JPH01207101A - Process and apparatus for producing concentrated liquid - Google Patents

Abstract

PURPOSE:To produce highly concentrated org. liquid from a mixture of org. liquids by using a combination of pervaporation process and separation process basing on a difference of specific gravities. CONSTITUTION:A mixture of org. liquids such as aq. soln. of butanol, etc., is supplied in a first stage to a permselective membrane 2 consisting of poly(1- methylsilyl-1-propyne), etc., and separated by the pervaporation process, and a permeated component is taken out by vaporizing under reduced pressure generated by a vacuum pump 4, and collected by cooling with a cooler 3. Then, in a second stage, the phase-separated collected liquid is separated further in a separating apparatus 5 basing on a difference of specific gravities, and separated concentrated liquid is collected in a storage tank 6 for the concentrated liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel method and apparatus for producing a concentrated liquid.

[Prior Art] Separation and concentration methods using membranes have been researched and developed, and are expected to develop in the future as an energy-saving method for producing concentrated liquids.

On the other hand, a separation method using a difference in specific gravity has been used for a long time as a concentration separation method such as liquid-liquid extraction.

Among the separation and concentration methods using membranes, the pervaporation method is not affected by osmotic pressure and has a wide range of applications as a method that allows the separation and concentration of mixed liquids in a wide range of concentrations. Such pervaporation membranes include, for example, membranes.

353 (1982) reported separation and concentration of alcohol/water using silicone rubber. Also, Unexamined Japanese Patent Publication No. 6
No. 0-75306 discloses a pervaporation method using a specific substituted acetylene polymer.

Among these separation membranes, silicone rubber and poly(1-trimethylsilyl-1-
Propyne) is a typical example.

However, silicone rubber has a separation coefficient α of about 7 for an ethanol aqueous solution, a permeation rate of about 0.2 kg/i·hr, and a separation coefficient α for a 2-propanol aqueous solution of about 12.
This shows the separation performance.

Poly(1-trimethylsilyl-1-propyne) is
Separation performance has been shown with a separation coefficient α of around 10 for an ethanol aqueous solution, a permeation rate of around 0.5kg/rrr-hr, and a separation coefficient α of around 20 for a 2-propertool aqueous solution. Concentration by pervaporation alone is not sufficient.

In addition, the separation and concentration method using the difference in specific gravity has been used for a long time, but this method alone can only separate liquids that are phase separated, and for homogeneous solutions, it is possible to separate the phase as a third component. It was necessary to add an extract.

Furthermore, no study has been conducted on these combinations.

[Problems to be Solved by the Invention] In order to solve the problems of the present invention, an object of the present invention is to provide a method for producing a highly concentrated organic liquid from a mixture of organic liquids, and an apparatus used therein.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following configuration.

[(1) In a method for producing a concentrated organic liquid from a mixture of organic liquids, the first stage is a selective permeation method.

(2) In an apparatus for producing a concentrated organic liquid from a mixture of organic liquids, the first stage is provided with pervaporation means using a selectively permeable membrane for separating the mixture of organic liquids, and then a cooler is provided, An apparatus for producing a concentrated liquid, further comprising a separation means that utilizes a difference in specific gravity in the second stage. ” In the present invention, the mixture of organic liquids is a mixture of an organic liquid and an organic liquid, or a mixture of an organic liquid and water,
and is a mixture that does not form a homogeneous solution at any temperature and/or concentration. Furthermore, the organic liquids include, for example, alcohols, ethers, ketones, esters, hydrocarbons, halogenated hydrocarbons, amines, aryls, vinyls, and nitriles. Here, specific alcohols include aliphatic alcohols such as methanol, ethanol, propatool, butanol, pentanol, hexanol, cyclohexanol, phenol, and furfural;
Examples include aromatic alcohols. Examples of ethers include chain-like ethers such as diethyl ether, ethylpropyl ether, butyl methyl ether, and tetrahydrofuran.
Examples include cyclic ethers. As ketones,
Examples include chain and cyclic ketones such as acrylaldehyde, ethyl methyl ketone, pentanone, hexanone, heptanone, and cyclohexanone.

Examples of esters include ethyl acetate. Examples of hydrocarbons include saturated, unsaturated aliphatic, and aromatic hydrocarbons such as hexane, heptane, octane, cyclohexane, benzene, toluene, and hexene. Examples of halogenated hydrocarbons include halogenated aliphatics and halogenated aromatics such as chloroform, carbon tetrachloride, dichloroethane, trichloroethane, trichloroethylene, tetrachloroethylene, and chlorobenzene.
Amines include diethylamine, triethylamine,
Examples include aniline and pyridine. Examples of aryls include aryl ether, arylethyl ether, and aryl chloride; examples of vinyls include acrylonitrile, methyl methacrylate, and styrene; and examples of nitriles include acrylonitrile, vinyl acetonitrile, and the like. Furthermore, when the mixture of these organic liquids is a mixture of an organic liquid and water, the organic liquid used is an organic liquid that does not form a homogeneous solution with water at any temperature and/or concentration, and specifically is 1-propyl alcohol, 1-butyl alcohol, 2
-Butyl alcohol, isobutyl alcohol, cyclohexanol, phenol, diethyl ether, ethyl pro- and ethyl ether, ethyl isopropyl ether, ethyl methyl ketone, hexanone, ethyl acetate, benzene, toluene, diethylamine, triethylamine, aniline, chloroform, carbon tetrachloride, Examples include lobenzene, dichloroethane, trichlorethylene, perchloroethylene, and the like. In addition, in the case of a mixture of organic liquids, an organic liquid that does not form a uniform solution at any temperature and/or concentration is used as the organic liquid. Specifically, octane/phenol, cyclohexane/ Aniline, cyclohexane/methanol, hexane/
Examples include combinations such as aniline and hexane/methanol.

The method and apparatus of the present invention are particularly effective for mixtures of organic liquids and water among mixtures of organic liquids, and are further effective for concentrating organic liquids among mixtures of organic liquids and water.

In addition, in the present invention, a selectively permeable membrane is a membrane used for separating and concentrating a liquid, and the material of the membrane, that is, the material of the part of the membrane that substantially has separation performance, is organic or inorganic. Preferably, an organic material is used, and more preferably an organic polymer is used. Organic polymers include vinyl polymers such as polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, polyvinylidene fluoride, polyacrylate, polymethacrylate, polystyrene, polyacrylonitrile, and dienes such as polybutadiene and polyisoprene. polymers, substituted acetylene polymers,
Examples include polyether polymers such as polyorganosiloxane, polyphenylene oxide, and polyethylene glycol, and polymers such as polyester, polyamide, polyimide, polythioether, and polysulfone. Among these polymers, polyorganosiloxanes and substituted acetylene polymers are preferably used. Further, as substituted acetylene polymers, poly(1-trimethylsilyl-1-propyne) and its copolymers or reactants thereof are preferred, and as polyorganosiloxanes, polydimethylsiloxane, its copolymers, and crosslinked products are preferred.

Furthermore, the permselective membrane in the present invention is a membrane mainly composed of homopolymers and/or copolymers of the above-mentioned polymers, and these polymers may contain other polymers and/or other organic monomers, as long as they do not impair the present invention. Inorganic substances may be blended.

In addition, the selectively permeable membrane in the present invention is a membrane having a portion made of the above-mentioned material and having substantially separation performance,
Homogeneous membranes and/or asymmetric membranes made of the above materials alone,
and/or composite membranes, but the present invention is not limited in any way by the structure of these membranes.

Furthermore, the form of the membrane includes flat membranes, hollow fibers, tubular membranes, etc., but the present invention is not limited to these forms in any way.

Furthermore, when using these permselective membranes, flat membranes are generally used as modules such as plate-and-frame or spiral membranes, while hollow fibers and tubular membranes are generally used as modules in which they are bundled. It does not depend on the form of these modules either.

The present invention performs the selective transmission described above as a first step.

In the present invention, the separation method using the difference in specific gravity is a method in which one or both of the phases are extracted separately from a solution that undergoes phase separation under certain conditions. There are two methods: a stationary method in which the phase is extracted, and a centrifugal separation method in which the separated phase is extracted by applying centrifugal force.

The apparatus of the present invention will be explained using the drawings.

First, 1 is a stock solution supply tank, which supplies the raw solution to the separation membrane 2. The stock solution refers to a mixture of concentrated liquids that are to be concentrated, and the separation membrane refers to a selectively permeable membrane. The permeate component is vaporized under reduced pressure by the vacuum pump (4) and taken out from the membrane, cooled by the condenser (3), and collected by condensation. The flocculated liquid obtained here was further separated by a separation device using a difference in specific gravity in No. 5, and taken out to a concentrated liquid storage tank No. 6. In addition, the other thin solution separated by the separation device using the difference in specific gravity of 5 was returned to the stock solution supply tank as a recovery liquid together with the components that did not pass through the membrane.

[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples in any way.

Reference example 1 1 g of poly(1-trimethylsilyl-1-propyne)
A casting solution was prepared by dissolving the solution in 00 ml of cyclohexane. This casting solution was cast onto a glass plate, and the solvent was evaporated at room temperature to obtain a film with a thickness of 30 μm.

Example 1 Using the film obtained in Reference Example 1, a film area of 20 - and a temperature of 40 was applied to a 1.18 wt% 1-butanol aqueous solution.
After separation by pervaporation for 3 hours at ℃ and 10 torr pressure on the permeate side, the cooled and collected permeate was separated by a static separation method, resulting in a concentration of 1- 80.2 wt%. 2.886 (l) of butanol solution was obtained. The separation coefficient α was determined to be 339.

Example 2 A 1.48 wt% i-butanol aqueous solution was separated in the same manner as in Example 1, and the i-butanol solution was concentrated to 83.6 wt%.
-2.000 butanol solutions were obtained. The separation coefficient α was found to be 339.

Example 3 A 1.16 wt % aqueous ethyl methyl ketone solution was separated in the same manner as in Example 1, and 2.89 g of an ethyl methyl ketone solution concentrated to 90.1 wt % was obtained. The separation coefficient α was found to be 775.

Example 4 When a 52 ppm aqueous benzene solution was separated in the same manner as in Example 1, 0.004 (l) of benzene with a purity of 99.9 wt% was obtained as a concentrated liquid.The separation coefficient α was determined to be 1.92 x 107. there were.

Example 5 When an aqueous chloroform solution of 5511)I)m was separated in the same manner as in Example 1, 99°9wt of concentrated liquid was obtained.
% purity of chloroform was obtained. The separation coefficient α was determined to be 1.81×107.

Example 6 A trichlorethylene aqueous solution of 389E)III was separated in the same manner as in Example 1, resulting in a concentration of 99.9% as a concentrated liquid.
0.009 g of trichlorethylene with a purity of 9 wt% was obtained. The separation coefficient α was determined to be 2.63×107.

[Brief explanation of the drawing]

The drawings are simplified illustrations of the concentrated liquid manufacturing apparatus used in Example 1 of the present invention. 1: Raw liquid supply tank 2: Separation membrane 3: Cooler 4: Vacuum pump 5: Separation device that utilizes specific gravity difference 6: Concentrated liquid storage tank

Claims (6)

[Claims] (1) In a method for producing a concentrated organic liquid from a mixture of organic liquids, in the first stage, the mixture of organic liquids is concentrated by pervaporation using a selectively permeable membrane, and then cooled and collected; A method for producing a concentrated liquid, which comprises visually obtaining a concentrated organic liquid from the phase-separated collection liquid by a separation method that utilizes a difference in specific gravity. (2) The method for producing a concentrated liquid according to claim (1), wherein the separation method using the difference in specific gravity is a stationary method or a centrifugal method. (3) The method for producing a concentrated liquid according to claim (1), wherein the selectively permeable membrane is mainly made of a substituted acetylene polymer or polyorganosiloxane. (4) In an apparatus for producing a concentrated organic liquid from a mixture of organic liquids, the first stage is provided with pervaporation means using a selectively permeable membrane for separating the mixture of organic liquids, and then a cooler is provided, An apparatus for producing a concentrated liquid, further comprising a separation means that utilizes a difference in specific gravity in the second stage. (5) The method for producing a concentrated liquid according to claim (4), wherein the separation means using a difference in specific gravity is a static type, and the separation method using a difference in specific gravity is a static type or a centrifugal type. (6) The apparatus for producing a concentrated liquid according to claim (4), wherein the selectively permeable membrane is mainly made of a substituted acetylene polymer or polyorganosiloxane.