JPH02229529A - Separation of fluid, separator and separation membrane - Google Patents

Abstract

PURPOSE:To enhance permeating velocity of fluid by fluidizing the fluid consisting of a plurality of components along single side of a separation membrane and regulating the fluid side to low temp. and regulating the component permeating side to high temp. CONSTITUTION:The inside of a casing 12 is comparted into both a fluid supply chamber 14 of a central part and the outflow chambers 15 of the permeated components of the left and right both side parts. The outflow ports 12c of the components are equipped to the casing 12 which are opened to the respective outflow chambers 15 of the permeated components. A heating element 16 is inserted into the inner hole of a separation membrane 11 and connected to a lead wire 17. Calorific value is controlled by regulating impressed voltage and the heating temp. of the separation membrane 11 is regulated. A compressor is connected to the inflow port 12a of fluid of the casing 12 and compressed air is supplied to the fluid supply chamber 14. This compressed air is fluidized along the outer circumference of the separation membrane 11 and allowed to flow out through an outflow port 12b and water permeats the separation membrane 11 and is allowed to flow out through the outflow ports 12c.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for separating fluids such as liquids, gases, or mixtures of the two, which are composed of a plurality of components, a separation device, and a separation membrane.

(Prior art) Methods for separating at least one type of component in the fluid described above include pervaporation, thermopervaporation, which separates volatile components in the fluid, and separation of condensable gas components in the gas. Condensable gas separation methods are known, and an example of barbeparation is disclosed in Japanese Patent Application Laid-Open No. 62-27300.
9 and Japanese Patent Application Laid-Open No. 63-258604, an example of thermopervalation is described in the publication ``Summary of the 52nd Annual Meeting of the Society of Chemical Engineers!'' (1987), page 28 J, a condensable gas separation method. An example is JP-A-53-145343,
JP-A-54-15349, JP-A-62-4272
This is shown in Publication No. 3, etc. In all of these methods, a separation membrane that selectively permeates components in the fluid is used, and the fluid to be treated is made to flow along one side of the separation membrane while reducing the pressure on the other side of the separation membrane. volatile components of
Specific components are separated from a fluid by adsorbing, condensing, and dissolving condensable components within the separation membrane, diffusing them to the other side of the membrane, and evaporating them from the other side. (Problem to be solved by the invention) By the way, in the separation of these specific components, the permeation rate of the component is related to the evaporation rate, and the permeation rate can be increased by increasing the reduced pressure state on the other side of the separation membrane to increase the evaporation rate. be able to. However, maintaining a high degree of vacuum on the other side of the separation membrane requires special equipment and power, and
Even if a high degree of vacuum is maintained, there is a limit to the evaporation rate, and it is difficult to significantly increase the permeation rate and improve the separation efficiency. In addition, the above-mentioned Unexamined Patent Publication No. 63-25
As shown in Publication No. 8604, an attempt was made to increase the permeation rate by embedding a heating element in the separation membrane and heating the entire separation membrane to heat the fluid to be treated and increase the pressure during permeation of the permeated components. is being done. However, what controls the permeation rate of the permeate component is the evaporation rate of the permeate component on the permeate side, and the permeation rate cannot always be increased sufficiently depending on the means of heating the entire separation membrane. In particular, when the fluid to be treated is humid air and condensable gas separation is performed such as dehumidification, heating the fluid (gas) to be treated does not increase the vapor pressure and the permeation rate cannot be increased. It is therefore an object of the present invention to address such problems.

(Means for Solving the Problems) The present invention relates to a method, a separation device, and a separation membrane for separating fluids such as liquids, gases, or mixtures of both, which are composed of a plurality of components. In a method for separating a fluid, the fluid is caused to flow along one side of a separation membrane, during which time at least one type of component in the fluid is selectively permeated through the separation membrane, and the permeated component is separated from the fluid. It is characterized by the items 1) to (5), respectively.

(l). The fluid side is kept at a low temperature and the component permeation side is kept at a high temperature. (2). heating the component permeation side of the separation membrane;

(3). The separation membrane is heated by a heating means that the separation membrane has integrally on the component permeation side. (4). Heating the separation membrane using a heating means installed on the component permeation side of the separation membrane. (5). Heating the separation membrane by flowing heated gas through the component permeation side of the separation membrane. Further, the separation apparatus according to the present invention is an apparatus for carrying out the above-described separation method, and is characterized by the following items (6) to (8). (6). a separation membrane accommodated in a casing that selectively permeates at least one type of component in the fluid; A fluid supply chamber having an inlet and an outlet, a permeate component outflow chamber located on the other side of the separation membrane and having an outlet for the permeate component, and heating means for the separation membrane.

(7). The separation is a plate-like, pipe-like, monolith-like or honeycomb-like membrane structure.

(♂》.The heating means is a heating element included in the separation membrane, a heating element disposed on the permeate component outflow chamber side, or a heated gas supplied to the outflow chamber.Furthermore, the present invention Such a separation membrane is a separation membrane employed in the above-mentioned separation method, and is characterized by the following (9): (9) At least one type of component in the fluid selectively permeates. and a permeable heating element that is integrally provided on the component-permeable side of the permeable membrane, is permeable to at least the component that permeates the permeable membrane, and generates heat when energized. In the present invention, the separation membrane may have a single layer structure consisting only of a permselective membrane, or may have a multilayer elliptical structure consisting of a thin permselective membrane and a porous support supporting it. Examples of selectively permeable membranes include organic membranes such as polytetrafluoroethylene membranes, polyimide membranes, and silicone rubber membranes, and inorganic membranes such as porous ceramic membranes, glass membranes, and fibrous or granular carbon membranes. These permselective membranes are appropriately selected depending on the type of fluid to be treated.Furthermore, since the separation membrane is heated, it is selected in consideration of heat resistance.

Further, in the present invention, the heating means may be an appropriate heater such as an electric heater or a radiant heater using a heat medium, or may be a hot air blower that supplies heated air. Examples of the permeable heating element of the separation membrane according to the present invention include those made of a material that generates heat when energized, such as wire mesh or sheet-like porous metal heating elements, ceramic heating elements typified by perovskite crystals, and carbon heating elements. be able to. As a means of integrating the permselective membrane and the permeable heating element, if the permeable membrane is an organic membrane, the method is to integrate it by pressure bonding or adhesive, and if the permeable membrane is an inorganic membrane, the method is to integrate the permselective membrane and the permeable heating element. There are methods of integrating such as electroless plating method, sputtering vapor deposition method, slurry coating method, etc.

(Operations and Effects of the Invention) In the separation method according to the present invention, by keeping the fluid side at a low temperature and the component permeation side at a high temperature, the fluid side of the separation membrane where the fluid flows rapidly is compared to the fluid side. A larger temperature gradient is generated between the component permeate side of the separation membrane through which a very small amount of permeate component flows out.

Therefore, the permeate components that are adsorbed, condensed, dissolved, evaporated, and diffused on the fluid side of the separation membrane are assisted in evaporation on the component permeation side of the separation membrane, increasing the permeation rate of the permeation components. Due to this, the separation method according to the present invention can significantly improve separation efficiency compared to conventional separation methods,
Furthermore, if the separation efficiency is made the same as before, the reduced pressure state on the component permeation side of the separation membrane can be lowered, making it possible to downsize or abolish the pressure reducing device, and significantly reducing the power required. Such an effective separation method can be carried out by each of the above-mentioned separation apparatuses according to the present invention, and a separation membrane equipped with a heating element according to the present invention described above can be employed as the separation membrane.

(Example) In this example, an air dehumidification experiment was conducted using an electric heater heating type separation device shown in Fig. 1. (l). Separation device 10 A pipe-shaped separation membrane 11 is supported by left and right partition walls 13 provided inside a cylindrical casing 12.
The interior is divided into a fluid supply chamber 14 in the center and permeated component outflow chambers 15 on both left and right sides. The casing 12 is provided with a fluid inlet 12a and a fluid outlet 12b that open to the fluid supply chamber 14, and a component outlet 12c that opens to each permeate component outlet chamber 15. A heating element 16 made of insulated nichrome wire or the like is inserted. The heating element 15 is connected to a lead wire 17 that passes through the component outlet 12c of the casing 11, and the amount of heat generated is controlled by adjusting the applied voltage.
Thereby, the heating temperature of the separation membrane 11 is adjusted. Also,
A compressor is connected to the fluid inlet 12a of the casing 12, and compressed air is supplied to the fluid supply chamber 14. The compressed air that has flowed into the fluid supply chamber 14 flows along the outer periphery of the separation membrane 11 and flows out from the outlet 12b, and during this time, moisture in the compressed air permeates through the separation chamber 15 and exits from the outlet 12c via the component outflow chamber 15. leak. (2l, separation 1
1I11 A two-layer separation membrane that selectively permeates moisture, made by carrying alumina sol on the outer periphery of an alumina pipe-shaped porous support with an outer diameter of 11 mm, an inner diameter of 8 mflI, and a length of 500 mm, and baking this at 250°C. It was adopted. (3). Temperature 22℃, pressure 4kg/supplied from dehumidification experiment compressor
12 of compressed air is passed through the separation membrane 11 at a flow rate of INI/win.
A dehumidification experiment was conducted by causing fluid flow around the outer periphery of the separation membrane 11, while setting the temperature inside the inner hole of the separation membrane 11 to various temperatures. Table 1 shows the atmospheric pressure dew point of the air after dehumidification at each set temperature. The atmospheric pressure dew point of the air before dehumidification was -6°C, and the amount of air that permeated with moisture was 20Ncc 7ain. (Left below) As is clear from Table 1, the higher the internal pore temperature of the separation membrane, the lower the dew point and the higher the dehumidification effect. This phenomenon is caused by the temperature gradient between both sides of the separation membrane, which facilitates evaporation on the moisture permeation side without causing any problems with moisture intrusion and condensation on the air supply side. This is understood to be due to an increase in the permeation rate. (Example 2) In this example, a dehumidification experiment in the air was conducted using a hot air heating type separation device shown in Fig. 2. (1). Separation device 2
0 A plurality of pipe-shaped separation membranes 21 are supported in parallel on left and right partition walls 23 provided in a cylindrical casing 22,
The interior of the casing 22 is divided into a fluid supply chamber 24 in the center and permeated component outflow chambers 25 on both left and right sides. A compressor is connected to the inlet 22a of the casing 22, and compressed air is supplied to the fluid supply chamber 24. Supply room 2
The compressed air flowing into the chamber 4 flows along the outer periphery of each separation membrane 21 and flows out from the outlet 22b, and during this time, moisture in the compressed air permeates through each separation membrane 21 and passes through the component outflow chamber 25 to the outlet 22c. It flows out from one side. Further, a hot air blower is connected to the other side of the outlet 22c of the casing 22,
Hot air at each set temperature is supplied into the inner hole of the l1i membrane 2l for each portion. The hot air heats each separation membrane 21 while flowing through the inner hole of each separation membrane 2l. (2J. Dehumidification experiment part 100 separation membranes as in the example were adopted as MH21, the temperature was 20℃ and the pressure was 5kg supplied from the compressor.
/cm2 of compressed air at a flow rate of 5Nm3/hr each minute! J
A dehumidification experiment was conducted by flowing the outer periphery of the iW 21 and flowing hot air at each set temperature into the inner hole of each separation membrane 21. Table 2 shows the atmospheric pressure dew point of the air after dehumidification at each set temperature. The atmospheric pressure dew point of the air before dehumidification is -8°C, and the amount of air that permeates with moisture is 0.15Nm'/
It was hr. As is clear from Table 2, the dehumidification efficiency is significantly high even when hot air is used as the heating means and the separation device is scaled up. (Example 3) A separation device in which three separation membranes 11 of the same type as the separation device 10 used in Example 1 and each having a built-in heating element 16 were supported in parallel was used. Set the temperature to 70℃, and the temperature supplied from the compressor is 20℃ and the pressure is 4.
A dehumidification experiment was conducted by flowing compressed air of kg/cm 2 around the outer periphery of each separation membrane 11 at a flow rate of 3N1/win.

In this case, the amount of air passing through each separation membrane 11 is 69Ncc.
/min.

In addition, as a comparative example, each separation membrane 11 in the above separation device
A dehumidification experiment was conducted without heating, by connecting a vacuum pump to one of the outlet ports 12c of the casing 12 and sealing the other outlet port 12c, and maintaining the inner hole of each separation M11 at a reduced pressure of 20 Torr. (Comparative Example 1). In addition, in the above separation device, each separation membrane 11 is not heated, and the air after dehumidification is used as sweep air to flow OjNl /
A dehumidification experiment was conducted by flowing at a flow rate of min, 0.6N1/1n (Comparative Example 2). Furthermore, in the above separation device, each separation J1i11 has a total air permeation amount of 0.
Three separation membranes with a rate of 3NI/win and 0.6NI/win were used, and a dehumidification experiment was conducted without heating each separation membrane (Comparative Example 3). Table 3 shows the atmospheric pressure dew point of the air after dehumidification and the air loss rate in each experiment. The atmospheric pressure dew point of the air before dehumidification is -6°C, and the air loss rate is calculated using the following formula. Air loss rate (%) = (air loss flow rate) / (supply air flow rate) The same level of separation efficiency was achieved as when the inner pore of the separation membrane was highly depressurized (Comparative Example 1), and it is recognized that the separation efficiency would be further improved if the pressure was reduced in the same way as Comparative Example 1. ．． (Example 4) In this example, an in-air dehumidification experiment was conducted using a hot air heating type separation device 30 using a honeycomb structure as a separation membrane shown in FIG. 3, and a separation membrane 21 in a separation device 20 shown in FIG. The separation was carried out using a hot air heating type separation apparatus in which the separation membrane 21A was replaced with a phase-separating glass separation membrane 21A.

(1). Separation device 30 A square column-shaped separation membrane 31 is supported by left and right partition walls 33 provided in a square cylindrical casing 32. Inside the casing 32, there is a permeated component outflow chamber 35 in the center, and a fluid supply chamber. 3
4A and a fluid outflow chamber 34B. Each cell of the separation membrane 31 is open to the fluid supply chamber 34A and the outflow chamber 34B, and the compressed air that has flowed into the supply chamber 34A from the inlet 32a flows through each cell of the separation membrane 31 and flows into the outflow chamber 34B. The water reaches the outlet and flows out from the outlet 32b. During this time, moisture in the compressed air passes through the separation membrane 31, reaches the component outflow chamber 35, and flows out from the outflow port 32c.

On the other hand, the casing 32 is provided with a hot air supply port 32d that opens into the component outflow chamber 35, and the hot air that flows into the component outflow chamber 35 from the supply port 32d flows around the outer periphery of the separation membrane 31 and flows out from the outflow port 32c. do. During this time, the hot air was separated into M4
Heat 31.

('2. Separation membrane 31 has a total of 16 cells arranged in 4 rows x 4 columns, the cell shape is square, the pitch is 4jmm, the wall thickness is 1.0mm, and the length is 5mm.
A honeycomb structure was employed in which an alumina sol was supported on the inner wall of each cell of an alumina porous support of 00a+m, dried and fired at 250''C.

(3). Separation membrane 21A A split-phase glass separation membrane with an outer diameter of 10 mm, an inner diameter of 7 mm, and a length of 500 cm and an average pore diameter of 4 OA.
This book was adopted.

(stomach). Temperature 25℃, pressure 5kg supplied from dehumidification experiment compressor
/cm2 of water vapor saturated compressed air at 6NI/win
For the separation membrane 31, the inside of each cell is made to flow, and for each N membrane 2LA, the outer periphery is made to flow, while the outer periphery of the separation membrane 31 and the inner periphery of each separation membrane 21A are heated with hot air. A dehumidification experiment was conducted with the temperature set. Table 4 shows the atmospheric pressure dew point and air loss rate of the air after dehumidification at each set temperature.

(The following is a blank space) Table 4 7/ / (Example 5) In this example, an ethanol dehydration experiment was conducted using the separation apparatus 40 shown in FIG. 4. The separation membrane 41 has a cylindrical shape with a bottom, an outer diameter of 10 mm, an inner diameter of 8 mm+, and an average pore diameter of 0.
Alumina sol was supported on the outer periphery of a 6 μm alumina porous support, dried and fired at 300°C, and then the outer periphery was further impregnated with 500 ppm polyvinyl/alcohol aqueous solution and dried. This separation [41] is set in the casing 42, a heating element 43 is inserted into the inner hole of the separation membrane 41, a vacuum bomb 44 is connected, and 70 wt% ethanol in the tank 45 is heated to 40°C with a supply bomb 46. It is circulated through the casing 42, and the degree of vacuum in the inner hole of the separation membrane 41 is increased to lOTo.
Dehydration experiments were conducted at each set temperature while maintaining the temperature at rr. Table 5 shows the amount of water permeated and the ethanol concentration in the permeated water at each set temperature. (Left below) 7/ Table 5/ As is clear from Table 5, the amount of water permeated in ethanol increases as the temperature inside the separation membrane increases, indicating that the dehydration efficiency improves. ing. However, almost no change was observed in the ethanol temperature in the permeated water.

(Example 6) In this example, an ethanol dehydration experiment was conducted using a separation apparatus 40 shown in FIG. 4. The separation membrane 41A has a cylindrical shape with a bottom, an outer diameter of 10 mm, an inner diameter of 8 cm, and an average pore diameter of 0.6.
Alumina sol was supported on the outer periphery of a micrometer-sized alumina porous support, dried, and fired at 300°C.
Concentration 50 by mixing 00 ppm carbon black
A two-layer elliptical structure was adopted, which was impregnated with 00 ppm aqueous polyvinyl alcohol solution and dried at 80°C, and the thin film on the outer periphery was conductive. In this separation fi41A, as shown in FIG. 4, an experiment was conducted by inserting a heating element into the inner hole to heat the inner circumferential side (example), and conductive leads were installed at the upper and lower ends of the separation fi41A. An experiment was conducted by crimping the wire and heating the entire outer thin film (comparative example). The other conditions for each experiment were the same as in Example 5. Table 6 shows the amount of water permeated and the ethanol concentration in the permeated water at each set temperature.

Table 6 As is clear from Table 6, in the example in which the inner peripheral side of the separation membrane (component permeation side) was heated, the dehydration efficiency was higher than in the comparative example in which the outer peripheral thin film of the separation membrane (fluid supply side) was heated. shows that it is improving.

(Example 7) In this example, a film-like permselective membrane 51a made of polytetrafluoroethylene shown in FIG. Using the integrated membrane ellipse (separation membrane 51), an experiment was conducted to concentrate a 10 wt % sulfuric acid aqueous solution by thermopervaporation, and the water permeation rate was measured.

The characteristics and experimental conditions of the separation membrane 5L were as follows, and the water permeation rate was 0.90 kg/m2-hr.

Rectangle 1 Encircle 51 (1) Permeable membrane 51a: Pore diameter 0.1 μm. Porosity 78% Thickness 0.2 mm (21 heating element 51b: fiber diameter 400 μm, (adjust the applied voltage so that the aqueous solution in contact with one side of the membrane is 50 °C) Kl1-: side of the membrane at room temperature 22 °C As a comparative example, only the above-mentioned permeable membrane 51 was used, and the above-mentioned sulfuric acid aqueous solution was heated to 50°C in advance to form the permeable membrane 51.
A permeation experiment was conducted by supplying The water permeation rate in this case was 0.88 kg/m2·h.

(Example 8) In this example, the pipe-shaped porous support 52 shown in FIG.
A membrane structure (separation membrane 52) having an alumina permselective membrane 52b on the outer periphery of the support 52a and a barium titanate permeable heating element 52c on the inner periphery of the support 52a is used. We conducted an experiment to dehumidify the air using vaporization and measured the water permeation rate. The characteristics and experimental conditions of the separation membrane 52 are as follows, and the water permeation rate is Oj kg/
It was m2・hr. This permeation rate is determined by the porous support 5
This value was the same as that obtained when a membrane structure having only the permeable membrane 52b on the outer periphery of 2a was used and the inner periphery side was maintained at a vacuum level of 10 torr.

(1) Support 52a: Alumina, pore diameter 1μm, porosity 38%, outer diameter 10mm, wall thickness 1mII (2) Permeable membrane 52b: alumina, pore diameter 20A, porosity 20%, thickness 7μ (Formed by coating the outer periphery of the support 52a with alumina sol and firing at 600°C) (3) Heating element 52C: barium titanate, particle layer thickness 20 μm, porosity 32%, (titanic acid with a diameter of 0.3 μm) Formed by coating the support 52a with a slurry of barium particles, drying and firing at 500°C.The temperature was maintained at 80°C during the experiment) Katsuichiichiλ Pressure 4.5 kg/cm2, temperature 23°C compression Air is supplied to the outer peripheral side of the separation membrane 52.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the separation device used in Example 1;
The figure is a sectional view of the separation device used in Example 2, FIG. 3 is a sectional view of the separation device used in Example 4, and FIG. 4 is a schematic diagram of the separation device used in Examples 5 and 6. , FIG. 5 is a partial cross-sectional view of the separation membrane employed in Example 7, and FIG. 6 is a partial longitudinal cross-sectional perspective view of the separation membrane employed in Example 8. Explanation of symbols 10, 20, 30, 40...separation device, 11, 21,
21A, 31, 41, 41A, 51, 52・Separation membrane, 5
1a, 52b... Permeable membrane, 5lb, 52c... Heating element, 12, 22, 32, 42... Casing, 14
, 24, 34・Fluid supply chamber, 15, 25, 35...Component outflow chamber, 16...Heating element.

Claims (9)

[Claims] (1) A fluid such as a liquid, gas, or a mixture of the two, consisting of multiple components, is caused to flow along one side of the separation membrane, and during this time, at least one type of component in the fluid is selectively removed by the separation membrane. 1. A fluid separation method in which a permeated component is separated from the fluid by permeation, the fluid separation method comprising: keeping the fluid side at a low temperature and the component permeation side at a high temperature. (2) A fluid separation method according to item 1, characterized in that the component permeation side of the separation membrane is heated. (3) A method for separating fluids according to item 2, characterized in that the separation membrane is heated by a heating means integrally provided on the component permeation side of the separation membrane. (4) A fluid separation method according to item 2, characterized in that the separation membrane is heated by a heating means provided on the component permeation side of the separation membrane. (5) The method for separating fluids according to item 2, characterized in that the separation membrane is heated by flowing a heated gas through the component permeation side of the separation membrane. (6) A separation device for carrying out the separation method according to item 1, wherein the separation membrane is housed in a casing and selectively permeates at least one type of component in the fluid; a fluid supply chamber partitioned by a separation membrane and located on one side of the separation membrane and having an inlet and an outlet for the fluid;
and a permeate component outflow chamber located on the other side of the separation membrane and having an outlet for the permeate component, and heating means for the separation membrane. (7) The fluid separation device according to item 6, wherein the separation membrane is a plate-shaped, pipe-shaped, monolith-shaped, or honeycomb-shaped membrane structure. (8) In the separation device according to item 6 or 7,
The heating means includes a heating element integrally provided on the component permeation side of the separation membrane, a heating element disposed on the permeation component outflow chamber side,
Or a fluid separation device characterized in that the heated gas is supplied to the outflow chamber. (9) A separation membrane employed in the separation method described in item 1, including a selectively permeable membrane through which at least one type of component in the fluid selectively permeates, and a component-permeable side of the permeable membrane. 1. A separation membrane comprising: a permeable heating element which is integrally provided with a permeable membrane, allows at least a component that passes through the permeable membrane to pass therethrough, and which generates heat when energized.