JPS63208549A - Separation of higher fatty acid ester mixture - Google Patents

Abstract

PURPOSE:To separate a higher fatty acid ester mixture, by bringing the higher fatty acid ester mixture into contact with a specific extracting fluid under a fixed condition, transferring into the liquid, passing the liquid through powder carrying silver nitrate, further extracting with ethyl acetate, separating and repeating combination of these operations. CONSTITUTION:A higher fatty acid ester mixture such as stearic ester, oleic ester, linoleic ester, etc., is brought into contact with an extracting fluid (especially preferably ethane, ethylene or CO2) which is inert to the esters and has 0-50 deg.C critical temperature at >= the critical temperature of the fluid under >=critical pressure and the esters are transferred into the extracting fluid. The extracting fluid is passed through a column packed with powder carrying silver nitrate, higher fatty acid esters having high unsaturation degree are adsorbed on the column, an extracting fluid containing a lower fatty acid ester such as ethyl acetate, etc., is made to flow in the column and extraction and separation are carried out. The higher fatty acid esters can be selectively separated under an extremely mild condition.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to the use of stearic acid ester, oleic acid ester, and linoleic acid, which are contained in large amounts in fish oil such as mackerel and sardine, and plants such as moon and primrose. This invention relates to a method for selectively separating higher fatty acid esters by efficiently and selectively extracting a mixture of higher fatty acid esters such as esters and lylunic acid esters from the mixture without modifying or altering the fatty acid esters. .

[Prior Art] Conventionally, general separation and extraction techniques for fatty acid esters include a natural fractionation method, a surfactant-applied fractionation method, a molecular distillation method, a solvent fractionation method, and an extraction method using furfural or propane. However, it is difficult to stably, quickly, inexpensively, and sufficiently concentrate and separate unsaturated fatty acid esters from low melting point, high iodine value oils by these methods.

That is, although the natural fractionation method has the advantage of being low in cost, it requires a long time for crystallization, and the separation efficiency of unsaturated fatty acid esters is not high.

In the molecular distillation method, polymerization and isomerization are likely to occur, which leads to denaturation, and the process is complicated because it requires a degassing device to remove volatile substances in advance.

In the solvent fractionation method, unsaturated fatty acid esters can be obtained with a somewhat high yield, but this requires relatively low temperatures, resulting in high costs, and it is difficult to remove the solvent.

[Problem to be Solved by the Invention 1] The present invention solves the following problems when extracting and separating each fatty acid ester from a mixture of higher fatty acid esters such as stearate, oleate, linoleate, and lylphate. The purpose of the present invention is to provide a method that can selectively separate thermally unstable substances under extremely mild conditions without altering their properties.

[Means for solving the problem J] Generally, when a gas and a solid or liquid are brought into contact, the amount of the solid or liquid that changes to the gas phase at normal pressure and room temperature is extremely small. However, when the type of gas is appropriately selected and the gas is at a temperature higher than the critical temperature and a pressure higher than the critical pressure, the amount of solid or liquid transferred to the gas phase increases dramatically.

Furthermore, as the degree of unsaturation of higher fatty acid esters increases, the affinity between silver nitrate and higher fatty acid esters increases.

The present inventor focused on these facts, and extracted higher fatty acid esters by using an extraction fluid that is chemically inert and has a critical temperature in the range of 0 to 50°C, and a temperature and pressure higher than the critical temperature. By passing through the powder supporting silver nitrate packed in the column after contact with pressure, particles with a higher degree of unsaturation can be supported in the column, and this column does not contain lower fatty acid esters such as ethyl acetate. However, by flowing the above extraction fluid, we discovered that higher fatty acid esters can be further extracted and separated depending on the degree of unsaturation, and by combining and repeating these operations, we completed the method of the present invention for separating higher fatty acid esters. I ended up doing it.

That is, in the present invention, a mixture of two or more types of higher fatty acid esters is heated to a temperature above the critical temperature and V to an extraction fluid that is chemically inert and has a critical temperature in the range of 0 to 50°C.
The higher fatty acid ester is transferred into the extraction fluid by contacting under pressure conditions higher than the critical pressure, and then the extraction fluid is passed through a column filled with powder supporting silver nitrate to remove the fraction in the mixture. A method for separating a mixture of 21 to 11 or more higher fatty acid esters trapped in a column in which the mixture is chemically inert and at a critical temperature. is 0~50℃
1 to 15 lower fatty acid esters are added to the extraction fluid in the range of
The present invention provides a method for separating the mixture, in which a portion of the higher fatty acid in the column is extracted by contacting a mixture containing 1% by weight of fatty acids at a temperature higher than the critical temperature and a pressure higher than the critical pressure.

The higher fatty acid esters to which the separation method of the present invention is applied are esters of saturated or unsaturated fatty acids having 12 to 24 carbon atoms.

The higher the extraction pressure in the present invention, the higher the solubility, but the lower the selectivity. From an economic standpoint, the pressure is 8.
It will be carried out at 0 to 200ky/cm2.

Although the extraction temperature must be higher than the critical temperature, it is desirable to use a temperature range of 1 to 50°C higher than the critical temperature in order to prevent deterioration of the extract.

As the extraction fluid used in the present invention, a substance having a critical temperature in the range of 0 to 50°C, for example, a substance mainly composed of carbon dioxide, ethane, ethylene, etc. can be used. As this critical temperature increases, the extraction temperature also increases, making it easier for unsaturated esters to undergo deterioration.

In the present invention, the extraction fluid used for extraction with a silver nitrate column includes ethyl valerate, ethyl butyrate, ethyl propionate,
Ethyl acetate - 1 to 15% by weight of any lower fatty acid ester
Add and use. The lower fatty acid ester used here is preferably an ester consisting of a fatty acid having 6 or less carbon atoms and an alcohol having 3 or less carbon atoms.

When the extraction fluid of the present invention contains these lower fatty acid esters, the affinity of the extraction fluid for higher fatty acid esters can be changed. This affinity can be determined depending on the type and content of the lower fatty acid ester.

Further, silver nitrate is supported on, for example, 65 to 100 mesh silica gel or alumina powder, and is used by filling a stainless steel column.

It is desirable to use a column temperature in a range of 20 to 50° C. higher than the critical temperature.

The amount of extraction fluid used varies depending on the amount of extraction and the composition and composition ratio of the higher fatty acid ester mixture, but is usually 100 to 200 times the amount of raw fatty acid ester per extraction operation.

In the present invention, as described above, the lower fatty acid may be added to the extraction fluid before the first stage extraction operation.

Alternatively, without using the silver nitrate column of the present invention, an extraction fluid containing 1 to 15 weight percent of the lower fatty acid ester defined above and having a critical temperature between 0 and 50"C can be heated to a temperature above the critical temperature. A separation method in which the target higher fatty acid ester is extracted by contacting the mixture with a higher fatty acid ester mixture at a temperature and a pressure higher than the critical pressure can also be used in combination with the separation method of the present invention.

As described above, the present invention firstly utilizes the extraction ability of the extraction fluid for higher fatty acid esters, secondly utilizes the difference in affinity of each higher fatty acid ester to the silver nitrate column depending on the degree of unsaturation, and thirdly This is a method of separating each ester from a higher fatty acid ester mixture by adding a lower fatty acid ester to the extraction fluid and utilizing the difference in affinity of each higher fatty acid ester to the extraction fluid depending on the degree of unsaturation.

On the other hand, the affinity of the extraction fluid or silver nitrate column for each higher fatty acid ester also differs depending on the class m of the extraction fluid, the extraction temperature, the extraction pressure, and the type and concentration of the lower fatty acid ester in the extraction fluid.

In the present invention, it is necessary to separate! 1. Depending on the type and composition ratio of the higher fatty acid ester in the mixture, the most suitable extraction conditions among the methods of the present invention are selected, and these extraction methods, including the method not using the nitric acid column described above, are Each higher fatty acid ester can be separated by combining 11 or more or repeating 2 or more times.

For example, stearate, oleate,
When separating higher fatty acid ester mixtures such as linoleic acid esters and linoleic acid esters, first, for example, carbon dioxide is used as an extraction fluid, and the mixture is brought into contact with the mixture at a temperature higher than its critical temperature and a pressure higher than its critical pressure. 6 Then, when this is passed through a silver nitrate column, only the stearate ester passes through the column,
Other esters are captured in the column. When an extraction fluid containing zero-order lower fatty acid esters is passed through the column, each higher fatty acid ester is sequentially extracted according to the difference in the solubility of the extraction fluid and the adsorption capacity of the column for each higher fatty acid ester. is extracted.

Even if such an operation is performed just once, the purity of each higher fatty acid ester will be high (although it is possible to increase the purity by repeating the extraction operation of the present invention for each extractor by changing the conditions as the case requires). end.

[Effect of the invention] Unlike conventional methods, the method of the present invention selectively extracts and separates higher fatty acid esters from a higher fatty acid ester mixture at room temperature, with simple operation and at low cost. It ends with

At this time, the treatment method of the present invention depends on the composition and composition ratio of the higher fatty acid ester mixture, extraction temperature, extraction pressure, amount of extraction fluid used, type of extraction fluid, and type of lower fatty acid ester added to the extraction fluid. Alternatively, the content can be appropriately selected and brought into contact with the mixture, which is advantageous because each higher fatty acid ester in the mixture can be separated individually in sequence.

[Example J The present invention will be explained in more detail with reference to Examples.

In the Examples, the fatty acid ester composition was determined by chromatography.

Example 1 7.98 g of a mixture of methyl stearate, methyl oleate, methyl sulfate, methyl lylunate (C+g+o
:Ct@;+:C+atz:C+t%2,28.95:
19.45:28.19:23,41) into the extractor, keep the temperature of the constant temperature bath at 38℃,
Contact was carried out by blowing at a rate of 6 OL/h using 7 cm2 of kg. The fluid containing a mixture of methyl stearate, methyl oleate, methyl linoleate, and methyl lylunate was introduced into a column filled with silica gel powder carrying silver nitrate. The column temperature here is 57°C.

The fluid passed through the column is filtered, pressure ? I
4! ! The mixture was led through a valve to a separator at normal pressure and a temperature of 38° C., and methyl stearate was separated from the mixture. The extraction rate and fatty acid composition of this extract are as shown in Table 1.2. By the method of the present invention, methyl stearate of saturated fatty acid methyl is extracted from the above fatty acid) chill mixture with high selectivity and high yield. You can see what you can get.

Example 2 7.90 g of a mixture of methyl stearate, methyl oleate, methyl linoleate, methyl lylunate (CI I+
O:CI @I l:CI @I t:c+s
, 3 =27.95:20.45:28.09:25.
51) into the extractor, increase the extraction pressure to III&, 7
cm'' and treated in the same manner as in Example 1 to obtain an extract.

The fatty acid composition and extraction rate of this extract were as shown in Table 3. It can be seen that compared to Example 1, the extraction rate increases with pressure. As expected, C1.

It can be seen that the separation efficiency is high.

Example 3 8.10 g of a mixture of methyl stearate, methyl oleate, methyl linoleate, methyl lylunate (C, .

:C+s++:CIs:x:CIs:*=27.55:
20.85:27.00:26.60) into an extractor and treated in the same manner as in Example 1 at an extraction pressure of 111 kg/cm'' and a column temperature of 80°C to obtain an extract. The fatty acid composition and extraction rate are as shown in Table 4.

Example 4 After Example 1, the mixture of methyl stearate, methyl oleate, methyl sulfate, and methyl lylunate held in the column was added to the fluid with 411% of ethyl acetate. % carbon dioxide was passed through the column at a rate of 6 OL/h in an amount of 91 kg 7 cm 2 and brought into contact with the column.

After contact, the fluid passed through a filter and a pressure regulating valve and was led to a separator at normal pressure and a temperature of 40°C to obtain an extract. The extraction rate and fatty acid composition of the extract are as shown in Table 5.1 It can be seen that methyl lylunate with an unsaturation degree of 3 can be obtained with high selectivity by the method of the present invention.

Table 1 Table 2 Table 3 Table #45 Comparative Example 1 10.31 g of triolein was placed in an extractor, kept at 40°C, and carbon dioxide gas containing 4% by weight of ethyl acetate was added to it at 200 kg Zc12 at a rate of 6 OL/h. Blow contact was made at a speed of . Here, the above fluid in which triolein was dissolved passed through a filter and a pressure control valve, and was led to a separator at normal pressure and temperature θ° C., where triolein was separated. After separation, ethyl acetate was removed under reduced pressure to obtain triolein. The triolein extraction rate was as shown in Table ptS6. It can be seen that the method of the present invention significantly increased the yield of unsaturated components. (The same applies to the effects of the following comparative examples.) Comparative Example 2 After charging 9.71 g of triolein and 9.73 g of tristearin into an extractor, it was treated in the same manner as in Comparative Example 1 to obtain an extract. . The fatty acid composition of this extract is 7th (C1a;
,/C,Ij. = 8.3).

Comparative Example 3 Methyl stearate 9.60g and methyl linoleate 9,
71 g was charged into an extractor and treated in the same manner as in Comparative Example 1 to obtain an extract. The fatty acid composition of this extract (C, s, 2
/C,Ij. =6.2) as shown in Table 7.

Comparative Example 4 Methyl stearate (9.829 g) and methyl oleate (9.829 g.
Carbon dioxide gas containing 280Ag/cm2.60% by weight
The mixture was blown at a rate of L/h and treated in the same manner as in Comparative Example 1 to obtain an extract. The molar ratio of the fatty acid composition of this extract was as shown in Table 7.

Table 6 4, Brief Description of the Drawings Figure M1 is a schematic diagram of an apparatus for carrying out the method of the invention.

In FIG. 1, the reference numeral 1 is a streak cylinder 12; 3 is a high-pressure pump; 4 is a cooler; 5 is an extractor; 6 is a pressure regulating valve;
is a column filled with powder carrying silver nitrate, 8 is a temperature regulator, 9 is a heating tape, 10 is an extractor, 11 is a thermocouple, 12 is a pressure gauge, 13 is an integrated flow meter, and 14 is a constant temperature bath. be.

Claims (1)

[Claims] 1. A mixture of two or more higher fatty acid esters is chemically inert to the esters and has a critical temperature of 0 to 50.
The ester is transferred into the extraction fluid by contacting it with an extraction fluid in the temperature range of 100° C. under conditions of a temperature higher than its critical temperature and a pressure higher than its critical pressure, and then the extraction fluid is mixed with a powder carrying silver nitrate. A method for separating a higher fatty acid ester mixture, which is characterized by passing a higher fatty acid ester mixture through a column packed with a higher fatty acid ester and adsorbing a higher fatty acid ester having a high degree of unsaturation onto the column. 2. The method for separating higher fatty acid ester mixtures according to claim 1, wherein the temperature is 1 to 50°C higher than the critical temperature of the extraction fluid. 3 The pressure is 10 to 150 kg/more than the critical pressure of the extraction fluid.
2. The method for separating higher fatty acid ester mixtures according to claim 1, wherein the pressure is as high as cm^2. 4. The method for separating higher fatty acid ester mixtures according to claim 1, wherein the extraction fluid is ethane, ethylene or carbon dioxide. 5. The method for separating a higher fatty acid ester mixture according to claim 1, wherein the higher fatty acid ester is an ester consisting of a fatty acid having 18 carbon atoms and an alcohol having 1 to 2 carbon atoms. 6. The method for separating higher fatty acid ester mixtures according to claim 1, wherein the powder supporting silver nitrate is silica gel or alumina. 7 A mixture of two or more higher fatty acid esters is chemically inert to the ester and has a critical temperature of 0 to 5.
The ester was brought into contact with an extraction fluid in the range of 0° C. under conditions of a temperature above its critical temperature and a pressure above its critical pressure, and the ester was transferred into the extraction fluid, and the extraction fluid was loaded with silver nitrate. After passing through a column filled with powder and adsorbing some of the higher fatty acid esters in the mixture, this is transferred to the adsorbed higher ester mixture at a temperature that is chemically inert and at a critical temperature. A higher fatty acid characterized in that it is eluted under conditions of a temperature higher than a critical temperature and a pressure higher than a critical pressure using a solution in which 1 to 15% by weight of a lower fatty acid ester is added to an extraction fluid having a temperature in the range of 0 to 50°C. How to separate mixtures.