JP7603925B2 - Continuous liquid-liquid separator and continuous liquid-liquid separation method - Google Patents

Description

The present invention relates to a continuous liquid-liquid separator and a continuous liquid-liquid separation method that continuously separates a two-phase liquid into a light liquid and a heavy liquid according to their respective specific gravities.

In the past, chemical synthesis processes were carried out using a batch method in which reactions and separation/purification were repeated in multiple stages, but this method produced a large amount of waste and had a low product yield. In recent years, therefore, in order to reduce the environmental impact and improve cost competitiveness, efforts have been made to switch to a flow method in which multiple reactions and separation/purification of the synthesized products are carried out continuously, achieving both reduced waste and high yield and selectivity.
As a means of separating and purifying a product in a flow method, a prior art is known in which a liquid to be extracted containing the product is contacted with an extracting liquid agent that is immiscible with the liquid to be extracted, and a two-phase liquid consisting of the liquid to be extracted and the extracting liquid containing the product is separated into liquid-liquid separation according to the specific gravities of the liquid and the extracting liquid.

For example, Patent Document 1 describes a continuous liquid separation device that separates a mixture of liquids with different specific gravities that flows into a chamber from a liquid inlet, and then discharges the upper and lower liquids from an upper and lower outlet, respectively, and that monitors the position of the interface in the chamber using an interface detection means and controls a flow rate adjustment means provided on at least one of the outlet paths to maintain the position of this interface at a predetermined position.

On the other hand, Non-Patent Document 1 describes a continuous liquid-liquid separator in which tiny flow paths are provided above and below a hydrophobic porous membrane made of polytetrafluoroethylene, parallel to the membrane surface, with an inlet at one end of the upper flow path, an outlet at the other, and an outlet at one end of the lower flow path. In this separator, a slug flow of water/hexane is passed through the flow path above the hydrophobic porous membrane, and the hexane permeates the hydrophobic porous membrane and is discharged from the outlet at the end of the flow path below the hydrophobic porous membrane, while the water does not permeate the hydrophobic porous membrane and is discharged from the outlet of the flow path above the hydrophobic porous membrane, thereby performing liquid-liquid separation.

Patent Document 2 also describes a continuous liquid-liquid separator that separates a two-phase liquid into a light liquid and a heavy liquid, discharging the light liquid from a light liquid outlet and the heavy liquid from a heavy liquid outlet, in which a heavy liquid permeable porous membrane is installed at the heavy liquid outlet, and the heavy liquid permeable porous membrane has a material and pore size that generates a heavy liquid retention force that prevents the light liquid from passing through even when there is a pressure difference between the upstream and downstream of the heavy liquid permeable porous membrane, and the light liquid outlet is equipped with a light liquid permeable porous membrane that has a pore size and membrane area such that the pressure upstream of the heavy liquid permeable porous membrane does not exceed the heavy liquid retention force.

JP 2008-6387 A JP 2019-130484 A

Ind. Eng. Chem. Res. 2013, 52, 10802-10808

As described in Patent Document 1, conventional continuous liquid-liquid separators required auxiliary devices, such as an interface monitor and a flow rate adjuster, for adjusting the liquid feed amount and liquid feed speed conditions in order to keep the interface position between the separated upper and lower layers constant.
On the other hand, in the continuous liquid-liquid separators described in Non-Patent Document 1 and Patent Document 2, a porous membrane that allows only one of the heavy liquid or the light liquid to pass through and does not allow the other to pass through is used to separate the heavy liquid and the light liquid, so no additional devices are required to monitor the interface or adjust the flow rate. However, since the selectivity of permeation and non-permeation of the porous membrane is utilized, the material and pore size of the porous membrane must be adjusted according to the wettability of the heavy liquid and the light liquid, and this separator has poor versatility.

The present invention was made in consideration of the current situation, and aims to provide a continuous liquid-liquid separator and a continuous liquid-liquid separation method that are highly versatile for use in a variety of solution systems and do not require additional devices for monitoring the interface or adjusting the flow rate.

The inventors of the present invention have conducted intensive research to solve the above problems, and have discovered that by discharging both the heavy liquid and the light liquid from a position higher than the inlet of the two-phase liquid and providing a liquid level adjustment mesh plate near the outlet of the light liquid that allows only the light liquid floating in the two-phase liquid to pass through, it is possible to continuously separate the two-phase liquid without using a porous membrane with poor versatility as described in Non-Patent Document 1 and Patent Document 2.

In order to solve the above problems, the present invention employs the following means based on the above findings.
[1] A continuous liquid-liquid separator having a structure in which a two-phase liquid consisting of at least two or more kinds of components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, is introduced from an inlet provided on the side of a chamber, and the light liquid and the heavy liquid are discharged from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet,
The chamber is provided with, in the order of the inflow direction of the two-phase liquid, a first chamber having the light liquid outlet on one of its side walls, and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall and connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid placed at the light liquid outlet to pass through,
A continuous liquid-liquid separator in which the light liquid outlet and the heavy liquid outlet are at the same height, the upper end of the light liquid outlet exceeds the height of the upper surface of the liquid level adjustment mesh plate, and the lower end of the light liquid outlet is within the height range from the lower surface to the upper surface of the liquid level adjustment mesh plate.
[2] A continuous liquid-liquid separator having a structure in which a two-phase liquid consisting of at least two or more kinds of components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, is introduced from an inlet provided on the side of a chamber, and the light liquid and the heavy liquid are discharged from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet,
The chamber is provided with, in the order of the inflow direction of the two-phase liquid, a first chamber having the light liquid outlet on one of its side walls, and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall and connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid placed at the light liquid outlet to pass through,
A continuous liquid-liquid separator, wherein the liquid level adjusting mesh plate is located above the inlet and below the light liquid discharge outlet, and a height _ho from the upper surface of the liquid level adjusting mesh plate to the lower end of the light liquid discharge outlet and a height _hw from the upper surface of the liquid level adjusting mesh plate to the lower end of the heavy liquid discharge outlet satisfy the following formula:

(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.)
[3] A continuous liquid-liquid separation method, comprising: introducing a two-phase liquid consisting of at least two or more components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, from an inlet provided on a side surface of a chamber; and discharging the light liquid and the heavy liquid from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet, respectively;
a chamber provided therein, in that order in the inflow direction of the two-phase liquid, with a first chamber having the light liquid outlet on one of its side walls and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid disposed at the light liquid outlet to pass therethrough;
A continuous liquid-liquid separation method, in which the light liquid discharge outlet and the heavy liquid discharge outlet are at the same height, and the liquid level adjustment mesh plate is positioned so that the upper end of the light liquid discharge outlet exceeds the height of the upper surface of the liquid level adjustment mesh plate, and the lower end of the light liquid discharge outlet is within the height range from the lower surface to the upper surface of the liquid level adjustment mesh plate.
[4] A continuous liquid-liquid separation method, comprising: introducing a two-phase liquid consisting of at least two or more components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, from an inlet provided on a side surface of a chamber; and discharging the light liquid and the heavy liquid from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet, respectively;
a chamber provided therein, in that order in the inflow direction of the two-phase liquid, with a first chamber having the light liquid outlet on one of its side walls and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid disposed at the light liquid outlet to pass therethrough;
A continuous liquid-liquid separation method, wherein the liquid level adjusting mesh plate is disposed above the inlet and below the light liquid discharge outlet, and a height _ho from the upper surface of the liquid level mesh plate to the lower end of the light liquid discharge outlet and a height _hw from the upper surface of the liquid level mesh plate to the heavy liquid discharge outlet satisfy the following formula:

(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.)

The present invention provides a continuous liquid-liquid separator and a continuous liquid-liquid separation method that are highly versatile for use in a variety of solution systems without the need for additional devices to monitor or adjust the interface.

Diagram explaining separation using the difference in specific gravity between heavy and light liquids A plot of the height of the interface between the heavy liquid and the light liquid (h _ow ) against the density of the light liquid (oil) (ρ _o ). FIG. 1 is a diagram illustrating interface fixing by openings in a liquid level adjusting mesh plate according to the present invention. A diagram explaining an experiment that demonstrated that the pressure (F _m /S) that prevents water from passing through a mesh plate is capillary pressure. A plot of the height of the water phase (h _w ) against the height of the oil phase (cyclohexane) (h _o ) in the demonstration experiment. FIG. 1 is a graph showing the relationship between the reciprocal (r ⁻¹ ) of the opening radius r of the mesh plate and the capillary pressure Pc (=F _m /S) obtained by experiment. FIG. 1 is a diagram illustrating a first embodiment of the present invention. FIG. 1 is a rear cross-sectional view showing an example of an apparatus according to a first embodiment of the present invention; FIG. 1 is a top cross-sectional view illustrating an example of an apparatus according to a first embodiment of the present invention. FIG. 1 is a diagram illustrating a second embodiment of the present invention. A photograph of the continuous liquid-liquid separator used in the examples taken from the front.

The present invention is a separator and separation method that continuously separates a two-phase liquid consisting of at least two or more components that separate into two phases, a light liquid and a heavy liquid, which are not completely miscible with each other, by using the difference in specific gravity between the heavy liquid and the light liquid. Both the heavy liquid and the light liquid are discharged from a position higher than the inlet of the two-phase liquid, and a liquid level adjustment mesh plate that allows only the light liquid floating in the two-phase liquid to pass through is provided at the same height as each of the outlets of the light liquid and the heavy liquid, or at a specified height between the outlet and inlet of the light liquid, thereby fixing the interface between the light liquid and the heavy liquid, and continuously separating and discharging each of the heavy liquid and the light liquid.

In the present invention, only light liquids pass through the openings in the liquid level adjustment mesh plate due to buoyancy, so the wettability of the liquid level adjustment mesh plate only needs to be controlled for heavy liquids, and there is no need to control the wettability for both light and heavy liquids as with the porous membranes in Non-Patent Document 1 and Patent Document 2, making versatile continuous liquid-liquid separation possible.

Hereinafter, an embodiment of the present invention (hereinafter, sometimes referred to as "the present embodiment") will be described. However, this is for the purpose of explaining the present invention and is not intended to limit the scope of the present invention.
In this specification, the use of "to" to indicate a range of values means that the values before and after it are included as the lower limit and upper limit.

<Continuous liquid-liquid separation using the difference in specific gravity between heavy and light liquids>
First, a continuous liquid-liquid separation will be described in which both the heavy liquid and the light liquid are discharged from a position higher than the inlet of the two-phase liquid by utilizing the difference in specific gravity between them.
FIG. 1 is a diagram for explaining, as an example, separation using the difference in specific gravity when water and oil are used as the heavy liquid and the light liquid, respectively.
In a separator having an oil phase outlet and an aqueous phase outlet at a position higher than the inlet of the two-phase liquid, as shown in the figure, if the height of the oil phase outlet, the height of the aqueous phase outlet, and the height of the interface of the two-phase liquid are H _o , H _w , and h _ow , respectively, and the density of the oil phase and the density of the aqueous phase are ρ _o and ρ _{w ,} respectively, then:
(H _o - _{h ow} ) ρ _o = (H _w - h _ow ) ρ _w
(However, all variables are positive.)
At this time, the aqueous phase and the oil phase are discharged from the oil phase outlet and the aqueous phase outlet, respectively.

For example, if ρ _w =1 and H _w =10,
(H _o - _{h o w} ) ρ _o = (10 - h _ow )
h _ow = (10-H _o・ρ _o )/(1-ρ _o )
It becomes.
FIG. 2 is a plot of h _ow versus ρ _o .
In the figure, 〇: H _o = 12, □: H _o = 11, ◆: H _o = 10, ×: H _o = 9

Since h _ow must be >0, when the oil phase outlet height (H _o ) is higher than the water phase outlet height (H _w ), the applicable oil (light liquid) density range becomes narrower, as shown in FIG.
On the other hand, as shown in FIG. 2, when the oil phase outlet height (H _o )=the water phase outlet height (H _w )=the interface height (h _ow ), it is applicable to all oils (light liquids).
In this case, however, it is necessary to fix the interface so that the aqueous phase does not discharge from the oil phase outlet.
In addition, even when the oil phase outlet height (H _o ) is lower than the water phase outlet height (H _w ), the present invention is applicable to all oils (light liquids).
However, even in this case, it is necessary to suppress the interface rise and fix the interface so that the aqueous phase is not discharged from the oil phase outlet.
In the present invention, a liquid level adjusting mesh plate is used as a means for fixing the interface.

The liquid level adjusting mesh plate has openings that allow light liquids to pass through but have a pressure (capillary pressure) that suppresses the passage of heavy liquids. Since light liquids pass through the openings of the mesh plate due to buoyancy, it is only necessary to control the capillary pressure (wettability) of the mesh plate for heavy liquids.
The shape of the opening may be either square or round, but if it is square, it shall have an opening diameter converted into a circle of radius r.

3A shows the capillary pressure when the heavy liquid is an aqueous phase and the material of the mesh plate is hydrophobic, while FIG. 3B is a diagram explaining the capillary pressure when the heavy liquid is an aqueous phase and the material of the mesh plate is hydrophilic. Whether the mesh plate is hydrophobic or hydrophilic, the capillary pressure of the openings in the mesh plate prevents the heavy liquid (aqueous phase) from passing through.
When the heavy liquid is an oil phase, a hydrophilic mesh plate is preferable because it provides a large capillary pressure, regardless of whether the light liquid is an oil phase or an aqueous phase.

<Demonstration experiment>
An experiment demonstrating that the pressure that prevents water from passing through the liquid level adjusting mesh plate is capillary pressure will be described below.
FIG. 4 is an explanatory diagram of a demonstration experiment using a hydrophobic mesh plate (made of PTFE, width 20 mm×depth 10 mm×thickness 0.5 mm).
If the pressure preventing the passage of water is _Fm /S, the load pressure of the oil is _Fo /S, the load pressure of the water is _Fw /S', the bottom area of the first chamber in the chamber is S, the bottom area of the second chamber is S', the density of the oil is _ρo , the density of the water _{is ρw} , the height of the oil phase (cyclohexane) is _ho , and the height of the water phase is _hw , then
F _w /S'=F _o /S+F _m /S
ρ _w・g_・h _w =ρ _o・g_・h _o +F _m /S
Therefore, the height of the aqueous phase (h _w ) is expressed by the following relational expression:

Four types of hydrophobic mesh plates were used, each having a round opening (pitch: distance between holes) with a hole diameter of 0.75 mm (pitch: 1 mm), a hole diameter of 1.0 mm (pitch: 1.5 mm), a hole diameter of 1.5 mm (pitch: 2.5 mm), and a hole diameter of 2 mm (pitch: 1.5 mm). Both the first and second chambers in the chamber were filled with an aqueous phase up to the height of the bottom surface of the hydrophobic mesh plate, and then an oil phase (cyclohexane) was dropped from above the first chamber in the chamber to a certain height. From this state, an aqueous phase (heavy liquid) was dropped from above the second chamber in the chamber to raise the water level, and the height of the aqueous phase from the bottom surface of the mesh plate when the water had passed through the mesh was measured.
FIG. 5 is a plot of the height of the water phase (h _w ) versus the height of the oil phase (cyclohexane) (h _o ).
As is clear from the above formula, in the graph, the slope indicates the specific gravity of oil (ρ _o ), and the Y-intercept indicates the pressure that prevents water from passing through.
Table 1 shows a summary of the hole (opening) diameter, inclination, and Y-intercept of the hydrophobic mesh plate in FIG.

The capillary pressure Pc of a heavy liquid at an opening of radius r is expressed by the following equation.
Pc=2γcosθ/r
(In the formula, γ represents the interfacial tension between the heavy liquid and the light liquid, and θ represents the contact angle of the heavy liquid.)
If it is assumed that the pressure (F _m /S) that prevents the passage of the heavy liquid through the liquid level adjusting mesh plate is the capillary pressure (Pc), it can be expressed by the following formula.
F _m /S=Pc=2γcosθ/r
(γ: interfacial tension between heavy liquid and light liquid, θ: contact angle of heavy liquid, r: mesh opening radius)
The following table shows the inverse (r ⁻¹ ) of the radius r of the mesh hole and the capillary pressure calculated from the Y intercept based on the above assumptions.

FIG. 6 is a diagram showing the relationship between the inverse (r ⁻¹ ) of the radius r of the mesh holes and the capillary pressure obtained by experiment.
The slopes in FIG. 6 all roughly coincide with the slope of 0.078 obtained when the literature values for interfacial tensions, cyclohexane-water γ _cw =50.49 mN, water-PTFE γ _wt =40.25 mN, and cyclohexane-PTFE γ _ct =1.22 mN, were used.
This means that the above assumption is correct, and the pressure that prevents water from passing through the mesh plate is the capillary pressure.

<Liquid level adjustment mesh plate>
In an embodiment of the present invention, the opening diameter of the liquid level adjusting mesh plate is preferably about 0.2 to 5.0 mm, and more preferably about 0.75 to 2.0 mm, so that two-phase solutions with various combinations of two liquids can be separated.
Furthermore, the pressure preventing water from passing through the liquid level adjustment mesh plate does not change depending on the number of openings in the liquid level adjustment mesh plate or their arrangement (pitch or whether they are evenly arranged), so the number of openings and their arrangement are not particularly limited.

In the embodiment of the present invention, the thickness of the mesh plate is not particularly limited as long as it does not warp, and is preferably 0.5 mm or more, more preferably 0.5 to 2 mm, and even more preferably 0.5 mm.

In addition, in the embodiments of the present invention, the material of the mesh plate may be either hydrophobic or hydrophilic, and is not particularly limited. For example, hydrophobic materials include polytetrafluoroethylene (PTFE), polyolefin, polystyrene, polyphenylene vinylene, polyvinyl chloride, etc., and when the heavy liquid is water, PTFE is preferred.
Examples of hydrophilic materials include hydrophilized polytetrafluoroethylene, acrylic resins such as polymethacrylate, polyamide, polyimide, polyester, polycarbonate, polyether, polyurethane, ceramics, and metals. When the heavy liquid is an organic solvent, polymethacrylate is preferred.

<Two-phase liquid>
The two-phase liquid usable in the embodiment of the present invention is a two-phase liquid consisting of at least two components that are completely immiscible with each other and separate into two phases, a light liquid and a heavy liquid, and examples of such two-phase liquids include water/pentane, water/hexane, water/heptane, water/octane, water/nonane, water/decane, water/cyclohexane, water/decalin, water/benzene, water/toluene, water/xylene, water/nitrobenzene, water/aniline, water/phenol, water/methyl acetate, water/ethyl acetate, water/propyl acetate, water/butyl acetate, water/diene, and the like. Examples of suitable solvents include ethyl ether, water/dipropyl ether, water/dibutyl ether, water/diphenyl ether, water/butanol, water/hexanol, water/heptanol, water/octanol, water/nonanol, water/decanol, water/butoxyethanol, water/triethylamine, water/chloroform, water/carbon tetrachloride, Fluorinert/water, methanol/hexane, methanol/cyclohexane, N,N-dimethylformamide/hexane, and N-methyl-2-pyrrolidone/hexane.

Other examples include three- or more-component two-phase liquids in which inorganic salts or organic compounds are dissolved in the two-component two-phase liquid. Other examples include liquid mixtures such as water/acetone, water/formaldehyde, water/tetrahydrofuran, water/N,N-dimethylformamide, water/dimethylsulfoxide, water/methanol, water/ethylene carbonate, and water/acetic acid in which inorganic salts or organic compounds are dissolved and the mixtures are separated into two phases, a light liquid and a heavy liquid.

[First embodiment]
FIG. 7 is a diagram showing a first embodiment of the present invention.
The first embodiment of the present invention is an embodiment in which the height of the light liquid outlet and the height of the heavy liquid outlet are the same (see [0021]). In this embodiment, as shown in Figure 7, a liquid level adjustment mesh plate is provided at the light liquid outlet to allow only the oil phase (light liquid) floating in the two-phase liquid to pass through, thereby fixing the interface between the light liquid (upper layer) and the heavy liquid (lower layer). Even if the height of the light liquid outlet and the height of the heavy liquid outlet are the same, the heavy liquid (lower layer) is not discharged from the light liquid outlet (upper layer outlet).

In order for the light liquid to float in the two-phase liquid and pass through the mesh plate and be discharged from the outlet, it goes without saying that the thickness of the liquid level adjustment mesh plate installed at the light liquid outlet does not exceed the diameter of the light liquid outlet, but the upper end of the light liquid outlet must exceed the height of the top surface of the liquid level mesh plate, and the lower end of the light liquid outlet must be within the range of height from the bottom surface to the top surface of the liquid level mesh plate.

8 and 9 are a rear sectional view and a top sectional view that typically show an example of the device according to the first embodiment of the present invention.
The side of the chamber is provided with an inlet for introducing the two-phase liquid.
Located within the chamber are a first chamber and a second chamber, a partition wall separating the first chamber and the second chamber, and a flow path connecting the first chamber and the second chamber located below the partition, and the first chamber and the second chamber each have a light liquid outlet and the heavy liquid outlet.
The light liquid discharge port and the heavy liquid discharge port are provided at a position higher than the inlet on the other side wall of the chamber, so that the light liquid discharge port and the heavy liquid discharge port are at the same height, and the light liquid and heavy liquid of the two-phase liquid are discharged from both discharge ports, respectively.
In addition, a liquid level adjustment mesh plate is provided at the light liquid discharge port of the first chamber, which allows only the light liquid floating in the two-phase liquid to pass through, and the interface between the light liquid and the heavy liquid is fixed by the liquid level adjustment mesh plate.

(Discharge of light and heavy liquids)
The two-phase liquid introduced from the inlet separates into a light liquid phase and a heavy liquid phase in the first chamber due to the difference in specific gravity, and only the light liquid passes through the liquid level adjustment mesh plate and is discharged from the light liquid outlet provided on the side wall of the first chamber.
On the other hand, of the introduced two-phase liquid, the heavy liquid flows into the second chamber through a flow path provided under the partition and is discharged from a heavy liquid discharge port provided in the side wall of the second chamber.

(Inlet)
An inlet provided on one side wall of the chamber is used to continuously introduce a two-phase liquid using a pump (not shown) or the like, and the pump and the inlet are connected by a pipe (not shown). The material, inner diameter, outer diameter, length, etc. of the pipe are not limited.
The position of the inlet is not particularly limited as long as it is a position where the introduced two-phase liquid can flow into the flow path connecting the first and second chambers in the chamber, but it is desirable for it to be located as low as possible below the separator.

(Light liquid outlet and heavy liquid outlet)
In this embodiment, the heights of the light liquid outlet and the heavy liquid outlet provided on the side wall of the chamber are set to be the same, so that even if there is a density difference between the heavy liquid and the light liquid, the heavy liquid and the light liquid can be continuously separated and discharged. It can be discharged.
Therefore, the side wall of the chamber on which the light liquid outlet and the heavy liquid outlet are arranged is not particularly limited, except that both outlets must be located at a higher position than the inlet. The inlet and the light liquid outlet are spaced apart from each other by a distance necessary for the light liquid in the two-phase liquid to separate and float in the first chamber due to the difference in specific gravity so that the light liquid is discharged from the light liquid outlet. It is necessary to have it.
To facilitate collection of the discharged liquid, a light liquid collection tube and a heavy liquid collection tube can be connected to the light liquid discharge port and the heavy liquid discharge port, respectively. The length etc. is not limited.

[Second embodiment]
The second embodiment of the present invention is an embodiment in which the height ( _ho ) of the light liquid outlet is lower than the height ( _hw ) of the heavy liquid outlet (see [0021]). In this embodiment, a liquid level adjusting mesh plate is provided above the inlet for the two-phase liquid and below the light liquid outlet, thereby fixing the interface between the light liquid and the heavy liquid, and the height _ho of the lower end of the light liquid outlet and the height _hw of the lower end of the heavy liquid outlet from the upper surface of the liquid level mesh plate satisfy the following formula:

(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.)

The relationship between the height _ho of the lower end of the light liquid outlet and the height _hw of the lower end of the heavy liquid outlet in the second embodiment will be described below.
As described above, the pressure that prevents the heavy liquid from passing through the mesh plate can be said to be the capillary pressure F _m /S. Therefore, in this embodiment, we investigated how far the liquid level adjusting mesh plate can be lowered, or how far the heavy liquid outlet can be raised, when there is a certain amount of pressure with which the heavy liquid presses the mesh plate.

As shown in FIG. 10, when the height of the light liquid outlet (h _o ) is lower than the height of the heavy liquid outlet (h _w ),
F _m /S≧F _w /S'-F _o /S=P _w-o ... (1)
(In the formula, S represents the bottom area of the first chamber, S' represents the bottom area of the second chamber, _Fm /S represents the pressure that suppresses the passage of water, _Fw /S' represents the load pressure of water (heavy liquid), _Fo /S represents the load pressure of oil (heavy liquid), and _Pw-o represents the load pressure difference.)
If the above formula is true, it functions as a continuous liquid-liquid separator.

P _w-o = ρ _w・h _w・g−ρ _o・h _o・g
=(ρ _w・h _w −ρ _o・_ho )・g...(2)
(In the formula, ρ represents density, h represents the height from the upper surface of the mesh plate to the lower end of the outlet, S represents the cross-sectional area of the pipe, and g represents the acceleration of gravity.)
Therefore, by substituting formula (2) into formula (1), F _m /S≧(ρ _w ·h _w − ρ _o ·h _o )·g
It becomes.
When the formula is summarized with respect to h _o , it is expressed by the following formula (3).

On the other hand, the capillary pressure Pc can be expressed by the following equation (4).
Pc=2γcosθ/r=F _m /S...(4)
From the above formulas (3) and (4), the height _ho of the lower end of the light liquid outlet and the height _hw of the lower end of the heavy liquid outlet from the upper surface of the mesh plate are expressed by the following formula (5).

(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.)
As described above, it is understood that the above formula (5) can determine how far the liquid level adjusting mesh plate can be lowered, or how far the heavy liquid phase outlet can be raised.

The present invention will be described in detail below with reference to examples. However, the examples are intended to be preferred examples of the present invention, and the present invention is not limited to these examples.

A device according to a first embodiment of the invention, as illustrated in Figures 8 and 9, was used to carry out continuous separation of a two-phase liquid.
FIG. 11 is a photograph taken from the front of the continuous liquid-liquid separator used in the examples.
The separator is made of an acrylic monomer and a chamber section (external size, width 46 mm x depth 15 mm x height 22 mm), a light liquid discharge section and a heavy liquid discharge section (external size, diameter 6 mm x length 30 mm, hole diameter 3 mm), an inlet (external size, width 15 mm x depth 9 mm x height 14 mm), a partition wall (width 2 mm x depth 10 mm x height 15 mm), a first chamber and a second chamber (size, width 20 mm x depth 10 mm x height 20 mm), a flow path connecting the first chamber and the second chamber (size, width 2 mm x depth 10 mm x height 5 mm), and a liquid level adjustment mesh plate (width 20 mm x depth 10 mm x thickness 0.5 mm) are integrally molded with a height (14 mm from the bottom surface of the first chamber) that coincides with the lower end of the light liquid discharge port (hole).
The opening shape of the liquid level adjusting mesh plate was a square with a wire diameter of 1 mm and a mesh size of 1 mm.

A liquid inlet tube (made of PTFE, 1/16 inch, inner diameter 1 mm) was connected to the inlet, and a two-phase liquid (slug flow) consisting of cyclohexane and water was introduced at a rate of 1 mL/min each.
As is clear from the photograph in FIG. 11, the water (colored with food coloring) did not pass through the mesh plate, and only cyclohexane (a colorless, transparent liquid) was discharged from the light liquid outlet, allowing for clean separation.
In addition, when the two-phase liquid consisting of cyclohexane and water was introduced at a rate of 5 mL/min each, the water (colored with food coloring) was also able to be separated cleanly without passing through the mesh plate.

Furthermore, separation of a two-phase liquid was performed in the same manner, except that the material and opening size of the two-phase liquid and the liquid level adjusting mesh plate were changed as shown in Table 3.
The liquid level adjusting mesh plate made of polytetrafluoroethylene (PTFE) had the same round openings as those used in the above-mentioned demonstration experiment.
The results are shown in Table 3. In the table, "x" indicates that the lower layer (heavy liquid) passed through the mesh plate, and "-" indicates that no experiment was carried out.

As a result, it was found that it was possible to separate various two liquids, such as water (heavy liquid)/low polarity solvent (light liquid), water (heavy liquid)/high polarity solvent (light liquid), high specific gravity organic solvent (heavy liquid)/water (light liquid), and organic solvent (heavy liquid)/organic solvent (light liquid).

According to the present invention, a product can be obtained in high yield and selectivity using a continuous liquid-liquid separator having a simple configuration, and therefore the present invention can be used in a continuous precision production process for functional chemicals.

Claims (4)

A continuous liquid-liquid separator having a structure in which a two-phase liquid consisting of at least two or more kinds of components which are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, is introduced through an inlet provided on a side surface of a chamber, and the light liquid and the heavy liquid are respectively discharged through a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet,
The chamber is provided with, in the order of the inflow direction of the two-phase liquid, a first chamber having the light liquid outlet on one of its side walls, and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall and connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid placed at the light liquid outlet to pass through,
A continuous liquid-liquid separator in which the heights of the light liquid outlet and the heavy liquid outlet are the same, the upper end of the light liquid outlet exceeds the height of the upper surface of the liquid surface mesh plate, and the lower end of the light liquid outlet is within the height range from the lower surface to the upper surface of the liquid surface mesh plate. A continuous liquid-liquid separator having a structure in which a two-phase liquid consisting of at least two or more kinds of components which are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, is introduced through an inlet provided on a side surface of a chamber, and the light liquid and the heavy liquid are respectively discharged through a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet,
The chamber is provided with, in the order of the inflow direction of the two-phase liquid, a first chamber having the light liquid outlet on one of its side walls, and a second chamber having the heavy liquid outlet on one of its side walls, a partition wall separating the first chamber from the second chamber, a flow path provided below the partition wall and connecting the first chamber to the second chamber, and a liquid level adjusting mesh plate that allows only the light liquid floating in the two-phase liquid placed at the light liquid outlet to pass through,
A continuous liquid-liquid separator, wherein the liquid level adjusting mesh plate is located above the inlet and below the light liquid discharge outlet, and a height _ho from the upper surface of the liquid level adjusting mesh plate to the lower end of the light liquid discharge outlet and a height _hw from the upper surface of the liquid level adjusting mesh plate to the lower end of the heavy liquid discharge outlet satisfy the following formula:
(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.) A continuous liquid-liquid separation method comprising: introducing a two-phase liquid consisting of at least two or more components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, through an inlet provided on a side surface of a chamber; and discharging the light liquid and the heavy liquid from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet, respectively;
a first chamber having the light liquid outlet on one of its side walls and a second chamber having the heavy liquid outlet on one of its side walls, the first chamber being disposed inside the chamber in that order in the inflow direction of the two-phase liquid, a partition wall separating the first chamber from the second chamber, a flow path connecting the first chamber to the second chamber, the flow path being disposed below the partition wall, and a liquid level adjusting mesh plate allowing only the light liquid suspended in the two-phase liquid disposed at the light liquid outlet to pass therethrough;
A continuous liquid-liquid separation method, in which the light liquid outlet and the heavy liquid outlet are at the same height, and the liquid level adjustment mesh plate is positioned so that the upper end of the light liquid outlet exceeds the height of the upper surface of the liquid level adjustment mesh plate, and the lower end of the light liquid outlet is within the height range from the lower surface to the upper surface of the liquid level adjustment mesh plate. A continuous liquid-liquid separation method comprising: introducing a two-phase liquid consisting of at least two or more components that are not completely miscible with each other and separate into two phases, a light liquid and a heavy liquid, through an inlet provided on a side surface of a chamber; and discharging the light liquid and the heavy liquid from a light liquid outlet and a heavy liquid outlet provided at a position higher than the inlet, respectively;
a first chamber having the light liquid outlet on one of its side walls and a second chamber having the heavy liquid outlet on one of its side walls, the first chamber being disposed inside the chamber in that order in the inflow direction of the two-phase liquid, a partition wall separating the first chamber from the second chamber, a flow path connecting the first chamber to the second chamber, the flow path being disposed below the partition wall, and a liquid level adjusting mesh plate allowing only the light liquid suspended in the two-phase liquid disposed at the light liquid outlet to pass therethrough;
A method for continuous liquid-liquid separation, comprising: arranging the liquid level adjusting mesh plate above the inlet and below the light liquid outlet, so that a height _ho from the upper surface of the liquid level adjusting mesh plate to the lower end of the light liquid outlet and a height _hw from the upper surface of the liquid level adjusting mesh plate to the lower end of the heavy liquid outlet satisfy the following formula:
(In the formula, h _o and h _w are positive values, ρ _o is the density of the light liquid, ρ _w is the density of the heavy liquid, r is the radius of the mesh opening, γ is the interfacial tension between the heavy liquid and the light liquid, and θ is the contact angle.)