JP7704334B2 - Slug flow generating device, chemical substance treatment device equipped with said slug flow generating device, slug flow generating method, and chemical substance treatment method using slug flow - Google Patents

Description

The present invention relates to a slug flow generating device, a chemical substance processing device equipped with the slug flow generating device, a slug flow generating method, and a chemical substance processing method using a slug flow. Here, processing refers to reaction or separation (extraction, absorption, crystallization, etc.) of chemical substances, or reaction separation.

In conventional chemical reaction processes, there has been a demand for efficiency through scaling up. In recent years, there has also been an increased demand for reducing the environmental load and saving resources and energy.
In the production of high-value-added products such as pharmaceuticals, functional chemicals, and fine chemicals, which are expected to grow in the future, batch production methods suitable for small-scale production are mainstream. However, since there is a large energy loss and a large amount of co-products are discharged, in recent years, there has been a movement to reduce losses between each batch processing step by using a flow production method (hereinafter referred to as "flow process") in which reactions and separation and purification are performed in a continuous operation. In addition, there is a movement in research and development to modularize each unit operation incorporated in the flow process so that it can be used to manufacture a wide variety of functional chemicals by rearranging reaction modules and separation and purification modules as needed (Non-Patent Document 1).

In a flow process, operations such as temperature adjustment, pressure adjustment, mixing, reaction, extraction, separation and purification are performed while a fluid flows through the pipes or through equipment connected to the pipes. The requirements for each unit operation module are that it be compact and process quickly. In particular, important targets in flow processes are processes involving the flow of multiphase fluids that are partially soluble or completely immiscible with each other (for example, liquid-liquid reaction, gas-liquid reaction, liquid-liquid extraction, gas-liquid extraction, gas-liquid separation, and liquid-liquid separation). In general, when aiming to make a process more compact and faster in processes involving multiphase fluids, it is important to reduce the interphase mass transfer resistance.

In multiphase fluid processes, the equipment can be made compact to actively utilize the flow state favorable for the target unit operation. In flow processes, which are usually aimed at small-scale production, the scale is smaller than that of the space handled in batch processes, and the flow rate is low, so the Reynolds number is low and laminar flow is dominant. Even in such laminar flow regions, slug flow (also called segmented flow or Taylor flow; flow state shown in Figures 1(a) and 1(b)), in which fluids of different phases in a separated state flow alternately, reduces mass transfer resistance by promoting interface renewal due to internal circulating flow within the slug caused by shear from the wall surface. In addition, since it is possible to form large fluid masses, it has the advantage that the time required for phase separation is relatively short (Patent Document 1).
FIG. 1 shows typical flow conditions of multiphase flow. For example, in the flow conditions shown in FIGS. 1(c) to (f), the effect of reducing mass transfer resistance cannot be obtained, whereas in the slug flow shown in (a) and (b), the effect of reducing mass transfer resistance due to the internal circulating flow is obtained.

Conventionally, slug flows have been generated by continuously pumping multiple fluids of different phases into a fluid junction using multiple pumps corresponding to each fluid, as shown in Figures 2(a) and 2(b) (for example, Non-Patent Document 2: Figure 2, 2.1. Experimental Setup).
This method can be realized by a simple device that only requires connecting a pump for pumping each of the multiple fluids to a fluid junction. Since the slug flow is generated spontaneously, the slug length cannot be controlled, but the liquid-liquid ratio can be changed during operation by changing the flow rate ratio of each pump.

In addition, Non-Patent Document 3 describes a method in which two pumps are constantly kept in a pressure-feeding state while a three-way electromagnetic valve installed at the fluid junction of the two liquids is periodically driven to alternately send liquids to the fluid junction and generate a slug flow. By using such a device, it is possible to send liquids alternately in a situation dominated by laminar flow. In addition, the slug length can be controlled by the valve switching frequency.

Non-Patent Document 4 describes how a slug flow can be generated by constantly flowing a continuous phase (carrier oil) and controlling the intermittent introduction of dispersed phase 1 and dispersed phase 2 by switching valves and starting and stopping the pump. By using this device, the flow rate and the length of each slug can be controlled by controlling the valve and pump while the pump is operating.

Non-Patent Document 5 describes a device that generates a slug flow by operating two piezoelectric micropumps in opposite phases through electronic control of voltage and frequency. Using this device, the flow rate and slug length can be controlled by controlling the voltage and frequency while the pump is operating. In addition, since the fluid is not blocked in principle, no pressurized state occurs within the pump or flow path.

JP 2020-32346 A

NEDO, "Development of continuous precision production process technology for functional chemicals" 2020/06/25, https://www.nedo.go.jp/activities/ZZJP_100152.html "Development of continuous precision production process technology for functional chemicals" Basic Plan, https://www.nedo.go.jp/content/100893512.pdf (last updated March 3, 2021) Madhvanand N. Kashid, Albert Renken, Lioubov Kiwi-Minske, Gas-liquid and liquid-liquid mass transfer in microstructure reactors, Chemical Engineering Science 66 (2011)3876-3897 Nobutaka Kadowaki, Development and Application of Three-Way Solenoid Valves for Micro Chemical Processes, Doctoral Thesis, Okayama University, Chapter 3, March 2014 Shusaku Asano, Yu Takahashi, Taisuke Maki, Yosuke Muranaka, Nikolay Cherkasov & Kazuhiro Mae, Contactless mass transfer for intra-droplet extraction, Scientific Reports, 10 (2020), pp. 7685-7693 Hidetaka Abe and Akinori Muto, Generation of Liquid-Liquid Slug Flow by Two Interlocking Pumps, Abstracts of Lecture at the 86th Annual Meeting of the Society of Chemical Engineers, K301 (March 8, 2021)

The effect of promoting mass transfer in a slug flow is such that there are optimum points for the flow rate and slug length depending on various fluid properties, and a technology is required that can independently and easily control the flow rate and slug length within a range that covers the optimum points, which differ depending on the fluid properties. It is also preferable to be able to control the slug length using a pump that is constantly pumping, without using a pump that stops and starts, which would cause flow rate fluctuations that could lead to process instability. However, a slug flow generating device that combines these two characteristics has not yet been developed.
In the device of Non-Patent Document 2, the slug flow is generated randomly, so the slug length is determined by the flow rate of each pump, the shape and size of the fluid junction, and the fluid properties, and there is almost no freedom in the design.
In the device described in Non-Patent Document 3, it is possible to control the slug length, but because the pump is constantly kept in a pressure-feeding state, there is a concern that the fluid may be blocked, causing the pump or flow path to become overpressurized and causing damage due to the load placed on the pump or flow path, or that the flow rate may fluctuate.
In the device described in Non-Patent Document 4, the pump is stopped when the valve is closed, so there is no need to worry about damage to the device due to pressurization, and multiple syringe pumps are synchronized to control the slug length and flow rate of each phase in a three-phase slug flow. However, since the liquid delivery is controlled by appropriately starting and stopping the pump that delivers the liquid, there is a concern that the process may become unstable due to fluctuations in the flow rate.
In Non-Patent Document 5, the fluid is not blocked and no pressurized state occurs in the pump or the flow path. In addition, due to the structure of the piezoelectric micro pump (hereinafter referred to as "PMP"), it is possible to independently control the amount of fluid pumped by one reciprocation of the diaphragm and the average flow rate by changing the amplitude width of the diaphragm by voltage and by changing the frequency of the voltage change, and as a result, it is possible to independently control the slug length and the flow rate. However, since the discharge pressure of the PMP is small, it is difficult to accurately control the liquid pumping characteristics. In addition, when changing the ratio of the slug lengths of the two fluids, it is necessary to replace the part or the PMP itself in order to change the amount of fluid pumped by one reciprocation of the diaphragm, and it was not easy to control.

In view of the above problems, the present invention aims to provide a slug flow generating device and a slug flow generating method that are suitable for a variety of interphase reactions and separation operations by controlling the slug length and independently and stably controlling the flow rate and slug length over a wide range without causing process instability due to fluctuations in flow rate or stoppage of liquid supply.

In order to solve the above problems, the present invention employs the following means.
[1] An apparatus for generating a slug flow of a plurality of fluids, the apparatus comprising: fluid holding sections for holding each of the plurality of fluids; a pump for constantly pressurizing each of the plurality of fluids; flow paths connecting the plurality of fluid holding sections to the pump and the pump to a fluid junction; and a slug flow generating flow path provided downstream of the fluid junction, wherein valves are provided in each of the flow paths between the fluid junction and the pump, and the valves are controlled so that one type of fluid is always pressurized to the fluid junction and the other fluids are discharged to a discharge flow path.
[2] The slug flow generating device of [1], wherein the discharge flow path is connected to the original fluid holding portion, and the discharged fluid is recovered in the original fluid holding portion.
[3] The slag flow generating device of [1], wherein the discharge flow path is connected to a fluid junction other than the fluid junction, and the discharged fluid is pumped to the other fluid junction, thereby providing a separate slag flow generating flow path in parallel.
[4] The slug flow generating device according to any one of [1] to [3], wherein reaction or separation is carried out in the slug flow generating channel.
[5] The slug flow generating device of any one of [1] to [4], wherein at least one of the pumps has a temperature control mechanism for maintaining the fluid flowing through the head in a liquid state.
[6] The slug flow generating apparatus according to [5], wherein one phase of the slug flow is liquefied carbon dioxide and the other phase is liquid.
[7] A chemical substance treatment device comprising the slug flow generating device according to any one of [1] to [6].
[8] The chemical substance treatment device according to [7], having a liquid-liquid separation mechanism downstream of the slug flow generating device.
[9] The chemical substance treatment device according to [8], further comprising a gas-liquid separation mechanism between the slug flow generating device and the liquid-liquid separation mechanism.
[10] A chemical substance treatment device according to [9], wherein a gas exhaust pipe equipped with a pressure control mechanism is connected to the upper part of the gas-liquid separation mechanism, and a liquid exhaust pipe connected to the liquid-liquid separation mechanism is connected to the lower part.
[11] A method for constantly pumping a plurality of fluids through respective flow paths leading from respective fluid holding sections to a fluid junction, and generating a slug flow in a flow path downstream of the fluid junction, comprising controlling a valve installed between the fluid junction and the pump to constantly pump one type of fluid to the fluid junction , and discharging the other fluids to a discharge flow path.
[12] The slug flow generating method according to [11], wherein the fluid discharged into the discharge flow path is recovered in the original fluid holding section.
[13] The slag flow generating method according to [11], wherein the fluid discharged into the discharge flow path is pumped to a fluid junction other than the fluid junction, and a slag flow is generated in parallel in a separate slag flow generating flow path.
[14] The method for generating a slug flow according to any one of [11] to [13], wherein reaction or separation is carried out in the flow path for generating the slug flow.
[15] The method for generating a slug flow according to any one of [11] to [14], wherein at least one of the pumps adjusts the temperature to maintain the fluid flowing through the head in a liquid state.
[16] The method for generating a slug stream according to [15], wherein one phase of the slug stream is liquefied carbon dioxide and the other phase is liquid.
[17] A method for treating a chemical substance, comprising the slug flow generating method according to any one of [11] to [16].
[18] The method for treating a chemical substance according to any one of [11] to [17] above, comprising subjecting the resulting slag stream to liquid-liquid separation.
[19] The method for treating a chemical substance according to [18], comprising subjecting the resulting slag stream to gas-liquid separation, followed by liquid-liquid separation.
[20] The method for treating a chemical substance according to [19], comprising discharging the gas separated by gas-liquid separation from the top while controlling the pressure, and discharging the liquid separated by liquid-liquid separation from the bottom.

According to the present invention, the flow rate and slug length can be controlled independently and easily, so that the slug flow controlled to the optimum flow rate and slug length enables high-speed processing while making the chemical production equipment compact.
In addition, since the pump can be kept in a constant pressure-feeding state, the stability of the process is less likely to be impaired.

Representative flow diagrams for multiphase flows: (a) two-phase slug flow, (b) three-phase slug flow, (c) parallel flow, (d) annular flow, (e) droplet flow, (f) dispersed flow. Diagram of a conventional slug flow generating device. (a) Two-phase system, (b) Three-phase system FIG. 1 shows the configuration of the slug flow generating device of the present invention. (a) Configuration using a two-phase system and a three-way valve, (b) Configuration using a three-phase system and a three-way valve, (c) Configuration using a two-phase system and a two-way valve, (d) Configuration including a two-phase system and pressurized gas, (e) Example of a parallel configuration Confluence patterns at fluid confluence points: (a) two-phase system, (b) three-phase system Graph showing the liquid delivery accuracy of plunger pumps and piezoelectric micro pumps (PMPs) FIG. 1 is a block diagram of a chemical substance treatment device using the slug flow generating device of the present invention. FIG. 13 is a diagram showing the relationship between the flow rate and the valve switching time and the total slug length in the examples of the present invention and the comparative examples. FIG. 13 is a diagram showing the relationship between the set value and the actual measured value of the slug length ratio in an embodiment of the present invention. FIG. 1 is a diagram showing control of valve switching time and switching time ratio, slug length and slug length ratio in an embodiment of the present invention.

The present invention relates to an apparatus and method for generating a slug flow in which each phase is introduced sequentially, and a chemical substance treatment apparatus and treatment method equipped with the above-mentioned slug generation apparatus, and is characterized in that the flow rate and the slug length of each phase are controlled by continuously operating pumps for sending each fluid of each phase, while operating switching valves installed upstream of the fluid junction of each flow path, so that only one fluid is always pumped to the fluid junction and the fluids other than that one are discharged to the discharge flow path.
Hereinafter, the present invention will be described based on an embodiment (hereinafter, referred to as "the present embodiment"); however, the present invention is not limited to the present embodiment.

[Pressure feed method]
The simplest configuration of a slug flow generating device is to prepare pumps for pumping one fluid as many as the number of fluids to be pumped, and connect the discharge ports of each pump to the same fluid junction, as shown in Figures 2(a) and 2(b). In this way, if all the fluids are introduced into the fluid junction at the same time (hereinafter referred to as the "simultaneous pumping method"), a slug flow will be generated within a specific flow rate range, and the slug length will be determined by the physical properties and flow path (Fig. 2 in Non-Patent Document 2).
In contrast, an alternating pumping method in which one fluid always flows through the fluid confluence (hereinafter referred to as the "alternating pumping method") is a pumping method that is more likely to generate a slug flow, and the slug length can be controlled by controlling the pumping time to the fluid confluence. There are two types of alternating pumping methods: a method in which the pump operates intermittently to pump the fluid intermittently to achieve alternating pumping to the fluid confluence (Patent Document 1: Claim 9, Non-Patent Document 4: Fig. 1), and a method in which the pump operates continuously to pump the fluid continuously while operating a switching valve installed at the fluid confluence to achieve alternating pumping to the fluid confluence (Non-Patent Document 3).

The pumping method for the slag generating mechanism of this embodiment is an alternating pumping method in which a valve is provided upstream of the fluid junction and one fluid always flows through the fluid junction, while each pump is continuously operated to pump the fluids continuously. This method is significantly different from the conventional alternating pumping method in which a valve provided at the fluid junction is used to switch between fluids. Figures 3(a) to (e) show an example of the device configuration.
3(a) and (b) show examples of configurations in which a slug flow of a two-phase or three-phase fluid is generated using a three-way valve, and the fluid discharged to the discharge flow path is collected in the original fluid holding section.
FIG. 3(c) shows an example of a configuration in which each three-way valve in FIG. 3(a) is replaced with two two-way valves.
FIG. 3( d ) is a configuration example when the two-phase fluid is liquid and gas. The flow of the liquid is the same as in FIG. 3( c ). However, in this configuration example, part of the gas flows from the pressurized gas storage unit to the fluid junction unit using a flow rate controller, and the other part is discharged from the discharge flow path.
FIG. 3( e ) shows a configuration example in which the discharge flow path is connected to another fluid junction, thereby making it possible to arrange the slug flow generating flow paths in parallel.
In any of the configuration examples, it is preferable to provide a back pressure valve in the discharge flow path as shown in FIG. 6 described later, since this makes it possible to adjust the switching accuracy of the valve.

Figures 4(a) and (b) show patterns in which multiple fluids join at a fluid joining section. However, the collision order and collision angles θ and θ' are not specified in Figure 4.

[pump]
The pump here is a fluid pressure-transfer device in the broad sense. Examples include plunger pumps, diaphragm pumps, and syringe pumps. A positive pressure fluid stock tank and a flow controller connected to it (mainly intended for pressure-transfer of gas; see FIG. 3(d)) for the purpose of pressure-transferring fluid, whether gas or liquid, are also defined as pumps.
The pump is preferably driven by a mechanical system that can obtain a high pumping force so as to perform precise liquid transfer, and is preferably driven by a camshaft that is eccentric in conjunction with the rotation of a motor. Representative examples include a plunger pump and a diaphragm pump. In particular, a multi-plunger pump having multiple heads (a housing that defines a space between a suction side valve and a discharge side valve that operate in a check manner) is preferable in order to prevent the generation of pulsating flow.

FIG. 5 shows a comparison of the liquid delivery accuracy between a plunger pump (NP-KX-220P, Nippon Precision Science Co., Ltd., maximum discharge pressure 10 MPa) used in the present embodiment described below, and a piezoelectric micropump (PMP) (APP-20KG, Takasago Electric Co., Ltd., standard discharge pressure 20 kPa) used in Comparative Example 2, in which reciprocation is performed electrically by a piezoelectric element. An example of the former result is shown in FIG. 5(a), and an example of the latter result is shown in FIG. 5(b). If the ^R2 value of the approximation line is used as an index, the former has ^R2 = 1.0 (> 0.999), and the latter has ^R2 = 0.968, which shows that the plunger pump has a higher liquid delivery accuracy than the PMP.

Generally, the amount of liquid that can be delivered by a syringe pump is limited by the syringe volume, but if the syringe reciprocates and the syringe pump is equipped with a mechanism that has piping with a valve in the flow path so that the syringe is in delivery mode in one direction and in suction mode in the opposite direction, this restriction is eliminated and the pump can be used for a constant pressure delivery method.

[fluid]
The multiple fluids are not completely miscible fluids, because miscible fluids do not form a slug flow. The fluids may be liquid-liquid, consisting of an aqueous phase and an oil phase, or gas-liquid, consisting of a liquid phase and a gas phase. The liquid phase may be a liquefied gas, for example, liquefied carbon dioxide. The fluid may be any one of supercritical fluids, subcritical fluids, and fluids in which ionic liquids are not miscible.

If one or more of the fluids is a gas at normal temperature and pressure, the fluid is liquefied as it passes through the pump head, so it is preferable for the head through which the fluid passes to have temperature and pressure regulating functions to maintain the fluid in a liquid state.
A preferred gas capable of producing a slug stream is carbon dioxide maintained below 31° C. and below its equilibrium temperature so as to maintain the gas in the liquid phase in the extraction field.

As an example of a combination of an aqueous phase and carbon dioxide, it is assumed that the carbon dioxide is liquefied when the pump discharges. In this case, it is preferable that the process is at or above the critical pressure of carbon dioxide (7.4 MPa), and a back pressure valve can be installed downstream of the slug flow region to control the pressure from the pump to the back pressure valve. Carbon dioxide can only replace organic solvents under high pressure conditions, so it is expected that hydrophobic valuables in the aqueous phase will be extracted by the high pressure carbon dioxide.

[Slug flow generation channel]
In the slug flow generating channel, a reaction or separation is carried out by utilizing the mass transfer promotion effect in the slug flow. Specifically, the reaction includes a liquid-liquid reaction, a gas-liquid reaction, a reaction involving a solid catalyst, separation by extraction, absorption, crystallization, or the like, or reaction separation. The mass transfer promotion effect has an optimum point for the flow rate and the slug length depending on various fluid properties, but in the slug flow generating channel of this embodiment, the flow rate and the slug length can be independently realized within a range that covers the optimum point that differs depending on the fluid properties.

[Chemical Substance Treatment Apparatus and Treatment Method]
In this embodiment, as illustrated in FIG. 6, after reaction, separation, or reaction separation takes place in the slug flow generating flow passage, a liquid-liquid separator is placed downstream of the slug flow generating flow passage, and if necessary, a gas-liquid separator is placed between the slug flow generating flow passage and the liquid-liquid separator, so that the phase containing the chemical substance can be continuously separated and purified.
When a gas-liquid separator is provided, a gas discharge pipe is connected to the top of the gas-liquid separator, and a liquid discharge pipe connected to the liquid-liquid separator is connected to the bottom. The gas discharge pipe is provided with a back pressure valve for controlling the pressure in the slug flow generating channel.

The present invention will be specifically described below based on examples and comparative examples. However, the examples are intended to illustrate preferred examples of the present invention, and the present invention is not limited by the examples. The device setting ranges in the examples are unrelated to the performance limits of the present invention.

Example 1
In the configuration shown in FIG. 3(a), the main components were two double plunger pumps (NP-KX-220P, Nippon Precision Science), two three-way valves (LVM105R, SMC Corporation), and one valve control timer (H5CX, Omron Corporation).
A tank storing toluene as liquid A (organic phase) was connected to one of the pumps via a suction pipe, and a tank storing water as liquid B (aqueous phase) was connected to the suction side of the other pump via another suction pipe. A three-way valve was installed in the middle of the discharge pipe of each pump on the discharge side, and the wiring of the two three-way valves was connected in reverse phase. The discharge pipe downstream of the three-way valve was connected to a fluid junction of liquid A and liquid B made of a SUS tee with an inner diameter of 2 mm, so that the two three-way valves were alternately opened to the fluid junction. A slug flow generation flow path made of a glass tube with an inner diameter of 2 mm and a length of 30 cm was connected downstream of the junction. The flow rate setting values of the two pumps were set to 1 to 20 mL/min so that the total flow rate of liquid A and liquid B was equivalent to 1 to 20 mL/min. The time when the flow path of the valve is connected to the fluid junction is defined as the open time, the open time of liquid A (organic phase) is t _or and the open time of liquid B (aqueous phase) is t _aq . The three-way valve was operated in three patterns: (t _or , t _aq ) = (1 sec, 1 sec), (0.25 sec, 0.25 sec), and (0.13 sec, 0.13 sec). When t _or + t _aq is one cycle, the number of cycles (frequency) per second is 0.5 Hz, 2 Hz, and 4 Hz, respectively. The length of the slug flow (l _or +l _aq ) (organic phase: l _or , aqueous phase: l _aq ) of the combined organic and aqueous phases in the slug flow generation flow path was measured. At this time, the ratio of the organic phase to the aqueous phase calculated from these set values is approximately 1:1 (the slag length ratio l _or /(l _or +l _aq )×100[%] is approximately 50%).

<Comparative Example 1>
Comparative Example 1 was carried out in the configuration shown in FIG.
Comparative Example 1 was conducted in the same manner as in Example 1, except that two double plunger pumps similar to those in Example 1 were used and each pump simultaneously pumped liquid A and liquid B at the same flow rate setting value, and the length of the slug flow in the slug flow generating channel was measured.

<Comparative Example 2>
Comparative Example 2 was carried out in the configuration described in Non-Patent Document 5. That is, two PMPs (APP-20KG, Takasago Electric Co., Ltd.) were wired to a micropump controller (MPC-200B, Takasago Electric Co., Ltd.) so as to operate in opposite phases, enabling alternate liquid transfer to the fluid junction. The pump was operated with the vibration frequency of a diaphragm built into the pump set to 40 Hz, and the applied voltage was controlled so that the total flow rate was approximately 40 to 60 mL/min, and the length of the slug flow in the slug flow generation channel was measured.

Example 2
Using the configuration shown in Figure 3 (a), the total flow rate of liquid A and liquid B was fixed at 10 mL/min, and the (t _or t _aq ) conditions were changed to (0.2 sec, 1.8 sec), (0.4 sec, 1.6 sec), (1.6 sec, 0.4 sec), (1.8 sec, 0.2 sec) at valve operation 0.5 Hz, (0.1 sec, 0.4 sec), (0.4 sec, 0.1 sec) at 2 Hz, and (0.05 sec, 0.2 sec), (0.2 sec, 0.05 sec) at 4 Hz, except that the same procedure was followed as in Example 1, and the slug length ratio calculated from the set values was in the range of 10, 20, 80, and 90%, which was designated Example 2. The slug length ratio l _or /(l _or +l _aq )×100% in the slug flow generating channel was measured in the same manner as in Example 1.

Example 3
3(c), that is, the function of opening and closing the flow path of each three-way valve was replaced by two two-way valves (normally closed type, normally open type).Other than that, the same configuration as in Examples 1 and 2 was used.
The flow rates of the two pumps were set so that the total flow rate of liquid A and liquid B was approximately 3.4 mL/min, and the valve switching conditions were (t _or , t _aq ) = (0.12 sec, 0.12 sec), (0.36 sec, 0.12 sec), (0.60 sec, 0.12 sec). Other than this, the same procedure as in Example 1 was followed. This is Example 3, and the lengths l _or and l _aq of each slug flow in the slug flow generating channel were measured.

FIG. 7 shows the slug length (l _or +l _aq ) at the total flow rate in Example 1 and Comparative Examples 1 and 2.
FIG. 8 shows the slag length ratio (l _or /(l _or +l _aq )×100[%]) in Example 2.
FIG. 9 shows the slug lengths of the organic phase and the aqueous phase in Example 3.

7, in Comparative Example 1, the slug length (l _or +l _aq ) was 7.8 mm to 20.6 mm when the total flow rate was in the range of 2 to 15 mL/min, and since slag generation was spontaneous, the total flow rate and the slug length were in a linked relationship, whereas in Example 1, the slug length (l _or +l _aq ) was in the range of 6.6 mm to 200 mm when the total flow rate was in the range of 4 to 15 mL/min. Therefore, it can be seen that a wider range of slug length than in Comparative Example 1 could be controlled independently of the flow rate.
In Comparative Example 2, the slug length (l _or +l _aq ) was 2.6 mm to 4.5 mm when the total flow rate was in the range of 39.6 to 61.8 mL/min. This suggests that the present invention is good at generating a slug flow with a longer slug length than Comparative Example 2.
It can also be seen that in the present invention, the plot of each Hz shows an approximate linearity.

Figure 8 shows that the slug length ratio (vertical axis of the graph) was obtained, which roughly corresponded to the slug length ratio calculated from the equipment settings. In particular, it was closest to the calculated value at 0.5 Hz. With the slug generation methods of Comparative Example 1 and Comparative Example 2, it was impossible to easily control such slug length ratio or slug length by electronic control.

According to Figure 9, while maintaining the total flow rate at approximately 3.4 mL/min and the aqueous phase slug length at approximately 2 mm, the organic phase slug length can be changed to 2.4 mm, 6.7 mm, and 10.7 mm by changing the valve opening and closing time. This shows that even in Example 3, which uses two two-way valves instead of one three-way valve, the slug length ratio or slug length can be controlled in the same way as in Examples 1 and 2.

The slug flow generating device of the present invention can stably generate a highly precise slug flow over a wide range of flow rates and slug lengths, facilitating mass transfer between different fluids and enabling high-quality chemical synthesis reactions. In addition, by connecting a liquid-liquid separation mechanism, a gas-liquid separation mechanism, etc. downstream of this generating device, it is expected that extraction and separation can be performed quickly and at low cost. This invention makes it possible to continuously perform processes from reaction to separation and purification of chemical substances, including a wide variety of functional chemicals. In addition, it is expected that the application of this invention is not limited to continuous processes, but can also be applied to reactions or extraction and separation performed in batch processes, allowing similar high-speed and low-cost performance.

Claims (20)

1. An apparatus for generating a slug stream of a plurality of fluids, comprising:
a fluid holding portion for holding each of the plurality of fluids;
a pump for constantly pumping each of the plurality of fluids;
a flow path connecting the plurality of fluid holding portions and the pump, and connecting the pump and a fluid junction portion,
A slug flow generating flow passage provided downstream of the fluid confluence portion,
A valve is provided in each flow path between the fluid junction and the pump,
The slug flow generating device is controlled such that one type of fluid is always pressure-fed to the fluid junction by the valve, and the other fluids are discharged to the discharge flow path. The slug flow generating device according to claim 1, in which the discharge flow path is connected to the original fluid holding portion, and the discharged fluid is collected in the original fluid holding portion. The slag flow generating device according to claim 1, wherein the discharge flow path is connected to a fluid junction other than the fluid junction, and the discharged fluid is pumped to the other fluid junction, thereby providing another slag flow generating flow path in parallel. The slag flow generating device according to any one of claims 1 to 3, in which reaction or separation takes place in the slag flow generating channel. The slug flow generating device according to any one of claims 1 to 4, wherein at least one of the pumps has a temperature control mechanism that keeps the fluid flowing through the head in a liquid state. The slug flow generating device according to claim 5, wherein one phase of the slug flow is liquefied carbon dioxide and the other phase is liquid. A chemical substance treatment device equipped with a slug flow generating device according to any one of claims 1 to 6. The chemical substance treatment device according to claim 7, which has a liquid-liquid separation mechanism downstream of the slug flow generating device. The chemical substance treatment device according to claim 8, further comprising a gas-liquid separation mechanism between the slug flow generating device and the liquid-liquid separation mechanism. The chemical substance treatment device according to claim 9, wherein a gas exhaust pipe equipped with a pressure control mechanism is connected to the upper part of the gas-liquid separation mechanism, and a liquid exhaust pipe connected to the liquid-liquid separation mechanism is connected to the lower part. A method for constantly pumping a plurality of fluids through respective flow paths from respective fluid holding portions to a fluid junction, and generating a slug flow in a flow path downstream of the fluid junction, comprising:
A slug flow generating method comprising controlling a valve installed between the fluid junction and the pump to constantly pump one type of fluid to the fluid junction and discharge the other fluids into a discharge flow path. The slug flow generating method according to claim 11, wherein the fluid discharged into the discharge flow path is collected in the original fluid holding section. The slag flow generating method according to claim 11, in which the fluid discharged into the discharge flow path is pumped to a fluid junction other than the fluid junction, and a slag flow is generated in parallel in a separate slag flow generating flow path. The slag flow generating method according to any one of claims 11 to 13, in which reaction or separation is carried out in the flow channel that generates the slag flow. The slug flow generating method according to any one of claims 11 to 14, wherein at least one of the pumps performs temperature control to maintain the fluid flowing through the head in a liquid state. The method for generating a slug flow according to claim 15, wherein one phase of the slug flow is liquefied carbon dioxide and the other phase is liquid. A method for treating a chemical substance, comprising the slug flow generating method according to any one of claims 11 to 16. A method for treating a chemical substance according to any one of claims 11 to 17, comprising liquid-liquid separation of the resulting slag stream. The method for treating a chemical substance according to claim 18, which includes subjecting the resulting slug stream to gas-liquid separation and then liquid-liquid separation. The method for treating a chemical substance according to claim 19, which includes discharging the gas resulting from gas-liquid separation from the top while controlling the pressure, and discharging the liquid resulting from liquid-liquid separation from the bottom.