JPH0259199B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for methyl esterifying free fatty acids in a deodorized distillate by-produced in the deodorizing process of fats and oils. Deodorizing scum, deodorizing sludge, hotwell oil soapstock, etc. (hereinafter referred to as "deodorizing scum", "deodorizing sludge", etc.) are by-products of the deodorizing process of soybean oil, rapeseed oil, cottonseed oil, safflower oil, sunflower oil, rice bran oil, corn oil, coconut oil, palm oil, palm kernel oil, etc. (deodorized distillate) includes tocopherols, sterins, hydrocarbons, glycerides,
Many free fatty acids coexist, with free fatty acids accounting for about 30 to 70%. Among these deodorized distillate compositions, tocopherols, which are usually contained in an amount of 0.5 to 20%, are substances useful as medicines, foods, or antioxidants, and tocopherol concentrates are produced by various methods. Normally, to obtain a tocopherol concentrate, it is necessary to remove free fatty acids, which are the main components of the deodorized distillate, but the general method is to methyl esterify this free fatty acid, and then use molecular distillation or ionization. Preparative separation using exchange resins or a combination of these can be considered. In addition, a method of solvent fractionation of a deodorized distillate or its hydrogenated product, a vacuum distillation method of a deodorized distillate, or a combination thereof can be considered. Among these, the general method conventionally used for methyl esterification of free fatty acids is to add 1 to 10 times the amount of methyl alcohol to the deodorized distillate or its saponified product, and then add 1 to 10 times the amount of methyl alcohol to the deodorized distillate or its saponified product. In this method, an esterification reaction is carried out, and after the reaction is completed, the remaining catalyst is neutralized or removed by washing with water. The obtained methyl ester product is then subjected to vacuum distillation, molecular distillation or ion exchange method and used to produce tocopherol concentrate. However, according to this methyl esterification method,
Since the deodorized distillate has low solubility in methyl alcohol, it is necessary to add a non-polar solvent such as toluene or hexane as a third component, or to perform the reaction in a heterogeneous system using high-speed stirring. Equipment for high-speed stirring becomes complicated. In addition, when a neutralization reaction is performed as a method for removing residual catalyst, it is necessary to separate the salts produced, and when using a water washing method, a small amount of sterine remains in the deodorized distillate after the desterine process. ,
It is extremely easy to emulsify when water is added, making separation extremely difficult. In order to eliminate the above-mentioned drawbacks of the conventional methyl esterification method, the present inventors focused on a methyl esterification method using an ion exchange resin as a catalyst, and as a result of intensive research, they found that The present invention was completed based on the discovery that by using a fluidization method for methyl esterification, the methyl esterification reaction can be carried out continuously and with high efficiency even in the absence of acid and alkali catalysts and third components. did. That is, the method for methyl esterification of deodorized oil and fat distillates of the present invention involves adding methyl alcohol to the deodorization distillate by-produced in the oil and fat deodorization process, and bringing the mixture into contact with a cation exchange resin by a fluidization method. It is characterized by methyl esterifying free fatty acids in the deodorized distillate. The fluidization method used in the present invention is to pack an ion exchange resin into a column, and supply deodorized distillate and methyl alcohol from the bottom of the column at a flow rate adjusted so that the ion exchange resin maintains a fluid state. Any method that extracts the methyl esterification reaction product from the top of the column may be used, such as the conventionally known countercurrent contact ion exchange method, McIlheny and
McConnel method, McNeil, Swinton, Weisc method,
Ion exchange methods such as the SRI method can also be applied. In order to compare with the fluidization method, the present inventors
We also investigated methyl esterification using a shaking method using an ion exchange resin, a fixed bed method such as a downflow method, etc. However, in the shaking method, methyl alcohol insoluble matter in the deodorized distillate adheres to the ion exchange resin. However, there is a disadvantage in that a very large amount of methyl alcohol must be used to wash and remove the insoluble matter during reaction or regeneration. In addition, in a fixed bed method such as a downflow method, the methyl alcohol insolubles in the deodorized distillate are precipitated in the resin column because the reaction is a heterogeneous system, and the rate of precipitation increases as the reaction progresses. do. In this case, precipitation can be prevented by adding a third component such as hexane, toluene, or xylene, but the equipment required to recover the solvent from the reaction product after the reaction is completed becomes complicated. Compared to these methods, according to the fluidization method, there is a very low possibility that the methyl alcohol insoluble content in the deodorized distillate will adhere to the ion exchange resin, and without adding the third component described above, Methyl esterification can be carried out continuously and with high efficiency. There are no particular limitations on the shape of the particles of the cation exchange resin used in the present invention, the type of functional groups, etc. Functional groups that are strongly acidic in terms of catalysis (e.g. sulfonic acid groups)
A hydrogen-type ion exchange resin is preferable in order to prevent impurity ions from entering the reaction system. Commercially available ion exchange resins such as Diaion PK206 and Diaion PK208 (manufactured by Mitsubishi Chemical Industries, Ltd.) can be used. The amount of methyl alcohol used in the present invention is preferably 1 to 50 times, more preferably 2 to 10 times, the amount of the deodorized distillate. The methyl esterification reaction proceeds as long as the reaction temperature is below the boiling point of methanol, but is preferably 50 to 65°C. In addition, the speed (flow rate) at which the mixture of the deodorizing mixture and methyl alcohol rises in the column is 0.32 to 2.15 m/
Although a range of min is preferable, there is no problem with the flow rate outside this range as long as the flow rate is such that the resin can remain in the column cylinder. There is usually no particular need to regenerate the ion exchange resin, and methyl esterification can be carried out continuously. According to the method of the present invention, it was confirmed that the final acid value of the deodorized distillate was significantly lower than when other ion exchange methods were employed, and the methyl esterification reaction was carried out with extremely high efficiency. Hereinafter, a more detailed explanation will be given by showing specific examples. Example 1 A sample having the composition shown below was subjected to a methyl esterification reaction at a liquid temperature of 60° C. by a shaking method, a downflow method, and a fluidization method. 1) Test sample solution Twice the amount of methyl alcohol was added to a deodorized soybean oil distillate (acid value 76.8), and the solution was used by dispersing it as much as possible. 2) Cation exchange resin Diaion PK206 made into H-type by prescribed operations 3) Method 3-1) Shaking method: Place the resin in a Sakaguchi flask and shake until the resin surface and sample solution surface are almost the same. A sample solution was added, and the reaction was carried out in a shaking constant temperature bath. The precipitate during the reaction was washed with methyl alcohol,
Matched to sample solution. 3-2) Downflow method: The resin was packed in a heat-insulated column with a jacket, and the reaction was carried out at a predetermined flow rate (SV, space velocity). The oil precipitated in the column was excluded from the acid value measurement. 3-3) Fluidization method: The resin was packed in a heat-insulating column with a jacket, a fluidized bed was formed at a predetermined flow rate, and the contact time between the sample solution and the resin was adjusted to 2 hours. The same procedure was used for the example). 3-4) Measuring method of final acid value After the methyl alcohol in the sample solution was distilled off after the reaction was completed, the final acid value was measured based on the standard oil and fat analysis method.

【table】

[Table] From Table 1, it was recognized that the methyl esterification reaction by the fluidization method was superior to the shaking method and the downflow method. Example 2 Five times the amount of methyl alcohol was added to rapeseed deodorized distillate (acid value 56.8) and while uniformly dispersing, the liquid temperature was
The methyl ester reaction was carried out by the fluidization method at 65°C and varying the flow rate. The ion exchange resin used was Tire Ion PK208, which had been made into an H type by a prescribed operation.

[Table] From Table 2, it was confirmed that esterification was sufficiently carried out under the above reaction conditions. Also, the flow rate
If the flow rate is 0.25 m/min, a fluidized bed will not be formed and the effect of the present invention will not be obtained, and if the flow rate is 2.5 m/min, the deodorized distillate will be removed from the column before methyl esterification is sufficiently performed. It was found that this was not desirable. Example 3 The same procedure as in Example 2 was carried out using cottonseed oil deodorized distillate (acid value 68.4), and the results shown in Table 3 were obtained.

[Table] Example 4 Sunflower oil deodorized distillate (acid value 71.3), safflower oil deodorized distillate (acid value 65.3), and palm oil deodorized distillate (acid value 95.2) were operated in the same manner as in Example 2. The results shown in Table 4 were obtained.

[Table] From Tables 1 to 4, it was confirmed that the methyl esterification of various vegetable oil deodorized distillates was sufficiently carried out under the above reaction conditions.

Claims (1)

[Scope of Claims] 1. Methyl alcohol is added to the deodorized distillate produced as a by-product in the deodorizing process of fats and oils, and the free fatty acids in the deodorized distillate are converted into methyl alcohol by contacting them with a cation exchange resin using a fluidization method. A method for methyl esterifying an oil and fat deodorizing distillate, which is characterized by esterification. 2 As a condition for the fluidization method, the flow velocity is 0.32 to 2.15 m/
The method for methyl esterifying a deodorized oil and fat distillate according to claim 1, wherein a fluidized bed is formed in a range of min.