as a solution or a mixed gas.

A multitubular separation membrane module is known as a device for separating components in a solution or mixed gas. The separation membrane element used in this multi-tubular separation membrane module is a tubular separation membrane made of zeolite or the like having fine pores about the size of the molecules to be separated. In order to separate a specific component from a fluid such as a solution or a mixed gas, the fluid of the solution is brought into contact with one (outer surface) of the separation membrane element, and the other (inner surface) is depressurized to thereby remove the specific component. A method of vaporizing and separating, a method of vaporizing a solution and bringing it into contact with a separation membrane in a gaseous state, and depressurizing a non-contact surface side to separate a specific component, and bringing a pressurized mixed gas into contact with the separation membrane Methods for separating specific components are known.

In such a multi-tubular separation membrane module, in order to increase the separation efficiency, it is necessary to efficiently bring a fluid such as a solution or a mixed gas to be separated into contact with the entire length of the separation membrane element.

Patent Documents

1 and 2 describe that a baffle is provided perpendicular to a tube (tubular separation membrane) in a multi-tubular separation membrane module in order to efficiently bring a fluid (liquid or gas) into contact with the membrane. Yes.

In the multi-tubular separation membrane module of Patent Document 1, a tube is inserted into each of a plurality of holes provided in a baffle, and an inner peripheral surface of the hole is in contact with the tube. For this reason, the membrane surface of the tube is covered with the inner peripheral surface of the hole, and the tube is equal to (number of baffles) × (number of holes in each baffle) × (area of the inner peripheral surface of the holes). The membrane area of the membrane is reduced and the membrane separation efficiency is lowered.

In the multi-tube separation membrane module of Patent Document 2, the diameter of the baffle tube (tubular zeolite separation membrane) insertion hole is made larger than the tube outer diameter, and a gap is formed between the inner peripheral surface of the hole and the outer peripheral surface of the tube. The part inserted into the hole of the tube is also made to contribute to membrane separation.

However, in Patent Document 2, a part of the outer peripheral edge of the baffle is notched in the chord direction, and most of the fluid to be treated passes through the notched part. For this reason, in Patent Document 2, the difference in fluid pressure between one side (upstream side) and the other side (downstream side) of one baffle is small, and the tube insertion hole inner peripheral surface and the tube outer peripheral surface The fluid to be processed does not pass through the gap at a high flow rate.

Patent Document 3 describes a multi-tubular separation membrane module in which a tubular member surrounding each tubular separation membrane of a multi-tubular separation membrane module is provided with a slight gap so that liquid can pass through the gap at high speed. ing. According to Patent Document 3, such a structure promotes the turbulent flow of fluid in the vicinity of the tubular separation membrane and spreads the fluid throughout the separation membrane, thereby improving the processing capacity of the multitubular separation membrane module.

However, in the multi-tubular separation membrane module of Patent Document 3, since a tubular member surrounding each tubular separation membrane is provided, the module weight increases and the cost also increases. Furthermore, since it becomes impossible to install a membrane in the portion occupied by the tubular member, the number of tubular separation membranes per module is reduced, and the membrane area is reduced.

Further, in Patent Document 3, in order to increase the gas linear velocity on the high pressure side, the gas passage cross-sectional area on the high pressure side is reduced, and further, the flow passage is reduced stepwise to increase the stage cut. Although the gas linear velocity of the high-pressure side gas is kept large, this gas linear velocity is a gas linear velocity calculated on average, and the difference in linear velocity at each part of the film is not taken into consideration. In particular, there is a risk that the transmission efficiency may partially decrease at a location where the gas flow direction changes.

In Patent Document 4, the module housing is partitioned into two or more spaces by partition walls parallel to the tubular separation membrane, and there is a flow hole for allowing gas to move between the spaces partitioned by the partition walls. Both the high-pressure side gas flow and the low-pressure permeate gas flow of the tubular separation membrane contained in each space are moved in series by a distance of more than twice the effective length of the tubular separation membrane into the tubular separation membrane. A multi-tubular separation membrane module having a structure capable of contacting is described.

However, in the multitubular separation membrane module of Patent Document 4, the gas flow rate along the tubular gas separation membrane is the same as that of the conventional one.

Japanese Unexamined Patent Publication No. 8-131781 Japanese Unexamined Patent Publication No. 2013-39546 International Publication No. 2004/035182 Japanese Unexamined Patent Publication No. 2007-160238

In the present invention, the flow rate of the fluid to be treated along the tubular separation membrane in the multi-tubular separation membrane module is large, thereby improving the membrane separation efficiency, and avoiding an increase in the weight of the multi-tubular separation membrane module. An object is to provide a multi-tubular separation membrane module.

The multi-tubular separation membrane module of the present invention includes a tubular housing, a plurality of tubular separation membranes disposed in the housing in the longitudinal direction of the housing, and fixed to the housing to support the tubular separation membrane. In a multi-tubular separation membrane module having a support plate and one or two or more baffles having an insertion hole through which the tubular separation membrane is inserted and disposed substantially parallel to the support plate in the housing, A gap is provided between the inner peripheral surface of the insertion hole and the outer peripheral surface of the tubular separation membrane, and includes a hole length A of the insertion hole, an inner diameter B of the insertion hole of the baffle, and an outer diameter C of the tubular separation membrane. The ratio A / (BC) to the difference is 0.67 to 50.

It is preferable that more than half of the fluid to be processed on the upstream side of the baffle flows through the gap and flows downstream.

The plurality of tubular separation membranes are preferably arranged so that the shortest distance between the tubular separation membranes is 2 mm to 10 mm.

Baffles are respectively arranged at positions within 20 cm from both ends of the tubular separation membrane. The support plates are preferably disposed on both ends of the housing.

In the multi-tubular separation membrane module of the present invention, the tubular separation membrane is inserted into the insertion hole of the baffle disposed in the housing, and the inner peripheral surface of the insertion hole and the outer peripheral surface of the gap separation membrane are There is a gap between them. Preferably, more than half of the fluid to be processed upstream of the baffle flows through the gap to the downstream side of the baffle. In such a multi-tubular separation membrane module of the present invention, the fluid to be treated passes through the gap between the inner peripheral surface of the insertion hole of the baffle and the outer peripheral surface of the tubular separation membrane at a high flow rate, and the tubular separation membrane At a high flow velocity. For this reason, the turbulent flow of the fluid to be processed along the surface (outer peripheral surface) of the tubular separation membrane is promoted, and the membrane separation efficiency is improved.

In the present invention, since a large number of tubular members are not provided as in Patent Document 3, an increase in weight and an increase in cost are avoided.

FIG. 1 is a cross-sectional view of the multi-tubular separation membrane module according to the embodiment along the axial direction of the housing. 2 is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. FIG. 5 is a perspective schematic diagram for explaining the function and effect of the present invention. FIG. 6 is a perspective schematic diagram for explaining the function and effect of the reference example. FIG. 7 is a cross-sectional view of a through hole portion of a baffle showing another embodiment. FIG. 8 is a cross-sectional view of the multi-tubular separation membrane module according to a different embodiment along the axial direction of the housing. FIG. 9 is a graph showing the results of Examples and Comparative Examples. FIG. 10 is a cross-sectional view of an insertion hole portion of a baffle showing another embodiment. FIG. 11 is a cross-sectional view of an insertion hole portion of a baffle showing another embodiment. FIG. 12 is a graph showing the results of Examples and Comparative Examples.

1 to 4, a multi-tubular separation membrane module 1 according to an embodiment of the present invention will be described.

The multi-tubular separation membrane module 1 includes a cylindrical housing 2, a support plate 4 fixed to one end of the housing 2 to support the tubular separation membrane 3, and a support plate provided at the other end of the housing 2. 5, a plurality of tubular separation membranes 3 arranged in a direction parallel to the axis of the housing 2, an end cover 6 attached to one end of the housing 2 so as to cover the support plate 4, and the other end of the housing 2 It has a blind plate 7 attached to the side and a baffle 8 arranged in the housing 2 in parallel with the

support plates

4, 5.

The fluid inlet 9 is provided on the outer peripheral surface on one end side of the housing 2, and the fluid outlet 10 is provided on the outer peripheral surface on the other end side. The inflow port 9 is provided so as to face the chamber 11 between the support plate 4 and the baffle 8 closest to the support plate 4. The outlet 10 is provided so as to face a chamber 15 between the support plate 5 and the baffle 8 closest to the support plate 5. In this embodiment, a plurality of (four in FIG. 1) baffles 8 are provided, and the

chambers

12, 13, and 14 are sequentially partitioned from the chamber 11 to the chamber 15 between the baffles 8. Yes. The number of baffles 8 is not limited to that shown in the figure.

Each baffle 8 is provided with a circular insertion hole (hereinafter also referred to as a hole) 8a through which the tubular separation membrane 3 is inserted, and the tubular separation membrane is inserted into each insertion hole 8a. The diameter of the insertion hole 8 a is larger than the diameter (outer diameter) of the tubular separation membrane 3, and a gap S is provided over the entire circumference between the inner peripheral surface of the insertion hole 8 a and the outer peripheral surface of the tubular separation membrane 3.

The

support plates

4 and 5 are provided with

openings

4 a and 5 a for supporting the tubular separation membrane 3. The tubular separation membrane 3 is inserted into the

openings

4a and 5a, and the space between the outer peripheral surface of the tubular separation membrane 3 and the inner peripheral surface of the

openings

4a and 5a is hermetically sealed.

One end side of each tubular separation membrane 3 is open toward the outflow chamber 16 between the end cover 6 and the support plate 4. The end cover 6 is provided with a separated permeate outlet 6a. The other end of the tubular separation membrane 3 supported by the support plate 5 may be open toward the chamber 17 between the support plate 5 and the blind plate 7 or may be sealed.

In this embodiment,

outward flanges

2a and 6b are provided on one end side of the housing 2 and the outer peripheral edge of the end cover 6, respectively, and the outer peripheral edge of the support plate 4 is a sealing material (not shown) on the

flanges

2a and 6b. These are fixed by bolts (not shown). The blind plate 7 is attached to a flange 2b provided on the other end side of the housing 2 by a bolt via a sealing material (not shown). The diameter of each baffle 8 is substantially equal to the inner diameter of the housing 2, and the outer peripheral surface of the baffle 8 is in contact with the inner peripheral surface of the housing 2, or is opposed through a slight gap.

In the above embodiment, since the thickness of the baffle 8 is uniform, the hole length of the insertion hole 8a (the length in the axial direction of the hole 8a) is equal to the thickness of the baffle 8. The thickness may not be uniform.

In the present invention, as shown in FIG. 4, the hole length of the hole 8a (the thickness of the baffle 8 in this embodiment) is A, the diameter of the insertion hole 8a is B, and the diameter (outer diameter) of the tubular separation membrane 3 is In the case of C, A / (BC) is 0.67 to 50, preferably 10 or less, particularly preferably 8 or less, more preferably 1 or more, and further preferably 2 or more.

In the multi-tube separation membrane module 1 configured as described above, the fluid to be treated is introduced into the chamber 11 of the housing 2 from the inlet 9, and the inner peripheral surface of the insertion hole 8 a of the baffle 8 and the outer periphery of the tubular separation membrane 3. It flows into the adjacent chamber 12 through the gap S between the surfaces, and then flows through the

chambers

13, 14, and 15 sequentially through the gap S of each baffle, during which some components of the fluid to be treated are tubular. It passes through the separation membrane 3 and is taken out from the tubular separation membrane 3 through the outflow chamber 16 and the outlet 6a. The fluid that has not permeated flows out of the multi-tubular separation membrane module 1 from the outlet 10.

In the embodiment shown in FIGS. 1 to 3, an end cover 6 is provided on one end side of the housing 2 and a blind plate 7 is provided on the other end side. However, like the multi-tube separation membrane module 1 ′ shown in FIG. In addition, an end cover 6 ′ and a support plate 4 ′ may be provided also on the other end side, and an outflow chamber 16 ′ may be provided between the other end side end cover 6 ′ and the support plate 4 ′. In this case, the other end side of the tubular separation membrane 3 is opened toward the outflow chamber 16 '. In FIG. 8, the support plate 5 is omitted. The structures of the end cover 6 ′ and the support plate 4 ′ are the same as the end cover 6 and the support plate 4. The other configurations in FIG. 8 are the same as those in FIG. 1, and the same reference numerals denote the same parts.

In the above embodiment, the insertion hole 8a has the same diameter from one surface of the baffle 8 to the other surface, but the angle θ = 10 on the inlet side and the outlet side of the insertion hole 8a as in the baffle 8 ′ of FIG. A taper of about 70 ° may be provided to reduce the fluid passage pressure loss of the gap S.

In the present invention, as shown in FIGS. 10 and 11, the baffle 8 may be provided with an insertion tube portion 8f extending from the peripheral portion of the insertion hole 8a. In FIG. 10, the insertion tube portion 8f is erected only on one plate surface of the baffle 8. In FIG. 11, the insertion tube portion 8f is provided on both plate surfaces. 10 and 11, the hole length of the insertion hole 8a is the sum of the thickness of the baffle 8 and the length of the insertion tube portion 8f. 10 and 11, a tapered portion as shown in FIG. 7 may be provided on the inner peripheral edge of the end portion of the insertion tube portion 8 f.

In this multi-tubular

separation membrane module

1, 1 ′, the fluid to be treated is substantially separated from the chamber on one side (upstream side) of the baffle 8 to the chamber on the other side (downstream side). Since the fluid flows only through S, the fluid to be processed passes through the gap S at a high flow velocity and flows along the tubular separation membranes 3 at a high flow velocity. For this reason, the turbulent flow of the fluid to be processed along the surface (outer peripheral surface) of each tubular separation membrane 3 is promoted, and the membrane separation efficiency is improved.

This effect becomes remarkable by setting the A / (BC) to 0.67-50. That is, if A / (BC) is larger than 50 because A is excessively large or (BC) is excessively small, the pressure loss when passing through the gap S becomes large. The flow rate of the fluid to be processed is reduced. If A / (BC) is smaller than 0.67 due to A being too small or (BC) being too large, the fluid to be treated passes through the gap S and then the tubular separation membrane. It becomes easy to flow away from 3. 5 and 6 explain this effect. As shown in FIG. 5, when A / (BC) is in the range of 0.67 to 50, the fluid to be processed that has passed through the insertion hole 8a flows along the tubular separation membrane 3 at a high flow rate. When A / (BC) is smaller than 0.67, the fluid to be processed that has passed through the insertion hole 8a can easily flow away from the tubular separation membrane 3.

The hole length A of the insertion hole 8a depends on the size of the module, but is preferably 0.8 mm or more, more preferably 1 mm or more, further preferably 3 mm or more, preferably 100 mm or less, more preferably 80 mm or less, even more preferably. Is 50 mm or less. If the value of the hole length A is too small, although it depends on the material of the baffle, flatness cannot be maintained, and if it is too large, the weight of the module may be excessively increased.

Further, the size (diameter) of the disk-shaped baffle 8 preferably matches the inner diameter of the housing, but a gap may exist when it is difficult to match from the viewpoint of handling. The gap is preferably as small as possible. In the present invention, 50% or more, particularly 65% or more of the fluid to be processed flowing from the one side (upstream side) chamber of the baffle 8 to the other side (downstream side) chamber passes through the gap S of the insertion hole 8a. It is preferable to be configured. If this condition is satisfied, the baffle may be a part of which the outer peripheral edge is notched, or may be provided with holes other than the insertion hole 8a.

The inner diameter B of the insertion hole 8a depends on the outer diameter of the tubular separation membrane 3, but is preferably 3 mm or more, more preferably 6 mm or more, further preferably 10 mm or more, preferably 20 mm or less, more preferably 18 mm or less, and even more preferably 16 mm. It is as follows.

In one baffle 8, it is preferable that the insertion holes 8a are arranged with an interval of 2 mm or more between them.

The outer diameter C of the tubular separation membrane 3 is preferably 3 mm or more, more preferably 6 mm or more, further preferably 10 mm or more, preferably 20 mm or less, more preferably 18 mm or less, and further preferably 16 mm or less. If the outer diameter C is too small, the strength of the tubular separation membrane may be insufficient and may be easily broken, and if it is too large, the membrane area per module is reduced.

The total length of the tubular separation membrane 3 is preferably 20 cm or more, and preferably 150 cm or less. If the length is shorter than this, the ratio of the portion covered as the connection is increased, so that the ratio of the exposed portion that can be used for the separation of the membrane is decreased, and if it is longer than this, the handling may be difficult.

The plurality of baffles are preferably the same size and the same shape, but different sizes and shapes may be used. In particular, when the permeation amount / supply amount is large, the amount of fluid to be supplied decreases as it approaches the outlet and the linear velocity decreases, so it may be effective to reduce the diameter of the insertion hole 8a as it approaches the outlet.

Although one baffle has a plurality of insertion holes, it is sufficient that at least one insertion hole satisfies A / (BC), preferably 50 (number)% or more, more preferably 80 (number)%. More preferably, 90 (number)% or more satisfies this. In particular, it is preferable that all the insertion holes satisfy this range.

When a plurality of insertion holes satisfy A / (BC), the plurality of insertion holes may have different values of A / (BC) within the range satisfying this, but they should be approximately the same value. Is preferred. The almost same value means that A / (BC) is within a range of ± 10%.

Further, when there are a plurality of baffles, at least one insertion hole of at least one baffle of each baffle should satisfy the above A / (BC), but preferably all the baffles satisfy the above conditions. Is preferred.

Further, it may be manufactured by setting different A / (BC) values between the baffles.

Of all the baffle insertion holes, preferably 50 (number)% or more, more preferably 80 (number)% or more, and still more preferably 90 (number)% or more satisfies A / (BC). It is. In particular, it is preferable that all the insertion holes of all the baffles satisfy A / (BC).

When a plurality of insertion holes of each baffle satisfy A / (BC), the plurality of insertion holes may have different values of A / (BC) within the range satisfying this, but are substantially the same value. It is preferable that The almost same value means that A / (BC) is within a range of ± 10%.

The material of the baffle is usually stainless steel, but is not particularly limited as long as it has heat resistance and supply under separation conditions and resistance to permeation components, and can be changed to other materials depending on the application.

It is preferable that the plurality of baffles be installed at equal intervals in the housing. The gap between the baffles is usually 10 cm or more, preferably 20 cm or more, usually 120 cm or less, preferably about 100 cm or less, although it depends on the length of the multi-tubular separation membrane module in the longitudinal direction.

In the present invention, it is preferable that baffles are respectively disposed at locations within 20 cm, particularly within 18 cm, particularly within 15 cm from both ends of the tubular separation membrane. This value differs depending on the position of the fluid inlet or outlet pipe and the pipe diameter, and should be placed closer to the module center than the part closest to the module center at the connection between the pipe and the housing body. Is preferred.

Also, there may be a metal member that is coaxially connected to the lower and upper ends of the tubular separation membrane. By arranging the baffle at the position of the metal member, it is possible to prevent the baffle from being damaged in contact with the zeolite membrane described in detail below.

In the multitubular separation membrane module of the present invention, the length of the cylindrical housing in the axial direction is usually about 40 cm to 2 m. Further, it is preferable that 19 to 550 tubular separation membranes are usually arranged, and the shortest distance between the tubular separation membranes is 2 mm to 10 mm. The size of the housing and the number of tubular separation membranes are appropriately changed depending on the amount of fluid to be processed.

At least one of the support plates that support the tubular separation membrane is fixed to the housing and disposed at one end of the housing. The other is preferably a multi-tubular separation membrane module that is disposed at the other end of the housing facing the support plate and has a support plate that supports the tubular separation membrane.

An insertion hole having the same circular center as the insertion hole of the baffle within 10 cm from the end opposite to the end supported by the support plate of the tubular separation membrane, and for supporting the membrane supporting the tubular membrane element in the insertion part It is preferable to have another support plate. By installing such a support plate, the shortest distance between the wall of the insertion hole and the membrane surface of the tubular separation membrane is kept constant at all points in the insertion hole of the baffle. Without such a support plate, the shortest distance between the wall of the insertion hole and the membrane surface of the tubular separation membrane is not kept constant, one side is wide, the opposite surface is narrow, and the wide open part is not There is a possibility that fluid may pass selectively.

The distance from the end opposite to the end supported by the support plate of the tubular separation membrane of the support plate is usually 10 cm or less, preferably 8 cm or less, more preferably 5 cm or less, particularly preferably 3 cm or less, usually 1 mm or more, preferably 3 mm or more.

The support plate is provided with a through hole, and a tubular separation membrane is inserted into the through hole and supported. The shape of the through hole is not particularly limited, and there are a structure in which the entire inner peripheral surface of the through hole is supported as a circle, a structure in which a protrusion is provided in a circle, and a tubular separation membrane is supported by the protrusion. In addition to the through hole, a structure such as a mesh having holes through which fluid can pass may be used. The area and shape of the mesh holes are not particularly limited as long as the strength as a support can be maintained.

It is preferable to coat the surface of the tubular separation membrane where it comes into contact with the support plate. Examples of the covering material include tapes such as fluororesin tapes and glass tapes, parafilms, films such as fluororesin films, silicone heat shrinkable tubes, fluororesin heat shrinkable tubes, and polyolefin heat shrinkable tubes. Among them, a heat shrinkable tube is preferable in terms of handling, and among them, a silicone heat shrinkable tube and a fluororesin heat shrinkable tube are preferable.

The portion of the tubular separation membrane that comes into contact with the support plate may be a membrane material, but when using, for example, a pin for sealing the end of the membrane, it is brought into contact with the support plate at the location of the sealing material. It is preferable. By contacting with the sealing material, the film itself is not touched, so that the possibility that the surface of the film is scraped or damaged is reduced. The material of the sealing material is not particularly limited, and examples thereof include SUS, aluminum, and fluororesin, and are appropriately selected according to the strength of the film itself, the fluid component, and the like.

The tubular separation membrane may be any tubular one having a separation membrane, but it is preferable that a zeolite membrane is formed on the surface of the tubular porous support.

Examples of the material of the tubular porous support include an inorganic porous support of a ceramic sintered body containing silica, α-alumina, γ-alumina, mullite, zirconia, titania, yttria, silicon nitride, silicon carbide and the like. It is done. Among these, an inorganic porous support containing at least one of alumina, silica, and mullite is preferable. The average pore diameter of the surface of the porous support is not particularly limited, but those having a controlled pore diameter are preferred, usually 0.02 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm. The above is usually in the range of 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less.

Zeolite is crystallized on the surface of the porous support to form a zeolite membrane. The main zeolite constituting the zeolite membrane usually contains a zeolite having an oxygen 6-10 membered ring structure, and preferably contains a zeolite having an oxygen 6-8 membered ring structure.

Here, the value of n of the zeolite having an oxygen n-membered ring indicates the one having the largest number of oxygen among pores composed of oxygen and T element forming the zeolite skeleton. For example, when there are 12-membered and 8-membered pores of oxygen, such as MOR type zeolite, it is regarded as a 12-membered ring zeolite.

An example of a zeolite having an oxygen 6-10 membered ring structure is AEI, AEL, AFG, ANA, BRE, CAS, CDO, CHA, DAC, DDR, DOH, EAB, EPI, ESV, EUO, FAR, FRA, FER, GIS, GIU, GOO, HEU, IMF, ITE, ITH, KFI, LEV, LIO, LOS, LTN, MAR, MEP, MER, MEL, MFI, MFS, MON, MSO, MTF, MTN, MTT, MWW, NAT, NES, NON, PAU, PHI, RHO, RRO, RTE, RTH, RUT, SGT, SOD, STF, STI, STT, TER, TOL, TON, TSC, TUN, UFI, VNI, VSV, WEI, YUG, etc. There is.

The zeolite membrane may be a single membrane of the zeolite, or the zeolite powder is dispersed in a binder such as a polymer to form a membrane, and the zeolite is fixed in a film form on various supports. A zeolite membrane composite may be used. The zeolite membrane may partially contain an amorphous component or the like.

The thickness of the zeolite membrane is not particularly limited, but is usually 0.1 μm or more, preferably 0.6 μm or more, and more preferably 1.0 μm or more. Moreover, it is 100 micrometers or less normally, Preferably it is 60 micrometers or less, More preferably, it is the range of 20 micrometers or less.

In the multi-tubular separation membrane module of the present invention, the fluid to be separated or concentrated may be a gas or liquid mixture composed of a plurality of components that can be separated or concentrated by the separation membrane element of the present invention. There is no particular limitation, and any mixture may be used, but it is preferably used for a gas mixture.

In the case where the mixture to be separated or concentrated is, for example, a mixture of an organic compound and water (hereinafter, this may be abbreviated as “hydrous organic compound”), when using a zeolite membrane, the water is zeolite. Due to the high permeability to the membrane, water is separated from the mixture and the organic compound is concentrated in the original mixture. A separation or concentration method called a pervaporation method (permeation vaporization method) or a vapor permeation method (vapor permeation method) can be used. The pervaporation method is a separation or concentration method in which a liquid mixture is directly introduced into a separation membrane, so that a process including separation or concentration can be simplified.

In the present invention, when the mixture to be separated or concentrated is a gas mixture composed of a plurality of components, examples of the gas mixture include carbon dioxide, oxygen, nitrogen, methane, ethane, ethylene, propane, and propylene. And those containing at least one component selected from normal butane, isobutane, 1-butene, 2-butene, isobutene, sulfur hexafluoride, helium, carbon monoxide, nitrogen monoxide, water and the like. Among the mixture of these gas components, the gas component having a high permeance passes through the separation membrane and is separated, and the gas component having a low permeance is concentrated on the supply gas side.

The multi-tubular separation membrane module of the present invention can be used in a separation apparatus by being connected depending on the amount of fluid or the desired degree of separation and concentration. If the amount of fluid is large or the target separation / concentration is high and processing cannot be performed sufficiently with one module, connect the piping so that the fluid from the outlet enters the inlet of another module. It is preferable. Moreover, it can be further linked according to the degree of separation and the degree of concentration to obtain the desired degree of separation and concentration.

A separation device in which the multi-tubular separation membrane module of the present invention is installed in parallel may be used to supply gas by branching the fluid. At this time, it is also possible to install modules in series with the modules in parallel. When the parallel modules are connected in series, the amount of gas to be supplied decreases in the serial direction and the linear velocity decreases. Therefore, it is preferable to reduce the number of parallel installations so as to keep the linear velocity appropriately.

∙ Permeated components when modules are arranged in series may be discharged for each module, or may be discharged by connecting the modules together. When connecting the modules, it is preferable to flow the transmission component of the downstream module to the transmission component of the upstream module. By making such a flow, the supply gas and the permeate gas are in AC contact and can be separated and concentrated with excellent performance.

(Example)
Examples The present invention will be described more specifically with reference to examples. However, the present invention is not limited to the description of the following examples unless it exceeds the gist.

[Example 1]
A gas separation simulation was performed on the separation module of the present invention.

The multi-tubular separation membrane module used in the simulation is the one in which the number of baffles 8 is two in FIGS. The multi-tubular separation membrane module 1 was installed so that the axial center line direction of the housing 2 was up and down so that the outlet 6a was at the top.

The housing inner diameter is 49.5 mm, and the total length is 240 mm. The tubular separation membrane has a diameter (= outer diameter C of the tubular separation membrane) of 6 mm, 19 are arranged so that the pitch is 9 mm, and one is located at the center and the apex of a regular hexagon around it In addition, six are arranged at equidistant positions from the vertices on a straight line connecting the vertices of the regular hexagon and the vertices. The exposed length of the film is 188 mm, and 19 films have an area of 0.067 m ² .

The housing is provided with an inlet 9 for supplying gas and an outlet 10 for discharging gas that has not permeated through the membrane at a position 93 mm from the center of the housing, and an inflow pipe and an outflow pipe with an inner diameter of 5 mm are connected to each other. Yes. Further, an outlet 6a through which the gas that has passed through the membrane gathers and passes is arranged, and an outlet pipe having an inner diameter of 6 mm is connected. The gas is supplied so that the gas flow outside the membrane and the gas flow that has passed through the membrane are in an alternating current.

Two baffles 8 are installed in the module, one at a position of 75 mm from the center. Each baffle is provided with 19 insertion holes 8a having centers that coincide with the centers of the separation membranes. . The diameter of the insertion hole (= inner diameter B of the insertion hole) is 7.5 mm, and there is a gap of 0.75 mm between the outer peripheral surface of the tubular separation membrane and the inner peripheral surface of the insertion hole. pass. The thickness of the baffle (= hole length A) is 3 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane is 2.0. It is.

The supply gas is a gas in which two kinds of components having different permeability are mixed, the permeance of the gas having high permeability is 4.0 × 10 ⁻⁷ mol / m ² spa, and the permeance of the gas having low permeability is 3.5 ×. 10 ⁻⁹ mol / m ² spa. The supply rate was 400 NL / min, and the gas composition was 40% for components with high permeability and 60% for gases with low permeability. The gas pressure was set to 3.5 Mpa.

The simulation uses general-purpose fluid analysis software ANSYS Fluent (R14) from ANSYS, and the membrane separation phenomenon cannot be evaluated with standard functions. Therefore, a subroutine that calculates the permeation amount from the partial pressure and permeability of each gas component is incorporated. Went. By performing permeation calculation using physical quantities at each position on the film, changes in local concentration due to the baffle effect can be evaluated. By determining the ratio of the amount of gas supplied to the gas component having high permeability and the amount of gas transmitted, the gas permeability with high permeability was obtained. The permeability of the highly permeable gas obtained by the simulation was 34.2%.

[Example 2]
Example except that the thickness of the baffle was 6 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane was 4.0 The same simulation as in Example 1 was performed with the same module as in Example 1. The permeability of the highly permeable gas obtained by the simulation was 34.2%.

[Example 3]
Example except that the thickness of the baffle is 10 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane is 6.7 The same simulation as in Example 1 was performed with the same module as in Example 1. The permeability of the highly permeable gas obtained by the simulation was 34.6%.

[Comparative Example 1]
Except that the thickness of the baffle is 0.75 mm and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane is 0.5. The same simulation as in Example 1 was performed using the same module as in Example 1. The permeability of the highly permeable gas obtained by the simulation was 32.4%. Compared with Examples 1 to 3, the gas permeability was low.

FIG. 9 shows the relationship between A / (BC) of Examples 1 to 3 and Comparative Example 1 and the permeability of highly permeable gas. It can be seen that there is a large difference in gas permeability between Comparative Example 1 and Examples 1 to 3.

Comparative Example 1 in which the ratio of the hole length, the difference between the inner diameter of the baffle insertion hole and the outer diameter of the tubular separation membrane is 0.5, the hole length, the inner diameter of the baffle insertion hole, and the outer diameter of the tubular separation membrane It can be seen that there is a large difference in gas permeability between Example 1 with a difference ratio of 2, Example 2 with the same numerical value of 4, and Example 3 with the same numerical value of 6.7.

[Example 4]
Next, a gas flow simulation was performed on a module having a structure different from that of the above-described examples and comparative examples.

The inner diameter of the housing is 83.1 mm and the total length is 412 mm. The tubular separation membrane has a diameter of 12 mm, 19 are arranged so that the pitch is 16 mm, one at the center and six at the apex of a regular hexagon around the center, and six at the periphery. Six pieces are arranged at equidistant positions from each vertex on a square vertex and a straight line connecting the vertexes. The exposed length of the film is 200 mm, and 19 films have an area of 0.143 m ² .

The housing is provided with an inlet 9 for supplying gas and an outlet 10 for discharging the gas that has not permeated through the membrane at a position 143 mm from the center of the housing. Has been. Further, an outlet 6a through which the gas that has permeated the membrane gathers and passes is arranged, and an outlet pipe having an inner diameter of 15.8 mm is connected. Gas is supplied so that the flow of gas outside the membrane and the flow of gas that has passed through the membrane are alternating.

Two baffles 8 are installed in the module, one on each metal member portion that is coaxially connected to the lower and upper ends of the tubular separation membrane at a position 75 mm from the center. Nineteen insertion holes 8a having a center coinciding with the center of the film are provided. The diameter of the insertion hole is 12.2 mm, and a gap of 1.0 mm exists between the outer peripheral surface of the tubular separation membrane and the inner peripheral surface of the insertion hole, and gas passes through this gap. The thickness of the baffle is 2 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane is 10.

The supply amount was 3200 NL / min, and the gas pressure was set to 5.0 MPa.

The simulation used general fluid analysis software ANSYS Fluent (R14) manufactured by ANSYS. In order to confirm the flow of the gas after passing through the baffle, the gas flow velocity vector is defined as a flow component parallel to the membrane and a flow perpendicular to the membrane on a plane perpendicular to the membrane 20 mm from the upstream baffle to the downstream side of the gas. It decomposed | disassembled into the component and each calculated the average value. Furthermore, the angle average value of the gas was obtained from the velocity ratio between the flow parallel to the film and the flow perpendicular to the film. A smaller value means a flow parallel to the membrane. The angle average value of the obtained gas was 5.9 °.

[Example 5]
The outer diameter C of the tubular separation membrane was 12.5 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane was 4. Except for this, the same modules as in Example 4 were used, and the same simulation as in Example 4 was performed. The angle average value of the obtained gas was 6.7 °.

[Comparative Example 2]
The outer diameter C of the tubular separation membrane is 15.5 mm, and the ratio A / (BC) between the hole length A and the difference between the inner diameter B of the baffle insertion hole and the outer diameter C of the tubular separation membrane is 0.57. Except that, the same simulation as in Example 4 was performed with the same module as in Example 4. The angle average value of the obtained gas was 16.9 °.

FIG. 12 shows the relationship between A / (BC) and the angle average value in Examples 4 and 5 and Comparative Example 2.

In Examples 4 and 5, the angle with respect to the membrane is small, and a substantially parallel flow is obtained along the membrane. On the other hand, in Comparative Example 2, it can be seen that the angle is large and the flow is oblique to the film.

This application is based on Japanese Patent Application No. 2013-179869 filed on Aug. 30, 2013, the contents of which are incorporated herein by reference.

According to the present invention, it is possible to provide a multitubular separation membrane module in which the flow rate of the fluid to be treated is large, the membrane separation efficiency is excellent, and an increase in weight is avoided.

DESCRIPTION OF SYMBOLS 1,1 'Multitubular separation membrane module 2 Housing 3

Tubular separation membrane

4,5 Support plate 6,6' End plate 6a Outlet 7 Blind plate 8 Baffle 8a Insertion hole 9 Inlet 10 Outlet 11-15 Chamber 16, 16 'Outflow chamber

Claims

A tubular housing;
A plurality of tubular separation membranes disposed in the housing in the longitudinal direction of the housing;
A support plate fixed to the housing and supporting the tubular separation membrane;
In a multi-tubular separation membrane module having an insertion hole through which the tubular separation membrane is inserted and having one or more baffles disposed substantially parallel to the support plate in the housing,
A gap is provided between the inner peripheral surface of the insertion hole and the outer peripheral surface of the tubular separation membrane,
A ratio of A / (BC) between the hole length A of the insertion hole and the difference between the inner diameter B of the insertion hole and the outer diameter C of the tubular separation membrane is 0.67-50. Type separation membrane module.
The multi-tubular separation membrane module according to claim 1, wherein more than half of the fluid to be processed on the upstream side of the baffle flows through the gap and flows downstream.
The multi-tubular separation membrane module according to claim 1 or 2, wherein the plurality of tubular separation membranes are arranged so that the shortest distance between the tubular separation membranes is 2 mm to 10 mm.
The multi-tubular separation membrane module according to any one of claims 1 to 3, wherein the baffles are respectively arranged at positions within 20 cm from both ends of the tubular separation membrane.
The multi-pipe separation membrane module according to any one of claims 1 to 4, wherein the support plates are respectively disposed on both end sides of the housing.
The multitubular separation membrane module according to any one of claims 1 to 5, wherein the tubular separation membrane is a zeolite separation membrane.
A separation apparatus comprising the multitubular separation membrane module according to any one of claims 1 to 6.