JP2785834B2 - Desalting purification method and apparatus for sugar liquid - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method and an apparatus for desalting and purifying a sugar solution, and more particularly, to a K column filled with a strongly acidic cation exchange resin, and a weakly acidic cation exchange resin. The present invention relates to an apparatus for desalting and refining a sugar solution, which is used in combination with an MB column mixed with a basic anion exchange resin.

In the present invention, the sugar liquid refers to glucose, isomerized sugar (glucose + fructose), starch sugar such as starch syrup, sorbitol, lactose, sucrose, various oligosaccharides and the like.

(Prior art) Purification of a sugar solution is performed to remove a wide range of impurities such as electrolytes and non-electrolytes derived from a production method, and an ion exchange resin capable of removing inorganic substances and coloring substances from relatively high molecular substances. Is generally employed. In other words, the method of purifying a sugar solution with an ion exchange resin can efficiently remove salts and other coloring substances, stabilize the quality of the product, facilitate quality control, and have a great economic advantage such as a reduction in processing time. .

The purification method using this ion-exchange resin will be described using, for example, the case of starch sugar as an example. The K-column filled with a strongly acidic cation-exchange resin and the A-column filled with a weakly basic anion-exchange resin are sequentially passed through a sugar solution. After the mixture, MB is a mixed bed of a strongly acidic cation exchange resin and a strongly basic anion exchange resin.
There are known a three-column type purification method in which the solution is passed through a column, and a method in which the solution is passed through a mixture of a strongly acidic cation exchange resin and a strongly basic anion exchange resin.

The former method employs the former K for the purpose of removing impurities.
The sugar solution may be passed through the -A column, but it is difficult to adjust the pH stability of the treatment solution obtained by the two-column treatment because the pH at the beginning of the passage is high and the pH decreases as the throughput increases. Thus, the treatment liquid may be colored in the next concentration step. Further, the quality (purity as measured by electric conductivity) of the treatment liquid is not sufficient. Therefore, in order to improve these, the treatment is performed in the final stage MB tower. However, this three-column type purification method has a problem that a large amount of a regenerant for the strongly basic anion exchange resin mixed in the MB column is used.

Further, as a common disadvantage of the former and the latter, since a strongly basic anion exchange resin is used, the sugar solution becomes alkaline when the sugar solution comes into contact with the anion exchange resin, and a part of the sugar component in the liquid to be treated is decomposed. When the liquid to be treated is glucose, an isomerization reaction occurs.

As a method for solving such a problem, a proposal has been made to use a mixture of a strongly basic anion exchange resin and a weakly basic anion exchange resin (Japanese Patent Publication No. 59-199000). It is difficult to satisfy both the quality and economical high throughput at the same time.

(Problems to be Solved by the Invention) The present inventor has intensively studied a method of treating a sugar solution that can simultaneously satisfy the various problems described above and simultaneously ensure high purity quality and high throughput. Then, the treatment solution treated with the strongly acidic cation exchange resin was mixed with a weakly basic anion exchange resin and a strongly acidic cation exchange resin.
It has been found that, when the solution is passed through a column, a treatment liquid having the same quality as that of the conventional three-column type sugar liquid purification method can be obtained, and the various disadvantages described above can be solved.

Such a finding was not expected at all under the prior art where it was considered common use to use a strongly basic anion exchange resin for ensuring high purity quality and stabilizing pH. The apparatus that can be configured based on this finding reduces the installation area of the equipment because there is one column less than the conventional three-column type, and is a method that does not use a strongly basic anion exchange resin. There is no fear of reaction or decomposition reaction,
In addition, since a weak basic anion exchange resin is used, the treatment amount is significantly superior to the case where a strong basic anion exchange resin is used. is there.

In the purification of sugar solutions, particularly in the purification of starch sugars, if the sugar solution can be passed through an ion-exchange resin at a high temperature at which decay does not occur due to propagation of microorganisms and treated, the industrial value is extremely large, In the conventional case using a basic anion exchange resin, the heat resistance temperature is 40 ° C., and the treatment cannot be carried out at 40 ° C. or higher, which is also a major obstacle. However, when using a weakly basic anion exchange resin as described above, there is no such problem, 40
There is a feature that the treatment can be performed at a temperature of not less than ° C.

One of the objects of the present invention based on the above knowledge is to provide a desalting and purifying apparatus for a sugar solution which can obtain a high-purity processing solution at a high throughput.

Another object of the present invention is to provide an apparatus for desalting and purifying a sugar solution which can obtain a treatment solution having a stable pH while ensuring the above-mentioned excellent effects.

Still another object of the present invention is to provide an apparatus capable of obtaining a processing liquid having a quality equal to or higher than that of a conventional three-column apparatus with a small facility.

Still another object of the present invention is to enable the treatment of starch and lactose at a high temperature of 40 to 70 ° C.

(Means for Solving the Problems) The feature of the method for desalting and refining a sugar solution of the present invention made to achieve the above object is that a raw sugar solution is treated with a strongly acidic cation exchange resin, It is to be treated with an ion exchange resin in which a cation exchange resin and a weakly basic anion exchange resin are mixed.

The apparatus for realizing the above method is characterized by comprising a K column filled with a strongly acidic cation exchange resin and an MB column filled and mixed with a strongly acidic cation exchange resin and a weakly basic anion exchange resin. Is passed through in the order of K tower-MB tower.

The strongly acidic cation exchange resin used in the present invention may be the same or different in both the K column and the MB column. Specific examples of the strong acid cation exchange resin that can be used include, for example, Amberlite (registered trademark, hereinafter the same) IR-120B, Amberlite 20
0C, Diaion (registered trademark, the same applies hereinafter) SKIB, and the like.

As the weakly basic anion exchange resin used in the MB tower, for example, Amberlite IR
A-68, IRA-93ZU, IRA-94S, and Diaion WA30 can be exemplified.

In the apparatus of the present invention, the mixing ratio of the anion exchange resin and the cation exchange resin charged in the MB column is, for example, in the range of 1: 1 to 5: 1, and preferably 2.5: 1.

In particular, the present invention, the treatment of starch sugar, lactose at 40-70 ℃,
By performing at a high temperature of preferably 50-70 ° C,
As compared with the case where the processing temperature is limited to about 40 ° C., an excellent feature is exhibited in which the growth of microorganisms is suppressed and the processing of suitably preventing the decay of the sugar solution can be realized. This high-temperature treatment depends on the flow rate of the sugar solution, but at 40 ° C or lower, the prevention of decay is not sufficiently improved, and at 70 ° C or higher, there is a risk of decomposition reaction, so that the above range may be set. Good.

(Examples) Hereinafter, the present invention will be described based on examples shown in the drawings.

FIG. 1 is for explaining the outline of the flow of the apparatus for desalting and refining glucose solutions of the present invention. The K column in the former stage is filled with a strongly acidic cation exchange resin. The latter MB column is filled and mixed with a strongly acidic cation exchange resin and a weakly basic anion exchange resin.

Example 1 The apparatus shown in FIG. 1 was filled with the ion exchange resin shown in Table 1 below, and glucose solution (B × 35 °, electric conductivity 640 μS / cm (25 ° C.)) was passed as a liquid to be treated. Liquid conditions: SV = 4, the temperature was 60 ° C., the liquid was passed in the order of K tower-MB tower, and the processing amount of the treated purified liquid recovered from the MB tower (processing amount per resin: //-AE
R) and the relationship between pH and electrical conductivity were measured, and the results are shown in FIGS. 2 and 3. Indicated.

Comparative Example 1 An apparatus for three-column treatment of KA-MB was charged with an ion-exchange resin as shown in Table 1 below, and the same liquid to be treated and the same liquid-passing conditions as in Example 1 were passed. The relationship between the treatment amount of the solution, pH and electric conductivity was measured, and the results were shown in FIGS. 2 and 3. Indicated.

The relationship between the treatment amount of the KA treatment solution, the pH and the electrical conductivity is shown in the figure for reference. Indicated by

From the results of the above Examples and Comparative Examples,
The pH was slightly lower than the target value of 5 to 6 in the 30 / -AER collecting solution at pH 4.4, but was obtained at pH 4.4, but the buffering action was due to the high electrical conductivity of the treatment solution of 2 μS / cm. Because of the lack of pH, the pH can be adjusted if necessary by adding a very small amount of alkali (eg, sodium bicarbonate solution).

In the treatment liquid of the comparative example, it can be seen that the pH significantly decreased and the electric conductivity also increased as the treatment volume increased. This is because glucose is decomposed by the alkali of the strongly basic anion exchange resin used in the MB column to generate organic acids and leak out due to the high temperature treatment of 60 ° C.

(Effects of the Invention) According to the method and apparatus for desalting and refining a sugar solution of the present invention, the quality of a treated solution can be obtained with high purity while satisfying a high throughput, and these requirements can be simultaneously satisfied conventionally. There is an effect that the problem without the device can be solved at once.

In addition, the apparatus of the present invention can obtain a treatment solution having a stable pH while securing the above-described excellent effects, and thus, there is a possibility of coloring which has conventionally been a problem in the concentration treatment or the like in the next step. There is an advantage that it can be eliminated.

Further, in the method of the present invention, since a strongly basic anion exchange resin is not used, there is an advantage that there is no possibility of isomerization reaction or decomposition reaction which has been a problem in the conventional apparatus. In particular, since a weakly basic anion exchange resin is used without using a strongly basic anion exchange resin, high-temperature treatment (50-70 ° C) becomes possible without causing isomerization reaction and sugar decomposition reaction. It is an effective countermeasure against liquid spoilage, and its industrial benefits are extremely large.

[Brief description of the drawings]

FIG. 1 is a diagram showing an outline of a flow of an apparatus according to the present invention,
FIG. 2 is a diagram showing the relationship between the treatment amount of the embodiment of the present invention and Comparative Examples 1 and 2 and the measurement results of pH, and FIG. 3 is a diagram showing the relationship between the present embodiment and Comparative Examples 1 and 2.
FIG. 4 is a diagram showing a relationship between a processing amount of the sample and a measurement result of an electric conductivity.

Claims (5)

(57) [Claims] (1) treating a raw sugar solution with a strongly acidic cation exchange resin and then treating it with an ion exchange resin obtained by mixing a strongly acidic cation exchange resin and a weakly basic anion exchange resin; Desalting purification method. 2. The method for desalting and purifying a sugar solution according to claim 1, wherein the sugar solution is starch sugar or lactose. 3. The method for desalting and purifying a sugar solution according to claim 2, wherein the temperature of the sugar solution passing therethrough is 40 to 70 ° C. 4. A K column filled with a strongly acidic cation exchange resin, and an MB column filled with a strongly acidic cation exchange resin and a weakly basic anion exchange resin.
An apparatus for desalinating and refining a sugar liquid, wherein the liquid is passed in the order of MB tower. 5. The apparatus for desalting and refining a sugar solution according to claim 4, wherein the sugar solution to be treated is starch sugar or lactose.