JPH03227996A - Production of alkylglycoside - Google Patents

Abstract

PURPOSE:To industrially and advantageously obtain the subject compound useful as surfactants, etc., by treating an unreacted substance-containing crude product using a pseudo-moving bed in which a feed inlet and taking outlet are intermittently and successively moved in an adsorber having the forefront and final packing columns combined to afford an endless form. CONSTITUTION:A crude alkylglycoside containing an unreacted alcohol as an impurity is treated by arranging an eluate feed inlet, a taking outlet for a strong adsorbed component solution, a feed inlet for a crude alkylglycoside solution and a taking outlet for a weak adsorbed component solution in the flow direction of a solution at a prescribed interval in the order mentioned and using a pseudo-moving bed for intermittently and successively moving the feed inlets and taking outlets in which a crude alkylglycoside solution and an eluate are fed and a strong and a weak adsorbed component solutions are simultaneously taken out to the downstream side in a group of packed columns in which the packed columns filled with a (non)polar adsorbent are connected in series with liquid passages and the forefront and the final packed columns are combined with the liquid passages to provide an endless form and flow the solution in one direction as an adsorber.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing alkyl glycosides widely used in surfactants and the like. In particular, the present invention relates to a method for producing an alkyl glycoside that can be purified simply, efficiently, and to a high degree of purity without causing decomposition of the alkyl glycoside during purification.

[Prior Art] Alkyl glycosides, which are sugar derivative surfactants, are hypoallergenic surfactants, and although they are nonionic surfactants, they themselves generate stable foam, and they do not interfere with other surfactants. It is known that it acts as a foam stabilizer for anionic surfactants, and has been attracting attention in recent years.

Such alkyl glyconodes are usually produced by the reaction of sugars and higher alcohols, but until now it has not been easy to purify them. This is mainly due to the following reasons. That is, the viscosity of crude alkyl glycoside containing impurities such as unreacted higher alcohols with high boiling points and coloring substances is generally high, and the diffusion rate of unreacted alcohol within it is slow, so it is necessary to improve the fluidity of crude alkyl glycoside. In order to reduce the amount of residual unreacted alcohol by distillation or the like, heating to a high temperature is necessary. However, the thermal stability of alkyl glycosides is limited, and therefore, heating to high temperatures causes some of the alkyl glycosides to decompose, and at the same time, a small amount of the alkyl glycosides present in the crude alkyl glycoside or due to the decomposition of the alkyl glycosides This is because unfavorable situations occur for the quality of the alkyl glycoside, such as denaturation of the resulting reducing sugar.

At the same time, for the economical production of alkyl glyconts, it is important to recover and reuse the excess residual unreacted higher alcohol after separating it from the crude alkyl glycont; however, heating to high temperatures during separation is important. If this is done, the quality of this recovered unreacted alcohol will deteriorate, and therefore, in the production of the next alkyl glycoside using this, it will be difficult to carry out 1. This will cause a deterioration in the quality of argyl glycosides.

As a method to solve the second problem, the reaction product containing excess unreacted higher alcohol is made into a thin film using a thin film evaporator, and the excess unreacted alcohol is evaporated in an extremely short residence time at a relatively high temperature. The method to do this is published in Japanese Patent Application Laid-Open No. 58-19490.
This is proposed in Publication No. 2. This suppresses the thermal decomposition of alkyl glycosides by extremely shortening the heating time, but even so, it is possible to avoid thermal decomposition to a certain extent ().
I can't do that.

Alternatively, unreacted Al-1- which does not require heating to high temperature
A method for separating the two is proposed in US Pat. No. 4,571,306. This method uses silicalite, which has a molecular sieving effect, as an adsorbent to preferentially adsorb alcohol, which has a smaller molecular size than alkyl glycosides, to purify alkyl glycosides. However, this method has a problem in that the degree of purification of the alkyl glycoside is limited because the amount of alcohol adsorbed on the adsorbent is small and the selectivity of adsorption between the alkyl glycoside and alcohol is low.

In addition, column chromatography using a packed column filled with an adsorbent such as solica gel requires an enormous amount of adsorbent and eluent, which poses an economical problem.

[Problems to be Solved by the Invention] The present invention provides a highly efficient and convenient method for removing impurities such as unreacted higher alcohols and colored substances without requiring high-temperature heating and therefore without thermal decomposition of glyconodes. The purpose of the present invention is to provide a method for producing pure alkyl glycosides.

1 Means for Solving Problems] In order to state the purpose described in -, it was discovered that excellent results could be achieved if alkyl glycosides were purified using an adsorption device using a pseudo-moving bed, and the present invention was accomplished. Ta.

That is, the present invention provides a method for producing alkyl glycoside by contacting crude alkyl glycoside containing unreacted alcohol as an impurity with a polar adsorbent or a non-polar adsorbent. The columns are connected in series through a liquid passage, and the first packed tower and the last packed tower are also connected through a liquid passage to form an endless structure. Retrieving the solution [2] Arrange the crude alkyl glycoside solution inlet and the weakly adsorbed component solution outlet in this order at predetermined intervals along the flow direction of the solution, and simultaneously supply the crude alkyl glycoside solution and the eluent. , a method for producing alkyl glyconodes, characterized by using a pseudo-moving bed in which a strongly adsorbed component solution and a weakly adsorbed component solution are taken out, and their supply ports and take-out ports are moved intermittently and sequentially to the downstream side. It is related to.

In the present invention, a pseudo moving bed is used as an adsorption device. By using a pseudo-moving bed, the adsorbent and eluent can be seen together. 2. Continuous operation is possible by countercurrent contact, which dramatically improves processing efficiency. can be significantly reduced.

An example of the use of a pseudo-moving bed is a fatty acid separation method (Japanese Patent Publication No. 13417/1983). However, no application example (J) has yet been reported regarding a method for producing alkyl glycosides from supported alkyl glycosides containing unreacted higher alcohols using a pseudo-moving bed.

The purified alkyl glycoside of the present invention can be obtained by first synthesizing an alkyl glycoside and then purifying it.

The di-alkyl glycoside may be synthesized by a well-known method. That is, for example, a method in which sugars and higher alcohols are directly acetalized in the presence of an acid catalyst, or a method in which sugars are acetalized in advance with a lower alcohol such as methanol, ethanol, propanobutanol, etc. to form a lower alkyl alcohol, and then , a method involving an acetal exchange reaction with a higher alcohol, etc. may be used.

Monosaccharides, oligosaccharides, or polysaccharides are used as the saccharides that serve as raw materials for the alkyl glycosides according to the present invention. Specific examples of monosaccharides include aldoses, such as allose, aldrose, glucose, mannose, trose, idose, galactose, sucrose, ribose, arabinose, gysylose, and lyxose.

Specific examples of oligosaccharides include maltose, lactose,
Examples include sucrose and maltotriose.

Specific examples of polysaccharides include hemicellulose, inulin, dextrin, dextran, quinilla, starch, and hydrolyzed starch.

Examples of the higher alcohol serving as a raw material for the alkyl glycoside according to the present invention include alcohols represented by the following formula (1).

RO(AO)nH... (1) (wherein, R represents a straight-chain or branched alkyl group having 6 to 22 carbon atoms, an alkenyl group, or an argylphenyl group, and A represents a straight-chain or branched alkyl group having 6 to 22 carbon atoms, or an argylphenyl group having 2 to 4 carbon atoms. It represents an alkylene group, and n is a number whose average value is 0 to 5.) Note that the alcohol may be an unreacted alcohol recovered from the crude algyl glycoside.

In the alkyl glycoside synthesis method of the present invention,
Regarding catalysts, reaction conditions, etc., known methods such as Japanese Patent Publication No. 4.7-24532 and U.S. Pat. No. 383931 can be used.
No. 8, European Patent No. 092355, Japanese Patent Application Publication No. 591393
97, Japanese Unexamined Patent Application Publication No. 58189], and No. 95 may be followed.

Next, the reaction mixture of alkyl glycosides obtained as described above, ie, the phase alkyl glycosides containing impurities such as unreacted higher alcohols and colored substances, is purified.

Before starting the purification operation, some unreacted higher alcohols, etc., are removed from the crude alkyl glycoside by preliminary distillation under relatively mild conditions that do not cause decomposition of the alkyl glycoside. You can stay there.

Adsorbents used in the present invention include polar inorganic adsorbents such as silica gel, activated alumina, and zeolite I, and polar adsorbents in which hydrophilic groups such as acrylamide groups and aminopropyl groups are chemically bonded to the surface of polar inorganic adsorbents. , polar polymer adsorbents such as methacrylic esters and vinyl acetate, non-polar polymer adsorbents made of copolymers of hydrophobic substances such as styrene-vinylbenzene, and octadecyl on the surface of polar inorganic adsorbents. Examples include non-polar adsorbents in which hydrophobic groups such as octyl groups and octyl groups are chemically bonded, and non-polar adsorbents in which hydrophobic groups such as octadecyl groups and phenyl groups are chemically bonded to the surface of a polar polymer.

Among these adsorbents, in consideration of separation performance, price, durability, etc., those preferable for use in the present invention are polar inorganic adsorbents, non-polar polymer adsorbents, or inorganic adsorbents with hydrophobic groups on the surface. It is a chemically bonded non-polar adsorbent. Although not particularly limited, specific examples of polar inorganic adsorbents include silica gel M, S, and GE manufactured by Dokai Chemical Industry Co., Ltd.
L D350-60Δ and I)-350-120A, Microbead Silica Gel MB- manufactured by Fuji Davison Chemical Co., Ltd.
4B and MID-5D, and examples of the activated alumina include Neobead D manufactured by Suikagaku Kagaku Kogyo Co., Ltd. Among non-polar polymer adsorbents, styrene-vinylhensen-based
Diaion HP-20 and HP-2 manufactured by Mitsubishi Chemical Industries, Ltd.
1. Amberlight XAD manufactured by Rohm and Haas
Examples of non-polar adsorbents in which octadecyl groups are chemically bonded to -2, XAD-4, etc. include Lomatrex ODS manufactured by Fuji Davison Chemical Co., Ltd., and the like.

The average particle size of the adsorbent is not particularly limited, but in consideration of separation performance and operability, it is preferably 50 to 1000 μm, more preferably 100 to 500 μm. If the particle size is too small, pressure loss will increase in the packed column, making operation difficult; if the particle size is too large, drift will occur and separation performance will deteriorate.

In the present invention, the solvent used as the eluent (J) is selected from a polarity suitable for each adsorbent, taking into account the adsorption properties of the argyl glycoside to be separated and unreacted alcohol.Represents the polarity of the solvent. The solubility parameter is used as an indicator.The solubility parameter is CM, Hansen (C,
M, Hansen), J Paintchik (J, Pa
1nt Tech, 39, I 04 (] 967
)). However, in the case of a mixture consisting of n components, calculation was performed using the following formula (2).

δ−i (Φl・δi) (2) (wherein, Φ
l is the volume fraction of component], and δ1 is the solubility parameter of component 1. ) When using a polar inorganic adsorbent as an adsorbent, there is a tendency that as the polarity of the eluent increases, the adsorption of alkyl glyconts and unreacted alcohol to the adsorbent decreases. The following relatively less polar solvents are suitable. Furthermore, considering operability and separation efficiency, the solubility parameter value is 8~8.
The solvent of I2 is more preferred.

In addition, when using a non-polar polymer adsorbent or a non-polar adsorbent with a hydrophobic group chemically bonded to the surface of an inorganic adsorbent, increasing the polarity of the eluent will increase the amount of argyl glycoside and unreacted alcohol. There is a tendency for the adsorbability to increase with respect to the adsorbent, and a relatively polar solvent having a solubility parameter value of 10 or more is suitable as an eluent.

Further, in consideration of operability and separation efficiency, solvents having a solubility parameter value of 12 to 17 are more preferable.

Specifically, the solvent used as an eluent in this method includes water, alcohols such as methanol, ethanol, propatool, isopropanol, butanol, and isobutanol, and ketones such as acetone, methyl ethyl ketone, and diethyl ketone. , ethers such as diethyl ether, tetrahydrofuran and dioxane, esters such as ethyl acetate, n-hexadi, n-hebutane, n-octane, is.

Saturated aliphatic hydrocarbons such as octane and n-decane, cycloaliphatic hydrocarbons such as cyclohexane, cyclopenkune, and decalin, aromatic hydrocarbons such as benzene and p-xylene,
and methylene chloride, chloroform, acetonitrile,
Examples include, but are not limited to, DMF, I)MSO, carbon disulfide, carbon tetrachloride, petroleum ether, and mixtures thereof.

Note that the selection of a solvent for good separation of alkyl glycosides and impurities can be determined by determining the pulse response or breakthrough response using a batch-type packed column.

Hereinafter, the pseudo moving layer used in this method will be explained in detail based on the drawings. As an example, we will take up the case where a polar adsorbent is used as the adsorbent and alkyl glycoside and unreacted alcohol are separated from crude alkyl glycoside as a raw material. At this time, the adsorption of the alkyl glycoside is greater than that of the unreacted alcohol, and the movement speed of the alkyl glycoside within the packed column is lower than that of the unreacted alcohol.

FIG. 1 shows an example of a pseudo moving layer device used in this method. The eluent supply port, the outlet for the alkyl glycoconide purified solution (strongly adsorbed component solution), the crude alkyl glycoconide solution supply port, and the outlet for the unreacted alcohol solution (weakly adsorbed component solution) that fall at a certain time are (a). ),
(b), (c) and (d). In addition to this, an eluent outlet (e) may be provided (', l) as required. When an eluent outlet (e) is provided, the space between (e) and (a) may be It is necessary to shut off the valve S.These (a), (b), (c), (d) and (e) are solenoid valves (
D, 〜, 2, FI〜+ 2, E+〜l 2, R
3-17, Ef, ~12 and S1-1. ) or by known means, such as a valve opening/closing device or a rotary valve system, to move intermittently and sequentially in the direction of liquid flow. still,
The packed columns C1 to C12 are filled with a polar adsorbent.

The packed tower group has liquid supply and extraction ports (a) and (1).
), (c) and (d). Packed towers C1-3 are in the first section, packed towers 04-6 are in the second section, packed towers 07-9 are in the third section, and packed towers CIO - are in the fourth section.
Section. The number of packed columns in each zone is three, but this number can be appropriately determined depending on factors such as separation conditions. The first section is for desorption of strongly adsorbed components, and the second section is for desorption of strongly adsorbed components.
The section functions to desorb weakly adsorbed components, the third section adsorbs strongly adsorbed components, and the fourth section functions to adsorb weakly adsorbed components.

A concentration distribution of alkyl glycoside and unreacted alcohol is formed in the liquid in the packed bed, and as the liquid flows down,
The concentration distribution moves downstream.

Following this movement, the supply port for the crude alkyl glycoside solution, the supply port for the eluent, the outlet for the purified alkyl glycoside solution, and the outlet for the unreacted alcohol solution are sequentially switched to the lower one. The switching may be performed simultaneously for the four types of openings, or may be performed at different times for each opening. The time for continuing introduction or withdrawal of liquid from the same opening is the unit packed column C1~,
Although it varies depending on the size of the column 2, the flow rate flowing down the packed column group, etc., it is usually several minutes to several tens of minutes. As a result of this switching, the positions of the four double compartments in the packed column group are moved accordingly. Accordingly, the concentration distribution of each component circulates through the packed column group while maintaining its size and relative position.

The degree of separation of argyl glycoside and unreacted alcohol is influenced by various factors, but the most important factors are:
This is the flow rate of the liquid in the packed column group and the time during which the liquid is continuously supplied or removed from the same opening. This is because moving the positions of the four types of openings downstream in the liquid flow is equivalent to moving the adsorbent upstream while keeping the opening positions constant, which changes the concentration distribution of each component in the packed bed. teeth,
This is because they are formed due to the interaction between the liquid flow and the adsorbent moving in the upstream direction. This moving speed is calculated by subtracting the length (L) of each unit packed column C1 to 2 by the time (T) for which liquid is continuously introduced or taken out from the same opening (L/T
). As is well known, in order to separate two components using a pseudo-moving bed, the moving speed of the weakly adsorbed component, i.e., unreacted alcohol, in the packed bed is set to 1, and in the first section, V, >
L/T, V in the second section, >L/T, Vl>L/T in the third section, V, <L/ in the fourth section
T, and the moving speed v2 of the strongly adsorbed component, i.e. alkyl glycoside, in the packed bed is v2>L/T in the first section,
In the second section, V2<L/T, in the third section, V2<L/T, and in the fourth section, V2<L/T. Note that the moving speed V of the weakly adsorbed component within the packed bed and the moving speed V of the strongly adsorbed component within the packed bed are determined by the liquid flow rate within the packed bed, but these are determined using a batch-type packed column. can be easily measured in advance. Therefore, the flow rate of the liquid and the time for which the liquid is continuously supplied or removed from the same opening are necessarily determined from these relationships.

Here, this method has been explained using the case of using a polar adsorbent as an example, but it can also be used when using a non-polar adsorbent, except that the adsorption properties of alkyl glycoside and unreacted alcohol are reversed. The same is true. That is, when a non-polar adsorbent is used, unreacted alcohol has greater adsorption than alkyl glycoside, and unreacted alcohol moves at a lower rate than alkyl glycoside in the packed column. Therefore, (d) is the outlet for the purified alkyl glycoside liquid, and (b) is the outlet for the unreacted alcohol solution.

The purified alkyl glycoside is then obtained from the alkyl glycoside fraction obtained as described above by removing the eluent by distillation or the like at a temperature such that thermal decomposition of the alkyl glycoside does not occur.

[Effects of the Invention] According to the present invention, in the step of separating unreacted alcohol from crude alkyl glycoside, in addition to no generation or contamination of impurities such as new colored substances or odor substances,
It is possible to easily remove some of the impurities that have already been generated or mixed in each step including the previous reactions, along with the unreacted alcohol, and it is possible to easily remove some of the impurities that are naturally generated or mixed in each step, including the previous reactions, and to produce products that cannot be produced using conventional methods. Argyl glycosides of extremely high quality in terms of color and odor can be efficiently produced.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

Reference Example A pulse response experiment was conducted to select the adsorbent and eluent in-house. Adsorbent was placed in a packed column with an inner diameter of 1.6 cm.
mQ filling, and the eluent was kept at a constant space velocity (I ~ 2 h
-') was distributed. Decyl glyconde and decyl alcohol were each dissolved in the eluent at a concentration of 25% by weight, and 05M (
2 were supplied. The change over time (pulse response curve) in the concentration of decyl glyconde or decyl alcohol eluted from the filled bath outlet [ ] was measured using a refractive index detector on which a calibration curve had been prepared in advance.

Figure 2 shows the pulse response curve when using silica gel (M, S, GEL D-350-60A, manufactured by Dokai Chemical Industry Co., Ltd.) as the adsorbent and acetone (the solubility parameter value is 98) as the eluent. . The horizontal axis is the dimensionless elution time, which is the amount of eluent introduced during the time from pulse introduction to elution divided by the adsorbent filling amount.

This shows that decyl glyconde and decyl alcohol elute at dimensionless times 075 and 12, respectively, and both components are well separated.

FIG. 3 shows the dimensionless elution time when the above silica gel is used as an adsorbent and the polarity of the eluent is changed. Figure 4 shows a styrene-vinylbenzene-based non-polar polymer adsorbent (Diaion HP-20, manufactured by Wangling Chemical Industry Co., Ltd.).
, 1) in the figure and a non-polar adsorbent (Chromatorex ODS, manufactured by Fuji Davison Chemical Co., Ltd., 2 in the figure) in which octadecyl groups are chemically bonded to silica gel are used as adsorbents, and the polarity of the eluent is changed. Shows dimensionless elution time.

The polarity of the eluent was such that a pure solvent or a mixture of two solvents was used to obtain various solubility parameter values.

The eluents used were acetone for silica gel,
Mixed solvents of acetone and water, or acetone and isopropyl alcohol, and styrene-divinylbenzene-based nonpolar polymer adsorbents include methanol and water, ethanol and water, isopropyl alcohol and water, or acetone and water. For a mixed solvent, a non-polar adsorbent in which octadecyl groups are chemically bonded to silica gel, a mixed solvent of ethanol and water or acetone and water was used.

From this result, when using a polar adsorbent, the greater the polarity of the eluent, the faster the elution of decyl glyconde;
It can be seen that when a non-polar adsorbent is used, the elution of decyl glyconde and decyl alcohol becomes slower as the polarity of the eluent increases.

These pulse response experiments are an effective means for selecting a combination of adsorbent and eluent suitable for use in the simulated moving bed of the present invention.

Example 1 Decyl alcohol I I 40 J (72.0 mol)
, anhydrous glucose 3240 g (18.0 mol) and paratoluenesulfonic acid monohydrate 96 y (0.5 mol)
) was heated and stirred in a reaction tank. After raising the temperature to 95° C., the system internal pressure was set to 40 mmHg and the dehydration reaction was started. At this time, N was blown into the reaction mixture at a rate of 5 N12/min to efficiently remove the generated water.

After 5 hours, after confirming that glucose was completely consumed, the reduced pressure was released, cooled, and neutralized with NaOH209. By-product polysaccharide was filtered off to obtain crude Argyl Klichond+27309 containing 33% by weight and 66% by weight of alkyl glycoside and unreacted alcohol, respectively.

Using the above crude alkyl glycoside as a raw material, a packed column 1 with an inner diameter of 1.6 cm and a length of 30 cm was prepared as shown in Fig. 1.
Connect each end of the two to the top of the next packed column and solenoid valve S1.
- Liquid take-off pipes (E, R, Ef) that are connected endlessly via piping through S +2 and grow the solenoid valves in the second flow of each solenoid valve.
Using an experimental device, three branched and connected liquid supply pipes (D, F) with a solenoid valve downstream were used.
As an adsorbent, Norika gel (manufactured by Asahi Glass, M, S, Gel
D~350-60A) was used to pack 60 μm into each packed column. The eluent is supplied from the liquid supply pipe, the raw material is supplied from the liquid supply pipe F, the strongly adsorbent alkyl glycoside is taken out from the liquid take-out pipe E, and the unreacted alcohol, which is weakly adsorbed, is taken out from the liquid take-out pipe R. Switching of each liquid inlet and outlet at fixed time intervals was performed by moving the opening and closing positions of the electromagnetic valves D, F, E, R, and Ef one tower at a time downstream of the liquid flow. In this example, the space between (e) and (a) was blocked and an eluent outlet was provided. Therefore, this position also moved downstream of the liquid flow at regular intervals.

The raw materials were supplied using a crude alkyl glycoside solution prepared by dissolving crude alkyl glycoside in acetate at a concentration of 50% by weight, and acetone was used as the eluent. The supply and withdrawal flow rates of the canned liquid are as follows: 04.4.8, 2004 for supply of crude alkyl glycoside solution, supply of eluent, withdrawal of purified alkyl glycoside solution, withdrawal of unreacted alcohol solution, and withdrawal of eluent, respectively. , 1.2112
The feeding and extraction ports were moved every 18 minutes.

FIG. 5 shows the amount contained in the alkyl glycoside purified liquid taken out. Figure 3 shows changes in concentration of alkyl glycoside and unreacted alcohol over time. FIG. 6 shows changes over time in the concentrations of alkyl glycoside and unreacted alcohol contained in the taken out unreacted alcohol solution. The purity of the alkyl glycoside in the alkyl glycoside purified liquid in a steady state was 98% by weight, and the recovery rate was 99% by weight. Also, the purified alkyl glycoside obtained after distilling off the eluent It was colorless (less than 1 Gardner in the form of a 50-fold aqueous solution), and there was no burnt odor that occurs due to thermal decomposition of alkyl glyconodes or sugars.

Example 2 The alkyl glycoside used in Example 1 was used as a raw material, and a styrene-divinylbenzene-based non-polar polymer adsorbent (manufactured by Mitsubishi Chemical Industries, Ltd., Diamond Ion RP) was used as an adsorbent.
Argyl glycocontate was purified in the same manner as in Example 1 using 88% isopropyl alcohol aqueous solution (solubility parameter value: 127) as the eluent. In this case, the unreacted alcohol becomes a strongly adsorbed component, and the alkyl glycont becomes a weakly adsorbed component.

The raw material was supplied as a crude alkyl glycoside solution in which the crude alkyl glycoside was dissolved in an eluent at a concentration of 50% by weight.

The supply amount and withdrawal flow rate of the tank solution were 01.40. 0.7
．． 25.0.9 m/min, and these feeding and unloading movements were carried out every 35 minutes.

The purity of the argyl glycoside in the alkyl glycoside purified liquid in the steady state was 97% by weight, and the recovery rate was 95% by weight. Further, the purified alkyl glycoside obtained after distilling off the eluent was colorless (less than 1 Gardner in a 50% by weight aqueous solution) and had no burnt odor.

Example 3 Decyl alcohol was used in an amount of 5 times the mole of anhydrous crucose, and para-toluene sulfonic acid monohydrate was used in an amount of 0.014 times the mole of anhydrous crucose, and a reaction was carried out by a known method. Then excess unreacted alcohol was heated to 150°C.
, 5 mmHg to remove unreacted decyl alcohol.
A crude alkyl glycocontate containing 8% by weight was obtained. The hue of this crude alkyl glycoside was pale yellow (Gardner 3 in the state of a 50% by weight aqueous solution).

Using the above crude alkyl glycoside as a raw material, a non-polar polymer adsorbent (styrene-divinylhensen) as an adsorbent (
Purification was carried out in the same manner as in Example 2, using Mitsubishi Kasei Corporation's Diaion HP20) and an 88% by weight methanol aqueous solution (solubility parameter value: 15.2) as the eluent.

In this case, the unreacted alcohol becomes a strongly adsorbed component, and the alkyl glycoside becomes a weakly adsorbed component.

The raw material was supplied as a crude alkyl glycoside solution in which crude alkyl glycoside was dissolved in an eluent at a concentration of 30% by weight.

The supply temperature and withdrawal flow rate of the combined solution were set at 03.55.15 for the supply of the crude alkyl glycoside solution, the supply of the eluent, the withdrawal of the purified alkyl glycoside solution, the withdrawal of the unreacted alcohol solution, and the withdrawal of the eluent, respectively. 3
．． The feeding and unloading ports were moved every 40 minutes.

The purity of the alkyl glycoside in the purified solution was 99.5% by weight, and the recovery rate was 90% by weight. Further, the purified alkyl glyconode obtained after distilling off the eluent was pale yellow (Gardner 3 in the state of a 50% by weight aqueous solution) and had almost no odor.

Comparative Example 1 Using the crude argyl glycoside used in Example 3 as a raw material, the raw material supply rate o was 115kg/h, processing temperature 180°C1
Distillation was carried out at a pressure of 0.5 mmHg to remove residual unreacted alcohol. The obtained argyl glyconodes are
The purity was 99.4% by weight, but it was colored red and yellow.
This is thought to be due to thermal decomposition of Gardner 6), argyl glycocontate, or sugar in the state of a wt% aqueous solution. There was a burning smell.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of an example of a pseudo-moving bed apparatus, and Figure 2 (J
Figures 3 and 4 show the relationship between the polarity of the eluent and the dimensionless elution time in the pulse response experiment. 2. Uses a non-polar adsorbent made by chemically bonding octadecyl groups to Norica gel.)
FIG. 5 and FIG. 6 are diagrams showing changes over time in the concentration of the pseudo-moving layer in the sampled liquid.

Claims (3)

[Claims] (1) When producing alkyl glycosides by contacting crude alkyl glycosides containing unreacted alcohol as impurities with polar adsorbents or non-polar adsorbents, a packed tower filled with adsorbent is used as an adsorption device in a liquid passage. In addition to being connected in series, the first packed tower and the last packed tower are also connected through a liquid passage to form an endless structure, and the packed tower group in which the solution flows in one direction has an eluent supply port, a strong adsorption component solution takeout port, The crude alkyl glycoside solution supply port and the weakly adsorbed component solution outlet are arranged in this order at predetermined intervals along the direction of solution flow, and at the same time the crude alkyl glycoside solution and eluent are supplied, the strongly adsorbed component solution and weakly adsorbed component solution are 1. A method for producing an alkyl glycoside, which comprises using a pseudo-moving bed by taking out an adsorbed component solution and sequentially moving these supply ports and take-out ports downstream intermittently. (2) The method for producing an alkyl glycoside according to claim 1, wherein a polar inorganic adsorbent is used as the adsorbent, and a solvent having a solubility parameter value of 15 or less is used as the eluent. (3) A claim in which a non-polar polymer adsorbent or a non-polar adsorbent in which a hydrophobic group is chemically bonded to the surface of an inorganic adsorbent is used as the adsorbent, and a solvent with a solubility parameter value of 10 or more is used as the eluent. 1. The method for producing an alkyl glycoside according to 1.