JP2016159211A - Separation membrane module and operation method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separation membrane module which can dry a separation membrane extremely easily, and provide an operation method of the same.SOLUTION: A separation membrane module 1 includes a cylindrical housing 2, a plurality of tubular separation membranes 3 which are formed of zeolite and are arranged in a longer direction of the housing 2, and an end pipe 4 connected to one end of the tubular separation membrane 3, and a support plate 5 for supporting the end pipe 4. In starting up the separation membrane module, gas for drying, of which a major component is carbon dioxide, is supplied in the housing 2 from a reservoir tank 55 or a carbon dioxide cylinder 60 to dry the separation membrane 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a separation membrane module used for separating some components from a fluid such as a solution or a mixed gas, and an operation method thereof.

  A separation membrane module is known as an apparatus for separating components in a solution or mixed gas. The tubular separation membrane used in this separation membrane module has a tubular porous ceramic support and a porous separation membrane made of zeolite or the like provided on the outer peripheral surface of the support. 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 (Patent Documents 1 and 2).

  When moisture adheres to the zeolite membrane, the separation performance of the zeolite membrane is lowered. Patent Document 3 describes that vapor condensation at start-up is prevented by heating the zeolite membrane with an electric heater.

JP 2013-39546 A JP 2011-152507 A JP 2009-39654 A

  According to the separation membrane module of Patent Document 3, by heating the zeolite membrane with an electric heater, water attached to the zeolite membrane can be removed, that is, the zeolite membrane can be dried.

  However, in Patent Document 3, it is necessary to install an electric heater along all the tubular zeolite membranes, resulting in high costs. In addition, work such as inspection and repair of the zeolite membrane becomes extremely troublesome.

  An object of this invention is to provide the separation membrane module which can dry a separation membrane very easily, and its operating method.

  The separation membrane module of the present invention has a housing and a separation membrane disposed in the housing, and is supplied with a fluid to be treated and takes out the fluid that has permeated the separation membrane. It is characterized by comprising a separation membrane drying means for supplying a drying gas mainly containing a characteristic gas into the separation membrane module.

  In one embodiment of the present invention, the separation membrane is a zeolite membrane, and the drying gas contains carbon dioxide as a main component.

  The membrane drying method for a separation membrane module according to the present invention is a method for operating such a separation membrane module, in which the separation membrane is dried with a drying gas when the separation membrane module is activated. In addition, after starting, it is preferable to dehydrate the gas to be processed.

  In the separation membrane module of the present invention, a drying gas mainly containing a separation membrane permeable gas is supplied into the separation membrane module to dry the separation membrane. When the separation membrane permeable gas permeates the separation membrane, water attached to the separation membrane is removed from the separation membrane along with the permeation gas, and the separation membrane is dried. Thereby, the separation performance of the separation membrane is improved.

  The membrane drying process is preferably performed at the time of starting the separation membrane module, but may be performed during the operation. During operation, it is preferable to prevent water from adhering to the separation membrane by dehydrating the gas to be treated supplied to the separation membrane module.

It is sectional drawing in alignment with the housing axial center line direction of the main-body part of the separation membrane module which concerns on embodiment. It is the II-II sectional view taken on the line of FIG. It is the III-III sectional view taken on the line of FIG. It is an expanded sectional view of an end pipe and a support plate. It is a flowchart of a separation membrane module.

  With reference to FIGS. 1-5, the separation membrane module which concerns on one embodiment of this invention is demonstrated.

  The separation membrane module 1 includes a cylindrical housing 2 having a cylindrical axis direction as a vertical direction, and a plurality of tubular separation membranes (zeolite membranes in this embodiment) 3 arranged in a direction parallel to the axis line of the housing 2. A support plate 5 provided in the lower part of the housing 2, a bottom cover 6 A attached to the lower end of the housing 2 and a top cover 6 B attached to the upper end, a lower part in the housing 2 parallel to the support plate 5, and A first baffle (rectifying plate) 7, a second baffle (rectifying plate) 8, and the like disposed on the upper part are provided. The first baffle 7 is disposed on the upper side of the support plate 5.

  In this embodiment, outward flanges 2a, 2b, 6b, 6c are provided on the lower and upper ends of the housing 2 and the outer peripheral edges of the bottom cover 6A and the top cover 6B, respectively, and these are fixed by bolts (not shown). Has been. The peripheral edge of the support plate 5 is supported by a support seat 2 t that is provided around the inner peripheral surface of the housing 2. A seal member is interposed between the outer peripheral portion of the lower surface of the support plate 5 and the upper surface of the support seat 2t.

  In this embodiment, the end tube 4 is connected to the lower end of the tubular separation membrane 3, and the end plug 20 is connected to the upper end of the tubular separation membrane 3. Although only seven tubular separation membranes are shown in FIGS. 1 to 3, a large number are actually provided as shown in FIG. Moreover, you may be set as the tubular separation membrane coupling body by which the 2 or more tubular separation membrane 3 was connected by the joint pipe (not shown).

  An inlet 9 for the fluid to be processed is provided on the outer peripheral surface of the lower portion of the housing 2, and an outlet 10 for the non-permeating fluid is provided on the outer peripheral surface of the upper portion. The inflow port 9 is provided so as to face the chamber 11 between the support plate 5 and the first baffle 7. The outlet 10 is provided so as to face the upper chamber 12 of the second baffle 8. Between the baffles 7 and 8 is a main chamber 13 for performing membrane separation.

  A plurality of rods 14 are erected from the bottom support plate 5, and the baffles 7 and 8 are supported by the rods 14. A male screw is engraved at the lower end of the rod 14 and is screwed into the female screw hole of the support plate 5. The baffles 7 and 8 are supported at a predetermined height by sheath tubes 14A and 14B (FIG. 4) fitted on the rod 14. The sheath tube 14 </ b> A is disposed between the support plate 5 and the baffle 7. The sheath tube 14 </ b> B is disposed between the baffles 7 and 8. The baffle 8 is mounted on the upper end surface of the sheath tube 14 </ b> B and is fixed by a nut screwed to the upper end of the rod 14. The number of baffles is not limited to this embodiment, and three or more baffles may be used.

  A seal member such as an O-ring, a V-packing, or a C-ring may be interposed between the outer peripheral surfaces of the baffles 7 and 8 and the inner peripheral surface of the housing 2.

  Each baffle 7, 8 is provided with circular insertion holes 7 a, 8 a for inserting the tubular separation membrane 3, and a connection body of the tubular separation membrane 3, the end tube 4 and the end plug 20 is provided in each insertion hole 7 a. , 8a. The diameters of the insertion holes 7a and 8a are larger than the diameters (outer diameters) of the tubular separation membrane 3, the end tube 4 and the end plug 20, and the inner peripheral surfaces of the insertion holes 7a and 8a, and the end tube 4 and the end plug 20 There is a gap between the outer peripheral surface and the entire circumference.

  An insertion hole 5 a into which the lower end of the end tube 4 connected to the tubular separation membrane 3 is inserted is provided on the upper surface side of the support plate 5. The insertion hole 5a has a cylindrical shape and extends from the upper surface of the support plate 5 to the middle in the thickness direction. The bottom of the insertion hole 5a faces the outflow chamber 16 below the support plate 5 through the small hole 5b and the large hole 5c.

  The tube hole 4a of each end tube 4 communicates with the outflow chamber 16 between the bottom cover 6A and the support plate 5 via the small hole 5b and the large hole 5c. The bottom cover 6A is provided with an outlet 6a for the separated permeated fluid.

  Although illustration is omitted, a groove is provided on the outer peripheral surface in the vicinity of the lower end of the end pipe 4, and an O-ring made of fluororubber, fluororesin, or the like is attached. Further, a groove concentric with the tube hole 4a of the end tube 4 is provided around the lower end surface of the end tube 4 and an O-ring is mounted. These O-rings are brought into close contact with the inner peripheral surface of the insertion hole and the bottom surface of the insertion hole 5a, whereby the outer surface of the end tube 4 and the insertion hole 5a are sealed. Note that only one of the O-ring on the outer peripheral surface of the end tube 4 and the O-ring on the lower end surface may be provided.

  As shown in FIG. 5, the upper end portion of the end tube 4 has a small diameter portion 4 g and is inserted into the lower portion of the tubular separation membrane 3. An O-ring is mounted in a groove provided around the outer peripheral surface of the small diameter portion 4g. An O-ring is also interposed between the lower end surface of the tubular separation membrane 3 and the step surface of the end tube 4. The connecting portion between the end tube 4 and the tubular separation membrane 3 may be sealed by using a heat shrinkable tube without using the O-ring as described above. It may be used.

  An end plug 20 is connected to the upper end of the tubular separation membrane 3. The end plug 20 has a cylindrical shape or a shape obtained by cutting a part thereof, and seals the upper end of the tubular separation membrane 3. A small diameter portion inserted into the tubular separation membrane 3 is provided at the lower end of the end plug 20. The end plug 20 and the tubular separation membrane 3 are sealed with an O-ring. Further, the end plug 20 and the tubular separation membrane 3 may be sealed by using a heat shrinkable tube without using an O-ring, or a heat shrinkable tube may be further used after using an O-ring.

  In order to reduce the weight of the end plug 20, a recess 20 v is formed from the upper end surface of the end plug 20. You may provide the drain hole which connects the bottom part of the recess 20v, and the side peripheral surface of the end plug 20. As shown in FIG.

  In this embodiment, since the end plug 20 is disposed on the upper end side of the tubular separation membrane 3, a load is applied to the tubular separation membrane 3, the end plug 20, and the end tube 4 in a direction in which their end faces are pressed against each other. Is on.

  However, in the present invention, the end tube 4 and the support plate 5 may be disposed on the upper end side of the tubular separation membrane 3, and the end plug 20 may be disposed on the lower end side of the tubular separation membrane 3. In this case, by providing a biasing member such as a spring for biasing the end plug 20 upward, the end surfaces of the tubular separation membrane 3, the end plug 20, and the end tube 4 are pressed against each other. It is preferable to apply a load.

  In this embodiment, the lower end portion of the end tube 4 of the connection body of the tubular separation membrane 3, the end tube 4 and the end plug 20 is inserted into the insertion hole 5 a provided in the support plate 5, and the tubular separation membrane 3 and the end A connecting body of the tube 4 and the end plug 20 is erected on the support plate 5. The end tube 4 and the support plate 5 can be easily connected in an airtight or liquid-tight manner simply by inserting the lower end portion of the end tube 4 into the insertion hole 5a. Moreover, since the insertion hole 5a is cylindrical, the operation | work which drills the insertion hole 5a in the support plate 5 is easy, and manufacture of the support plate 5 is also easy. Therefore, it is possible to shorten the manufacturing period of the separation membrane module and reduce the manufacturing cost.

  In order to dry the tubular separation membrane 3, the separation membrane module 1 is provided with a drying gas supply means mainly containing a separation membrane permeable gas in the housing 2.

  FIG. 5 is a flowchart showing an example. A supply pipe 30 for the gas to be processed that has passed through the water vapor separator 29 is connected to the inflow port 9, and a valve 31 is provided. A non-permeating fluid outlet 10 is connected to a non-permeating fluid outlet pipe 40 and is provided with a valve 41. A permeating fluid outlet pipe 50 is connected to the permeating fluid outlet 6a, and a valve 51 is provided. On the upstream side of the valve 51, a sorting pipe 52 branches from the pipe 50, and is connected to the inlet of the reservoir tank 55 via a valve 53 and a booster pump 54. The outlet of the reservoir tank 55 is connected to the downstream side of the valve 31 in the pipe 30 through a pipe 56 and valves 57 and 58. A carbon dioxide gas cylinder 60 is connected between the valves 57 and 58 of the pipe 56 via a pipe 61 and a valve 62.

  In the separation membrane module 1 configured as described above, the valves 31, 41, 51 are opened and the valves 53, 57, 58, 62 are closed during normal operation. After the water vapor is removed by the water vapor adsorber 29, the fluid to be treated is introduced into the chamber 11 of the housing 2 through the pipe 30 and the inlet 9, and the inner peripheral surface of the insertion hole 7 a of the baffle 7 and the end pipe 4. The air flows into the main chamber 13 through the gap between the outer peripheral surface, passes through the main chamber 13, and then flows out into the chamber 12 through the gap between the insertion hole 8 a of the baffle 8 and the end plug 20. While flowing through the main chamber 13, some components of the fluid to be processed permeate the tubular separation membrane 3 and flow out from the tubular separation membrane 3 to the pipe 50 through the outflow chamber 16 and the outlet 6 a. The fluid that has not permeated flows out from the outlet 10 to the pipe 40.

  In this embodiment, the gas to be treated contains carbon dioxide. The carbon dioxide gas passes through the zeolite tubular separation membrane 3, and a gas mainly composed of carbon dioxide gas flows into the pipe 50.

  At an appropriate time of operation, the valve 53 is opened and the pump 54 is operated to increase the pressure of carbon dioxide as a main component and introduce it into the reservoir tank 55. After the pressure in the reservoir tank 55 reaches the specified pressure, the valve 53 is closed, the pump 54 is stopped, and a gas containing carbon dioxide as a main component is stored in the reservoir tank 55. The pressure is usually preferably set to 0.1 MPaG or more and 1.0 MPaG or less. There is no restriction on the pump for boosting pressure, but it is preferable to use a pump that does not contain foreign matter or oil.

  When starting up the separation membrane module 1, the valves 51, 57, 58 are opened, the valves 31, 41 are closed, and a gas mainly composed of carbon dioxide in the reservoir tank 55 is supplied into the housing 2. Thereby, the carbon dioxide gas in gas permeate | transmits the zeolite-made tubular separation membrane 3, and the adhering water | moisture content is removed. That is, the water adhering to the separation membrane 3 is quickly removed from the separation membrane 3 by evaporating by the carbon dioxide flow that permeates the separation membrane 3 or moving to the secondary side of the membrane. Is dried and the separation performance is restored. Alternatively, the valves 57, 58, 59 may be opened and the valves 31, 41, 51 may be closed, and carbon dioxide gas that permeates the membrane and contains a large amount of moisture may be purged from the valve 59 to the atmosphere. There are a method of managing the completion of drying by the supply time of carbon dioxide gas, and a method of confirming that the moisture concentration in the permeating gas has been measured and reached a specified value or less. Further, the gas supplied to the separation membrane 3 at the time of drying can be further accelerated by heating by the heater 70. The gas temperature on the heater outlet side is usually 20 ° C. or higher, desirably 35 ° C. or higher, more preferably 50 ° C. or higher.

  When the gas containing carbon dioxide as the main component is not stored in the reservoir tank 55, carbon dioxide is supplied from the carbon dioxide gas cylinder 60 into the housing 2, and the separation membrane 3 is dried. After the drying of the separation membrane 3, the operation is shifted to normal operation.

  The flow in the main chamber 13 and the flow in the tubular separation membrane 3 may be cocurrent or counterflow, and the inflow port 9 and the outflow port 10 of the fluid to be processed may be interchanged.

  The separation membrane module 1 may be used with the top cover 6B side up as shown in FIG. 1 or may be used with the bottom cover 6A side up. Further, the separation membrane module 1 may be installed and used horizontally so that the direction connecting the bottom cover 6A and the top cover 6B is substantially horizontal.

  In this embodiment, a large number of tubular separation membranes 3 are arranged in parallel and the membrane area is large, so that membrane separation is performed efficiently.

  In this embodiment, the end pipe 4 and the end plug 20 connected to the upper and lower ends of the tubular separation membrane 3 are inserted into the insertion holes 7a and 8a of the baffles 7 and 8, respectively. Therefore, even if the tubular separation membrane 3 vibrates or swings so that the end tube 4 and the end plug 20 come into contact with the inner peripheral surfaces of the insertion holes 7a and 8a, the zeolite membrane is not damaged and is stably operated over a long period of time. It can be performed.

  The separation membrane module of the present invention can be used 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.

  The separation membrane modules of the present invention may be installed in parallel to branch the fluid and supply gas. 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 the modules are arranged in series may be discharged for each module, or may be discharged by connecting the modules together.

  Hereinafter, suitable materials for each member constituting the separation membrane module of the present invention will be described.

  As the steam separator 29, a casing in which a steam absorbent such as zeolite or silica gel is accommodated in a casing is suitable. However, a condenser that condenses steam by a cooling method can also be used.

  Examples of the material of the end tube 4 and the end plug 20 include, but are not limited to, metals, ceramics, resins, and the like that do not allow fluid to permeate. The material of the baffles 7 and 8 and the joint tube 17 is usually a metal material such as stainless steel, but is not particularly limited as long as it has heat resistance and supply under separation conditions and resistance to a permeation component. It can be changed to other materials.

  The tubular separation membrane 3 preferably has a tubular porous support and a zeolite membrane as an inorganic separation membrane formed on the outer peripheral surface of the porous support. Examples of the material of the tubular porous support include inorganic sintered porous ceramics and metal sintered bodies containing silica, α-alumina, γ-alumina, mullite, zirconia, titania, yttria, silicon nitride, silicon carbide, and the like. A quality support may be mentioned. 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 the 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, 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.

  However, the present invention may use a tubular separation membrane having a separation membrane other than the zeolite membrane.

  The outer diameter 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 is too small, the strength of the tubular separation membrane may be insufficient and may be easily broken. If it is too large, the membrane area per module will be reduced.

  The length of the portion of the tubular separation membrane 3 covered with the zeolite membrane is preferably 20 cm or more, and preferably 200 cm or less.

  In the separation membrane module of the present invention, the tubular separation membrane may be a single tube type or a multi-tube type, and usually 1 to 3000, particularly 50 to 1500 are arranged, and the shortest distance between the tubular separation membranes is 2 mm to 10 mm. It is preferable to arrange so as to be. The size of the housing and the number of tubular separation membranes are appropriately changed depending on the amount of fluid to be processed. The tubular separation membrane may not be connected by the joint tube 17.

  In the separation membrane module of the present invention, the target fluid to be separated or concentrated is not particularly limited as long as it is a gas or liquid mixture composed of a plurality of components that can be separated or concentrated by the separation membrane. However, it is preferably used for a gas mixture.

  For the separation or concentration, a separation or concentration method called a pervaporation method (pervaporation 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, hydrogen, methane, ethane, ethylene, and propane. , Propylene, normal butane, isobutane, 1-butene, 2-butene, isobutene, toluene and other aromatic compounds, sulfur hexafluoride, helium, carbon monoxide, nitrogen monoxide, water, etc. The thing containing a component is mentioned. 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. Therefore, in the above description, the gas to be treated is a carbon dioxide-containing gas, but the separation membrane permeable component in the gas to be treated may be other than carbon dioxide.

DESCRIPTION OF SYMBOLS 1 Separation membrane module 2 Housing 3 Tubular separation membrane 4 End pipe 5 Support plate 5a Insertion hole 5c Large hole 6A Bottom cover 6B Top cover 6a Outlet 7, 8 Baffle 7a, 8a Insertion hole 9 Inlet 10 Outlet 11, 12 Chamber 13 Main chamber 14 Rod 16 Outflow chamber 20 End plug 29 Steam separator 30, 40, 50, 52, 56, 61 Piping 31, 41, 51, 53, 57, 58, 59, 62 Valve 54 Pump 55 Reservoir tank 60 Carbon dioxide gas cylinder 70 heater

Claims (5)

A housing;
A separation membrane disposed in the housing,
In the separation membrane module in which the fluid to be treated is supplied and the fluid that has passed through the separation membrane is taken out,
A separation membrane module comprising a separation membrane drying means for supplying a drying gas mainly composed of a separation membrane permeable gas into the separation membrane module.   2. The separation membrane module according to claim 1, wherein the separation membrane is a zeolite membrane, and the drying gas contains carbon dioxide as a main component.   3. The separation membrane module according to claim 2, wherein the drying gas is a gas generated by concentrating carbon dioxide gas by a membrane separation process of the separation membrane module. A method for operating the separation membrane module according to any one of claims 1 to 3,
A method for operating a separation membrane module, wherein the separation membrane is dried with the drying gas when the separation membrane module is activated.   5. The method for operating a separation membrane module according to claim 4, wherein the gas to be treated supplied to the separation membrane module is dehydrated.

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