JP2019141829A - Liquid-liquid extraction method and apparatus with high-tension carbon dioxide using micro mixer - Google Patents

Abstract

To provide a high-speed liquid-liquid extraction process capable of being established continuously and industrially.SOLUTION: The method for the liquid-liquid extraction of a valuable material by means of high-pressure carbon dioxide is provided, the valuable material being an extract object included in an aqueous raw material solution. This method is characterized in that the aqueous raw material solution and the high-pressure carbon dioxide are each continuously supplied to a high-pressure environment and mixed with each other by a micro mixer (14), and are passed through, via a residence pipe, a first pressure control valve (15) that control the pressure of the micro mixer and that of the residence pipe, this decompressed fluid is supplied to a separator (17), and the high-pressure carbon dioxide and the extract object are discharged from the top of the separator (17), and are caused to pass through a second pressure control valve (19) that controls pressure, and thereby being mixed with a precipitation suppressing fluid (18) that suppresses the precipitation of the extract object solved in the high-pressure carbon dioxide and extracted aqueous solution is discharged from a level control valve (21) provided below while the liquid surface level of the separator (17) is kept constant by a liquid surface sensing means that senses the liquid surface level.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method and an apparatus for liquid-liquid extraction of valuable materials contained in an aqueous solution with high-pressure carbon dioxide, and in particular, quickly and uniformly mixed using a micromixer for mixing both fluids and extracted instantaneously. The present invention relates to a liquid-liquid extraction method and apparatus in which an equilibrium state is reached and then separated into a high-pressure carbon dioxide and an extraction target in an upper part and an aqueous solution after extraction in a lower part by a separator.

  As an alternative to low-polar organic solvents, the use of high-pressure carbon dioxide, including supercritical states, is proposed. That is, the density, viscosity, and dielectric constant of high-pressure carbon dioxide are almost the same values as those of low-polar organic solvents such as benzene, hexane, and toluene, which can be substituted. Carbon dioxide has solvent characteristics only in a high-pressure environment. When the pressure is reduced to atmospheric pressure, the solvent characteristics are lost. And since it vaporizes instantaneously with atmospheric temperature, the separation from the chemical substance dissolved in the high-pressure carbon dioxide is very easy, and energy for drying is unnecessary.

  Therefore, extraction techniques in the food field using the above-described characteristics of high-pressure carbon dioxide have been studied for a long time, and some have been put into practical use. For example, Non-Patent Document 1 describes a method of extracting caffeine from coffee beans to obtain caffeine-less coffee and natural product-derived caffeine. Patent Document 1 discloses a method for extracting ginger extract from ginger powder. Furthermore, Patent Document 2 discloses a method for extracting cholesterol from mayonnaise. As described above, when food is targeted, the extractables or extraction residue is taken directly into the body, so there is concern about residual solvents in extraction processes using existing organic solvents. By using carbon dioxide as a solvent, safety can be essentially secured. Similarly, in addition to foods, it is expected to use a process that utilizes the solvent characteristics of high-pressure carbon dioxide for the extraction technology of products that are directly taken into the body, such as pharmaceuticals and cosmetics.

  Conventionally used organic solvents are used for the extraction of chemical substances in current food, medicine and pharmaceutical manufacturing processes. Design of a single solvent or mixed solvent that can achieve maximum solubility with a small amount of addition to the solubility parameter (SP value) of the target extract, and extract the target by lyophilization or vacuum distillation after solvent extraction Is intended to separate the solvent so that it does not undergo thermal denaturation and to convert it into a solvent that will not cause any problems when taken into the body. In this manufacturing process, measures for reducing the residual solvent risk as much as possible are defined as GMP (Good Manufacturing Process) standards.

  FIG. 3 shows an apparatus flow for extracting caffeine from coffee beans that have been put into practical use. The high-pressure carbon dioxide supplied to the condenser is sufficiently cooled, the temperature in the condenser is kept constant, and the saturated vapor pressure at that temperature is controlled. For example, when it is controlled at 5 ° C., it becomes constant at 4 MPa. A pre-cooler is installed between the condenser and the high-pressure pump to cool the carbon dioxide that has been sufficiently liquefied and cooled to a high pressure so that vapor lock does not occur in the high-pressure pump that discharges liquid carbon dioxide at a high pressure. High pressure discharge with carbon dioxide pump. The high-pressure carbon dioxide discharged at high pressure becomes supercritical carbon dioxide when heated to 31 ° C. or higher by a heater. The solid raw material containing the extraction target is filled in the extraction tank, and high-pressure carbon dioxide is supplied from the lower part of the extraction tank, so that the high-pressure carbon dioxide is impregnated in the solid raw material, and the extraction target in the solid raw material reaches the surface. Move and dissolve in high pressure carbon dioxide outside the solid for extraction.

  The extraction object dissolved in the high-pressure carbon dioxide flows into the evaporator through a back pressure valve that controls the pressure of the extraction tank to be constant. The evaporator pressure is lower than that of the extraction tank, and since it is connected to the condenser, it has the same pressure as the condenser and the same temperature. The gas-liquid ratio after decompression is determined by the temperature and pressure upstream of the back pressure valve at the outlet of the extraction tank. The extraction target is dissolved in high-pressure carbon dioxide in a high-pressure environment, but when the pressure is reduced, the carbon dioxide is separated into gas and liquid, the solubility in gaseous carbon dioxide decreases instantaneously, and the extraction target is liquid dioxide. Dissolved or entrained in carbon. Therefore, since liquid carbon dioxide and an extraction target are present in the lower part of the evaporator, the extraction target and liquid carbon dioxide are discharged by periodically blowing from the lower part of the evaporator, and the liquid carbon dioxide is instantly gasified. Since it evaporates to carbon dioxide, the extraction object can be recovered.

  Since most of the high-pressure carbon dioxide extraction processes require carbon dioxide to be reused, an internal heater is provided as a heating means inside the evaporator. Alternatively, it is necessary to evaporate liquid carbon dioxide at the temperature and pressure (here, 5 ° C., 4 MPa) of the high-pressure carbon dioxide recovery system by heating from the outer periphery of the evaporator. For that purpose, means for detecting the liquid level of liquid carbon dioxide is required (see, for example, Patent Document 3).

  Evaporated liquid carbon dioxide dissolves organic matter distributed in vapor phase, vapor-liquid equilibrium gas phase together with carbon dioxide partially evaporated by decompression, so after removing organic matter in activated carbon tank, It is liquefied and collected by a condenser and recycled.

  By the way, the extraction technique using high-pressure carbon dioxide that has been studied conventionally has some barriers to practical use as described below.

  First, the solubility of the extraction target in high-pressure carbon dioxide is low. Among inorganic gases, there is no gas other than high-pressure carbon dioxide that can dissolve organic substances, but the solubility of organic substances in high-pressure carbon dioxide is as low as 1 wt% at the highest, and 99 high-pressure dioxides are used to extract one caffeine. Carbon is required and an efficient process cannot be expected. This increases the size of the processing process when the amount of extraction processing of the solid material including the extraction target is large. Further, even when the concentration of the extraction target in the solid is high, the solubility process is limited, so that the processing process is also enlarged in this case. In either case, a large-scale apparatus is required on the premise that high-pressure carbon dioxide is circulated and reused.

  Second, it is mass transfer rate limiting for moving the extraction object in the solid to the surface of the solid. Conventional extraction technology using high-pressure carbon dioxide often involves the extraction object contained in a solid, high-pressure carbon dioxide permeates inside the solid, moves along with the extraction object, It reaches the solid surface and is dissolved and extracted in high-pressure carbon dioxide existing around the solid. The extraction rate is not fast because the mass transfer within the solid is limited.

  Thirdly, the equipment cost is increased due to the large pressure vessel. Since the solid matter is filled in the high-pressure vessel for processing, the high-pressure vessel becomes larger as the amount of treatment increases. In calculating the strength of the cylindrical body of the high-pressure container, the wall thickness increases proportionally as the container inner diameter increases. The material used for the high-pressure vessel is mostly forged products, and there are almost no cases where the seam welding type (semi-seam), which has no limitation on the production size, is used for strength. Therefore, since it is necessary to forge each product as an ingot, the material is expensive, and the forging size is limited, so that the container size is limited. Therefore, in the case of a large throughput process, the plant cost tends to increase such as parallelization of a plurality of processes.

  Fourth, since the solid matter is taken in and out of the high-pressure vessel, it is a semi-batch type treatment, so the treatment efficiency is not high. It takes a loss time, not a production time, while taking in and out the solid matter.

  In spite of the above-mentioned problems, there is no concern about the residual solvent of high-pressure carbon dioxide in the object that can be taken into the human body, especially the food object process. It is operating.

  In recent years, although raw materials are targeted for solids, both high-pressure carbon dioxide with hydrophobicity and water with hydrophilicity are supplied to the extraction tank, and for example, the solids are kept in hydrophilic water in the extraction tank. Then, a technique has been proposed in which a hydrophilic substance to be extracted is dissolved in water, and high-pressure carbon dioxide having hydrophobicity is bubbled from the bottom to dissolve the hydrophobic organic substance in high-pressure carbon dioxide (for example, patents). Reference 4).

  However, as shown in FIG. 4, in the method disclosed in Patent Document 4, a liquid level exists in the extraction tank, and a liquid level gauge or a differential pressure gauge (differential pressure transmitter) is used as the detection means. No means has been disclosed for making the liquid level in the extraction tank constant. Furthermore, regarding the inner diameter of the extraction tank, there is no disclosure of liquid level detection means such as a change in inner diameter, and the level displacement between fluids having a small density difference such as water and high-pressure carbon dioxide is reduced, so it is assumed that controllability is remarkably lacking The In addition, the outflow line on the high-pressure carbon dioxide side has a container for trapping water entrained with water droplets, but there is no means for discharging water from the container, and due to time issues, Water that you don't want to mix in will flow in. Further, in the method disclosed in Patent Document 4, although the gas-liquid contact efficiency is improved by using the dispersion plate as much as possible, when the dispersion plate is used in the middle of the aqueous phase, it exists in the lower portion of the dispersion plate. The contact efficiency between water and high-pressure carbon dioxide is poor, and an effect that greatly improves the gas-liquid contact efficiency cannot be expected.

  In Non-Patent Document 2, in a liquid-liquid extraction technique using high-pressure carbon dioxide using a micromixer, a raw material aqueous solution and high-pressure carbon dioxide are continuously supplied, instantaneously reached equilibrium with a microdevice, and reduced in pressure to be separated. Describes a liquid-liquid extraction method using a microdevice. In this apparatus flow, the separator is a normal vertical cylindrical container, and is not a mechanism for detecting the liquid level and continuously controlling the liquid level. Therefore, it is not a process that can be established continuously and industrially.

  In Non-Patent Documents 3 to 5, liquid-liquid equilibrium measurement using a microdevice assumes that the liquid-liquid instantaneously reaches an equilibrium state with the microdevice. In these apparatus flows, a visualization cell is used in order to obtain liquid-liquid equilibrium data, and it is specialized for state observation. Therefore, the liquid level is not detected and the liquid level is not continuously controlled.

  In Non-Patent Document 6, biaryl compounds, which are basic substances of organic fine chemicals and are useful building blocks of pharmaceuticals, and basic skeletons of liquid crystal molecules and OLED phosphorescent materials, are synthesized by the so-called “Suzuki coupling reaction”. States that. However, at the same time as the synthesis of the target substance, co- and by-products exceeding the stoichiometric amount were by-produced, and an increase in the cost for separation and purification of the target substance was a problem. Specifically, the Suzuki coupling reaction is a chemical reaction in which water is used as a reaction medium and a biaryl compound is obtained by cross-coupling an organic boron compound and an aryl halide using a palladium catalyst and a base. Therefore, in order to make a raw material exist uniformly in a reaction field, the raw material is often dissolved and supplied in a hydrophilic organic solvent. In this reaction, palladium is used as a heterogeneous catalyst, and a base is used as a homogeneous catalyst, and a large amount of inorganic salt is produced as an aqueous solution as a by-product. Accordingly, the fluid after completion of the reaction is mainly composed of a mixture of water and a hydrophilic organic solvent, and is a mixture of a hydrophobic target substance, a palladium catalyst, and a high concentration inorganic salt.

  Patent Document 7 describes an apparatus for continuous mixing of high-temperature carbon dioxide, and Non-Patent Document 7 describes high-pressure carbon dioxide extraction of vanillin.

JP 2005-143308 A JP-A-5-146276 JP 2008-014876 A JP 2008-055255 A JP 2008-012453 A JP 2013-188654 A JP 2012-086145 A

Peker, H., Srinivasan, M. P., Smith J. M., Mccoy, B. J., “Caffeine extraction rates from coffee beans with supercritical carbon dioxide”, AIChE J. 38 (1992) 761-770. Candela C. D. and Thomas G., “Procsess intensification by the use of micro device for liquid fractionation with supercritical carbon dioxide, Chem. Eng. Res. Des. 108 (2016) 139-145. M. Togo, Y. Inamori and Y. Shimoyama, “Phase transitions on (liquid + liquid) equilibria for (water + 1-methylnaphthalene + light aromatic hydrocarbon) ternary systems at T = (563, 573, and 583) K”, J. Chem. Thermodyn. 55 (2012) 1-6. M. Togo, T. Maeda, A. Ito, Y. Shimoyama, “Phase equilibria for the [{water + 1-methylnaphthalene + p-xylene}] system at T = (573, 623 and 653) K”, J. Chem. Thermodyn. 61 (2013) 100-104. M.Togo, T.Maeda, A.Ito, Y.Shimoyama, “Measurement and correlation of phase equilibria for (water + aromatic hydrocarbon) binary mixture at T = (573 to 623) K using microfluidic mixing” J. Chem. Thermodyn .67 (2013) 247-252. C. Liu, X. Rao, Y. Zhang, X. Li, J. Qiu, Z. Jin, “An aerobic and very fast Pd / C-catalyzed ligand-free and aqueous Suzuki reaction under mild conditions, Eur. Org. Chem. (2013) 4345-4350. K. Brudi, N. Dahmen, H. Schmieder, “Partition coefficients of organic substances in two-phase mixture of water and carbon dioxide at pressures of 8 to 30 MPa and temperatures of 313 to 333 K”, J. Supercrit. Fluids 9 (1996) 146-151.

  As described above, there has been no proposal of a process that can be established continuously and industrially for high-speed liquid-liquid extraction at the present time.

  In light of the above problems, the present inventors have conducted extensive research and development, and as a result, have reached the present invention in which high-pressure carbon dioxide is mixed with a micromixer and subjected to high-speed liquid-liquid extraction for liquid substances. That is, the target is a hydrophobic organic substance in an aqueous solution, mixed using high pressure carbon dioxide and micromixing, dramatically improving mass transfer compared to conventional high pressure carbon dioxide extraction from solids, The extraction equilibrium is reached instantly. Further, the high pressure carbon dioxide and the aqueous solution are separated instantaneously by the separator.

  That is, the method according to the present invention is a method for liquid-liquid extraction of a valuable material that is an extraction target contained in a raw material aqueous solution with high-pressure carbon dioxide, and continuously supplying the raw material aqueous solution and the high-pressure carbon dioxide to a high-pressure environment, respectively. Then, the mixture is mixed by a micromixer, passed through a retention pipe, and passed through a first pressure control valve for controlling the pressure of the micromixer and the retention pipe, and the reduced pressure fluid is supplied to the separator, High pressure carbon dioxide and the extraction object are discharged, mixed with a precipitation suppression fluid that suppresses the precipitation of the extraction object dissolved in the high pressure carbon dioxide, and passed through a second pressure control valve that controls the pressure. On the other hand, the aqueous solution after extraction is discharged from the level control valve at the lower part of the separator while the liquid level of the separator is made constant by the liquid level detecting means for detecting the liquid level. That.

  Furthermore, an apparatus according to the present invention is an apparatus for liquid-liquid extraction of an extraction target contained in a raw material aqueous solution with high-pressure carbon dioxide, a raw material aqueous solution high-pressure supply means for continuously supplying the raw material aqueous solution to a high-pressure environment, and the high pressure High-pressure carbon dioxide high-pressure supply means for continuously supplying carbon dioxide to the high-pressure environment, a micromixer that mixes the respective high-pressure fluids, a retention pipe that stays for a predetermined time after mixing in the micromixer, and the mixer And a first pressure control valve for controlling the pressure of the stay pipe, and a fluid decompressed via the first pressure control valve is supplied to the separator, and an outlet thereof is along the inner surface of the separator, or the separation A connecting pipe having an inner diameter of 2 mm or more so as to collide with the inner surface of the vessel, and an extraction target discharge line for discharging high-pressure carbon dioxide dissolving the extraction target from above in the separator. And a second pressure control valve for controlling the pressure of the separator in the extraction target discharge line, and suppressing the precipitation of the extraction target dissolved in the high-pressure carbon dioxide reduced in pressure by the second pressure control valve A precipitation suppression fluid high pressure supply means for supplying the precipitation suppression fluid before the second pressure control valve and mixing in the mixer; a liquid level detection means for detecting a liquid level in the separator; and A lower level control valve and a post-extraction fluid discharge line that discharges the aqueous solution after extraction, and temperature control means for adjusting the raw aqueous solution and the high-pressure carbon dioxide to an arbitrary temperature, the raw aqueous solution and the high-pressure dioxide Carbon is continuously supplied to each high-pressure environment, mixed by the micromixer, passed through the retention pipe, and passed through a first pressure control valve that controls the pressure of the micromixer and the retention pipe. The above-described fluid is supplied to the separator, and the high-pressure carbon dioxide and the extraction target are discharged from above, and the precipitation-suppressing fluid that suppresses the precipitation of the extraction target dissolved in the high-pressure carbon dioxide is mixed with the separator The level control of the lower part of the separator is made constant while the liquid level detecting means passes the second pressure control valve for controlling the pressure and the liquid level detecting means for detecting the liquid level is made constant. The aqueous solution after extraction is discharged from the valve.

It is a figure which shows the liquid-liquid extraction apparatus by a high pressure carbon dioxide using the micro mixer of this invention. It is a figure which shows the separator of this invention. It is a figure which shows the high pressure carbon dioxide extraction apparatus which made the solid object of the conventional method object. It is a figure which shows the high-pressure carbon dioxide extraction apparatus for the liquid substance of the conventional method.

  First, for comparison, a high-pressure carbon dioxide extraction apparatus according to a conventional method is shown.

  As shown in FIG. 3, carbon dioxide targeted for solid matter is supplied to the condenser 41 in a liquid state from a cylinder or lorry. The condenser 41 is sufficiently cooled by the chiller 42. The condenser 41, the liquefied carbon dioxide tank 43, the precooler 44, the evaporator 51, and the activated carbon container 55 serve as a carbon dioxide recovery system. Among these, the condenser 41 is only capable of temperature control and has the largest volume. Therefore, according to the temperature of the condenser 41, the pressure is uniquely controlled by the saturated vapor pressure, and the entire recovery system becomes the pressure.

  It is preferable to provide a chiller 42 as a cooling mechanism in the condenser 41 and a heating means (not shown) inside in order to shorten the recovery time when the cooling is excessive. For example, when the temperature of the condenser 41 is controlled to 5 ° C., the saturated vapor pressure of carbon dioxide at 5 ° C. is 4 MPa. Therefore, the lower limit of the recoverable pressure when a booster such as a booster of the carbon dioxide recovery system is not used is 4 MPa. It becomes.

  The carbon dioxide cooled and liquefied by the condenser 41 is stored in the liquefied carbon dioxide tank 43, and a precooler 44 is provided in the suction line of the high-pressure carbon dioxide pump 45 to sufficiently subcool the inside of the high-pressure carbon dioxide pump. This prevents the pressure increase failure due to the occurrence of vapor lock. When high-pressure carbon dioxide discharged under high-pressure conditions exceeds 31 ° C. in the heater 46, it becomes supercritical carbon dioxide. The flow rate of high-pressure carbon dioxide is measured using a mass flow meter 47. For example, a Coriolis flow meter can be used. The mass flow meter 41 may be either upstream or downstream of the heater 46.

  Then, it flows into the extraction tank 48 and dissolves the extraction object in high-pressure carbon dioxide. A heat exchanger 49 is provided downstream of the extraction tank 48. The temperature and pressure of high-pressure carbon dioxide before decompression are heated and cooled as necessary to determine the gas-liquid distribution ratio of carbon dioxide after decompression. The extraction pressure is controlled to be constant by the pressure control valve 50.

  The carbon dioxide after depressurization flows into the evaporator 51. Since the evaporator 51 is connected to the carbon dioxide recovery system, when the condenser 41 is controlled at 5 ° C. and 4 MPa, the pressure of the evaporator 51 is also 4 MPa. Therefore, when the conditions of the extraction tank 48 are 40 ° C. and 20 MPa, if the pressure is reduced to 5 ° C. and 4 MPa without heating and cooling in the heat exchanger 49, 30% becomes gas and 70% becomes liquid. For example, if heating is performed at 102 ° C. and 20 MPa in the heat exchanger 49 before decompression, the gas becomes 100% when decompressed to 5 ° C. and 4 MPa. The fluid temperature before depressurization is determined by the thermal stability of the object to be extracted and the gas-liquid distribution ratio in the evaporator.

  Here, a case where the pressure is reduced from 40 ° C. and 20 MPa to 5 ° C. and 4 MPa to become 30% gas and 70% liquid carbon dioxide will be described. 70% of liquid carbon dioxide is stored in the lower part of the evaporator 51. The extraction object is also stored in the lower part of the evaporator 51 at the same time. In general, the solubility of the extraction object in liquefied carbon dioxide at 5 ° C. and 4 MPa is lower than the solubility in supercritical carbon dioxide at 40 ° C. and 20 MPa.

  Moreover, even if it is dissolved in liquid carbon dioxide, when discharging the extraction object from the lower part of the evaporator 51, a high pressure carbon dioxide and the extraction object are placed in the separation tank 54 by providing a discharge valve 54 a at the lower part. Recovery is possible, and the evaporator 51 and the separation tank 54 are partitioned by a discharge valve 54a, and the pressure of the separation tank 54 is reduced to atmospheric pressure, whereby the extraction target can be collected and recovered.

  In any case, the location of the extraction object is determined by the specific gravity difference between 5 ° C. and 4 MPa liquid carbon dioxide (density: 0.896 g / cc) and the extraction object. If not, it is present on the top or bottom surface of liquid carbon dioxide. The liquid level detection means of the evaporator using the differential pressure gauge (differential pressure transmitter) 52 can be performed by the method described in Patent Document 3 described above.

  In order to make the liquid level of liquid carbon dioxide measured using the differential pressure gauge 52 installed in the evaporator 51 constant, the output of the internal heater 53 is controlled by the display value and the target value of the differential pressure gauge 52. And has a mechanism for evaporating liquid carbon dioxide at 5 ° C. and 4 MPa. At that time, although the extraction target is gas-liquid distributed according to the distribution coefficient, the arrangement of the internal heater 53 is considered with respect to the inner diameter of the evaporator 51 so that the liquid carbon dioxide is not boiled vigorously.

  Moreover, it is preferable to include heating control using thyristor and PID control. The extraction object is periodically collected in the separation tank 54 from the lower part of the evaporator 51 through the discharge valve 54a. The gaseous carbon dioxide evaporated by the evaporator 51 and the carbon dioxide vaporized by the fluid conditions (temperature, pressure) upstream of the pressure control valve 50 include the extraction target for the distribution coefficient on the gaseous carbon dioxide side. . An activated carbon tank 55 is provided to remove the extraction object accompanied by the gaseous carbon dioxide. The gaseous carbon dioxide, which has been restored to cleanliness through the activated carbon tank, is returned to the condenser 41, liquefied, and recycled in the plant.

  This circulation-reuse-type high-pressure carbon dioxide process is frequently used as a conventional high-pressure carbon dioxide extraction method for solids such as caffeine extracted from coffee beans. This process was an energy intensive process in which heating and cooling were repeated many times, such as cooling with the condenser 41, heating with the heater 46 at the outlet of the pump 45, and heating with the evaporator 51. However, in order to extract an object to be taken directly into the body, such as food, using an existing organic solvent, the risk of residual solvent cannot be excluded, so an extraction technique using high-pressure carbon dioxide is adopted.

The conventional high-pressure carbon dioxide extraction method for such solids has the following problems.
(1) The solubility of the extraction target in high-pressure carbon dioxide is low.
(2) Since the extraction target is present in the solid, the high-pressure carbon dioxide needs to reach the inside of the solid where the extraction target is present, and the mass transfer rate is controlled.
(3) The equipment cost increases due to the large pressure vessel.
(4) Since solids are processed, it is necessary to put in and out of the high-pressure vessel, and the processing efficiency is not high.

  Regarding the above (1), it is difficult to say that it is an appropriate method because it leads to an increase in initial cost and running cost, such as an increase in solubility by a higher pressure condition or an increase in solubility by a method by addition of an entrainer. As for (2), there is no solution other than crushing to increase the surface area as long as the extraction target is present in the solid. Since (3) and (4) are solids, there is no solution.

  Further, in the apparatus of FIG. 3, the object to be extracted is included in the solid object, but the apparatus in FIG. 4 is limited to the object to be extracted included in the liquid. Here, the carbon dioxide recovery system and the high-pressure carbon dioxide supply system are almost the same. The difference is that the extraction tank 68 is supplied with the raw material aqueous solution from the raw material aqueous solution tank 69 from the upper part via the high pressure raw material aqueous solution pump 70, and is supplied with the high pressure carbon dioxide from the lower part to make a countercurrent contact. It is the structure which guides the aqueous solution of.

  It is considered that the extraction tank 68 has a structure in which the raw material aqueous solution supplied from the upper part is evenly distributed to the section of the extraction tank 68 and flows down, and the high-pressure carbon dioxide supplied from the lower part is also efficient with the raw material aqueous solution. It is presumed that the device is in contact with the Moreover, while the cocurrent contact cannot exceed the partition coefficient wall, the countercurrent contact is below the solubility, the concentration of the extraction target in high-pressure carbon dioxide will exceed the concentration defined by the partition coefficient. Can do. However, this process has not been put into practical use.

  In the present invention, solids that are raw materials of the high-pressure carbon dioxide extraction technique that has been conventionally performed are limited to aqueous solutions, and further, extraction objects are limited to hydrophobic valuables existing in the raw aqueous solution. Alternatively, in the case of synthesizing a biaryl compound by the Suzuki coupling reaction, the fluid after completion of the reaction is mainly composed of water and a hydrophilic solvent, a mixture of a hydrophobic extraction target, a palladium catalyst, and a high concentration inorganic salt. Yes, this was used as the raw material for extraction in this technology. Any extraction raw material is required to be a uniform fluid in order to perform continuous extraction.

  By making the extraction raw material a uniform fluid, it is possible to solve some of the problems of the practical application barrier of extraction technology using high-pressure carbon dioxide that has been conventionally performed. In addition, as an application field, separation and purification processes in the manufacturing process of foods, medicines and pharmaceuticals, and cosmetics can be mentioned. This field has the utility of replacing conventional organic solvent extraction technology with high pressure carbon dioxide extraction technology because the product is taken directly into the body.

  Next, countermeasures against barriers to the practical application of the high-pressure carbon dioxide extraction technology described above will be described.

  First, the solubility of organic substances in high-pressure carbon dioxide is low. In order to increase the solubility of hydrophobic valuables in high-pressure carbon dioxide, it is impossible unless an entrainer (cosolvent) is added. This entrainer addition is feasible only when a processing scale is small and a high added value extraction target is obtained. However, when obtaining an extraction target having a large processing scale and a high added value, the additive solvent increases the running cost.

  On the other hand, hydrophobic valuables, which are extraction objects present in the raw material aqueous solution, are originally low in water solubility, generally low in concentration, and cannot be rate-controlled for dissolving high-pressure carbon dioxide. In addition, when the amount of the raw material aqueous solution is large, there is no change in that a process for circulating and reusing high-pressure carbon dioxide used in the same manner as in the past is required.

  Second, it is mass-controlled. Since the conventional raw material is an aqueous solution compared to the solid material, both the aqueous raw material solution and high-pressure carbon dioxide can be fed with a high-pressure pump. In addition, by using a micromixer for mixing both fluids, the mixing interface area can be increased to promote mass transfer. As will be described later, both fluids are mixed and reach an extraction equilibrium state in a few seconds, enabling high-speed liquid-liquid extraction.

  Thirdly, the equipment cost is increased due to the large container. When the raw material is a solid material, a large pressure vessel is necessary. However, when the raw material is an aqueous solution, the raw material can be discharged with a high-pressure pump, mixed with a micromixer, and separated with a small separator. That is, a large pressure vessel is not necessary. The equipment has been downsized, saving space and greatly reducing equipment costs.

  Fourthly, the processing efficiency is reduced due to the semi-batch processing. Since this is a continuous process as described above, the processing efficiency is increased.

  Therefore, the inventors scrutinized the problems of the existing technology and led to the invention.

  First, a liquid-liquid extraction apparatus using high-pressure carbon dioxide using a micromixer according to one embodiment of the present invention will be described with reference to FIG. Here, it is limited to the raw material aqueous solution containing a hydrophobic organic substance.

  As shown in FIG. 1, the raw material aqueous solution is filled in a raw material aqueous solution tank 1 and discharged at high pressure using a high pressure raw material aqueous solution pump 2. The pump 2 that generates the high-pressure fluid may be a pump having a quantitative property, and any type such as a plunger type, a diaphragm type, a piston type, and an intensifier type may be used.

  Moreover, it is preferable to provide a pressure gauge 3, a pressure sensor 4, and a safety valve 5 at the outlet of the high-pressure pump 2. Further, the raw material aqueous solution is heated to an arbitrary mixing temperature by the preheating means 6 before being mixed with the high-pressure carbon dioxide. The preheating means 6 is not limited to such means as hot water, electricity, or a heating medium.

  The high-pressure carbon dioxide is sufficiently cooled and liquefied from the siphon cylinder (or lorry storage) 7 through the precooler 8 to the liquefaction temperature or lower, and then connected to the suction of the high-pressure carbon dioxide pump 9 to quantitatively analyze the high-pressure environment. Discharged. The high-pressure carbon dioxide pump is not limited to a plunger type, a diaphragm type, a piston type, an intensifier type, and its model, and any type can be used as long as it can continuously discharge an arbitrary flow rate at a high pressure. In addition, it is preferable to cool the pump head to avoid discharge failure due to vapor lock. Further, the high pressure carbon dioxide uses the high pressure carbon dioxide return pressure control valve 12 instead of the safety valve, sets the maximum discharge pressure with the first pressure control valve 15a or the second pressure control valve 19 described later, and more It is preferable to have a structure in which the pressure is returned to the suction portion of the high-pressure carbon dioxide pump so that the pressure does not increase.

  Further, a pressure gauge 10 and a pressure sensor 11 are provided in the high-pressure carbon dioxide discharge line. Similar to the raw material aqueous solution, a preheater 13 for heating to the temperature of the mixing unit 14 is provided, and the heating means is not limited in its method such as warm water, electricity, and heating medium heating. The raw material aqueous solution and the high-pressure carbon dioxide are rapidly mixed by the micro mixer 14 to form a pseudo-homogeneous fluid.

  Here, the micro mixer 14 is an internal flow path of 2 mm or less, preferably 1 mm or less, and the shape thereof is a micro T mixer, a micro Y mixer, a micro swirl mixer, a comba micro mixer, an interdigital micro mixer, A multistage divided flow path type micromixer 14 is preferable.

  For example, the micro-T mixer is a Swagelok gas chromatograph joint SS-1F0-3GC (product number) or the like, and this joint is a T-shaped joint for 1/16 inch. This internal flow path has a micro size with an inner diameter of 0.3 mm, and the length of the micro flow path is as short as 1.3 mm, thereby reducing pressure loss. A normal standard type T-shaped joint SS-100-3 (product number) has a flow path with an inner diameter of 1.3 mm and a length of 9 mm. The micro T-shaped mixer is overwhelmingly higher in mixing performance than the standard T-shaped mixer. The micro-Y mixer is provided by, for example, YMC.

  The micro swirl mixer is sold by Sugiyama Shoji Co., Ltd. (see, for example, Patent Document 5).

  The interdigital micromixer is manufactured by IMM, Mainz, Germany. Although this mixer divides the flow path, the strength of the structure inside the mixer is low, so there is a tendency for pressure loss to be reduced by dividing the flow path, but the mechanical strength of the internal structure is low. Since the pressure loss is low, the allowable pressure loss is low, the processing amount and the fluid viscosity have upper limits, and the processing amount of several tens of cc / min level is the upper limit. The micro-T mixer, the micro-Y mixer, and the micro-swirl mixer are one-point mixing type micro-mixers, provided that the viscosity of the fluid to be mixed is low. If the viscosity is high, a pressure loss occurs in the microchannel, and the processing flow rate must be kept low.

  The comber type micromixer is an improvement of the above-mentioned interdigital micromixer. However, since the strength of the internal structure is high together with the multistage divided flow path type micromixer, the allowable pressure loss is high. Although it has member strength, it is preferable that the member pressure loss in a continuous process is not so large. For example, when the pressure loss of the mixer is less than 1 MPa in a multistage divided flow path type micromixer, the amount of processing is several t even if it is a laboratory level mixer when calculated with the raw material aqueous solution and high-pressure carbon dioxide. / Hr can be realized.

  A first pressure control valve 15a may be provided downstream of the micromixer 14 so that the pressure of the micromixer 14 and the pressure of the separator 17 can be set independently. Further, the first pressure control valve 15a can be omitted. The first pressure control valve 15a is equipped with an electropneumatic positioner that converts an electric signal of a control output for controlling a measured value of a pressure sensor (not shown) that measures the pressure after mixing into a set value. As long as the opening degree adjusting valve is controlled by air pressure, the type of the valve is not limited. For example, there is a mini-kin (trade name) manufactured by Fujikin and a control valve manufactured by Research Control. Further, it is a back pressure valve manufactured by Tescom.

  A pipe that releases the pseudo-homogeneous fluid into the separator 17 in the downstream pipe of the first pressure control valve 15 a is used as the connecting pipe 16. The outlet of the connecting pipe 16 is directed to create a flow along the inner surface of the separator 17 or to collide with the inner surface of the separator 17 without spraying the pseudo-uniform fluid in the separator 17.

  In addition, it has a “mechanism for suppressing entrainment” that promotes separation from high-pressure carbon dioxide by combining droplets by using a demister together in the separation region. Even if it is a quasi-homogeneous fluid, the raw material aqueous solution is a liquid, so it is thought that when atomized to spray, it becomes mist and entrained in high-pressure carbon dioxide. When flowing into the separator 17, it is considered that the high pressure carbon dioxide and the raw material aqueous solution are separated into two phases. The high-pressure carbon dioxide in which the extraction object phase-separated in the separator is dissolved, the aqueous solution after extraction are continuously discharged from the upper part of the separator, and the aqueous solution after extraction is extracted from the lower part of the separator. To do. For this purpose, a differential pressure gauge 20 for detecting the liquid level of the aqueous solution after extraction is provided. Details of the means for detecting the liquid level by the differential pressure gauge 20 will be described later. Further, the liquid level detection means may be an electrode type or a capacitance type in addition to the differential pressure gauge.

  The pressure of the separator 17 is controlled to be constant using the second pressure control valve 19. The second pressure control valve 19 is an electropneumatic device that converts an electrical signal of a control output for controlling a measured value of a pressure sensor (not shown) that measures the pressure of the separator 17 to a set value into an air pressure. As long as the valve is an opening control valve with air pressure control with a positioner, its type is not limited. For example, there is a mini-kin (trade name) manufactured by Fujikin and a control valve manufactured by Research Control. Further, it is a back pressure valve manufactured by Tescom.

  The liquid level in the separator 17 of the aqueous solution after extraction is detected by the differential pressure gauge 20, and the liquid level is controlled to be constant by the level control valve 21. As the differential pressure gauge 20, for example, EJX130J-DMSOH-7A0DD / JF3 / G11 / M61 / Z (withstand pressure 42 MPa, measurable differential pressure range 0 to 400, or 700 KPa, product number) manufactured by Yokogawa Electric Corporation can be applied. However, the present invention is not limited to this. The type of the level control valve 21 is not limited as long as it is an air pressure control opening control valve with an electropneumatic positioner that converts an electric signal of a control output for controlling the level measurement value to a set value. Absent. For example, a control valve with an electropneumatic converter is preferable, although the type such as Minucon (trade name) manufactured by Fujikin Co., Ltd. or a barometer manufactured by Research Control Co., Ltd. is not limited.

  When high-pressure carbon dioxide in which the extraction target is dissolved is discharged from the upper part of the separator 17 through the second pressure control valve 19 under reduced pressure, the high-pressure carbon dioxide becomes atmospheric pressure and at the same time loses the solubility of organic matter. If the object is solid at normal temperature, it will solidify in gaseous carbon dioxide at atmospheric pressure. Further, since carbon dioxide is a gas having a large Joule-Thompson effect, the surrounding fluid is rapidly cooled when the pressure is reduced from high pressure to atmospheric pressure. Even if the extraction object is a liquid at normal temperature, it may be solidified by cooling due to the Joule-Thompson effect. That is, if the high-pressure carbon dioxide in which the extraction target is dissolved is decompressed as it is, there is a high risk of solid deposition and clogging.

  Therefore, the precipitation suppression fluid 18 is mixed with the pipe 18a before decompression of the high-pressure carbon dioxide as necessary. Here, the precipitation inhibiting fluid 18 must be a good solvent for the extraction object. Specifically, water, ethanol, and 2-propanol are preferable. Moreover, it is also possible to perform a diversion solvent and concentration operation simultaneously with extraction using the organic solvent as the precipitation suppression fluid 18 with respect to the hydrophobic valuable material which is an extraction object. Although not shown, the means for supplying the precipitation suppression fluid 18 is continuously supplied using a high-pressure pump equivalent to the high-pressure raw material aqueous solution pump, and the mixer of the high-pressure carbon dioxide and the precipitation suppression fluid dissolving the extraction object is: The one equivalent to the micromixer 14 is used.

  FIG. 2 shows the structure of the separator 17. Here, a high pressure micro-differential pressure gauge is used as the level detection means, but the means is not limited and may be an electrode type or a capacitance type. Although there is a float contact type as a level detection method, since the detection unit is discontinuous and intermittent operation, the liquid surface moves up and down. For example, in the case of the cylindrical body type separator 17, the level detection method can maintain a constant liquid level such that the means for continuously measuring the liquid level performs PID control of the operation of the level control valve 21 a. This makes it possible to ensure process stability. As will be described later, when the post-reaction fluid of the Suzuki coupling reaction is an extraction raw material, an electrolyte is preferably present in the aqueous solution, so that an electrode-type liquid level meter is preferable.

である。差圧計には空気の圧力もかかっているものの、水比重の１／１０００であるため無視できる。高圧二酸化炭素が上部に存在すると、差圧計への導管内の分離器上部側、すなわち高圧二酸化炭素側の密度が大きくなるため、大気圧での差圧と大きく異なる。 The measurement principle of the differential pressure gauge 20 represents the liquid level with the pressure from the reference plane. With the differential pressure gauge 20 as a reference plane, when the upper fluid is air at atmospheric pressure with respect to the water level of H1 [m], the pressure P generated in the differential pressure gauge is

It is. Although the air pressure is also applied to the differential pressure gauge, it is negligible because it is 1/1000 of the water specific gravity. When high-pressure carbon dioxide is present at the upper part, the density on the upper side of the separator in the conduit to the differential pressure gauge, that is, the high-pressure carbon dioxide side becomes large, so that it is greatly different from the differential pressure at atmospheric pressure.

  The density of high-pressure carbon dioxide varies depending on its temperature and pressure. For example, in the case of 40 ° C., 18 MPa, 40 ° C., and 22 MPa, the density is 0.820 g / cc and 0.857 g / cc. Specifically, not only the control stability of the second pressure control valve 19 of the high-pressure carbon dioxide line 18a controlling the pressure of the separator 17, but also the controllability of the liquid level control valve 21a even if the pressure is constant. If the liquid level is low, the pressure drops because the high-pressure carbon dioxide is discharged from the lower part when the liquid level is completely discharged.

  Therefore, the liquid level controllability greatly affects the time stability of the liquid-liquid extraction process. The liquid level control of the lower water when handling high pressure carbon dioxide close to the water density as the upper fluid needs to consider the density of the high pressure carbon dioxide.

である。 With reference to FIG. 2, the differential pressure transmitter display when high-pressure carbon dioxide of 40 ° C. and 20 MPa is present in the upper portion and 40 ° C. and 20 MPa of water is present in the lower portion will be described. The differential pressure associated with the differential pressure transmitter is

It is.

で表される。ここで、例えば、内径１００ｍｍの円筒状の分離器の場合、水の流入流量を１０ｃｃ／ｍｉｎとする場合、１ｍＡｑ＝９．８０６６５ｋＰａの液面上昇速度は、０．０２１２３１ｍｍ／ｓである。大気圧で発生する差圧上昇速度は、０．０００２０８２１ｋＰａ／ｓとなる。一方、４０℃、２０ＭＰａ、密度０．８４ｇ／ｃｃの高圧二酸化炭素が上部を満たしている場合、同じ液面上昇速度０．０２１２３１ｍｍ／ｓの場合、差圧上昇速度は０．００００３３３ｋＰａ／ｓと１６％に低下する。液面レベルを一定に調節するためには、目標設定値に対して単位時間当たりに変化する液面レベル、即ち差圧上昇速度に応じてレベル制御弁のＰＩＤ制御を行う。その場合、差圧計２０の測定範囲が０〜７００ｋＰａであり、上記差圧上昇速度は非常に小さい。 Here, if the specific gravity γ [kgf / m ³ ] is obtained by multiplying the density by gravity acceleration, the differential pressure is

It is represented by Here, for example, in the case of a cylindrical separator having an inner diameter of 100 mm, when the inflow rate of water is 10 cc / min, the liquid level rising speed of 1 mAq = 9.80665 kPa is 0.021231 mm / s. The rate of differential pressure increase generated at atmospheric pressure is 0.00020821 kPa / s. On the other hand, when high-pressure carbon dioxide having a temperature of 40 ° C., 20 MPa, and a density of 0.84 g / cc fills the upper part, when the same liquid level rise rate is 0.021231 mm / s, the differential pressure rise rate is 0.0000333 kPa / s, 16 %. In order to adjust the liquid level to be constant, PID control of the level control valve is performed according to the liquid level that changes per unit time with respect to the target set value, that is, the differential pressure increase rate. In that case, the measurement range of the differential pressure gauge 20 is 0 to 700 kPa, and the differential pressure increase rate is very small.

  Therefore, the controllability of the level control valve is remarkably improved by reducing the inner diameter of the level detector so that a numerical value change appears in the differential pressure gauge 20. When the inner diameter of the level detector is reduced from 100 mm to 10 mm, the inflow rate of water is 10 cc / min and the liquid level rise rate is 0.021231 mm / s (inner diameter 100 mm) to 2.12314 mm / s (inner diameter 10 mm). To do. When the upper fluid is high-pressure carbon dioxide of 40 ° C. and 20 MPa, the differential pressure increase rate is 0.0000333 kPa / s (inner diameter 100 mm) to 0.003329 kPa / s (inner diameter 10 mm). Since the length is the square of the length, the differential pressure increase speed increases 100 times. Therefore, the control response of the level control valve sufficiently increases the time stability.

  Next, the operation of the above-described apparatus will be described with reference to FIG.

  Here, the raw material and the object to be extracted are an aqueous solution and a hydrophobic valuable material contained in the raw material aqueous solution, respectively. When this is liquid-liquid extracted with high pressure carbon dioxide, the raw material aqueous solution in the raw material aqueous solution tank 1 is continuously supplied to the high pressure environment from the pipe P1. Further, the carbon dioxide in the carbon dioxide cylinder 7 is continuously supplied from the pipe P2 to the high pressure environment after the pressure is increased by the high pressure carbon dioxide pump 9. These are preheated through the preheaters 6 and 13 and mixed in the micromixer 14.

  The fluid after mixing passes through a residence pipe 15 having an arbitrary residence time. The residence pipe 15 needs to be optimized according to the treatment flow rate and the extraction target, but the mixed fluid of the raw material aqueous solution and the high-pressure carbon dioxide generally has a pressure loss of less than 1 MPa while maintaining a turbulent state. The residence time calculated from the volume flow rate of the mixed fluid and the internal volume of the residence pipe is less than 30 seconds, preferably less than 20 seconds.

  In the case of obtaining a higher extraction rate and separation efficiency by operating the pressure of the mixer 14 and the retention part (retention pipe) 15 and the pressure of the separation part (separator) 17 at different pressures, the first pressure control valve 15a. To provide a pressure section. On the other hand, when the pressure of the mixer 14 and the retention part 15 and the pressure of the separation part 17 may be the same pressure, the first pressure control valve 15a can be omitted.

  Although the mixed fluid of the raw material aqueous solution and the high-pressure carbon dioxide has low mutual solubility, it becomes a pseudo-uniform fluid by the micro mixer 14. This increases the extraction efficiency of the extraction target, which is a hydrophobic organic substance in the raw material aqueous solution, but it is necessary to separate this pseudo-uniform fluid. The density of high-pressure carbon dioxide is, for example, constant at 40 ° C., 0.63 g / cc at 10 MPa, 0.84 g / cc at 20 MPa, 0.91 g / cc at 30 MPa, 0.96 g / cc at 40 MPa, and 0 at 50 MPa. It becomes .99 g / cc, and there is almost no difference from the density of the aqueous solution of 1.0 g / cc under the high pressure condition where the general high pressure carbon dioxide extraction yield is high. Both fluids that do not dissolve each other are separated by specific gravity difference, and separation is difficult when the specific gravity difference is small. Since the solubility in carbon dioxide of the extraction object extracted and dissolved in high-pressure carbon dioxide changes depending on the temperature and pressure, the specific gravity difference with the aqueous solution is changed by changing the temperature and pressure within the range that can be dissolved in carbon dioxide. To separate. For this purpose, it may be important to change the pressure of the micromixer 14 and the retention part 15 and the pressure of the separation part 17 by the pressure control valve 15a.

  For example, when the extraction conditions are 40 ° C. and 30 MPa and the separation conditions are 40 ° C. and 20 MPa, if the target extract is present in high-pressure carbon dioxide, the specific gravity was 0.09 g / cc in the extraction part. The difference is expanded to 0.16 g / cc by the separation unit 17 and becomes a stable detection range of a differential pressure gauge used for separation performance and liquid level detection due to a difference in specific gravity. For example, in the case of extraction by slightly raising the temperature of high-pressure carbon dioxide, when the temperature is constant at 60 ° C., 0.29 g / cc at 10 MPa, 0.72 g / cc at 20 MPa, 0.83 g / cc at 30 MPa, and 0.83 at 40 MPa. It becomes 0.93 g / cc at 89 g / cc and 50 MPa. Although high pressure carbon dioxide can change the density at any temperature and pressure, it should be noted that the solubility of the extraction object also changes.

  The high-pressure carbon dioxide and the aqueous solution are quasi-homogenized by the micromixer 14 and then flow into the separator 17 through the connecting pipe 16. A pipe 18 a that discharges high-pressure carbon dioxide in which an extraction target is dissolved is connected to the upper portion of the separator 17. As described above, when the pressure of the micromixer 14 and the retention pipe 15 and the pressure of the separator 17 are controlled by the same pressure, the pressure control valve 19 that controls the pressure of the entire process is provided in the extraction target discharge line.

  As will be described later, the end opening of the connecting pipe 16 that flows into the separator 17 is expanded to have an inner diameter of 3 mm or more, and the flow rate of the pseudo-homogeneous fluid is lowered to eject droplets into the separator 17. It is preferable not to let this occur.

  Further, when the high pressure carbon dioxide in which the extraction target is dissolved by the pressure control valve 19 is opened to the atmospheric pressure, the extraction target dissolved in the high pressure carbon dioxide is solid-deposited in the depressurization process, so that the pressure controllability is deteriorated. . In order to suppress the precipitation of the extraction object, it is preferable to directly mix the precipitation suppression fluid 18 with the high-pressure carbon dioxide in which the extraction object before decompression is dissolved to suppress the solid precipitation of the extraction object during the decompression.

  In addition, a means for detecting the level of the aqueous solution after extraction staying in the lower part of the separator 17 is provided. A level control valve 21a is provided in the aqueous solution discharge pipe 21 below the separator 17 so that the liquid level measured by the liquid level detection means is controlled to be constant.

  Here, the high-pressure carbon dioxide is preferably high-pressure carbon dioxide including a supercritical state. The critical point of carbon dioxide is 31 ° C. and 7.4 MPa, and supercritical carbon dioxide is one that exceeds the critical temperature and critical pressure. The extraction target handled here is assumed to be a substance that is subject to denaturation depending on the temperature depending on the substance, the operating temperature is 30 to 60 ° C., more preferably 40 to 60 ° C., and the operating pressure is 8 to 60 MPa. The pressure is preferably 20 to 40 MPa.

  If the valuables contained in the aqueous solution are organic substances that dissolve in high-pressure carbon dioxide, including the supercritical state, that is, if the extraction target is a specific hydrophobic valuable substance in a large amount of hydrophobic solvent, It is difficult to extract a specific hydrophobic value even if it has solvent ability. Utilizing the solvent characteristics of high-pressure carbon dioxide, when a hydrophobic valuable substance dissolved in a trace amount in the raw material aqueous solution is an extraction target, the polarities of the raw aqueous solution and high-pressure carbon dioxide are greatly different, so they do not dissolve each other Is the point. The micromixer 14 makes a quasi-homogeneous fluid, creates a mass transfer field, performs extraction with a very short residence time, and immediately separates it with the separator 17 to complete the extraction / separation operation.

  Here, the extraction raw material can be a fluid after completion of the reaction when the biaryl compound is synthesized by the Suzuki coupling reaction. This is characterized in that a mixture of a hydrophilic organic solvent and water is a main component, and there is a hydrophobic valuable material as an extraction target in it. Hydrophobic valuables that are the extraction target in the extraction raw material are liquid-liquid extracted with high-pressure carbon dioxide, and the mixture of the hydrophilic organic solvent and water remains in the liquid. An example of the hydrophilic organic solvent is alcohol.

  As a catalyst, a palladium catalyst and an inorganic salt as a reaction byproduct coexist. As a result, the biaryl compound of the target object contained in the processing fluid of the coupling reaction is extracted with high-pressure carbon dioxide, and the separation and purification process in which the inorganic salt as a reaction by-product remains in the aqueous alcohol solution can be realized. Be expected.

  Here, it is preferable that the precipitation suppression fluid 18 is a good solvent for the extract. The extraction object is extracted from the raw material aqueous solution by high-pressure carbon dioxide, and the pressure is reduced through the second pressure control valve 19 installed in the extraction object discharge line 18a from the upper part of the separator. Carbon dioxide has a solvent effect only under high-pressure conditions, but loses its effect instantly when the pressure is reduced to atmospheric pressure. As a result, the extraction object dissolved in the high-pressure carbon dioxide is deposited in an atmospheric pressure environment. Depending on whether the extraction target is solid or liquid in a normal temperature and normal pressure environment, the state of the extraction target deposited when high-pressure carbon dioxide is reduced to atmospheric pressure changes. Regardless of whether the extraction object after decompression is solid or liquid, high-pressure carbon dioxide is rapidly cooled because it is a fluid that cools the surrounding fluid when decompressed from high pressure to atmospheric pressure, that is, the Joule-Thompson effect is large. In that case, even a liquid is solidified, or in the case of a solid, it is deposited as it is.

  Furthermore, when carbon dioxide is depressurized from most conditions to atmospheric pressure except for very high temperature conditions, it becomes a solid-gas condition via a triple point, so a part of the carbon dioxide becomes ice. The place to solidify is in the vicinity of the outlet from the inside of the second pressure control valve 19 that performs depressurization, and in order to avoid the trouble of the clogging of precipitation, the precipitation suppression fluid is added to the high-pressure carbon dioxide in which the extraction target before decompression is dissolved. It is preferred to mix 18 directly.

  In particular, when the amount of treatment is large, an expensive one cannot be used as the precipitation suppression fluid 18, so water, an alcohol aqueous solution, or alcohol is used. Further, when the amount of treatment is small, it is also possible to simultaneously perform extraction, solvent inversion, and concentration by using a hydrophobic organic solvent as the precipitation suppression fluid.

  In addition to the hydrophobic valuables, a part of the alcohol component is also extracted into the high-pressure carbon dioxide, so that it is possible to consider not supplying the precipitation suppression fluid 18. As a result, the alcohol concentration of the extraction raw material is reduced, and the solubility of the hydrophobic valuable material is also reduced. As a result, the hydrophobic valuable material is easily extracted into the high pressure carbon dioxide, that is, the partition coefficient to the high pressure carbon dioxide is increased. It is possible to rise.

  Further, in the separator 17, the outlet of the connecting pipe 16 is configured to be along the inner surface of the separator 17 or to collide with the inner surface of the separator 17. Here, when a fluid flows through a smooth pipe line, the state of flow differs between the vicinity of the pipe wall and the vicinity of the center portion. The main cause is that a frictional force always acts on the fluid flowing in the vicinity of the tube wall regardless of the type of object, viscosity, and flow velocity. According to Prandtl, "The flow velocity distribution near the pipe wall is determined by the density of the fluid, the coefficient of kinematic viscosity, the pipe surface friction stress, and the distance from the wall, and is independent of the Reynolds number, which is the quantity that represents the flow of the entire pipe." Was revealed. This is called Prandtl's wall law. Thereby, it is possible to separate high-pressure carbon dioxide having a viscosity difference of 10 times from the aqueous solution after extraction.

  Here, although it is a pseudo-homogeneous fluid, the high-pressure carbon dioxide and the aqueous solution are not compatible with each other. Although the specific gravity is close, the viscosity is different. For example, the viscosity of water at 40 ° C. and 20 MPa is 0.655 cP, and the viscosity of high-pressure carbon dioxide is about 10 times different from 0.078 cP. In order to separate fluids with different viscosities, when a flow along a solid wall is created, the viscous fluid (in this case, water) forms a viscous bottom layer on the wall surface, so the velocity of the flow along the wall is slow, Water is easily separated from the pseudo-uniform fluid. Accordingly, the inner diameter of the connecting pipe 16 is increased so that the fluid does not flow or spray on the inner surface of the separator 17 and the ejection flow velocity is lowered, and then the aqueous solution adheres along the wall by colliding with the inner surface of the separator 17. Thus, it is preferable to have a structure that generates a flow along the wall.

  In addition, it is also possible to install a demister on the upper part of the separator 17 for the purpose of accelerating the separation by uniting the splashes so that the fluid flowing into the separator 17 is not sprayed and entrained in the separator 17 It is. As long as this demister exhibits a function of suppressing entrainment without causing pressure loss, it may be a simple one such as “stainless steel scrubber”, and its form is not particularly limited with emphasis on performance.

  Here, as shown in FIG. 2, the liquid level in the separator 17 is detected by using a high-pressure micro-differential pressure gauge 20 that is individually connected by a high-pressure pipe from the upper part and the lower part in the separator 17. If each of the separators is not connected to a high pressure micro differential pressure gauge, the differential pressure measurement is not stabilized by the ejector effect, and an accurate liquid level cannot be detected. An upper part of the separator 17 has a separation region 33 having a larger cross-sectional area than the lower liquid level measurement region 34 in order to efficiently separate the high-pressure carbon dioxide in which the extraction target is dissolved from the aqueous solution after extraction. In order to detect the liquid level of the aqueous solution after extraction, it is preferable to use a separator 17 having a liquid level measurement region 34 having a smaller cross-sectional area than the upper separation region 33. Needless to say, the first pressure control valve 15a, the second pressure control valve 19, and the level control valve 21a are selected from the flow rate, the differential pressure before and after, and the fluid viscosity. Various known methods can be used as a method of detecting the liquid level using the differential pressure gauge 20.

  In the differential pressure gauge 20, piping is independently connected to the high-pressure carbon dioxide environment in the upper part and the aqueous solution after extraction in the lower part. Alternatively, the piping of the aqueous solution after the lower extraction is connected from the lower part on the H side of the differential pressure gauge 20, and further, the piping is made so that the H side upper and lower connection part of the differential pressure gauge 20 passes through the upper part on the H side of the differential pressure gauge 20. It is also possible to connect the pipe on the upper side of the H side to the high-pressure carbon dioxide at the upper side of the separator 17 and connect it to the upper side on the L side of the differential pressure gauge 20.

この関係式で示すように水密度と高圧二酸化炭素密度の差分が位置ヘッドの計測のポイントとなる。即ち、Δρが小さいと、位置ヘッドの計測値の変化が小さくなるため工夫が必要となる。前述の通り、原料水溶液と高圧二酸化炭素の混合流体において、相互溶解性は低いもののマイクロ混合器１４によって疑似均一流体となる。

As shown by this relational expression, the difference between the water density and the high-pressure carbon dioxide density is the point of measurement of the position head. In other words, if Δρ is small, the change in the measurement value of the position head is small, and thus a device is required. As described above, the mixed fluid of the raw material aqueous solution and the high-pressure carbon dioxide has a low mutual solubility but becomes a pseudo-uniform fluid by the micromixer 14.

  This increases the extraction efficiency of the extraction target, which is a hydrophobic organic substance in the raw material aqueous solution, but it is necessary to separate this pseudo-uniform fluid. Therefore, as described above, the inner diameter of the connecting pipe 16 flowing into the separator 17 is as thick as 3 mm or more, the flow velocity of the flowing fluid is slowed, and the outlet of the connecting pipe 16 is along the inner surface of the separator 17 or separated. It is preferable to make it collide with the inner surface of the vessel 17.

  Since the solubility in carbon dioxide of the extraction object extracted and dissolved in high-pressure carbon dioxide changes depending on the temperature and pressure, the temperature and pressure are changed within the range where the extraction object can be dissolved in carbon dioxide, In order to obtain and separate the specific gravity difference from the aqueous solution, it may be important to change the pressure of the micromixer 14 and the retention unit 15 and the pressure of the separation unit 17 by the pressure control valve 21a. Although high pressure carbon dioxide can change the density at any temperature and pressure, it should be noted that the solubility of the extraction object also changes. Therefore, the separator 17 is required to have two roles of quasi-uniform fluid separation and responsiveness for liquid level control.

  Here, the responsiveness for controlling the liquid level will be described with reference to FIG.

  In the upper part of the separator 17, a separation region 33 for promoting the specific gravity difference separation of the pseudo-uniform fluid is provided. In the separation region 33, the inner diameter of the connecting pipe is not reduced by 1/16 inch so that the pseudo-uniform fluid is ejected at a high speed and is not atomized when flowing into the separator. The quasi-homogeneous fluid is made to collide with the inner wall of the separator, or is made to flow along the inner wall. In addition, a demister is installed on the upper part of the separation region 33 in order to suppress entrainment of droplets. Furthermore, without increasing the inner diameter of the separation region 33, it is possible to assume a droplet particle size and not to increase the rising flow velocity below the settling velocity, that is, the linear velocity of the separation region.

  Next, in order to detect the liquid level and improve the liquid level control response in the separator 17 of the aqueous solution after extraction, the inner diameter of the liquid level detection region 34 should be designed appropriately with respect to the inflow rate. Is very important. In the case of a system that opens and closes the level control valve 21a so that the liquid level is constant, the liquid level increases when the level control valve 21a is closed, and decreases when the level control valve 21a is opened. For this purpose, the responsiveness of the liquid level is important with respect to the inflow rate, and therefore it is necessary to design the inner diameter of the level detection region where the level changes within at least several minutes.

  Here, according to the measurement principle of the differential pressure gauge described above, the aqueous solution pipe below the separator 17 is connected to the high pressure side, and the high pressure carbon dioxide pipe above the separator 17 is connected to the low pressure side. In the measured value of the differential pressure gauge, the density of both fluids greatly affects. An arbitrary amount of water is filled in the separator, and ΔP representing the water level measured at atmospheric pressure is filled with high-pressure carbon dioxide of 40 ° C. and 20 MPa at the top. Since the density of carbon) increases, ΔP representing the water level decreases because the density difference greatly affects ΔP. Therefore, even if the flow rate of the extracted aqueous solution that flows in is constant, the level increase rate in a high-density high-pressure carbon dioxide environment is smaller than the level increase rate under atmospheric pressure.

  In order to ensure the stability of the level control, if there is no amount of level displacement between 1 and 2 minutes, the level of the detected liquid level is made constant. It becomes difficult to determine the PID control variable of the valve. Therefore, when using a high-pressure micro-differential pressure gauge as a means for detecting the liquid level of an aqueous solution of a fluid having a small density difference from the aqueous solution after extraction, such as high-pressure carbon dioxide, the smaller the inner diameter of the level detection region, the unit Since the level displacement amount per time can be increased, the control response of the level control valve can be ensured.

  Further, it is very important to appropriately select the orifice flow coefficient Cv value of the level control valve. When the Cv value of the level control valve is larger than the appropriate value, when the level control valve is opened, the level in the separator decreases, and the volume corresponding to the changed level of the high-pressure carbon dioxide inflow can be satisfied. If not, the pressure will drop. In that case, the solubility in high-pressure carbon dioxide also decreases at the same time, and a certain extraction operation cannot be performed.

  Further, when the closing operation is performed, the aqueous solution after extraction is not discharged from the level control valve until the level control value is increased, and therefore, intermittent outflow occurs. Stable control is a state in which the input flow rate and the discharge flow rate are constant and flow continuously, and cannot be said to have good controllability. Further, when the Cv value of the level control valve is smaller than the appropriate value, it becomes impossible to discharge the extracted aqueous solution after extraction, which is an essential problem.

As described above, the process of extracting the hydrophobic valuables contained in the raw material aqueous solution at high speed with high-pressure carbon dioxide is achieved by the separator of high-pressure carbon dioxide and aqueous solution, liquid level detection, and level control technology. Here, the following settings were made.
-The raw material was an aqueous solution, and the hydrophobic organic substance contained therein was used as the extraction target.
The raw material was a mixture of a hydrophilic organic solvent and water, and the hydrophobic organic substance contained therein was used as the extraction target.
・ Continuously supply raw materials and high-pressure carbon dioxide, and instantly and uniformly mix using a micromixer.
・ Because it becomes the above pseudo-homogeneous fluid, mass transfer can be promoted, so that extraction equilibrium is reached in a short time.
・ A pipe that connects the pseudo-homogeneous fluid to the mixer and the separator from the first pressure control valve creates a flow along the wall surface or collides with the wall without spraying the pseudo-homogeneous fluid in the separator. It has a mechanism that creates a flow and further uses a demister at the top of the separator to coalesce the droplets and promote separation from high-pressure carbon dioxide.
・ A line will be provided to discharge high-pressure carbon dioxide in which the extraction target is dissolved from the upper part of the separator. In addition, a precipitation-suppressing fluid is continuously supplied as necessary so that the extraction object does not precipitate after decompression, and the extraction object before decompression is mixed with dissolved high-pressure carbon dioxide to suppress the precipitation of the extraction object. .
・ Separator is a separation area for separating high-pressure carbon dioxide and raw material aqueous solution with the extraction target dissolved in the upper part, and level detection for detecting the liquid level of the extracted aqueous solution stored in the lower part of the separator It has a structure divided into regions. In addition, the inner diameter of the level detection region is smaller than the inner diameter of the separation region, and has an appropriate inner diameter that can improve controllability according to the amount of inflow.
-It has a level control valve that discharges the aqueous solution after extraction from the lower part of the separation continuously at a constant level.

  Next, more specific examples of the liquid-liquid extraction method and apparatus using high-pressure carbon dioxide using the above-described micromixer will be described.

(Device configuration)
In the embodiments described later, unless otherwise specified, the apparatus configuration is as described below.

  In FIG. 1, a plunger type metering pump (manufactured by Nippon Seimitsu Co., Ltd.) was used as the high-pressure raw material aqueous solution pump 2. The aqueous raw material solution was heated by circulating it for a predetermined time in a water bath maintained at a constant temperature. The high-pressure carbon dioxide is connected to the suction of the high-pressure carbon dioxide pump 9 from the cylinder 7 through the precooler 8 and is quantitatively discharged to the high-pressure environment. As the high-pressure carbon dioxide pump 9, a plunger type metering pump (manufactured by Nippon Seimitsu Co., Ltd.) was used. The preheater 13 which heats to the temperature of a mixing part similarly to raw material aqueous solution was provided, and the hot water heating by the water bath was used as the heating means. The raw material aqueous solution and the high-pressure carbon dioxide are rapidly mixed by the micro mixer 14 to form a pseudo-homogeneous fluid.

For the micro mixer, a 1/16 inch micro T-shaped mixer (inner diameter 0.3 mm, manufactured by Swagelok, trade name: Low Dead Volume Tea) was used. The first pressure control valve 15a is omitted. A pipe that opens the pseudo-uniform fluid into the separator 17 in the downstream pipe is used as the connecting pipe 16. The connecting tube 16 was a 1/4 inch SUS316 tube. As the second pressure control valve 19, a back pressure valve manufactured by Tescom was used. A differential pressure gauge manufactured by Yokogawa was used as the differential pressure gauge 20, and a control valve manufactured by Research Control was used as the level control valve 21. Ethanol or 2-propanol was used for the precipitation suppression fluid 18 to be joined to the CO ₂ side outlet. A plunger type metering pump (manufactured by Nippon Seimitsu Co., Ltd.) was used as a means for supplying the precipitation suppression fluid 18, and a 1/8 inch micro T-shaped mixer (manufactured by Swagelok Co., Ltd.) was used as the mixer.

(Raw material aqueous solution)
In Example 1, an aqueous solution in which 0.1 g of vanillin, 0.03 g of vanillic acid, and 0.015 g of acetovanillone were dissolved in 100 g of water was used as the raw material aqueous solution. In Examples 2 to 4 and Comparative Examples 1 to 4, an aqueous solution in which 0.015 g of guaiacol was further dissolved in the above aqueous solution was used as a raw material aqueous solution. In Examples 5 to 7, an aqueous solution in which 7.6 g of sodium bicarbonate was further dissolved in the above aqueous solution was used as a raw material aqueous solution.

  In Example 8 and Comparative Example 5, the black liquor obtained from the papermaking process was used as the raw material aqueous solution. This black liquor contains vanillin 0.092 wt%, vanillic acid 0.028 wt%, acetovanillone 0.018 wt%, guaiacol 0.013 wt%, salt (a mixture of salts mainly composed of sodium hydrogencarbonate) 7.6 wt% It is a solution containing more than 90 wt% of unidentified organic components in terms of carbon.

In Examples 9 to 12, ethanol-water containing p-cyanobiphenyl, K ₂ CO ₃ , KHCO ₃ , KBr, B (OH) ₃ assumed as a solution after the cross-coupling reaction as the raw material aqueous solution, etc. A volume mixed solution was used. The reference concentrations are p-cyanobiphenyl 1.9 wt%, K ₂ CO ₃ 1.6 wt%, KHCO ₃ 1.1 wt%, KBr 1.4 wt%, B (OH) ₃ 0.7 wt%, 0.2, 0. 5. Used as a raw material solution of 1.0 standard concentration.

(Analysis method)
With respect to each of the obtained CO ₂ side and liquid side samples, the concentration of vanillin, vanillic acid, acetovanillone and guaiacol, or p-cyanobiphenyl was measured by analysis using HPLC. Based on this result, to calculate the flow rate of each component in the CO ₂ side-fluid side, the yield was calculated for each component in CO ₂ side-fluid side by dividing a feed flow rate of each component. Further, by dividing the weight or mole fraction of each component in the CO ₂ side of the liquid side by weight or mole fraction of each component was calculated partition coefficients of the CO ₂ side of each component.

(Example 1)
The raw material aqueous solution flow rate was about 10 g / min, the CO ₂ flow rate was 40 g / min, the extraction temperature was 40 ° C., and the extraction pressure was 20 MPa. By inserting a spacer made of Teflon (registered trademark) into a separator having an inner diameter of 40 mm, the inner diameter of the separation section was 20 mm, and the inner diameter of the liquid level control section was 10 mm. In this example, ethanol was used as the precipitation suppression fluid. The flow rate of the precipitation suppression fluid was set to be equal to the CO ₂ flow rate.

Table 1 shows the yield and distribution coefficient on the CO ₂ side and liquid side in the examples. The vanillin extraction rate on the CO ₂ side at 40 ° C. and 20 MPa was 75.4%. The distribution coefficient of vanillin to the CO ₂ side was 0.75 g / g (1.83 mol / mol), but this value is close to 1.94 mol / mol in Non-Patent Document 7 described above. It was confirmed that a value close to the equilibrium partition coefficient was obtained.

(Example 2)
An extraction experiment was performed under the same conditions as in Example 1 except that the extraction pressure was 15 MPa. The extraction rate of vanillin on the CO ₂ side at 40 ° C. and 15 MPa was 69.9%. The distribution coefficient of vanillin to the CO ₂ side was 0.57 g / g (1.39 mol / mol), which is close to 1.41 mol / mol of Non-Patent Document 7 described above, and at 20 MPa. It was confirmed that a value close to the equilibrium partition coefficient was obtained as in

(Example 3)
An extraction experiment was performed under the same conditions as in Example 1 except that the extraction pressure was 10 MPa. The extraction rate of vanillin on the CO ₂ side at 40 ° C. and 10 MPa was 53.0%. The distribution coefficient of vanillin to the CO ₂ side was 0.28 g / g (0.67 mol / mol), which is a value close to 0.68 mol / mol of Non-Patent Document 7 described above, and is 20 and 15 MPa. It was confirmed that a value close to the equilibrium partition coefficient was obtained as in the case of.

  From Examples 1 to 3, it has been clarified that the extraction rate and the distribution coefficient can be controlled by pressure in the range of 10 to 20 MPa. Moreover, it was clarified that a value close to the equilibrium partition coefficient can be obtained at 40 ° C. regardless of the pressure.

Example 4
An extraction experiment was performed under the same conditions as in Example 1 except that the extraction temperature was 60 ° C. The vanillin extraction rate on the CO ₂ side at 60 ° C. and 20 MPa was 66.9%. The partition coefficient of vanillin to the CO ₂ side was 0.51 g / g (1.25 mol / mol).

  From Examples 1 and 4, it was clarified that the extraction rate and the distribution coefficient can be controlled at a temperature of 40 to 60 ° C. at a pressure of 20 MPa.

(Comparative Example 1)
An extraction experiment was performed under the same conditions as in Example 1 except that the CO ₂ flow rate was 20 g / min. The yield of vanillin on the CO ₂ side was 60.0%. The partition coefficient of vanillin to the CO ₂ side was 0.75 g / g (1.88 mol / mol). At 40 ° C. and 20 MPa, it was confirmed that the extraction rate of each component to the CO ₂ side was determined by the flow rate ratio of CO ₂ and the raw material aqueous solution without greatly changing the distribution coefficient.

(Comparative Example 2)
An extraction experiment was performed under the same conditions as in Example 2 except that the CO ₂ flow rate was 20 g / min. The yield of vanillin on the CO ₂ side was 52.9%. The partition coefficient of vanillin to the CO ₂ side was 0.55 g / g (1.35 mol / mol). Even at 40 ° C. and 15 MPa, it was confirmed that the extraction rate of each component to the CO ₂ side was determined by the flow rate ratio of CO ₂ and the raw material aqueous solution without greatly changing the distribution coefficient.

(Comparative Example 3)
An extraction experiment was performed under the same conditions as in Example 3 except that the CO ₂ flow rate was 20 g / min. The yield of vanillin on the CO ₂ side was 34.7%. The partition coefficient of vanillin to the CO ₂ side was 0.26 g / g (0.64 mol / mol). Even at 40 ° C. and 10 MPa, it was confirmed that the extraction ratio of each component to the CO ₂ side was determined by the flow rate ratio of CO ₂ and the raw material aqueous solution without greatly changing the distribution coefficient.

(Comparative Example 4)
An extraction experiment was performed under the same conditions as in Example 4 except that the CO ₂ flow rate was 20 g / min. The yield of vanillin on the CO ₂ side was 49.7%. The partition coefficient of vanillin to the CO ₂ side was 0.49 g / g (1.19 mol / mol). Even at 60 ° C. and 20 MPa, it was confirmed that the extraction rate of each component to the CO ₂ side was determined by the flow rate ratio of CO ₂ and the raw material aqueous solution without greatly changing the distribution coefficient.

According to Comparative Examples 1 to 4, it was confirmed that when the CO ₂ flow rate was lowered, the CO ₂ extraction rate was lowered without significantly changing the distribution coefficient.

(Example 5)
An extraction experiment was performed under the same conditions as in Example 1 except that a sodium bicarbonate-containing raw material aqueous solution was used as the raw material aqueous solution. The yield of vanillin on the CO ₂ side was 80.4%. The partition coefficient of vanillin to the CO ₂ side was 1.13 g / g. Compared with Example 1, the extraction rate and partition coefficient of vanillin, acetovanillone and guaiacol to the CO ₂ side increased, and vanillic acid had the opposite result.

(Example 6)
An extraction experiment was performed under the same conditions as in Example 5 except that the extraction pressure was 15 MPa. The yield of vanillin on the CO ₂ side was 75.9%. The partition coefficient of vanillin to the CO ₂ side was 0.85 g / g. Compared to Example 2 where extraction was performed under the same conditions except that sodium bicarbonate was included, the extraction rate and partition coefficient of vanillin, acetovanillone, and guaiacol to the CO ₂ side increased, and vanillic acid had the opposite result. It was.

(Example 7)
An extraction experiment was performed under the same conditions as in Example 5 except that the extraction pressure was 10 MPa. The yield of vanillin on the CO ₂ side was 57.6%. The partition coefficient of vanillin to the CO ₂ side was 0.36 g / g. Compared to Example 3 where extraction was performed under the same conditions except that sodium bicarbonate was included, the extraction rate and distribution coefficient of vanillin, acetovanillone, and guaiacol to the CO ₂ side increased, and vanillic acid had the opposite result. It was.

When Examples 5 to 7 were compared with Examples 1 to 3, when sodium hydrogen carbonate was contained, the partition coefficient of vanillin / acetovanillone / guaiacol to the CO ₂ side increased and the partition coefficient of vanillic acid decreased. It is considered that the presence of a salt such as sodium hydrogen carbonate changes the polarity of water or forms vanillic acid salt, thereby changing the solubility in each solvent and thus the partition coefficient. This suggests that the partition coefficient can also be controlled by controlling the concentration of the introduced salt.

(Example 8)
A black liquor was used as the raw material aqueous solution. Further, a Teflon (registered trademark) spacer was placed in a separator having an inner diameter of 40 mm, so that the inner diameter of the liquid level control unit was 20 mm. The extraction temperature was 40 ° C. and the pressure was 20 MPa. The flow rate of the raw material aqueous solution was about 10 g / min, and the CO ₂ flow rate was 60 g / min. Other than the above, the second embodiment is the same as the first embodiment.

Table 3 shows the results. The extraction rate of vanillin was 81.3%, and the distribution coefficient of vanillin to the CO ₂ side was 0.77 g / g. The partition coefficients of vanillic acid, acetovanillone, and guaiacol to the CO ₂ side were 0.00, 1.29, and 0.77 g / g, respectively. As in the aqueous solutions of Examples 1 to 7 and Comparative Examples 1 to 4, it was confirmed that vanillin could be extracted at an extraction rate exceeding 80% even in a system containing a large amount of organic matter.

(Comparative Example 5)
An extraction experiment was performed under the same conditions as in Example 8 except that the CO ₂ flow rate was 40 g / min. The extraction rate of vanillin was 77.0%, and the partition coefficient of vanillin to the CO ₂ side was 0.81 g / g. The partition coefficients of vanillic acid, acetovanillone, and guaiacol to the CO ₂ side were 0.01, 1.42, and 2.26 g / g, respectively. Compared to Example 8, the flow rate of CO ₂ with respect to the raw material aqueous solution is small, so the extraction rate of vanillin and the like is considered to have decreased.

Example 8 and Comparative Example 5, in this embodiment the black liquor that contains unidentified organic matter highly concentrated unlike the first embodiment as a raw material aqueous solution, to the CO ₂ side in Example 1 and the same level It was confirmed that high vanillin / acetovanillone / guaiacol yield and partition coefficient were obtained.

Example 9
As the raw material aqueous solution, an ethanol-water equivalent mixed solution containing p-cyanobiphenyl, K ₂ CO _3, KHCO ₃ , KBr, and B (OH) ₃ assumed as a solution after the cross-coupling reaction was used. In Example 9, p-cyanobiphenyl 1.9 wt%, K ₂ CO ₃ 1.6 wt%, KHCO ₃ 1.1 wt%, KBr 1.4 wt%, B (OH) ₃ 0.7 wt% as one reference concentration, A 0.2 standard raw material solution was used. The raw material aqueous solution flow rate was about 18 g / min, the CO ₂ flow rate was 40 g / min, the extraction temperature was 40 ° C., and the extraction pressure was 20 MPa. In this example, 2-propanol was used as the precipitation inhibiting fluid. The flow rate of the precipitation suppression fluid was set to be equal to the CO ₂ flow rate.

For each sample of the resulting CO ₂ side-fluid side, by analysis using HPLC, and measuring the concentration of p- cyanobiphenyl. Based on this result, to calculate the flow rate of the p- cyanobiphenyl in CO ₂ side-fluid side, calculate the yield of p- cyanobiphenyl in CO ₂ side-fluid side by dividing the flow rate of the p- cyanobiphenyl did. The yields of p-cyanobiphenyl on the CO ₂ side and liquid side were 89.8% and 11.3%, respectively. This example shows that the target component can be obtained at a high extraction rate even in a mixed aqueous solution containing an equal amount of ethanol to water.

(Example 10)
An extraction experiment was performed under the same conditions as in Example 9, except that the reference concentration was 0.5, the extraction temperature was 60 ° C., the raw material aqueous solution flow rate was about 5.8 g / min, and the CO ₂ flow rate was 12 g / min. . The yields of p-cyanobiphenyl on the CO ₂ side and liquid side were 84.6% and 15.0%, respectively.

(Example 11)
An extraction experiment was performed under the same conditions as in Example 10 except that the reference concentration was 1.0. The yields of p-cyanobiphenyl on the CO ₂ side and liquid side were 86.4% and 10.0%, respectively.

From Examples 10 and 11, it is possible to treat a uniform high-concentration aqueous solution by raising the extraction temperature. By maintaining the extraction rate at 80% or more, a mass flow rate of 1.2 to 5.4 g / h Showed that p-cyanobiphenyl can be recovered on the CO ₂ side.

(Example 12)
An extraction experiment was performed under the same conditions as in Example 9 except that the deposition inhibiting fluid was not fed. It was possible to stably recover p-cyanobiphenyl together with ethanol contained in the raw material aqueous solution on the CO ₂ side. The yield on the CO ₂ side of p-cyanobiphenyl was 87.7%.

According to Examples 9 to 11, p-cyanobiphenyl, K ₂ CO ₃ , KHCO ₃ , KBr, which is assumed as a solution after the cross-coupling reaction, having a pressure of 20 MPa and a temperature of 40 to 60 ° C. It was shown that p-cyanobiphenyl as the target substance can be stably recovered on the CO ₂ side in a yield of 80% or more from an ethanol-water equivalent mixed solution containing B (OH) ₃ . Example 12 shows that the target substance can be recovered on the CO ₂ side by simultaneously extracting the alcohol component contained in the aqueous solution on the CO ₂ side without using a precipitation suppression fluid.

  As mentioned above, although the Example by this invention and the modification based on this were demonstrated, this invention is not necessarily limited to this, A person skilled in the art will deviate from the main point of this invention, or the attached claim. Various alternative embodiments and modifications could be found without doing so.

1,71 Raw material aqueous solution tank 2,70 Raw material aqueous solution pump 3,10 Pressure gauge 4,11 Pressure sensor 5 Safety valve 6,13 Preheater 7 Cylinder 8 Precooler 9,45 Carbon dioxide pump 12 Pressure control valve 15a First pressure control Valve 19 Second pressure control valve 14 Mixer 17 Separator 16 Connecting pipe 20, 52 Differential pressure gauge 21a Level control valve 15 Retention pipe 18 Precipitation suppression fluid 21 Aqueous solution discharge pipe 33 Separation area 34 Liquid level detection area 41 Condenser 42 Chiller 43 Liquefied carbon dioxide tank 44 Precooler 51 Evaporator 54 Activated carbon container 46 Heater 47 Mass flow meter 48 Extraction tank 49 Heat exchanger 50 Pressure control valve 54a Discharge valve 53 Internal heater 54 Separation tank 68 Extraction tank

Claims (15)

A method for liquid-liquid extraction of an extraction target contained in a raw material aqueous solution with high-pressure carbon dioxide,
The raw aqueous solution and the high-pressure carbon dioxide are each continuously supplied to a high-pressure environment and mixed by a micro mixer, passed through a retention pipe, and passed through a first pressure control valve that controls the pressure of the micro mixer and the retention pipe, Supplying this depressurized fluid to the separator;
A second pressure control valve that controls the pressure by discharging the high-pressure carbon dioxide and the extraction object from above, mixing with this a precipitation-inhibiting fluid that suppresses the precipitation of the extraction object dissolved in the high-pressure carbon dioxide. Pass through
On the other hand, a micro-mixer characterized in that the aqueous solution after extraction is discharged from the level control valve at the lower part of the separator while the liquid level of the separator is made constant by the liquid level detecting means for detecting the liquid level. Liquid-liquid extraction method using high-pressure carbon dioxide used.   The liquid-liquid extraction method according to claim 1, wherein the high-pressure carbon dioxide is in a supercritical state.   The liquid-liquid extraction method according to claim 1, wherein the extraction target is an organic substance that dissolves in the high-pressure carbon dioxide.   The liquid-liquid extraction method according to any one of claims 1 to 3, wherein a main component of the raw material aqueous solution is a mixture of a hydrophilic organic solvent and water.   The liquid-liquid extraction method according to claim 4, wherein the main component of the raw material aqueous solution is a mixture of inorganic salts.   6. The liquid-liquid extraction method according to claim 4, wherein a part of the hydrophilic organic solvent is caused to be extracted by the high-pressure carbon dioxide together with the extraction object, thereby suppressing the supply of the precipitation suppressing fluid.   The micro mixer is any one of a micro T mixer, a micro Y mixer, a micro swirl mixer, a comber micro mixer, an IMM interdigital micro mixer, and a multistage divided channel micro mixer. Item 7. The liquid-liquid extraction method according to one of Items 1 to 6.   The liquid-liquid extraction method according to claim 1, wherein the precipitation suppression fluid is a good solvent for the extraction object.   The inner diameter of the connecting pipe flowing into the separator is set to 2 mm or more, the flow velocity of the flowing fluid is reduced, and the outlet of the connecting pipe is made to collide with the inner surface of the separator or collide with the inner surface of the separator. The liquid-liquid extraction method according to claim 1, wherein separation of the high-pressure carbon dioxide and the water is promoted.   10. The liquid level according to claim 1, wherein the liquid level detection means is a liquid level meter of any one of an electrode type, a capacitance type, and a differential pressure type. Extraction method. The liquid level detection means consists of a high pressure micro differential pressure gauge connected by high pressure piping independently from the upper and lower parts in the separator,
A separation region having a cross-sectional area larger than that of the lower liquid level measurement region is provided at the upper part of the separator to promote separation of the high-pressure carbon dioxide in which the extraction target is dissolved and the aqueous solution after extraction. The liquid-liquid extraction method according to claim 1, wherein the liquid-liquid extraction method is one of claims 1 to 10. An apparatus for liquid-liquid extraction of an extraction target contained in a raw material aqueous solution with high-pressure carbon dioxide,
A raw material aqueous solution high pressure supply means for continuously supplying the raw material aqueous solution to a high pressure environment;
High-pressure carbon dioxide high-pressure supply means for continuously supplying the high-pressure carbon dioxide to the high-pressure environment;
A micro-mixer that mixes each high-pressure fluid;
A retention tube that retains for a predetermined time after mixing in the micromixer;
A first pressure control valve for controlling the pressure of the mixer and the residence pipe;
A fluid whose pressure has been reduced through the first pressure control valve is supplied to the separator, and its outlet is made to collide with the inner surface of the separator or collide with the inner surface of the separator. Tube,
An extraction object discharge line for discharging high-pressure carbon dioxide in which the extraction object is dissolved from above in the separator;
A second pressure control valve for controlling the pressure of the separator in the extraction object discharge line;
Precipitation suppression fluid that supplies a precipitation suppression fluid that suppresses the precipitation of the extraction object dissolved in the high-pressure carbon dioxide decompressed by the second pressure control valve before the second pressure control valve and mixes it with a mixer High pressure supply means;
A liquid level detection means for detecting a liquid level in the separator;
A level control valve at the bottom of the separator and a post-extraction fluid discharge line for discharging the aqueous solution after extraction;
Adjusting the raw aqueous solution and the high-pressure carbon dioxide to an arbitrary temperature, and
The raw material aqueous solution and the high-pressure carbon dioxide are continuously supplied to the high-pressure environment, mixed by the micromixer, passed through the residence pipe, and passed through the first pressure control valve that controls the pressure of the micromixer and the residence pipe. And supplying the pressure-reduced fluid to the separator, discharging the high-pressure carbon dioxide and the extraction target from above, and suppressing the precipitation of the extraction target dissolved in the high-pressure carbon dioxide. The precipitation control fluid is mixed and passed through the second pressure control valve for controlling the pressure. On the other hand, the liquid level detecting means for detecting the liquid level makes the liquid level of the separator constant while maintaining the liquid level of the separator. A liquid-liquid extraction apparatus using high-pressure carbon dioxide using a micromixer, wherein the aqueous solution after extraction is discharged from the lower level control valve.   The micro mixer is any one of a micro T mixer, a micro Y mixer, a micro swirl mixer, a comber micro mixer, an IMM interdigital micro mixer, and a multistage divided channel micro mixer. Item 13. The liquid-liquid extraction device according to item 12.   The liquid-liquid extraction device according to claim 13, wherein the internal flow path of the micromixer is 1 mm or less. The liquid level detection means is composed of a high-pressure micro differential pressure gauge that is independently connected by a high-pressure pipe from the upper and lower parts in the separator, and the upper part of the separator has a cross-sectional area that is lower than that of the lower liquid level measurement region. The liquid-liquid according to any one of claims 12 to 14, wherein a large separation region is provided to promote separation of the high-pressure carbon dioxide in which the extraction object is dissolved and the aqueous solution after the extraction. Extraction device.

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