JPS5889907A - Method for separating liquid mixture - Google Patents

Abstract

PURPOSE:To efficiently separate or concentrate an org. liquid mixture through pervaporation, by using a membrane of a ternary polymer of fluorinated olenfin type monomers. CONSTITUTION:A mixture of org. liquids or water and an org. liquid is separated or concentrated by pervaporation, and the membrane to be used is made of a ternary copolymer of fluorinated olefin, fluorovinyl polyether, and fluorovinyl monoether, and it has 0.01-3m.equiv./g ion exchange capacity, thus permitting pervaporation operation to be enhanced in efficiency and rate of separation or concentration. Suitable operation temp. and pressure are 0-200 deg.C and 0- 100kg/cm<2>, respectively. This membrane is superior in flexibility, and good in mechanincal strength, but it may be supported on a porous base plate and used in a reinforced form.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for separating or separating a liquid mixture containing at least an organic liquid as one of its components (hereinafter abbreviated as an organic liquid mixture) by pervaporation using a specific polymer membrane. Concerning the method of concentrating.

A process for separating organic liquid mixtures using porous, uniform polymeric membranes has been previously described in U.S. Pat.
This is taught in Specification No. 2, etc. This separation process is generally called a pervaporation process using a membrane, in which the liquid to be treated is supplied to the primary side (high pressure side) of the polymer membrane, and substances that are easily permeable are fed to the secondary side (low pressure side). This is a method of preferentially transmitting it as vapor. This membrane separation method separates or concentrates liquid mixtures that could not be separated using conventional simple methods, such as azeotropic mixtures, mixtures with close boiling points and low relative volatility, and mixtures containing substances that polymerize or modify when heated. It is attracting attention as a new way to do so.

Conventionally, the polymer membranes used in such separation methods include bolyene, polypropylene, l-lose-based polymers, boria, crylonitrile, polyamide, polyester, and polysene.

The first known membrane is made of tetrafluoroethylene or a copolymer thereof. However, when such a membrane is used to separate an organic liquid mixture by pervaporation, the following practical difficulties are encountered. In other words, (11) Since the concentration ratio (separation coefficient σAB) caused by an organic liquid mixture passing through a polymer membrane once is small, it takes a very large number of steps to concentrate or separate it to the desired concentration. It must be passed through a membrane. Generally, the separation factor αAB is as follows.

(2) Since the amount of permeation of an organic liquid mixture through a polymer membrane (generally expressed as the permeation amount per unit membrane surface area, unit membrane thickness, and unit time) is small, the membrane surface area must be very small, or The thickness of the polymer membrane must be extremely thin. Therefore.

In the former case, the equipment cost becomes excessive, and in the latter case, problems arise in the strength and durability of the membrane.

As the above-mentioned improved process, a method using a polymer membrane in which a sulfonic acid group or the like is bonded to a polymer base, a method using a specific polyamide membrane, a method using a phonomer polymer membrane, etc. are disclosed in Japanese Patent Application Laid-open No. It is disclosed in Japanese Patent No. 52-111888, Japanese Publication No. 52-111889, Japanese Publication No. 54-33278, Japanese Publication No. 54-55279, etc.

As a result of various studies and examinations on means for separating or concentrating various organic liquid mixtures by Verheber oxidation, the present inventors have discovered that fluorinated olefin compounds such as tetrafluoro-1-tyrene and ,Power! It has been demonstrated that a polymer membrane made of a copolymer with a specific combination of a -7/L-4-vinyl ether compound σ) containing a monophonic acid type organic group can solve the above-mentioned problems.

That is, the present invention describes a liquid mixture containing an organic liquid as one of its constituents by the general formula cr,=czz'
, (where 2 and 2' are 10, -CI, -F, or -CF), and the general formula (%) is an integer of 4, and α and r will never be 0 at the same time,
x, x' and X'' are -F or a perfluorinated primary alkyl group having 1 to 5 carbon atoms, and A is -CN.

-COF, -COOHl-COOR', -COO・
←, or -CON R"R', where R1 has 1 or more carbon atoms
20 alkyl groups, the question is a metal atom or -NR'R'R'
RI, X is the valence number of M, Ro, R1, R4
, R", R" and Ro are hydrogen atoms or one of Ro);
It is made of a terpolymer with a fluorovinyl monoether compound represented by the general formula % formula % number, Y is selected from the above X, and A' is selected from the above A), and its ion exchange capacity It is an object of the present invention to provide a novel method for separating liquid mixtures, which is characterized in that separation is performed by pervaporation using a polymer membrane having a dry resin of 0.001 to 3 milliequivalents (77 grams).

The polymer membrane in the present invention has excellent flexibility and good mechanical strength. When obtaining a copolymer that forms such a polymer film, the composition ratio of the above fluorovinyl polyether compound (1) trifluorovinyl monoether compound and the fluorinated olefin compound in the copolymer is (a) is related to the ion exchange capacity which is linked to the performance of the membrane, so the sum of the above (1) and the fluorophenyl ether compound having the carboxylic acid type functional group 00 is preferably 0.1 in the copolymer. ~50 molar ratio, %C (is 1
It is preferable that the amount is about 40 mono[%]. The amount of each compound (1) and (Itl) in the total value of the compounds (1) and (Itl) is related to the copolymer and also to the mechanical performance of the polymer membrane, such as tumble-drying properties and film-forming properties. Therefore, it is important that the compound (1)/compound (IO) (molar ratio) is
Preferably.

01-5,0. In particular, it is preferable to set the value to 02 to 2.0.

To explain the present invention in more detail below, the fluorovinyl polyether compound 0), which is a monomer compound constituting the copolymer, has the general formula CF, =cv- as described above.
0-CF, (CFXOCF, ) -(CFX')
-β (CF, 0CFX") -A γ where a, β, f, is 0~
5. r is particularly preferably 0 to 1, x% Particularly preferred.

A preferred representative example is:

cF', :CFOCF, CF(CF, )OCF,
CF, CF, cooco, CF, =cvo(
CF, )s-OCFCOOCH,, CF.

CFx = CFO(CFx)40CFCOOCHI
1CF.

CF, =crocr, CF? -0CF, CF,
C.O.F.

■ C.F.

CF! =CFOCF*CF(CFI)OCFCOF
C.F.

Examples include.

In addition, the fluorovinyl mo7 ether compound (rI) is
As above, the general formula CF, -CF+(CFY), -A'
where δ, Y, and A' are as described above, but δ is preferably 2 to 4, -Y is preferably -F, and A' is preferably one from the viewpoint of ease of polymerization. 〇〇F, -COO
R+ is preferred. The preferred/representative example is CFs ""CFO(C'*) 2-4-CO0C
Hs.

CFI = CFO-(CF,)2-4COOCiHa,
CF, :CFO(CF, )2-4-COF.

Expressed by talent.

Furthermore, the 7-nominated olefin compound tnI is represented by the general formula CF2:CZZ' as shown in 0) above.
% 2' is as shown in the table below, and its preferred representative examples include polyethylene tetrafluoride, ethylene trifluorochloride,
Examples include propylene hexafluoride, ethylene trifluoride, and hynyritene fluoride.

Generally, perfluoro compounds are preferred, and tetrafluoroethylene is particularly preferred.

Incidentally, A and A' in the specific polymer membrane of the present invention may be selected as described above from the viewpoint of copolymerization reactivity, etc., but may also be selected depending on the organic liquid mixture to be pervaporated. It can be selected as appropriate.

For example, it is possible to convert the functional groups into an appropriate form after forming a polymer film. Examples of M include metal atoms such as alkali metals and alkaline earth metals, or -NR4R''RmR1.

In producing the above copolymer, one or more of the above compounds may be used, and the resulting copolymer may also be modified by copolymerizing other θ) monomers. It's common. for example.

By using CF, :CFOR, (R is a perfluoroalkyl group having 1 to 10 carbon atoms) in combination, further flexibility can be imparted to the obtained film, or cr, = cll-C
F=Cpg, CF,=CF-0(CF,), ~5-O
By using dihinyl monomers such as CF=CF.

It is also possible to crosslink the resulting copolymer. Furthermore, one or more types of other functional monomers having a sulfonic acid type functional group can also be used in combination.

Means for carrying out the copolymerization include peroxy compounds, with or without inert organic or aqueous solvents;
Known means such as carrying out the reaction under the action of a polymerization initiation source such as an ab compound, ultraviolet rays, or ionizing radiation can be employed. For example, 1% Publication No. 48-2223, Special Publication No. 48-207
It is carried out by the method described in Japanese Patent Publication No. 88 and Japanese Patent Publication No. 48-41942. As for the polymerization method, various methods such as bulk polymerization, solution polymerization, suspension polymerization, and precipitation polymerization can be adopted.

The heptad-containing copolymer of the present invention may be a graft copolymer or a flock copolymer, but the 11-phonic acid type functional groups are uniformly dispersed in the copolymer and a uniform ion exchange container lid is formed. A copolymer obtained by directly copolymerizing each of the above-mentioned monomer compounds is particularly preferable in that a polymer membrane having the above-mentioned monomer compounds can be obtained.

In the present invention, means for forming a polymer membrane from a fluorine-containing copolymer having a specific carboxylic acid type functional group (hereinafter abbreviated as carboxylic acid type fluororesin) as described above may be any known means, For example, press molding, roll molding, extrusion molding, solution casting, dispersion molding, powder molding, etc. are used.

In the present invention, a carbonic acid type fluororesin is employed, and in a preferred embodiment, the ion exchange capacity is selected from a wide range of 0.01 to 3 milliequivalents/g dry resin as described below. The ion exchange capacity is preferably 0.
A level of 1 to 2.2 milliequivalents/gram dry resin is employed. In addition, from the viewpoint of mechanical strength as a polymer membrane, the molecular weight of the carbonic acid type fluororesin is preferably 50°C or less, preferably about 70 to 300°C, expressed as the value of T, which will be described later. It is.

In this specification, the term "TQJ" is defined as follows. That is, the temperature at which the volume flow rate of 100 g++j/sec, which is related to the molecular weight of the polymer, is TQff
i defined. In this case, the volumetric flow rate was determined by using a polymer with one -COOCH carboxylic acid type functional group, and melting the polymer from an orifice with a length of 111% and 2 mm at a constant temperature under a pressure of 30 kg/ffl. It shows the amount of polymer flowing out and flowing out in units of 1/sec.

In addition, "ion exchange capacity" was determined as follows. That is, a carbonic acid type fluororesin in which the carbonic acid type functional group was a -COOH group was allowed to stand at 60°C for 5 hours in 1N HCl to completely convert it to the H type.

It was thoroughly washed with water so that no HCl remained.

After that, 0.5f of this H-type resin was diluted with 0.1N NaOH.
In a solution of 25 ml' and 25 ml of water.

It was incubated for 2 days at room temperature. Next, the resin was taken out, and the Na01l υ)1° in the solution was mixed with 0.1N of )IcI.
This is what is required by back titration with ζ).

The phosphoric acid type fluororesin of the present invention may be prepared by using a polymer of olefin such as bolyene, polypropylene, polytetrafluorophylene, etc., as necessary during film formation.
It is also possible to blend and mold fluorine-containing copolymers such as copolymers of ethylene and tetrafluoroethylene.
Or fabrics made of stiff polymers, such as cloth.

The membrane can be reinforced by supporting the copolymer with a support made of nonwoven fabric or porous film. The weight of the resin forming the blend or support is:
It is not included in the above ion exchange capacity value.

The polymer membrane made of carbonic acid type fluororesin used in the present invention is a non-porous uniform membrane, and its thickness is 1 to 25 mm.
0 micron, preferably about 5 to 180 micron. If the film thickness is too thin, the film will lack strength or durability. Furthermore, if the membrane is too thick, the amount of permeation of the liquid mixture becomes small, making it impractical. The shape of the polymer membrane is usually a flat membrane, but it can also be used in other shapes, such as a cylindrical shape or a hollow fiber shape, to increase the surface area. Furthermore, various reinforcing means may be applied, such as embedding a reinforcing material such as a cloth in the membrane, or laminating the membrane on a porous reinforcing body.

The method of the present invention uses the above-mentioned carbonic acid type fluororesin membrane, -
It is carried out using a device that is divided into a secondary chamber and a secondary chamber.

- The next chamber contains the organic liquid mixture to be separated or concentrated in liquid form, while the two chambers are reduced in pressure by an appropriate method, or
or circulating other liquids or gases. In this way, the organic liquid mixture is permeated through the polymer membrane and separated or concentrated by pervaporation. - The liquid inside the next chamber is preferably circulated externally or internally, or - agitated by providing a suitable stirring device inside the next chamber. Certain polymer membranes.

The primary chamber and the secondary chamber are partitioned off by a suitable method, but it is advantageous in terms of durability to support them with, for example, a perforated reinforcing plate. - Substances that permeate the polymer membrane from the next chamber are taken out from the second chamber and collected. 2. Usually, it is desirable to appropriately heat the secondary chamber and/or the secondary chamber using a suitable heating device, such as a heating jacket.

The separation method of the present invention is carried out over a wide range of temperatures, typically from 0 to 200°C, preferably from room temperature to 100°C.
Selected from a range of degrees.

If the temperature is too high, problems will arise in maintaining the shape of the polymer membrane, and if the temperature is too low, the amount of liquid permeated will be small. Generally, the higher the temperature, the greater the amount of permeation (separation coefficient). In addition, the pressure range that can be adopted is usually from vacuum to 100kg.
/i, preferably vacuum ~30X? /d, and if the pressure is too high, it becomes difficult to maintain the shape of the polymer membrane.

Organic liquid mixtures that can be separated by the method of the present invention include various combinations, such as mixtures of organic substances that cannot be separated by normal distillation methods due to the presence of azeotropic points, and mixtures of organic substances whose boiling points are close to each other. This is particularly effective in the case of mixtures of organic substances that are difficult to separate by distillation due to their presence. In addition, all of the organic liquid mixtures may be mutually uniformly dissolved, or some of them may exceed the solubility and precipitate into a suspended state (・.

However, the organic liquid mixture needs to be in a liquid state in its mixed state within the above-mentioned implementation temperature range and at normal pressure or within the employed pressure range.

Examples of such organic liquid mixtures include benzene/cyclohexano, benzene/
Mixtures of organic substances such as n-hexane, methanol [/acetone, benzene/methanol L, acetone 7/rippho/1 person; water/isopropano+1 water/ethanol, water/n-propano-, rl, water /γrino lal-
J-) [, Water/2-Methogycy L-Tano+1. Water/isositanol, water/n-butano-1, water/2-sitanol + 1 water/fluor L frill γ/l cole, water in-
Water/alcohol mixtures such as pental, water/2-pental, water/4-methyl-1-butano/1: water/tetrahydrofuran, water/water/water such as methyl ethyl ketone, water/methyl ethyl ketone, etc. Examples include organic solvent mixtures.

1. Mixtures with boiling points close to each other include ethylbenzene/styrene, p-ethylbenzene/
p-ri p-L styrene, torcomine/methylcyclohexane, butadiene/butenes, butadiene/butanes, n
Other examples include water/glycerin, water/glycols, water/purpylene chlorohydrin, water/purpylene chlorohydrin, water/butene/, I-butene, etc.
Examples include epichlorohydrin, water/hydrazine, and isomer mixtures.

Furthermore, the method of the present invention can be applied to the mixture of stiff straw not only in a two-component system as described above but also in a multi-component system including a ternary or more component system. Of course, the method according to the invention can also be applied to mixtures containing organic and inorganic substances, such as wastewater containing organic liquids.

The mixing ratio of the liquid mixture to be treated can be changed within an arbitrary range, but in general, the closer the ratio is to an isothermal mixture, the higher the concentration ratio will be. If the desired purity cannot be obtained by passing through a polymer membrane once (-membrane concentration), pass it through a similar device multiple times (multi-stage concentration).
It is also possible to concentrate or separate the organic liquid mixture to the desired extent.

Examples of the present invention will be described in more detail below, but it goes without saying that the present invention is not limited in any way by such explanations. )O(CF, )
40 parts by weight of scoocHJ and CF, -C
60 parts by weight of Fw)sCOOCHsυ), trichlorotriolethane, and 7./hisisosol-TIJ nitrino as a catalyst were charged into a 200 mt stainless steel pressure-resistant reaction vessel. After sufficiently degassing with liquid nitrogen, the reaction vessel was The temperature was raised to 70°C, and tetrafluoroethylene was charged to carry out the reaction. After 18 hours, the flow rate was 100 m.
A terpolymer having a temperature of 180° C. and a temperature of 180° C. was obtained. The terpolymer was press-molded at 200°C to a thickness of 1
It was made into a film of 00μ.

After hydrolyzing the film in a caustic sorter,
Treated at 0°C for 16 hours, then dried at 70°C for 24 hours, leaving an ion exchange volume'! 1. Obtain a film of 10 n+sq//f. A mixed solution of water and isopropanol/L (isopropanol water-
82/1 B, weight ratio) is separated L1. Temperature 40°0
, the permeate side pressure is 10-1 to Hg, the odor coefficient is 23.6, and the permeation amount is 306 f/g/hr.

Example 2゜CF, two CFOCFgCF (CFm) OCPICF (
CFs)O(CFs)l 50 parts by weight of C00CHx and CF, =CFO(CF, ), C00CH,
A copolymerization reaction with tetrafluoroethylene was carried out in the same manner as in Example 1, using 50 parts by weight of 50 parts by weight, to obtain a terpolymer having an ion exchange capacity of 0.98 meq/P.

The copolymer was press-molded into a film with a thickness of 100 μm. After hydrolyzing the film in a caustic saw, the functional group is changed to -COOH type in hydrochloric acid.

Treated in pure water at 90°C for 16 hours and dried at 70°C for 24 hours.

A mixed solution of water and ethanol (ethanol/water = 94/6, weight ratio) was separated using barber ball rayon using a loading/unloading method. The separation coefficient of the water obtained at 40° C. and 10 −1 Hg with respect to ethanol was 5.94, and the permeation amount was 742 f/77/·hr.

Procedural amendment (bin) April 2, 1980 Haruki Shimada, Commissioner of the Patent Office1, Indication of the case, 1988 Patent Application No. 1883872, Name of the invention Method for separating liquid mixtures3, Person making the amendment Case and Relationship Patent applicant address 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Name (
004) Asahi Glass Co., Ltd. 6. Number of inventions increased by amendment None 7. Subject of amendment Specification

Claims (1)

[Claims] A liquid mixture having a small amount of organic liquid as one of its constituents is defined by the general formula CFs-CZZ' (here!). 2 and 2' are -14, -(:l, -F or A fluorinated olefin compound represented by the general formula %) is an integer of 4, and a and r cannot be 0 at the same time.
, x, x' and X" are -F or a perfluoroalkyl group having 1 to 5 carbon atoms, and ^ is 10N. -COF, -Coo)!, -COOR', -C
OO・-! -, or -〇〇NR"R', R1 is an alkyl group having 1 to 20 carbon atoms, and U is a metal atom or -NR
IR'R'R', X is the valence number of M, R1
%Bm, Ha, R@, R@ and R' Gt Water XJ
A fluoropovinyl polyether compound represented by the general formula %, Y is selected from the above X, and ^' is selected from the above ^). It consists of a terpolymer with a fluorovinylmo/ether compound, and its ion exchange capacity is 0.
．． 1. A method for separating a liquid mixture using a polymer membrane having a dry resin of 0.01 to 3 milliequivalents/gram, the separation being carried out using a barbeque rayon.