JPS59302A - Separation apparatus - Google Patents

Abstract

PURPOSE:To make it possible to separate or concentrate valuable components from a liquid mixtute in high selectivity, in an apparatus for separating a liquid mixture by an osmostic vaporization method, by providing a turblent stream generating means in the flowpassage in a supply side. CONSTITUTION:In a separation apparatus, stirrers 14 or ultrasonic oscillating plates or barrier plates are provided in the supply side flowline of a supply liquid 4 formed by a separation membrane 2 and the wall 13 of the separation apparatus and the liquid in the flow passage is bought to a turblent flow state. By this mechanism, low concn. components in a mixture are selectively permeated through the separation membrane 2 to be removed in good efficiency. If the structure of this separation membrane is set to such a condition that the ratio of the unit area of the separation membrane/the unit volume of the supply side flow passage is larger than 0.05cm<-1> and lower than 10cm<-1> and the void ratio of the supply side flowpassage is below 30%, an especially suitable separation state is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for the separation and/or concentration of liquid mixtures by pervaporation, and more particularly to a novel and efficient separation apparatus structure.

Conventionally, in membrane separation methods for solutes and solutions using reverse osmosis and ultrafiltration, it has been known that the separation performance of the membrane itself deteriorates due to concentration polarization and the formation of a gel layer at the membrane interface. In order to prevent this, the structure of the separation device has been devised and various methods for removing the gel layer have been devised, and some of them have been put into practical use. In the pervaporative separation method, there have been very few reports on the occurrence of concentration polarization or how to eliminate it. However, even in the pervaporation separation method, even though the separation system is a liquid-liquid mixed system, for example, when the composition ratio of the components in the mixture is quite uneven, the separation performance of the membrane is excellent and the less If the permeation rate of the component is high, the membrane interface? At ζ the concentration of the permeate component decreases and an a-degree polarized layer is formed at the membrane interface, as occurs in reverse osmosis. In particular, in the pervaporation separation method, when a homogeneous membrane is used to separate each component of a mixture based on the difference in solubility of 114%, the concentration polarization layer formed at the membrane interface causes the membrane to This causes a significant decrease in cutting performance and a decrease in permeation speed. However, until now, in the pervaporative dispensing method, no device has been developed to prevent the formation of the above-mentioned /S yield polarized layer.

Based on the above-mentioned koji points, the inventors of the present invention have conducted extensive research on a useful pervaporative separation device that can be put to practical use, and as a result, they have arrived at the present invention.

An object of the present invention is to provide a highly efficient separation device for highly selectively separating valuable components from a liquid mixture, or in a pervaporation method, and particularly for components with low concentration Ik in a mixture. It is very suitable for selectively transmitting. The objective is to provide a practical separation device.

To explain the uninvented separation device, the uninvented separation device is a device that separates a liquid mixture consisting of at least two types of components by a pervaporation method, and includes a turbulence generating means in the flow path on the supply side. This is a separation device characterized by having:

The separation method of the present invention is particularly useful in applications where low-level components in a liquid mixture are efficiently and selectively permeated through a membrane to be removed.

The separation device of the present invention will be explained in more detail. The separation device of the present invention generates a flow in the feed liquid flow path,
By making the concentration of the feed liquid in the flow path uniform, the minute 11
This method can sufficiently maintain the performance of the M membrane and also increase the concentration efficiency per unit area of the separation membrane, making it extremely practical. When the blood flow generating means as in the present invention is not provided, if the flow rate of the feed liquid is shifted considerably, the feed liquid in the flow path becomes a laminar flow, so the flow rate at the boundary surface of the separation membrane is very small. As a result, concentration polarization is formed, resulting in a decrease in the apparent separation performance of the membrane. Also, if the flow rate of the feed liquid is increased until turbulence occurs,
Although the escape separation performance is maintained, the residence time of the feed liquid in the separation device is shortened, resulting in a disadvantage that the concentration efficiency per unit area of the separation membrane is reduced.

The blood flow generating means in the present invention is not particularly limited in shape or size, but is capable of generating sufficient turbulence even if the flow rate of the supply liquid is small, and has a volume gap in the flow path of the supply liquid. It is preferable to use one that can increase the ratio as much as possible. When the flow rate of the feed liquid is low and the volumetric porosity of the flow path is large, the residence time of the feed liquid in the separation device increases, and the concentration efficiency per unit area of the bent membrane increases, making it impractical for practical use. It becomes a powerful separation device.

The blood flow generating means in the present invention includes those that can actively bring the liquid in the flow path into a turbulent state, and those that can actively bring the liquid in the flow path into a turbulent state. , which create turbulent flow conditions. Typical examples of turbulent flow generation means that actively create a circulation state in a flow path include a stirrer such as a propeller or screw, a circulation pump, an ultrasonic oscillator, a heat source, etc. It is installed inside the road. For example, FIG. 1 is an explanatory diagram showing an example of the present invention, in which a stirrer 14 is provided in the supply side channel. 13 is a separation device wall, 2 is a separation membrane, and 4 is a feed liquid. The stirrer 14 may be one that rotates so as to mainly push out the feed liquid in a direction parallel to the separation membrane 2, as shown in FIG. FIG. 3 shows an example in which a circulation pump 25 is installed in the supply liquid flow path. The circulation pump 25 sucks the supply liquid 4 from the supply liquid flow path and jets out the liquid at a predetermined jetting speed to generate a circulation flow, that is, an active flow within the supply liquid flow path.

Further, FIG. 4 shows an example in which an ultrasonic oscillation plate 23 is installed in the supply liquid flow path, and FIG. 5 shows an example in which a heat source 24 is installed.

The number and size of the turbulent flow generating means installed above, as well as the ability to generate turbulent flow, depend on the size of the separator and the temperature and ratio of the liquid mixture to be separated. All you have to do is select.

Examples of ways to create a turbulent flow state by controlling the flow of the supply liquid include filling with irregularly shaped fillings such as glass wool or rock wool, or filling with fabrics of inorganic or polymeric figurines knitted into a mesh or net shape. , Filled with an inorganic or polymeric compound molded product with an uneven surface, 8 balls of beads.

Fillers made of inorganic materials or polymer compounds such as porous bodies and amorphous solids, and fillers such as Raschig rings and Lessing rings used as packing materials for packed towers.
There are methods such as forming the inner wall of the separation device itself into an uneven shape, installing a baffle plate, and providing a spiral flow path in the inner wall of the separation device itself. Such examples are shown in FIGS. 6 to 14. Fig. 6 shows an example in which the supply side flow path is filled with glass wool 19, Fig. 7 shows an example in which the feed side flow path is filled with polytetrafluoroethylene net 20, and Fig. 8 shows the inner wall 1 of the separation device.
An example in which a baffle plate 15 is provided on the inner wall 1 of the separation device is shown in Fig. 9.
3 is provided with a dome-shaped protrusion 16, FIG. 10 is an example in which a separator inner wall 17 is provided with unevenness, FIG. 11 is an example in which a helical channel 18 is provided in the separator inner wall 13, and FIG. An example in which a streamlined flow transformer 21 is provided in the supply side flow path, FIG. 13 is an example in which a polyethylene sphere-shaped molded product 22 is filled,
The figure is a schematic explanatory diagram showing an example in which the supply side channel is filled with glass beads 3. In addition, in FIGS. 6 to 14, l
2 is a separation device main body, 2 is a separation membrane, and 4 is a feed liquid. In addition, as a turbulence generating means, the above means alone,
Alternatively, two or more means can be used simultaneously.

Furthermore, in the present invention, it is particularly suitable when the above-described turbulence generating device is used and the structure of the separation device meets the following conditions.

u++ 30%〈Porosity of supply side flow path (-■) Value of L f
If it is less than 0.0 FI ctn ', the distance between the membranes or the distance between the membrane and the inner wall of the separation device will become large, so even if a turbulent flow generating means such as the present invention is used, It becomes difficult to make the concentration of the liquid mixture in the supply side flow path uniform.Also, when the value of L exceeds lQCm', there is As the distance becomes smaller, it becomes difficult to provide a means for generating turbulence, and the residence time of the feed liquid in the separation device becomes shorter, so the concentration efficiency per unit area of the membrane decreases. The value of L needs to be at least 30%. If the value of L is less than 30π, the concentration efficiency will decrease and the pressure loss in the channel will increase, so it will take a lot of energy to supply the liquid. This is disadvantageous in practice because it requires/depends on the separation device having the above structure.It is particularly suitable if a mudflow generating means is provided in the separation device having the above structure.

Among these, the use of fillers such as beads, porous balls, amorphous solids, etc. as means for generating turbulent flow is particularly effective because it can be used in all types of separation cells and is inexpensive. The above-mentioned filling is preferably filled under the following conditions.

If the value of F is less than 10,000, the porosity of the flow path becomes too small and the pressure loss increases, and the value of F becomes F+X.
If it is more than 10', the number of fillers will decrease and the porosity of the flow path will increase, so the mud flow generation effect will be lost. If the value is less than 5 CIA', the porosity of the channel becomes too large and the concentration efficiency per unit area of the membrane decreases. If the filler is filled under the above conditions, it is possible to obtain a highly efficient separation device.

There are no particular restrictions on the material of the mudflow generating means of the present invention, but there are ceramics such as glass and ceramics, and inorganic materials such as carbon and silicon.1. High molecular compounds such as polyamide, polyethylene, polytetrafluoroethylene, and silicone resin 1 Metal materials such as stainless steel, brass, and aluminum are available, and these materials alone or in combination of two or more can be separated. Considering the properties of the liquid mixture, it can be used in various ways.

Next, to explain the pervaporation separation method of the present invention, it is a method that utilizes the difference in membrane permeability of mixture components when a substance is permeated by the difference in chemical potential between the components on the supply side and the permeate side of the membrane. Specifically, the supply side is brought into contact with a liquid mixture containing at least two components through the membrane, and the components that permeate into the permeation chamber are quickly removed from the membrane surface. Separate the mixture and/or
or concentrate. The conditions of the permeation chamber are such that the separation performance of the membrane can be maintained by reducing the pressure below atmospheric pressure, heating, and flowing a carrier gas. If the amount is υ, it is also possible to open the permeate side to the atmosphere and remove the permeate components by natural convection.

The shape of the separation membrane to which the present invention can be applied is not particularly limited, and may be a flat membrane, a cylinder, or a hollow fiber, and can be selected in consideration of the target to be separated, etc. can.

The separation membrane used in the separation device of the present invention is not particularly limited, but the better the separation performance, the more effective results can be obtained. In practice, a practical separation membrane needs to have a separation coefficient of 5 or more, preferably 10 or more. For example, in the separation of a water-organic compound mixture system, the non-applicants are using Tokkosho! '11-4103+1, Special Publication No. 52-29988, Special Application No. Sho F+5-1098
No.90, patent application No. 5FI-114684, patent application No. 114684, patent application No. 114684
-96500 or patent application No. 1161F12/1984
The membrane proposed in this paper is very suitable.

The reason why the uninvented separation device is able to maintain the separation performance of the membrane even at a very low flow rate of the feed liquid is because the velocity vector of the feed liquid is always parallel to the membrane surface due to the installation of the repulsion generating means. However, the concentration at the membrane interface is lower due to the effects such as the fact that turbulence can also occur vertically to the membrane surface, and the flow rate of the feed liquid near the means for generating turbulence is higher than the average flow rate. This is thought to be because polarization can be suppressed. The separation apparatus of the present invention can fully demonstrate the performance of a separation membrane and provide a separation apparatus with high efficiency, and is very useful industrially.

In the present invention, the unit area of the separation membrane is the flow path length 1 c
, is the effective membrane area per nr, and the unit volume of the supply side flow path is the flow path length 1 when no turbulence generating means is provided.
It is the volume of the flow path per cm, and the equivalent volume per packing is the volume calculated by a X X (mean square radius of the packing) 3.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1-6 The separation membrane used was manufactured as follows.

A copolymer of SO % ethylene and 20 wt % methacrylate II/methyl acid was saponified and neutralized (neutralization degree -33).
A thin film containing 40% of the ethylene-based copolymer having -COOH and -C00Na groups obtained by mol%) is heated to form a raw fabric. Next, the original fabric was treated with fuming sulfuric acid containing 12% free sulfur trioxide at 35°C for 10 minutes, washed in the order of concentrated sulfuric acid, diluted sulfuric acid, and water.
Hydrolyzed at 60℃ with potassium hydroxide aqueous solution,
After neutralization, washing with water and drying, the content of sulfonic groups was 2.7Fl! J equivalent/gram film.

The total effective membrane area of the separation membrane is 200Cm, L, V.

The entire separation apparatus filled with glass beads as shown in FIG. 14 was connected to the apparatus shown in FIG. 15 under conditions such that the values of F and S were as listed in Table 1. Then, 90% by weight ethanol water was supplied to the feed liquid side at a flow rate of 1 cm/sec, the permeate side was maintained at a vacuum of 5 μHg, and continuous separation was performed at an operating temperature of 40°C. As shown in Table 1, the results showed that excellent separation coefficients and permeation rates were achieved, and the efficiency of ethanol concentration per unit area of the separation membrane was also high.

*Separation coefficient The separation coefficient is a value measured using the following formula.

The water permeation amount (9) is expressed as unit membrane area (m) and unit time (h
This is the value converted into r).

Ethanol concentration rate: 90% by weight This indicates the degree to which ethanol water is concentrated in the separation device, and is calculated from the following formula.

A hydrophilized sulfonic acid (-803H) type membrane is placed in a certain amount of calcium chloride (IN) aqueous solution to achieve equilibrium, and the hydrogen chloride generated in the solution is removed with a caustic soda aqueous solution of OIN (potency = f). , titrated using phenolphthalein as an indicator, and the value X(oc) divided by the dry weight W(7) in the potassium salt state is 1i. - Content of f-X nurphone group - □ (milliequivalents/crumb) Comparative Example 1 Using the same separation membrane and separation device as in Example 1, continuous flow was carried out without providing a turbulence generation means in the flow path on the supply side. Separation was performed. As a result, as shown in Table 1, it was found that the separation performance, permeation rate, and ethanol concentration efficiency of the membrane were also considerably lower than when the turbulence generation means of the present invention was used.

Table 1

[Brief explanation of the drawing]

Figures 1 to 14 are schematic illustrations showing examples of the separation apparatus of the present invention, and Figure 15 is a schematic illustration showing a continuous separation apparatus incorporating a separation apparatus filled with glass beads as shown in Figure 14. It is a diagram. 1: Separation device main body 2: Separation membrane 3 glass beads 4: Supply liquid 5: Constant temperature chamber 6: Trap 7: Manometer 8: Villany vacuum gauge 9: Vacuum pump lO: Supply liquid reservoir 11: Supply liquid feed pump 12: a Condensate reservoir 13: Separation device wall 14: Stirrer 15: Jammer plate 16: Dome-shaped protrusion] 7: Separation device inner wall with unevenness 18: Spiral channel 19 Nigeras wool 20: Polytetrafluoroethylene? Net 21: Streamlined current transformer 22: Spherical molded product 23: Ultrasonic oscillation plate 24:
Heater 25: Circulation Pump Applicant Asahi Dow Co., Ltd. Agent Yutaka 1) Zen Yuji 4 Figure 5 Figure 6N Horse 7 Figure Funeral 8 Figure Atsushi 9 Figure 10 City 11 Figure Atsushi 12 Figure Horse 13 Figure 4

Claims (3)

[Claims] (1) A device for separating a liquid mixture consisting of at least two components of persimmons by pervaporation, characterized by having a turbulent flow generating means in a flow path on the feed liquid side. (2) Claim No. 2, characterized in that the structure of the separation device satisfies the following conditions. Unit volume of side flow path <10cm-1 (ii) 3o% porosity of supply side flow path (3) The separation device according to claim 1 or (2), characterized in that the supply channel is filled with a filler under the following conditions.