JP7238567B2 - MEMBRANE SEPARATION SYSTEM AND METHOD FOR SEPARATION OF ORGANIC COMPOUND/WATER MIXTURE - Google Patents

Description

TECHNICAL FIELD The present invention relates to a membrane separation system having membrane modules installed in series in multiple stages, and a method for separating an organic compound/water mixture using this membrane separation system.

As a method for separating water from a water/ethanol mixture, Patent Document 1 discloses that membrane modules are installed in two stages in series, and a water/ethanol mixture is supplied to the raw fluid chamber of the membrane module in the first stage. Feeding the retentate fluid of the first stage membrane module to the feed chamber of the second stage membrane module is described. In this patent document 1, the entire amount of the non-permeating fluid of the first stage membrane module is supplied to the second stage membrane module, and purified ethanol is obtained only from the second stage membrane module. I can't get it.

Patent Document 2 describes a method for producing alcoholic products using a distillation column and a multistage membrane module, but does not describe a method for producing alcoholic products with different water concentrations.

JP 2016-203078 A International publication WO2018/139635

An object of the present invention is to provide a membrane separation system capable of extracting hydrous organic compounds having different water concentrations, and a method for separating an organic compound/water mixture using this membrane separation system.

A membrane separation system of the first invention is a membrane separation system comprising a membrane module having a raw fluid chamber and a permeate fluid chamber separated by a zeolite separation membrane, wherein first to n-th (n is Integer of 2 or more) in a membrane separation system in which a raw fluid is supplied to the raw fluid chamber of the first membrane module, one of the non-permeating fluids of at least some of the membrane modules other than the n-th membrane module and a take-out means for taking out the non-permeated fluid from the n-th membrane module to the outside of the membrane separation system. is taken out of the membrane separation system without

In one aspect of the first invention, n is 3 or more, and the extracting means includes a first stage extracting means for extracting a portion of the non-permeating fluid from the first membrane module and a non-permeating fluid from the n-th membrane module. n-th stage extraction means.

In one aspect of the first invention, n is 3 or more, and a part of the non-permeating fluid of each of the first to (n-1)th membrane modules and the non-permeating fluid of the n-th membrane module are joined together. Said removal means are provided for removal out of the membrane separation system without causing any disturbance.

In the first invention, n is preferably 3 or more, and the upper limit is 18, for example.

A membrane separation system of a second invention is a membrane separation system comprising a membrane module having a raw fluid chamber and a permeate fluid chamber separated by a zeolite separation membrane, wherein the raw fluid is supplied to the raw fluid chamber; , a second membrane module in which part of the non-permeating fluid of the first membrane module is supplied to the raw fluid chamber; and third to k-th (k is an integer of 4 or more) membrane modules connected in series. wherein the remainder of the non-permeate fluid of the first membrane module is supplied to the raw fluid chamber of the third membrane module to separate the non-permeate fluid of the second membrane module and the non-permeate fluid of the kth membrane module, respectively. It is characterized by comprising a take-out means for taking out the membranes to the outside of the membrane separation system without merging them. Preferably k is 4 or more, and an upper limit is 18, for example.

In one aspect of the first and second inventions, decompression means for decompressing the permeate fluid chamber of each membrane module is provided.

In one aspect of the first and second inventions, each extraction means is provided with a cooling means for cooling and condensing the non-permeating fluid.

A separation treatment method for an organic compound/water mixture of the present invention is a separation treatment method for an organic compound/water mixture using the membrane separation system of the first or second invention, wherein the raw fluid chamber of the first membrane module is and the non-permeating fluid is taken out from each taking-out means without merging the non-permeating fluids.

According to the membrane separation system of the present invention and the method for separating an organic compound/water mixture using the same, the non-permeated fluids taken out by the respective take-out means are taken out of the membrane separation system without being merged, so that the water-containing fluids with different water concentrations are taken out of the membrane separation system. Organic compounds can be obtained.

1 is a configuration diagram of a membrane separation system according to an embodiment; FIG. It is a block diagram of the membrane separation system which concerns on another embodiment.

Embodiments will be described below with reference to the drawings.

FIG. 1 shows a membrane separation system according to a first embodiment. This membrane separation system comprises membrane modules 10, 20, 30 arranged in series in three stages. The interior of each membrane module 10, 20, 30 is separated into a raw fluid chamber and a permeate fluid chamber by zeolite membranes 10a, 20a, 30a. The permeate fluid chamber of each membrane module 10 , 20 , 30 is decompressed by decompression device 19 or 26 .

A source fluid (in this embodiment, a mixture of organic compounds and water) is heated by a heater (heat exchanger) 1 to be vaporized, and then sent through a pipe 2 to a source fluid chamber of the first membrane module 10. supplied. The source fluid supplied to the source fluid chamber of the first membrane module 10 may be liquid. By heating the raw material fluid, the membrane separation efficiency is improved.
The permeate fluid chamber of the first membrane module 10 is decompressed by the decompression device 19, and the raw material fluid is subjected to membrane separation treatment by the zeolite membrane 10a. Specifically, water vapor in the raw material fluid permeates the zeolite membrane 10a and is separated from the organic compound/water mixture.

The organic compound/water mixture as a non-permeating fluid with a reduced water concentration flows out from the raw fluid chamber of the first membrane module 10 to the pipe 11, and part of it is supplied from the pipe 12 to the cooler 13 and cooled, condense. The condensed organic compound/water mixture is taken out of the membrane separation system through the pipe 14 as a first purified fluid.

The remainder of the non-permeating fluid from the pipe 11 is supplied to the raw fluid chamber of the second membrane module 20 via the pipe 15, and membrane separation processing is performed in which water vapor permeates the zeolite membrane 20a. The organic compound/water mixture as a non-permeable fluid whose water concentration is further reduced by this treatment is supplied to the raw fluid chamber of the third membrane module 30 through the pipe 21, and the membrane separation process in which water vapor permeates the zeolite membrane 30a. is done. The organic compound/water mixture as the non-permeable fluid whose water concentration is further lowered by this treatment is supplied from the pipe 31 to the cooler 32 and is condensed. The condensed organic compound/water mixture is taken out of the membrane separation system through the pipe 33 as a second purified fluid.

As mentioned above, the permeate chambers of the membrane modules 10, 20, 30 are evacuated by the evacuator 19 or 26. FIG. The permeating fluid (water vapor in this embodiment) in the permeating fluid chamber of the first membrane module 10 is supplied from the pipe 16 to the cooler 17, cooled to become condensed water (first separated fluid), and passed through the pipe 18. taken out. A decompression device 19 is connected to this pipe 18 .

The water vapor in the permeating fluid chamber of the second membrane module 20 is supplied to the cooler 24 through the pipes 22 and 23, cooled to become condensed water (second separated fluid), and taken out through the pipe 25. A decompression device 26 is connected to the pipe 25 .

The permeating fluid chamber of the third membrane module 30 is connected to the piping 23 via the piping 34, and the water vapor in the permeating fluid chamber of the third membrane module 36 is cooled together with the water vapor from the permeating fluid chamber of the second membrane module 20. It is cooled in vessel 24 and condensed water is taken out from pipe 25 .

In this embodiment, water is membrane-separated in the first membrane module 10 and the first purified fluid whose water concentration is lower than that of the raw material fluid is taken out from the pipe 14 .

In addition, the non-permeating fluid of the first membrane module 10 is further subjected to two-stage membrane separation treatment in the second and third membrane modules 20 and 30, and the second purified fluid whose moisture concentration is further lowered than that of the first purified fluid is piped 33. taken out from

In this way, two purified fluids (organic compound-water mixtures) with different water concentrations are obtained.

The membrane separation system of the first embodiment is configured to obtain the second purified fluid by the membrane modules 20 and 30 installed in two stages in series. A second purified fluid may be obtained by means of membrane modules installed in series.

In addition, part of the non-permeating fluid of each membrane module in the second stage and before the final stage is taken out of the membrane separation system without being combined with the non-permeating fluid of the membrane modules in the other stages, and the membrane in each stage The remainder of the non-permeate fluid of the modules may be supplied to the raw fluid chambers of the subsequent membrane modules, respectively.

For example, part of the non-permeating fluid of the second membrane module 20 may be taken out from the pipe 21 and used as the second purified fluid, and the non-permeating fluid from the pipe 33 may be used as the third purified fluid.

FIG. 2 shows a membrane separation system according to a second embodiment. In FIG. 2, members that are the same as or correspond to those in the membrane separation system of FIG. 1 are denoted by the same reference numerals.

This membrane separation system has four membrane modules 10 , 20 , 30 , 40 . The interior of each membrane module 10, 20, 30, 40 is separated into a raw fluid chamber and a permeate fluid chamber by zeolite membranes 10a, 20a, 30a, 40a. The permeate fluid chamber of each membrane module 10 , 20 , 30 , 40 is decompressed by decompression device 19 or 26 .

A source fluid (in this embodiment, a mixture of organic compounds and water) is heated by a heater (heat exchanger) 1 to be vaporized, and then sent through a pipe 2 to a source fluid chamber of the first membrane module 10. supplied. The permeate fluid chamber of the first membrane module 10 is decompressed by the decompression device 19, and the raw material fluid is subjected to membrane separation treatment by the zeolite membrane 10a. Specifically, water vapor in the raw material fluid permeates the zeolite membrane 10a and is separated from the organic compound/water mixture.

The organic compound/water mixture as a non-permeating fluid with a reduced water concentration flows out from the raw fluid chamber of the first membrane module 10 to the pipe 11, and part of it flows from the pipe 12 to the raw fluid chamber of the second membrane module 20. It is supplied and further membrane-separated. The non-permeate fluid of the second membrane module 20 is supplied to the cooler 13 through the line 12' to be cooled and condensed. The condensed organic compound/water mixture is taken out of the membrane separation system through the pipe 14 as a first purified fluid.

The remainder of the non-permeating fluid from the pipe 11 is supplied to the raw fluid chamber of the third membrane module 30 through the pipe 15, and membrane separation processing is performed in which water vapor permeates the zeolite membrane 30a. The organic compound/water mixture as a non-permeable fluid whose water concentration has been further reduced by this treatment is supplied to the raw fluid chamber of the fourth membrane module 40 through the pipe 21, and the membrane separation process in which water vapor permeates the zeolite membrane 40a. is done. The organic compound/water mixture as the non-permeable fluid whose water concentration is further lowered by this treatment is supplied from the pipe 31 to the cooler 32 and is condensed. The condensed organic compound/water mixture is taken out of the membrane separation system through the pipe 33 as a second purified fluid.

Also in this embodiment, the permeate fluid chambers of the membrane modules 10, 20, 30, 40 are evacuated by the evacuator 19 or 26. FIG.

The permeate fluid chambers of the first membrane module 10 and the second membrane module 20 are decompressed by decompression devices 19 . The structure of the decompression mechanism for the permeate fluid chamber of the first membrane module 10 is the same as in FIG. 1, and the same reference numerals denote the same parts. The permeate fluid chamber of the second membrane module 20 communicates with the pipe 16 via the pipe 28 and is decompressed by the decompressor 19 .

The decompression mechanisms of the permeate fluid chambers of the third membrane module 30 and the fourth membrane module 40 are the same as the decompression mechanisms of the second membrane module 20 and the third membrane module 30 in FIG. 1, and the same reference numerals denote the same parts. there is

In this embodiment, water is membrane-separated in the first and second membrane modules 10 and 20 and the first purified fluid whose water concentration is lower than that of the raw fluid is taken out from the pipe 14 .

In addition, the non-permeating fluid of the first membrane module 10 is further subjected to two-stage membrane separation treatment in the third and fourth membrane modules 30 and 40, and the second purified fluid whose moisture concentration is further lowered than that of the first purified fluid is piped 33. taken out from

In this way, two purified fluids (organic compound-water mixtures) with different water concentrations are obtained.

In the membrane separation system of the second embodiment, the membrane modules 30 and 40 installed in two stages in series are configured to obtain the second purified fluid. A second purified fluid may be obtained by a membrane module that has been assembled.

In addition, a part of the non-permeating fluid of each membrane module before the final stage is taken out of the membrane separation system without being combined with the non-permeating fluid of the membrane modules of the other stages, and the non-permeating fluid of each membrane module is taken out. may be supplied to the raw fluid chambers of the subsequent membrane modules.

For example, part of the non-permeating fluid of the first membrane module 10 may be taken out from the pipe 11 (or 12 or 15) and used as the purified fluid, and part of the non-permeating fluid of the third membrane module 30 may be taken out from the pipe 21 It may be a purified fluid.

Other dehydration equipment such as a distillation column may be installed in the preceding stage of the membrane separation system of the present invention.
<Organic compound>
The hydrous organic compound to which the present invention is applied is not particularly limited, but examples thereof include hydrous organic compounds such as hydrous organic acids, hydrous alcohols and hydrous organic solvents. More specifically, hydrous citric acid, succinic acid, ethylenediaminetetraacetic acid, tartaric acid, salicylic acid, oxalic acid, acetic acid, formic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, benzoic acid, Organic acids such as acrylic acid, adipic acid, malonic acid, apple acid, phthalic acid, glycolic acid, terephthalic acid, fumaric acid; phenols; methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, butyl alcohol, isobutyl alcohol, s - alcohols such as butyl alcohol and t-butyl alcohol; ketones such as acetone and methyl isobutyl ketone; aldehydes; ethers such as dioxane and tetrahydrofuran; nitrogen-containing organic compounds such as amides such as dimethylformamide and N-methylpyrrolidone esters such as acetic ester; organic solvents such as hexane and toluene;
The content of water in the hydrous organic compound to be treated is not particularly limited, and for example, it can be applied to hydrous organic compounds having a water content of 5% by weight or more.
<Zeolite separation membrane>
A porous support-zeolite membrane composite having a zeolite membrane formed on a porous support is usually used as the zeolite separation membrane.

The porous support functions as a support that supports the zeolite membrane. The material constituting the porous support is not particularly limited, and any porous inorganic substance having chemical stability that allows zeolite to crystallize into a film on its surface can be used. good too. Specific examples include sintered ceramics such as silica, α-alumina, γ-alumina, mullite, zirconia, titania, yttria, silicon nitride and silicon carbide. Among them, alumina such as α-alumina and γ-alumina and mullite are preferable, and alumina is particularly preferable.

The porous support itself need not have molecular sieving ability. The porous support is provided with fine pores (pores, voids) communicating from the outside to the inside. A known porous support having pores can be used.

The porous support has a porosity of usually 20% or more, preferably 25% or more, more preferably 30% or more, and usually 80% or less, preferably 60% or less, more preferably 50% or less. The average pore diameter is usually 0.01 μm or more, preferably 0.05 μm or more, more preferably 0.1 μm or more, and the upper limit is usually 20 μm or less, preferably 10 μm or less, more preferably 5 μm or less. A porous support having such pores can appropriately support a zeolite membrane with sufficient strength, and can allow molecules that have passed through the zeolite membrane to permeate at a sufficient speed. Alternatively, it is possible to allow the molecules to reach the zeolite membrane with sufficient velocity. Furthermore, even if pressure is applied from the sealing member by caulking, it will not easily crack. Incidentally, the porosity and pore size of the porous support can be easily specified by a mercury porosimetry method, observation of a cross section with an SEM, or the like. Similar to the average pore diameter, it can also be calculated from volume and mass using true specific gravity.

The thickness of the porous support is not particularly limited as long as it has a predetermined strength. For example, it is preferable to set the thickness to 0.5 mm or more, although it depends on the material, porosity, and the like. More preferably, it is 0.8 mm or more. More preferably, it is 1.3 mm or more.

The inner diameter of the porous support is also not particularly limited as long as it has a predetermined strength. For example, the ratio of the inner diameter to the thickness of the porous ceramic support 1a (inner diameter (mm)/thickness (mm)) is preferably set to 20 or less, although it varies depending on the material, porosity, and the like. It is more preferably 17 or less, still more preferably 13 or less, and particularly preferably 9 or less.

The length (axial length) of the porous support is not particularly limited.

A zeolite membrane is a thin layer formed on the surface of a porous support. The form of the zeolite membrane is not particularly limited as long as it can exhibit molecular sieving ability appropriately.

The zeolite membrane is preferably an aluminosilicate, but metal elements such as Ga, Fe, B, Ti, Zr, Sn, and Zn may be used instead of Al as long as the performance of the membrane is not significantly impaired. Elements such as Ga, Fe, B, Ti, Zr, Sn, Zn, and P may also be included.

Further, the skeleton of the crystalline zeolite forming the pores of the zeolite membrane is preferably an oxygen 8-membered ring or less, more preferably an oxygen 6- to 8-membered ring.

Examples of zeolite structures include AEI, AFG, ANA, CHA, DDR, EAB, ERI, ESV, FAR, FRA, FAU, GIS, ITE, KFI, LEV, LIO, LOS, LTA, LTN, MAR, PAU, RHO , RTH, SOD, STI, TOL, UFI, and the like. Among these, it is preferable to use a membrane composed of AEI, CHA, DDR, ERI, FAU, KFI, LEV, PAU, RHO, RTH, SOD, LTA, UFI type zeolite, and CHA, DDR, LTA, FAU type More preferably, membranes composed of zeolites are used. The n value of zeolite having an oxygen n-membered ring indicates the largest number of oxygen elements among the pores composed of the zeolite skeleton and T elements (elements other than oxygen constituting the skeleton).

When synthesizing a zeolite membrane as a zeolite membrane, an organic template (structure-directing agent) can be used as necessary, but usually there is no particular limitation as long as the template can create the desired zeolite structure, and there is no template. It is not necessary to use if it is possible to synthesize with

Although the thickness of the zeolite membrane is not particularly limited, it is usually 0.01 μm to 30 μm, preferably 1 μm to 15 μm.

Examples of the method of forming a zeolite membrane on the surface of a porous support include a method of crystallizing zeolite into a membrane on the surface of the porous support (see, for example, International Publication No. 2013/125660). ).

1 heater 10, 20, 30, 40 membrane module 10a, 20a, 30a, 40a zeolite separation membrane 13, 17, 24, 32 cooler 19, 26 decompression device

Claims (7)

A membrane separation system comprising a membrane module having a feed fluid chamber and a permeate fluid chamber separated by a zeolite separation membrane,
It comprises first to n-th (n is an integer of 2 or more) membrane modules connected in series,
In a membrane separation system in which a raw fluid is supplied to the raw fluid chamber of the first membrane module,
extracting means for extracting a portion of the non-permeating fluid of at least some of the membrane modules other than the n-th membrane module to the outside of the membrane separation system;
and extracting means for extracting the non-permeating fluid of the n-th membrane module out of the membrane separation system,
The non-permeated fluids from each withdrawal means are withdrawn from the membrane separation system without being merged with each other ,
A membrane separation system , wherein each said withdrawal means is provided with cooling means for cooling and condensing the non-permeating fluid . n is 3 or more, and as the extracting means,
a first stage extracting means for extracting a portion of the non-permeating fluid of the first membrane module;
2. The membrane separation system according to claim 1, further comprising an n-th stage extracting means for extracting the non-permeating fluid from the n-th membrane module. n is 3 or more, and a part of the non-permeating fluid of each of the first to (n-1)th membrane modules and the non-permeating fluid of the n-th membrane module are discharged outside the membrane separation system without merging respectively. 2. A membrane separation system according to claim 1, characterized in that said withdrawal means are provided to withdraw. In a membrane separation system comprising a membrane module having a feed fluid chamber and a permeate fluid chamber separated by a zeolite separation membrane,
a first membrane module in which the source fluid is supplied to the source fluid chamber;
a second membrane module in which a portion of the non-permeate fluid of the first membrane module is supplied to the source fluid chamber;
a third to k-th (k is an integer of 4 or more) membrane modules connected in series;
supplying the remainder of the non-permeate fluid of the first membrane module to the raw fluid chamber of the third membrane module;
A membrane separation system, comprising a take-out means for taking out the non-permeate fluid of the second membrane module and the non-permeate fluid of the k-th membrane module to the outside of the membrane separation system without merging them. 5. The membrane separation system according to any one of claims 1 to 4, further comprising depressurizing means for depressurizing the permeate fluid chamber of each membrane module. 6. The membrane separation system according to any one of claims 4 to 5, characterized in that each of said extraction means is provided with cooling means for cooling and condensing the non-permeating fluid. A separation treatment method for an organic compound/water mixture using the membrane separation system according to any one of claims 1 to 6,
supplying an organic compound/water mixture to the source fluid chamber of the first membrane module;
A separation treatment method for an organic compound/water mixture, wherein the non-permeating fluids are taken out from the respective taking-out means without merging the non-permeating fluids.

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