JP3109849B2 - Supercritical gas extraction method from foaming liquid raw material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for extracting a foamable liquid raw material using a supercritical gas.

[0002]

2. Description of the Related Art Conventionally, a wide variety of liquid raw materials have been extracted using a supercritical gas as a medium.

[0003] This extraction is generally performed according to the following steps. That is, first, a gas whose temperature has been raised and raised to a supercritical state is introduced into an extractor filled with a liquid raw material, and a target substance is extracted into the gas. Next, the gas containing the extract is introduced into the separator to collect the extract.

On the other hand, the raffinate of the liquid raw material remaining in the extractor is recovered by reducing the pressure in the extractor to atmospheric pressure. However, in this step, the extractant dissolved in the raffinate liquid expands rapidly with decompression, depending on the type of the liquid raw material, and causes the raffinate liquid to foam significantly. For this reason, it becomes difficult to collect or transport the raffinate, and foam generated in the extractor interferes with the subsequent process.

[0005] As a countermeasure against the foaming, it has been proposed to gradually reduce the pressure in the extractor or leave the extractor until the foaming state disappears. However, each of these methods requires a long time, which poses a problem in practical use in a plant, particularly when a continuous extraction operation is performed.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to solve the conventional disadvantages described above and to suppress foaming during the recovery of the raffinate. Another object of the present invention is to provide a method for extracting a supercritical gas from a liquid raw material having a foaming property, which enables a continuous extraction operation.

[0007]

According to the present invention, there is provided a method for extracting a supercritical gas from a foamable liquid raw material, comprising the steps of continuously introducing a foamable liquid raw material into an extractor; Introducing a gas, contacting the liquid raw material, extracting the target substance in the liquid raw material into a supercritical gas, and introducing the gas containing the extract obtained in the above step to the first separator Separating the extract from the gas in the separator, and maintaining the raffinate in the extractor at a pressure higher than the pressure at which the liquid raw material starts foaming in advance, thereby altering the raffinate. And introducing the gas dissolved in the raffinate to the second separator heated to a temperature that can be separated, and heating the introduced raffinate for a predetermined time in the second separator. Allowing the gas to remain and separating the gas dissolved in the raffinate solution; To release gas separated from the raffinate in the second separation unit, and a step of discharging the raffinate after gas separation to atmospheric pressure.

[0008] In the prior art described above, the inventor performs extraction using a supercritical gas on various foamable liquid raw materials,
After the extraction operation, the pressure was gradually reduced and the foaming state was observed. As a result, it was found that this foaming occurs rapidly when the pressure falls below a certain pressure (depending on the type of liquid raw material used). On the other hand, after the extraction operation, the pressure for starting the foaming is 3 to 5 kg / cm ^2. After heating at a high pressure and heating to 50 to 60 ° C. for 30 to 60 minutes, the pressure was reduced to atmospheric pressure and the foaming state was observed. As a result, almost no foaming was observed. Thus, by applying this method, the method for extracting a supercritical gas from a foamable liquid raw material of the present invention was completed.

[0009]

According to the method for extracting a supercritical gas from a foamable liquid raw material of the present invention, the raffinate introduced into the second separator is:
Since the pressure in the second separator is kept higher than the pressure at which foaming of the liquid material starts, rapid foaming in the separator is prevented. Further, the raffinate is stably heated in the second separator at a temperature within a range that does not deteriorate, and the gas dissolved in the raffinate is separated. Therefore, in the extraction from the liquid raw material having a foaming property, the raffinate is recovered stably without foaming, and a continuous extraction operation is achieved.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. Note that this embodiment is described for the purpose of facilitating understanding of the present invention, and does not limit the present invention. FIG. 1 shows the flow of a general apparatus for implementing the method of the present invention.

The apparatus comprises an extractor 1 for performing an extraction operation from a liquid raw material, a first separator 2 for recovering an extract, and a second separator 3 for recovering a raffinate. The vessels are interconnected by piping through various valves.

In the apparatus, the foaming liquid raw material is continuously introduced into the extractor 1 from the upper part thereof by the metering pump 4. As the foamable liquid raw material, for example, honey,
Publica and the like. On the other hand, the gas serving as a medium is pressurized to a predetermined pressure by the metering pump 5 and further heated to a supercritical state by the heat exchanger 6, and then the extractor 1
From the bottom. As this gas, carbon dioxide can generally be used. Thus, the gas introduced into the extractor 1 comes into contact with the liquid raw material and extracts the target substance in the liquid raw material into the gas.

Next, the gas containing the extract obtained as described above is introduced through the pressure control valve 7 into the first separator 2 maintained at a constant pressure by the pressure control valve 8. The pressure in 2 is reduced to separate the extract from the gas. Thereafter, the obtained extract is recovered through a valve 9, and the separated gas is discharged through a pressure control valve 8.

On the other hand, the raffinate in the extractor 1 is introduced into the second separator 3 through the flow control valve 10. The separator 3
The inside is preliminarily maintained at a pressure exceeding a pressure at which the liquid raw material starts foaming by a valve 11 and a pressure adjusting valve 12, so that the raffinate does not change in quality and the gas dissolved in the raffinate can be separated. Until heated. The pressure and temperature depend on the liquid raw material used, and need to be adjusted according to the raw material. Next, in the second separator 3, the introduced raffinate is heated and retained for a predetermined time to separate gas dissolved in the raffinate. After this,
The separated gas is released through the pressure control valve 12,
The raffinate after gas separation is discharged through the flow control valve 13. Next, a specific supercritical gas extraction operation according to the steps in the flow of FIG. 1 described above will be described.

(Example 1: Extraction from honey)
And honey, and carbon dioxide as a medium gas
Using the element, according to the steps in the flow of FIG.
An extraction operation was performed. The extraction conditions are as follows: raw material flow rate 0.5 ml / mi
n., flow rate of carbon dioxide 1mg / min., pressure 200k in extractor 1
g / cm^Two At the same temperature of 40 ° C and the pressure inside the first separator 2 of 0 kg / cm^Two ,
Same temperature 0 ° C, pressure in second separator 3 10kg / cm^Two , The same temperature
50 ° C, the retention time of the raffinate in the second separator 3 to 30 minutes
I set each.

After the operation, an appropriate amount of the raffinate discharged through the flow rate control valve 13 is collected in a measuring cylinder, and the volume (A) immediately after the discharge of the raffinate, and this is left for 24 hours, so that almost no bubbles are formed. The volume (B) in a completely disappeared state was measured. Based on these volume values, the foaming amount was calculated according to the following equation. Foaming amount = (volume increased by foaming) / (raw material volume) = (AB) / B

As a comparison, a supercritical gas is extracted from honey by a conventional method, and the raffinate is recovered from the extractor 1 without using the second separator 3, and the foaming amount is reduced in the same manner as described above. Calculated.

As a result, the bubbling amount of the honey raffinate recovered by the method of the present invention is 1/100 that of the conventional method.
Decreased to 4.7. In the conventional method, the discharged raffinate was hardly disappeared by leaving it for about 30 minutes after discharge.

(Example 2: Extraction from publica) Using publica as a liquid raw material and carbon dioxide as a gas serving as a medium, the following steps in the flow of FIG.
An extraction operation was performed. The extraction conditions were as follows: raw material flow rate 1 ml / min.
Carbon dioxide flow rate 30g / min., Pressure 250kg / cm in extractor 1
^Two At the same temperature of 50 ° C and the pressure in the first separator 2 of 20 kg / cm ² At the same temperature, 30 ° C, and the pressure inside the second separator 3 20kg / cm ² , The same temperature 70
C. and the residence time of the raffinate in the second separator 3 were set to 30 minutes.

After the operation, the foaming amount of the discharged raffinate was calculated in the same manner as in Example 1 above. As a comparison, supercritical gas extraction from publica was performed by a conventional method,
The raffinate was recovered from the extractor 1 without using the second separator 3, and the foaming amount was calculated as described above. As a result, the foaming amount of the Pubica raffinate recovered by the method of the present invention is:
It was reduced to 1 / 4.2 of that of the conventional method.

[0021]

As described in detail above, the method for extracting a supercritical gas from a foamable liquid raw material according to the present invention suppresses foaming at the time of recovering the raffinate, and enables a continuous and stable extraction operation. It has a remarkable effect in making it possible.

[Brief description of the drawings]

FIG. 1 is a diagram showing a flow of a general apparatus for performing a supercritical gas extraction method according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Extractor, 2 ... First separator, 3 ... Second separator, 4, 5
... fixed amount pump, 6 ... heat exchanger, 7, 8, 12, ... pressure control valve, 9, 11 ... valve, 10, 13 ... flow control valve

Continued on the front page (72) Inventor Yoshio Yonei 6-2 Umegaoka Midori-ku, Midori-ku, Yokohama-shi, Kanagawa Prefecture Inside the Tobacco Central Research Institute of Tobacco Inc. (72) Inventor Jin Shigematsu 6-2 Umegaoka, Midori-ku, Yokohama-shi, Kanagawa (56) References JP-A-3-250001 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B01D 11/00-11/04 A23L 1/04-1/09

Claims (1)

(57) [Claims] 1. A step of continuously introducing a foamable liquid raw material into an extractor, and introducing a supercritical gas into the extractor;
Contacting with the liquid raw material to extract the target substance in the liquid raw material into a supercritical gas, and introducing the gas containing the extract obtained in the above step into the first separator, In the step of separating the extract and the gas in, the raffinate in the extractor is maintained at a pressure exceeding the pressure at which the liquid raw material starts foaming in advance, the raffinate does not change and the raffinate Introducing the gas dissolved therein into a second separator heated to a temperature at which the gas can be separated, and heating and retaining the introduced raffinate for a predetermined time in the second separator to extract Separating the gas dissolved in the residual liquid, and releasing the gas separated from the raffinate in the second separator,
Discharging the raffinate after gas separation to atmospheric pressure, the method comprising extracting a supercritical gas from a foamable liquid raw material.