JPH03265697A - Method and apparatus for continuous preparation of soap - Google Patents

Abstract

PURPOSE:To improve the rate of reaction and to make an apparatus compact in size in the continuous production of soap by the ester saponification method by carrying out the reaction in a complete mixing reactor beforehand and then in a plug flow reactor. CONSTITUTION:Saponification is carried out by use of a continuous reaction apparatus which consists of a combination of the 1st reaction section and the 2nd reaction section in the continuous method for preparing soap by the saponification of fatty acid/lower alcohol esters. The 1st reaction section consists of at least one complete mixing reactor, and the 2nd reaction section consists of at least one plug flow reactor. Saponification should preferably be carried out in the complete mixing reactor until the rate of saponification reaches 20-80%, and then in the plug flow reactor. An apparatus for practicing the method comprises arranging raw material storage tanks 3 and 4 for fatty acid/ lower alcohol esters and alkali agents each, the complete mixing reactor 1, the plug flow reactor 2 and a saponificate extracting port 7 in the order and connecting them in series.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing soap, and more specifically to a method for producing high-quality soap using a compact facility using fatty acid lower alcohol ester as a raw material. Regarding the device.

[Conventional technology and issues to be solved]

Soap manufacturing methods include the neutral fat saponification method, in which soap is produced by saponifying animal and vegetable oils with alkali metal hydroxides, and the fatty acid saponification method, in which soap is produced through a neutralization reaction using fatty acids obtained by decomposing fats and oils as raw materials. Neutralization methods and ester saponification methods using lower alcohol esters of fatty acids as raw materials are generally known. However, each process has its advantages and disadvantages.

Although the neutral fat saponification method does not require the production of fatty acids or lower alcohol esters from fats and oils, it requires highly refined high-quality fats and oils from the viewpoint of soap quality, and it is extremely difficult to purify by-product glycerin. requires a complicated process. The fatty acid neutralization method uses fatty acids that are easy to purify as raw materials, yields high-quality soap, has a very fast reaction rate during soap production, and allows continuous production with compact equipment, making it the most effective method at present. This is a common method. However, since the melting point of the raw fatty acid is high, there is a high possibility that the fatty acid will undergo thermal deterioration, and there are also difficulties in handling, so there are problems in terms of equipment.

On the other hand, the ester saponification method, like the fatty acid neutralization method, is easy to purify with a fatty acid lower alcohol ester, and the soap obtained is equivalent to or higher in quality than the fatty acid neutralization method. In addition, handling operability, which is a disadvantage of the fatty acid neutralization method, is also very good because the fatty acid lower alcohol ester has a low melting point. However, the reaction rate during saponification is slower than that of the fatty acid neutralization method, and larger soap manufacturing equipment is required than the fatty acid neutralization method.

One method of increasing the reaction rate in the ester saponification method is to use a continuous loop reactor and recycle the soap produced into the reaction system (Japanese Patent Publication No. 44-670).

However, although this method is effective to some extent, the residence time is long and the reactor volume is also large.

In addition, the quality of the soap obtained by the ester saponification method is affected by the long residence time in the case of the above method using a continuous loop reactor (Japanese Patent Publication No. 44-670), which results in poor whiteness and odor due to thermal deterioration. The soap quality was not completely satisfactory.

Therefore, an object of the present invention is to improve the size of the equipment by improving the reaction rate, which is the drawback of the ester saponification method.

Furthermore, the objective is to reduce the thermal history during soap production by shortening the reaction time, thereby obtaining high quality soap.

[Means to solve the problem]

As a result of intensive studies to improve the drawbacks of conventional methods, the inventors of the present invention discovered that when carrying out a saponification reaction using fatty acid lower alcohol ester as a raw material, the reaction was carried out in a complete mixing reactor in advance, and then in a plug flow reactor. The present invention was completed based on the discovery that extremely high quality soap with little coloring and odor can be economically produced using a compact device by carrying out the reaction in a .

That is, the present invention provides a method for continuous production of soap by saponification of fatty acid lower alcohol esters, in which a first reaction section comprises at least one complete mixing reactor and a second reaction section comprises at least one plug flow reactor. The present invention relates to a method for continuous production of soap, characterized in that a saponification reaction is carried out using a continuous reaction device having a combination of reaction sections. Alternatively, the present invention provides (a) a raw material storage tank for fatty acid lower alcohol ester and an alkali agent, (b) a complete mixing reactor, (c) a plug flow reactor, and (
(b) To provide a continuous soap manufacturing apparatus characterized in that saponified product outlet ports are connected and arranged in series in this order.

The continuous soap manufacturing apparatus used in the present invention will be explained with reference to the schematic diagram shown in FIG.
is a complete mixing reactor, 2 is a plug flow reactor, and the fatty acid lower alcohol ester in the storage tank 3 and the alkali agent in the storage tank 4 are continuously fed into the complete mixing reactors 1 and 2 by raw material feed pumps 5 and 6, respectively. The saponified product is supplied to a continuous reaction device combining the plug flow reactor 2, and the saponified product after the saponification reaction is taken out from the saponified product take-out lower at the outlet of the plug flow reactor. Furthermore, when combining the complete mixing reactor 1 and the plug flow reactor 2, it is important to use them in this order.

However, in this case, an intermediate reactant transfer pump may be installed between 1 and 2.

A plug flow reactor is a front type (tube) reactor that exhibits plug flow properties in the fluid flowing through it.

In the present invention, it is important that at least one complete mixing reactor and at least one plug flow reactor are arranged in this order. When using a plug flow reactor, the arrangement may be as follows, for example.

・Complete mixing reactor - Complete mixing reactor - Plug flow reactor ・Complete mixing reactor - Complete mixing reactor - 1 plug flow reactor 1 plug flow reactor ・Complete mixing reactor - Plug flow reactor - Plug flow reactor The fatty acid lower alcohol ester used in the present invention is an ester of a fatty acid having an alkyl group or an alkenyl group having 8 to 24 carbon atoms and an alcohol having 1 to 5 carbon atoms. Specific examples include vegetable oils such as palm kernel, palm stearin, coconut oil, olive oil, castor oil, sesame oil, cottonseed oil, soybean oil, tung oil, peanut oil, and rapeseed oil, or animal fats and oils such as beef tallow, pork tallow, and whale oil. or a lower alcohol ester of a fatty acid derived from a mixture thereof, and the lower alcohol is an alcohol having 1 to 5 carbon atoms such as methanol ethanol.

The alkaline agent used for saponification in the present invention is
It is an alkali metal hydroxide such as caustic soda or caustic potash, or a salt thereof, and its aqueous solution concentration is preferably 15 to 60% by weight, more preferably 20 to 35% by weight. If the aqueous solution concentration is below this range, a large amount of water must be removed during the subsequent drying process, which increases the drying load, which is not preferable. Also, if it exceeds this range,
Methanol tends to remain during drying, which is undesirable.

The saponification reaction temperature in the present invention is preferably 70 to 150°C, more preferably 80 to 110°C.

If the reaction temperature is below this range, the saponification reaction rate will be reduced, and if it is above this range, the color, odor, etc. of the soap obtained will be adversely affected.

When carrying out the method of the present invention, the reaction rate of the saponification reaction is 2.
It is desirable to carry out the saponification reaction in a complete mixing reactor until the reaction rate reaches 0 to 80%, and to carry out the reaction in a plug flow reactor when the reaction rate is higher than that. The reason is that the saponification reaction rate curve over time of fatty acid lower alcohol ester is S
It is based on the use of an autocatalytic reaction-like behavior in which there is an initial induction period and the reaction rapidly progresses after a certain amount of reaction products have been produced.

In other words, the reaction rate is small at the beginning of the reaction, but as the reaction progresses, the concentration of the reaction product that is assumed to act as a catalyst increases, so the reaction rate increases and reaches its maximum value, but the consumption of reaction raw materials increases. As the reaction progresses, the reaction rate decreases. Therefore, the reaction rate in saponification is 99% with the minimum reactor volume.
In order to obtain such a high reaction rate, it is sufficient to use a complete mixing reactor until the conversion reaches the maximum reaction rate, and then use a plug flow reactor thereafter. Reaction rate is 20~
The reason why it is specified that it reaches 80% is that the maximum value of the saponification reaction rate of fatty acid lower alcohol ester exists within this range. In addition, the raw material fatty acid lower alcohol
Depending on conditions such as the type of ester and the concentration of alkali agent,
It is more preferable that the reaction rate in the complete mixing reactor reaches 30 to 70%.

Furthermore, in carrying out the present invention, monoglyceride, diglyceride, or a mixture thereof (hereinafter simply referred to as glyceride) may be added to the fatty acid lower alcohol ester in order to accelerate the reaction rate of the saponification reaction. It is presumed that the acceleration effect of the saponification reaction by glyceride is due to the fact that glyceride acts as an emulsifier between the fatty acid lower alcohol ester and the aqueous phase, and improves the reaction rate by controlling the emulsion.

In a preferred embodiment of the present invention, there is no particular problem with the glyceride that can be added as long as it is derived from long-chain fatty acids, but monoglycerides and diglycerides with a fatty acid composition corresponding to the fatty acid lower alcohol ester used as the raw material for soap can be used. is preferable in terms of the physical properties of the resulting soap.

For example, it is a glyceride having an alkyl group or an alkenyl group having 8 to 24 carbon atoms.

In the present invention, the amount of glyceride added is 1 to 20% by weight.
(lower alcohol ester to fatty acid) is desirable, and more preferably 2 to 10% by weight. If the amount of glyceride is below this range, the desired reaction rate will not be achieved in the saponification reaction, while if the amount of glyceride is above this range, it may adversely affect the physical properties of the resulting soap. .

In the present invention, lower alcohol and water are distilled off from the saponified product after the saponification reaction using a flash evaporator according to a conventional method. It is preferable that the amount of lower alcohol remaining in the dried product is 0.2% by weight or less, and the amount of water remaining in the dry product is 10 to 15% by weight or less.

After drying the saponified product (soap neat) obtained as above, the residual lower alcohol in the molded soap is extremely small, and the reaction rate of the soap produced is almost 100%.
The soap has a light whiteness of 90 or more, and has excellent properties with a pleasant odor.

〔Effect of the invention〕

According to the present invention, a method for economically producing extremely high quality soap with little coloring and odor is provided. Furthermore, according to the present invention, by using a complete mixing reactor and a plug flow reactor in combination, it is possible to achieve a significant downsizing of the reaction apparatus, and the volume of the reactor for the fatty acid method is the same or smaller. It can be the reactor volume. Furthermore, the residence time of the raw materials and saponified materials during the saponification reaction is short, and therefore it is possible to obtain a soap of extremely high quality with little thermal deterioration.

〔Example〕

The present invention will be described below with reference to Examples, but it goes without saying that the present invention is not limited to these Examples.

Example 1 Distilled palm kernel methyl ester 60% by weight and distilled palm stearin methyl ester 40% by weight both at 50% by weight.
Dissolve and mix at °C. This mixed methyl ester and 25
The weight% NaOH aqueous solution was prepared at a NaOH/methyl ester molar ratio of 1.02, an average residence time of 18.9 minutes, and an inlet raw material volumetric flow rate of the total NaOH aqueous solution and methyl ester of 37.
Continuous feeding was carried out to an apparatus that combined a complete mixing reactor and a plug flow reactor as shown in FIG. 1 with a reaction volume of 0.707 cm maintained at 90° C. at cc/min. The monoglyceride content in the raw material methyl ester was 0.5% by weight (based on the raw material methyl ester).

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160° C. and 4 Qtorr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13% by weight, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. The items are 5 points: appearance, whiteness, odor, 7 hand washing tests, and rapid foaming properties.

Regarding the quality evaluation items, soap of good quality was obtained for all 5 items.

Example 2 Distilled palm kernel methyl ester 60% by weight and distilled palm stearin methyl ester 40% by weight both at 50% by weight.
Dissolve and mix at °C. This mixed methyl ester and 25
The weight% NaOH aqueous solution was prepared at an NaOH/methyl ester molar ratio of 1.02, an average residence time of 12.4 minutes, and an inlet raw material volumetric flow rate of the total NaOH aqueous solution and methyl ester of 37.
Continuous feeding was carried out to an apparatus that combined a complete mixing reactor and a plug flow reactor as shown in FIG. 1 with a reaction volume of 0.461 and maintained at 90° C. at cc/min. The monoglyceride content in the raw material methyl ester was 0.5% by weight (based on the raw material methyl ester), and further 5% by weight (based on the raw material methyl ester) of monoglyceride was added thereto.

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160° C. and 4 Qtorr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13% by weight, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. The items are 5 points: appearance, whiteness, odor, 7 hand washing tests, and rapid foaming properties.

Regarding the quality evaluation items, soap of good quality was obtained for all 5 items.

Comparative Example 1 Distilled palm kernel methyl ester 60% by weight, distilled palm stearin methyl ester 40% by weight, both in a ratio of 50% by weight.
Dissolve and mix at °C. This mixed methyl ester and 25
% by weight NaOH aqueous solution, NaOH/methyl ester molar ratio 1.02, average residence time 418, 9 minutes, inlet raw material volumetric flow rate of the sum of NaOH aqueous solution and methyl ester 3
Reaction volume 15.51 maintained at 90 t under conditions of 7 cc/min
was continuously fed into a complete mixing reactor. The monoglyceride content in the raw material methyl ester was 0.5% by weight (based on the raw material methyl ester).

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160° C. and 4 Qtorr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13ir1%, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. When quality was inspected for the following five items: appearance, whiteness, odor, 7 hand-washing test, and rapid lathering, it was found that due to the deterioration of methyl esters and saponified products due to heat history, appearance, whiteness, odor, 7 hand-washing test, and The results showed that both rapid foaming properties were inferior to the product of Example 1.

Comparative Example 2 Both were mixed at a ratio of 60% by weight of distilled palm kernel methyl ester and 40% by weight of distilled palm stearin methyl ester.
Dissolve and mix at °C. This mixed methyl ester and 25
The wt% NaOH aqueous solution was prepared at an NaOH/methyl ester molar ratio of 1.02, an average residence time of 44.9 minutes, and a Na0t (inlet raw material volumetric flow rate of the sum of the aqueous solution and methyl ester) of 3.
Reaction volume 1.66 maintained at 90°C under conditions of 7cc/min
f was continuously fed into a plug flow reactor. The monoglyceride content in the raw material methyl ester was 0.5% by weight (based on the raw material methyl ester).

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160° C. and 4 Qtorr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13% by weight, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. When quality was inspected for the following five items: appearance, whiteness, odor, hand washing test, and rapid lathering, it was found that the appearance, whiteness, and odor of Example 1 were poor due to deterioration of methyl esters and saponified products due to heat history. The results showed that the product was inferior to that of other products.

Comparative Example 3 Distilled palm kernel methyl ester 60% by weight, distilled palm stearin methyl ester 40% by weight, both in a ratio of 50% by weight.
Dissolve and mix at °C. This mixed methyl ester and 25
wt% NaD)I aqueous solution at NaOH/methyl ester molar ratio 1.02, average residence time 272, 3 min, NaOH
Reaction volume maintained at 90°C under conditions of inlet raw material volumetric flow rate of 37 cc/min including aqueous solution and methyl ester: 10.0
Continuously fed into a 8 J thorough mixing reactor. The monoglyceride content in the raw material methyl ester is 0.5% by weight (
(based on raw material methyl ester) and further added 5% by weight (based on raw material methyl ester).
Monoglyceride of raw material methyl ester) was added.

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160 t and 40 torr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13% by weight, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. When quality was inspected for the following five items: appearance, whiteness, odor, 7 hand-washing test, and rapid lathering, it was found that due to the deterioration of methyl esters and saponified products due to heat history, appearance, whiteness, odor, 7 hand-washing test, and The results showed that both rapid foaming properties were inferior to the product of Example 2.

Comparative Example 4 Distilled palm kernel methyl ester 60% by weight and distilled palm stearin methyl ester 40% by weight both at 50% by weight.
Dissolve and mix at °C. This mixed methyl ester and 25
The weight% NaOH aqueous solution was prepared at a NaOH/methyl ester molar ratio of 1. o2, average residence time 29.7 minutes, total inlet raw material volumetric flow rate of NaOH aqueous solution and methyl ester 37
Reaction volume maintained at 90°C under cc/min conditions: 1.101!
The feed was continuously fed into a plug flow reactor. The monoglyceride content in the raw material methyl ester was 0.5% by weight (based on the raw material methyl ester), and further 5% by weight (based on the raw material methyl ester) of monoglyceride was added thereto.

The conversion rate of the soap neat from the outlet was 99% or more, and this neat was treated at 160° C. and 4 Qtorr to continuously distill off methanol and water.

The moisture content in the obtained chips was 13% by weight, and the methanol content was 0.2% by weight or less.

Next, the chips were stamped using a conventional method, and their performance as soap was evaluated. When quality was inspected for 5 items: appearance, whiteness, odor, 7 hand wash test, and rapid lathering, it was found that the appearance, whiteness, and odor were as low as Example 2 due to deterioration of methyl ester and saponified products due to heat history. The results showed that the product was inferior to that of other products.

These results are summarized in Table-1.

Durability: Average residence time (space time) is defined by the following formula.

Book 2: Soap quality inspection method described below: Soap quality evaluation method 1, appearance (visual observation) Take the sample on a watch glass and observe the appearance (condition, color, etc.) of the sample under natural light from the north or daylight fluorescent light. and will be evaluated in the following three stages.

If it is equivalent to the standard sample...pass If it is slightly different from the standard sample...if it is clearly different from the standard sample that requires attention...fail 2. Whiteness (color difference meter) Scrape the surface of the sample flat and measure it with a color difference meter ( Nippon Denshoku Co., Ltd.G
I set it to Z optical 5 sensor).
The a and b values are determined and the whiteness is determined using the following formula.

Whiteness=100-(100-L)"+a'+b" Whiteness of 90 or higher is considered to be a pass.

3. Smell (direct method) The sample and standard sample are kept at the same temperature.

The sample and standard sample are directly smelled, and the quality and intensity of the odor are compared and evaluated using the following three levels.

If it is equivalent to the standard sample...If there is a slight difference from the acceptable standard sample...If there is a difference from the standard sample that requires attention
・・Failure 4. Hand washing test The sample was hand washed with tap water at 25±1℃, and the overall feeling such as foaming, uneven melting, roughness, etc. was compared with the feeling of hand washing test with a standard sample in advance, and the following 4. Compare in stages.

The whole feeling is very good...1 Overall feel is good...2 Overall feel is normal...3 The overall feeling is bad...4 A score of 2 or less is considered a pass.

5. Fast foaming property Measurement method 1) Plane one side of the sample smooth with a carpenter's plane.

2) Rinse the sponge thoroughly with water, squeeze out the water, and attach it to the Lather Quick Machine.

3) Place water in the sample container under sunlight for about 8 minutes and adjust the temperature to 25°C.

4> Attach the sample to the soap holder, set the count to 0, and start the test.

5) Record the number of strokes when the water surface in the test container is covered with bubbles.

Judgment: The number of strokes at this time is taken as the value of rapid foaming property, and a value of 20 or less is considered to be a pass.

Lazar Quick Machine This tester is constantly exposed to constant water quality and temperature, and has a mechanism that uniformly rubs the surface of the soap with a rubber sponge that is rinsed off.

The body of the tester consists of a shaft driven longitudinally by a five-cotch yoke driven by a motor.

The sponge holder is a flat metal plate to which the sponge is fixed with water-soluble adhesive and attached to the bottom of the shaft. The soap holder is a metal box with pleats on both sides, and the soap sample is tightened downwards using a screw attached to the upper pleats, and the holder is stopped by the lower pleats. The soap holder is supported perpendicularly to the shaft fitted in the bearing and is fixed approximately 15 cm above the water surface of the test container.

The soap holder with the soap sample attached faces parallel to the moving sponge, and when the shaft descends to the bottom, the sponge passes through the soap holder and immerses into a cylindrical stainless steel container containing 4.51 water. The sponge also passes through the soap holder as the shaft rises. The vertical movement speed is 2
The pressure is set at 2st/min, and the sponge and soap are always kept in contact with a constant pressure using a balance weight.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the apparatus used in the present invention. 1... Complete mixing reactor 2... Plug flow reactor 3... Fatty acid lower alcohol ester storage tank 4...
Alkaline agent storage tank 5.6... Raw material feed pump 7... Saponified product outlet

Claims (1)

[Scope of Claims] 1. In a method for continuous production of soap by saponification of fatty acid lower alcohol esters, a first reaction section consisting of at least one complete mixing reactor and a second reaction section consisting of at least one plug flow reactor are provided. 1. A method for continuously producing soap, characterized in that a saponification reaction is carried out using a continuous reaction device combining reaction sections. 2. The saponification reaction is carried out in a complete mixing reactor until the reaction rate of the saponification reaction reaches 20 to 80%, and when the reaction rate is higher than that, the reaction is carried out in a plug flow reactor. The method for continuously producing soap according to claim 1. 3. (a) raw material storage tanks for fatty acid lower alcohol ester and alkali agent, (b) complete mixing reactor, (c) plug flow reactor, and (d) saponified product outlet are connected in series in this order. A continuous soap manufacturing device characterized by the following: