JP4382208B2 - Supercritical fluid extraction device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
[0002]
The present invention relates to a supercritical fluid extraction apparatus in which desired extraction conditions are set by adding a solvent to a supercritical fluid to change the solubility.
[Prior art]
[0003]
The extraction method using a fluid in a supercritical state is higher in safety than the extraction method using an organic solvent, and is generally unstable to heat because it can be extracted under a temperature condition of about 40 ° C to 80 ° C. Recently, it has attracted attention as a stable extraction method suitable for the extracted substances.
[0004]
FIG. 2 is a schematic diagram showing the configuration of a conventional supercritical fluid extraction apparatus that employs, for example, carbon dioxide (CO ₂ ) as a fluid. In the apparatus, an extraction system path 18 at the center of the apparatus is shown in the figure. The fluid cylinder 1, the pressure pump 2, the mixer 11, the extraction container 3, the detector 4, the pressure control device 5, and the recovery container 6 are sequentially connected by piping.
[0005]
In the supercritical fluid extraction apparatus configured as described above, after supplying carbon dioxide from the fluid cylinder 1 into the extraction system path 18 and substituting the carbon in the system with carbon dioxide, on the fluid inlet side of the extraction container 3. The fluid flowing in the extraction container 3 is made to be equal to or higher than the critical pressure (for example, about 73 atm in the case of carbon dioxide) by the pressurizing pump 2 for increasing the pressure of the fluid and the pressure control device 5 for adjusting the pressure (back pressure) on the same fluid outlet side In addition, the carbon dioxide in the extraction vessel 3 is supercritical fluid (hereinafter, simply referred to as fluid) by controlling the pressure to a critical temperature (about 31 ° C. in the case of the carbon dioxide) or higher by the thermostatic bath 12. In this state, a desired component is extracted from a predetermined sample substance placed in the extraction container 3, and the extraction state is monitored by the detector 4.
[0006]
Next, the same fluid in which the extracted components extracted as described above are dissolved is guided to the pressure control device 5, and the pressure is controlled to be reduced below the critical pressure. As a result, at the outlet side of the pressure control device 5, the fluid returns to the original carbon dioxide gas, and the extracted components dissolved in the fluid are precipitated and separated and recovered in a predetermined recovery container 6. .
[0007]
By the way, in this case, when extraction is performed using a supercritical fluid having a single composition such as carbon dioxide, a disadvantage is that the dissolving power is small as compared with the case where an organic solvent is used. However, there is no problem with this point because the solubility can be increased by adding a small amount of solvent to the supercritical fluid. This solvent is generally called an entrainer, and the above-mentioned conventional apparatus is provided with an entrainer container 7 as shown in the figure, and the entrainer in the entrainer container 7 is provided with an entrainer liquid feed pump 8 and an opening / closing valve 9. (Solvent supply line) 10 is injected from the upstream side of the extraction container 3 into the extraction line 18 via the mixer 11, and the mixer 11 allows the entrainer to It is designed to be mixed evenly.
[Problems to be solved by the invention]
[0008]
As described above, the conventional supercritical fluid extraction device has a structure in which carbon dioxide is continuously supplied from the fluid cylinder 1 and at least during the extraction, and carbon dioxide is always released from the pressure control device 5. . That is, since it is a constant distribution system, the required amount of carbon dioxide (fluid) increases. In addition, when the optimum extraction conditions are examined by changing the solubility of the extraction component to a desired level by changing the concentration of the entrainer (solvent) in the extraction container 3, only a certain entrainer concentration is required for one extraction. Only the extraction status can be confirmed. For this reason, every time the concentration of the entrainer is changed, the sample material as the material to be extracted must be replaced with a new one to check the extraction state, and extraction is repeated many times until the optimum extraction conditions are found. An operation must be performed. Therefore, there is a problem that a large amount of sample material is required and the examination time is long.
[0009]
The present invention has been made to solve the above problems, respectively provided switching valves in each of between the upstream and the detection container and the pressure control device of the extraction vessel, between these switching valve By arranging a reflux system in parallel, a closed fluid circulation system is formed via the extraction container and the detector, and a solvent metering device is separately provided in the middle of the extraction to complete the extraction. Fluid and sample to be used so that extraction can be repeated through the extraction container and detector without releasing a predetermined amount of fluid to the outside and monitoring of the extraction state can be performed. The aim is to provide a supercritical fluid extraction device that can reduce the required amount of substances and can study optimal extraction conditions efficiently in a short time. It is an.
[Means for Solving the Problems]
[0010]
In order to achieve the above object, the present invention is configured with the following problem solving means.
[0011]
That is, in the supercritical fluid extraction device according to the first aspect of the present invention, an extraction system line in which a fluid cylinder, a pressure pump, an extraction container, a detector, and a pressure control device are sequentially connected to each other by the piping and the extraction container of the extraction system path A solvent supply path for supplying a predetermined solvent upstream, and by adding a predetermined solvent to the fluid in a supercritical state of the predetermined fluid, the solubility of the sample material is changed to supercritical fluid extraction apparatus for extracting a predetermined component, upstream of the extraction vessel of said extraction system path and provided each changeover valve in each of between the detector and the pressure control device, between the respective switching valves And forming a closed fluid circulation system that circulates the fluid through the extraction container and the detector by juxtaposing a reflux system for refluxing the fluid that has passed through the detector to the extraction container side. To, it is characterized in that separate the middle of the fluid circulation passage is provided a quantitative injection device of a given solvent.
[0012]
Therefore, in this configuration, extraction or monitoring of the extraction state is repeatedly performed through the extraction container and the detector without discharging a predetermined amount of fluid to the outside through the closed circulation system until the extraction is completed. Will be able to. As a result, the amount of fluid used can be reduced and extraction can be performed efficiently in a short time.
[0013]
Also, a metering injection device capable of adding a certain amount of solvent while maintaining a supercritical state in the middle of a fluid circulation system comprising a combination of an extraction system and a reflux system between the two switching valves. Since it is provided, the solvent concentration in the circulation system can be changed stepwise while the closed system is maintained. As a result, it becomes possible to measure the solubility for a plurality of types of solvent concentration addition conditions in a single extraction, thereby reducing the amount of sample material used when determining the optimum extraction conditions using a solvent. It is possible to shorten the examination time.
DETAILED DESCRIPTION OF THE INVENTION
[0014]
Next, an embodiment of the present invention will be described in detail with reference to FIG.
[0015]
That is, first, FIG. 1 is a schematic view similar to FIG. 2 showing the configuration of the supercritical fluid extraction apparatus according to one embodiment of the present invention. As shown in the figure, this supercritical fluid extraction apparatus is a normal extraction excluding the case where a fluid cylinder 1 filled with, for example, carbon dioxide (CO ₂ ), a pressurizing pump 2 for increasing fluid pressure, and examination of extraction conditions are examined. When working, the mixer 11 for injecting and mixing the entrainer (solvent) from the entrainer container 7 into the extraction system 18, the first switching valve 13, and the extraction conditions are examined, and a certain amount of entrainer (solvent) is injected. Fixed quantity injection device 17, extraction container 3 into which sample substance to be extracted is placed, detector 4 for extraction level (saturation level) monitor, second switching valve 14, and pressure by relief of a part of fluid to the outside The pressure control device 5 for controlling the (back pressure), the recovery container 6 for recovering the extracted components, and the extraction system path 18 connected in order by piping, and the entrainer container at the time of the normal extraction operation And the entrainer supply system 10 for supplying the entrainer (solvent) from the detector 11 to the mixer 11 via the entrainer liquid feed pump 8 and the open / close valve 9, and the fluid passing through the detector 4 at the time of examining the extraction conditions. A circulation pump 15 for reflux circulation is provided on the upstream side of the container 3, and the second switching valve 14 and the first switching valve 13 are connected by a pipe similar to the extraction system path 18 to connect the first and second valves. And a part of the extraction system 18 having the extraction vessel 3 and the detector 4 between the switching valves 13 and 14 and a reflux system 19 constituting a supercritical fluid circulation system (refer to a closed loop indicated by a chain arrow). It has become.
[0016]
The entrainer (solvent) metering device 17 is provided in an appropriate part of the circulation system.
[0017]
Therefore, in this structure, the fluid cylinder 1 and the recovery container 6 are communicated in a straight line as indicated by the broken line arrow by the switching operation of the first and second switching valves 13 and 14 of the extraction system 18. A loop communication state and a closed-loop circulation system state in which the upstream side of the upstream metering injection device 17 of the extraction container 3 and the downstream side of the detector 4 communicate with each other through the reflux system channel 19 from the open loop communication state. By switching to, the metering injection device 17, the extraction container 3, and the detector 4 between the first switching valve 13 and the second switching valve 14 in the extraction system path 18 are returned to the reflux system having the circulation pump 15. By switching to the closed circulation path state via the path 19, a predetermined fluid can be circulated at all times as indicated by a chain line arrow.
[0018]
That is, in this configuration, prior to the original extraction operation using the entrainer (solvent) from the entrainer supply system 10, the extraction is first performed when obtaining the optimum extraction condition of the concentration of the supplied entrainer (solvent). The container 3 is filled with the sample substance, and all the three-way three on-off valve portions of the first and second switching valves 13 and 14 are opened, and the extraction system path 18 and the reflux system path 19 are The carbon dioxide as a fluid is started to flow from the fluid cylinder 1 to each. And after replacing the air of all the systems including the extraction system path 18 and the reflux system path 19 with carbon dioxide, the pressure pump 2, the pressure control device 5, and the thermostatic chamber 12 are used to adjust to a predetermined pressure and temperature. To form a supercritical state. When the supercritical state is formed, the first and second switching valves 13 and 14 are then switched to open and close the opening / closing valve portion on the pressure pump 2 side and the opening and closing side on the pressure control device 5 side. The valve section is closed to form the above-described circulation system path, and the fluid in the supercritical state is circulated by the circulation pump 15 as indicated by a chain line arrow.
[0019]
Then, a part of the extracted component in the sample substance in the extraction container 3 is dissolved in the circulating fluid, and the extraction container 3 and the detector 4 are repeatedly used while the dissolved state is monitored by the detector 4. It will circulate and flow.
[0020]
Then, as a result of monitoring by the detector 4, when it is confirmed that the action of dissolving the extracted component in the circulating supercritical fluid is saturated, a fixed amount of entrainer (solvent) is removed by the quantitative injection device 17. Then, the dissolved state of the extracted component is monitored again by the detector 4. By repeating this process, the entrainer (solvent) is added stepwise to accurately measure the dissolution characteristics of the extracted components at each step.
[0021]
On the other hand, when measuring the dissolution characteristics of a predetermined pure substance in a supercritical fluid flowing in the circulation system, the pure substance is saturated with respect to the supercritical fluid having a predetermined flow rate. However, after a predetermined amount or more that remains undissolved, that is, a supersaturated amount of pure substance is placed in the extraction vessel 3 and carbon dioxide is supplied from the fluid cylinder 1 to replace the air in each system with carbon dioxide. The extraction container 3 is heated by the thermostatic bath 12 and pressurized by the pressurizing pump 2 to make the carbon dioxide a supercritical fluid having a predetermined temperature and pressure, and the first switching valve 13 and the second switching valve 13 The switching valve 14 is switched to form the above-described circulation system state, and the supercritical fluid is circulated by the circulation pump 15 in the same manner as described above to saturate the pure substance in the supercritical fluid. ) So as to stepwise added. In this way, the dissolution characteristic of the pure substance at each stage can be accurately measured in the same manner as described above.
[0022]
By the above method, it is possible to clarify the dissolution characteristics with respect to a plurality of levels of entrainer addition conditions with the same sample material.
[0023]
As described above, in the supercritical fluid extraction device of the present invention, an extraction system line in which a fluid cylinder, a pressure pump, an extraction container, a detector, and a pressure control device are sequentially connected by a pipe, and the extraction container upstream of the extraction system path. A solvent supply system for supplying a predetermined solvent to the side, and in a supercritical state of the predetermined fluid, by adding the predetermined solvent to the fluid, the solubility of the sample material is changed to change the predetermined amount in the sample material. In the supercritical fluid extraction device for extracting the components of the above, a switching valve is provided on each of the upstream side of the extraction vessel and the downstream side of the extraction vessel between the detector and the pressure control device, A closed fluid circulation system that circulates the fluid through the extraction container and the detector by arranging a reflux system that recirculates the fluid that has passed through the detector to the extraction container side between these switching valves. Shape As well as, it is characterized by separately providing the metering injection device of a given solvent in the middle of the fluid circulation path.
[0024]
Therefore, in this configuration, extraction or monitoring of the extraction state is repeatedly performed through the extraction container and the detector without discharging a predetermined amount of fluid to the outside through the closed circulation system until the extraction is completed. Will be able to. As a result, the amount of fluid used can be reduced and extraction can be performed efficiently in a short time.
[0025]
Also, a metering injection device capable of adding a certain amount of solvent while maintaining a supercritical state in the middle of a fluid circulation system comprising a combination of an extraction system and a reflux system between the two switching valves. Since it is provided, the solvent concentration in the circulation system can be changed stepwise while the closed system is maintained. As a result, it becomes possible to measure the solubility for a plurality of types of solvent concentration addition conditions in a single extraction, thereby reducing the amount of sample material used when determining the optimum extraction conditions using a solvent. It is possible to shorten the examination time.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a configuration of a supercritical fluid extraction device according to an embodiment of the present invention.
FIG. 2 is a schematic diagram showing a configuration of a supercritical fluid extraction apparatus according to a conventional example.
[Explanation of symbols]
1 is a fluid cylinder, 2 is a pressure pump, 3 is an extraction container, 4 is a detector, 5 is a pressure control device, 6 is a recovery container, 8 is an entrainer feed pump, 9 is an open / close valve, and 10 is an entrainer supply system , 11 is a mixer, 12 is a thermostatic bath, 13 is a first switching valve, 14 is a second switching valve, 15 is a circulation pump, 17 is a metering device, 18 is an extraction system, and 19 is a reflux system. is there.

Claims (1)

An extraction system path in which a fluid cylinder, a pressure pump, an extraction container, a detector, and a pressure control device are sequentially connected by a pipe and a solvent supply system path for supplying a predetermined solvent to the extraction container upstream side of the extraction system path are provided. In the supercritical fluid extraction apparatus for extracting a predetermined component in a sample material by changing the solubility of the sample material by adding a predetermined solvent to the fluid in a supercritical state of the predetermined fluid. upstream of the extraction vessel system path and respectively provided switching valves in each of between the detector and the pressure control device, reflux fluid passing through the detector between each of these switching valves are refluxed to the extraction vessel side By arranging the system paths in parallel, a closed fluid circulation system path for circulating the fluid through the extraction container and the detector is formed, and a predetermined solvent quantitative injection device is separately provided in the middle of the fluid circulation system path. Supercritical fluid extraction device, characterized in that the provided.

Images