JPH0692596B2 - Purification method of fatty acid and triglyceride - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention contains a triglyceride and a fatty acid or an alcohol ester thereof, for example, a triglyceride and a fatty acid contained in a hydrolysis reaction liquid of fats and oils, a transesterification reaction liquid of fats and oils, and the like. And / or an alcohol ester.

[Prior Art] Generally, in the oil and fat industry, a small amount of a fatty acid or its alcohol ester contained as an impurity in a raw material oil and fat is separated and removed, or a triglyceride and a fatty acid contained in a reaction solution in a hydrolysis reaction or a transesterification reaction of the oil and fat. Alternatively, it is industrially essential to efficiently separate the alcohol ester. Therefore, conventionally,
A crystallization method, a distillation method, a method of allowing an alkali to act, etc. have been mainly used. However, in the crystallization method, it is difficult to efficiently separate triglyceride from fatty acid or its alcohol ester, and a large-scale refrigerator is required on an industrial scale, which is economically disadvantageous. On the other hand, the distillation method requires high temperature and high pressure and thus requires a large amount of energy, and has a drawback that the triglyceride, fatty acid or alcohol ester thereof to be processed is thermally modified or thermally decomposed. Further, the method using an alkali has drawbacks that the separation efficiency is insufficient and that a process for dealkalizing the fatty acid after separation is required.

Therefore, it has been desired to develop a technique capable of accurately and economically separating triglyceride from fatty acid and / or its alcohol ester at low temperature and low pressure.

[Structure of the Invention] The present inventors have conducted various studies on a method for separating a fatty acid and / or its alcohol ester from a triglyceride precisely and inexpensively. As a result, if a simulated moving bed is used, a hydrophobic adsorbent can be used. The inventors have found that continuous separation of triglyceride and fatty acid and / or its alcohol ester is possible by using a synthetic adsorption resin and an organic solvent as a desorbing agent, and have completed the present invention.

The term "fatty acid" as used in the present invention means saturated fatty acids such as capric acid, undecanoic acid, lauric acid, myristic acid, arachidic acid, stearic acid, palmitic acid, arachidonic acid, eicosapentaenoic acid, myristoleic acid, petroselinic acid, elaidin. Acid, linoleic acid, linolenic acid, γ-linolenic acid, docosahexaenoic acid, oleic acid, those containing all unsaturated fatty acids such as palmitoleic acid, "alcohol ester", these fatty acids, methyl ester, ethyl ester, It includes all lower alcohol esters such as propyl ester.

The "triglyceride" referred to in the present invention includes all triglycerides, diglycerides and monoglycerides having the above fatty acids as esters.

That is, according to the present invention, the adsorbent is housed inside, and the front end and the rear end are connected by the liquid passage to form an endless shape, and the liquid is circulated in one direction. A liquid containing a fatty acid and / or an alcohol ester thereof and a triglyceride and an organic solvent that is a desorbing liquid are introduced, and at the same time, a triglyceride purified liquid and a fatty acid and / or an alcohol ester purified liquid thereof are extracted from a packed bed, In the packed bed, (1) an inlet for a liquid containing a fatty acid and / or its alcohol ester and triglyceride as a raw material liquid, (2) an outlet for a purified liquid of a fatty acid or its alcohol ester, and (3) an organic solvent as a desorbed liquid. The inlet port and the (4) triglyceride purified liquid outlet port are arranged in this order along the direction of fluid flow, and these are connected to the fluid in the bed. There is provided a method of purifying oils and fats, which comprises using a simulated moving bed consisting of moving intermittently sequentially their position in the direction of the les.

A so-called simulated moving bed, that is, a packed bed that contains a solid adsorbent and has a front end and a rear end connected by a fluid passage so that fluid can circulate in the bed, The desorbed fluid inlet, adsorbate fluid outlet, raw material fluid inlet, and non-adsorbate fluid outlet are provided along with the fluid flow of the above, and each fluid is continuously introduced from each inlet or outlet. By withdrawing and switching each inlet and outlet with the downstream one at regular time intervals, the raw material fluid is relatively easily adsorbed by the solid adsorbent (adsorbate component) and the component relatively hard to be adsorbed ( Techniques for separating into non-adsorbed components are known (Japanese Patent Publication No.
-15681), as an example of using such a technique, as a method for producing fructose (see JP-A-53-88335).
And maltose separation method (see Japanese Patent Laid-Open No. 67000/1985). However, an application example of a method for precisely separating triglyceride from fatty acid and / or its alcohol ester using a simulated moving bed has not been reported at all, and its application has been difficult.

Hereinafter, the present invention will be described in more detail.

The hydrophobic synthetic adsorption resin used in the present invention has a skeleton of a copolymer of styrene and divinylbenzene, for example, Amberlite XAD4 manufactured by Rohm and Haas, Sumitomo Chemical Co., Ltd. Duolite S861, Examples thereof include DIAION HP-10 and HP-20 manufactured by Mitsubishi Kasei Co., Ltd., but are not limited thereto. The particle size of the adsorbent resin is not particularly limited, but is preferably 300 to 600 μm in order to prevent uneven flow in the bed. Further, the pore size of the adsorbent resin is preferably 50 to 150 Å from the viewpoint of mass transfer, but is not particularly limited thereto.

The higher the temperature at which the solution is passed, the higher the separation ability is obtained.

As the organic solvent used as the releasing agent in the present invention, a mixed solvent of a polar solvent and a nonpolar solvent can be used. As the polar solvent, alcohols such as methanol, ethanol, propanol, isopropanol, butanol, acetone,
Ketones such as methyl ethyl ketone and diethyl ketone, ethers such as diethyl ether and tetrahydrofuran,
In addition, substances such as methylene chloride, chloroform, DMF, and DMSO are used as the nonpolar solvent, saturated aliphatic hydrocarbons such as n-hexane, n-heptane, n-octane, iso-octane, and n-decane, cyclohexane, decalin. Examples thereof include cycloaliphatic hydrocarbons such as benzene, aromatic hydrocarbons such as benzene and p-xylene, but are not limited thereto. The mixing ratio of the polar solvent and the non-polar solvent can be appropriately set according to the affinity of the triglyceride and the fatty acid and / or the alcohol ester thereof and the adsorbent. For example, when ethanol is used as the polar solvent and n-hexane is used as the non-polar solvent, good separation can be achieved by setting the mixing ratio of both to ethanol / hexane = 1/9 to 3/7. The raw material triglyceride and fatty acid and / or alcohol ester thereof can be dissolved in the above-mentioned organic solvent and supplied, but this is not essential.

Hereinafter, the method of the present invention will be described in more detail with reference to the drawings.

FIG. 1 is a schematic view of an example of a simulated moving bed used in the present invention. In FIG. 1, the inside of the packed bed, which is the main part of the simulated moving bed, is divided into 16 unit packed beds, the number of which is the composition, concentration and concentration of triglyceride and fatty acid and / or its alcohol ester. It can be appropriately determined according to factors such as the size of the device. In FIG. 1, each unit packed bed is filled with a hydrophobic synthetic adsorption resin, and a space is provided between each unit packed bed. In each space, an inlet for a mixed solution of triglyceride and a fatty acid or its alcohol ester to the packed bed, an inlet for an organic solvent that is a desorbed liquid, an outlet for a purified triglyceride solution from the packed bed, and a fatty acid and / or its alcohol Four types of ester refined liquid outlets are open (however, most of them are omitted in FIG. 1). The installation of this space is not essential, but when the mixture of triglyceride and fatty acid and / or its alcohol ester and the desorbed liquid which are introduced into the packed bed are introduced into this space, the fluid flowing down in the bed is circulated. It is preferable because it can be rapidly diffused and mixed into the inside.

In FIG. 1, a mixed solution of triglyceride and fatty acid and / or its alcohol ester is introduced into the space 19,
An organic solvent is introduced into the space 11 as a desorbed liquid. Further, the purified liquid of triglyceride is extracted from the space 15, and the purified liquid of fatty acid or its alcohol ester is extracted from the space 23. Therefore, the packed bed is an adsorption zone composed of four unit packed beds 109 to 112, and four unit packed beds 113.
~ 116 primary purification zone, 4 unit packed beds 101-10
It consists of 4 desorption zones and 4 zones of 4 unit packed beds 105-108. The action of each zone is equal to that of a known simulated moving bed in which triglyceride is the adsorbate component and fatty acid and / or its alcohol ester is the non-adsorbate component.

A concentration distribution of triglyceride and fatty acid and / or its alcohol ester is formed in the liquid in the packed bed, and this concentration distribution moves downstream while maintaining its shape. In order to follow this movement, a mixed liquid of triglyceride and fatty acid and / or its alcohol ester to the packed bed or an inlet for an organic solvent, and a triglyceride purified liquid and a fatty acid and / or its alcohol ester purified liquid are taken out from the packed bed. Is sequentially switched to that below. The switching may be performed for four types of openings at the same time, or may be shifted for each opening in time. The time for continuing the introduction or withdrawal of the liquid from the same opening varies depending on the size of the unit packed bed, the flow rate of the liquid flowing through the bed, etc., but is usually several minutes to several tens of minutes. By this switching, the above-mentioned four zones are successively moved to the positions occupied by the packed bed. However, the length of each zone is always almost constant and circulates through the packed bed while maintaining its size and relative position.

The degree of separation of triglyceride and fatty acid and / or its alcohol ester in a simulated moving bed using a hydrophobic adsorption resin as an adsorbent is affected by various factors, and the most significant factor is the flow rate of the liquid in the bed, It is the time for continuing the introduction or withdrawal of the liquid from the same opening. This means that switching the liquid inlet and outlet to the downstream opening is equivalent to moving the hydrophobic adsorbent resin in the upstream direction with the inlet and outlet positions fixed if the viewpoint is changed. And the concentration distribution of each component in the floor is
It is inferred from the fact that it is formed by the interaction with the liquid moving in the upstream direction. This moving speed corresponds to the length (l) of each unit packed bed divided by the time (T) during which the introduction or withdrawal of the liquid is continued from the same opening (l / T). As is well known, in order to separate two or more components by a simulated moving bed, the moving speed V ₁ of the non-adsorbate component in the packed bed is
Is V ₁ > l / T in the adsorption zone, v ₁ <l / T in the primary purification zone, v ₁ > l / T in the desorption zone, and v ₁ > l / T in the secondary purification zone. , the moving velocity v in ₂ adsorption zone v ₂ <in l / T, 1 primary purification band v ₂ <l / T of the packed bed of adsorbate component in the desorption zone v _2> l / T, In the secondary purification zone, v ₂ <l / T may be set. Therefore, the flow rate of the liquid and the time during which the liquid is continuously introduced or withdrawn from the same opening are inevitably determined from these relationships. On the other hand, the moving velocity v ₂ of the non-adsorbates in the packed bed moving speed v ₁ and adsorbate component ingredients, is determined by the liquid flow rate in the packed bed, easily using a packed bed of these batch It goes without saying that you can actually measure.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

Example Olive oil and oleic acid were separated using a simulated moving bed consisting of 16 columns having an inner diameter of 1 cm and a length of 20 cm. The concentration of both olive oil and oleic acid in the raw material liquid is 20 g /
And was dissolved in a mixed solvent of ethanol and hexane (ethanol / hexane = 2/8). A hydrophobic adsorption resin (XAD4 manufactured by Rohm and Haas) was used as the adsorbent, and a mixed solvent of ethanol and hexane (ethanol / hexane = 2/8) was used as the desorption liquid. The raw material liquid supply rate is 1.38 ml / min, the desorbed liquid supply rate is 4.27 ml / min, the olive oil refined liquid is withdrawn at 2.83 ml / min, and the fatty acid refined liquid is withdrawn at a flow rate of 2.83 ml / min. The liquid and desorbed liquid supply ports and the olive oil purified liquid and oleic acid purified liquid withdrawal ports were moved every 5 minutes.

As a result, oleic acid was not contained at all in the purified olive oil solution, and the steady state was reached in about 60 minutes, and 97% of the olive oil contained in the raw material solution was recovered in the steady state.

[Effects of the Invention] According to the present invention, triglycerides and fatty acids can be precisely separated under mild conditions of low temperature and low pressure. In addition, since the method of the present invention is a continuous operation, it is possible to easily perform automation, and as an advantage of the simulated moving bed, it is possible to save the amounts of the adsorbent and the organic solvent that is the desorbed liquid. It can be mentioned as an effect.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a simulated moving bed used in the purification method of the present invention.

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Claims (1)

[Claims] 1. A hydrophobic synthetic adsorption resin as an adsorbent is housed inside, and a front end and a rear end are joined by a liquid passage to form an endless form, and a liquid circulates in one direction. A liquid containing a raw material liquid of fatty acid and / or its alcohol ester and triglyceride and an organic solvent which is a mixed solvent of a polar solvent and a non-polar solvent as a desorbing agent are introduced into the packed bed, and at the same time, a purified liquid of triglyceride from the packed bed. And a fatty acid and / or an alcohol ester purified liquid thereof are withdrawn, and in the packed bed, (1) a liquid feed port containing a fatty acid and / or its alcohol ester and triglyceride as a raw material liquid, (2) a fatty acid or its The fluid flow of the alcohol ester purified liquid outlet, (3) the organic solvent inlet which is the desorbed liquid, and (4) the triglyceride purified liquid outlet. Of fatty acids and triglycerides characterized by using a simulated moving bed which is arranged in this order along the direction of and which moves them intermittently in the direction of fluid flow in the bed. Purification method.