JP2002355100A - Mixed bed molasses-purifying device, method for regenerating mixed bed molasses-purifying device and method for purifying molasses - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixed bed molasses-purifying device capable of preventing gradual pH shift of the treated liquid to acidic side in repetitive treating cycles. SOLUTION: This mixed bed molasses-purifying device comprises a mixed bed molasses-purifying device 1 filled with a strong basic anion exchange resin and a weak cation exchange resin and is characterized by having a corrector 2 discharging a regeneration waste liquid below a separating interface 6 between an upper layer strong basic anion exchange resin 3 and a lower layer weak cation exchange resin 4 when the cation exchange resin is a free acid form in regenerating process of the ion exchange resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mixed-bed type sugar liquid purifying apparatus for desalting and decolorizing a sugar liquid, a method for regenerating a mixed-bed type sugar liquid purifying apparatus, and a method for purifying a sugar liquid.

[0002]

2. Description of the Related Art To purify a sugar solution, a raw sugar solution is subjected to a pretreatment such as carbonation saturation, filtration of granular activated carbon, filtration of bone charcoal and the like, followed by an ion exchange treatment as a post treatment. The ion exchange treatment as a post-treatment includes an ion exchange treatment for decolorization and an ion exchange treatment for desalination.

In an ion exchange treatment for the purpose of desalting, a pretreated sugar solution is treated with a single bed of a strongly basic anion exchange resin, and then treated with a single bed of a weakly acidic cation exchange resin. Reverse treatment using a two-bed purifier, and a mixed-bed type in which the pretreated sugar liquid is treated and desalted by a mixed-bed purifier in which a strongly basic anion exchange resin and a weakly acidic cation exchange resin are mixed. There is processing.

[0004] Reverse processing is widely used industrially, but has the problem that the processing purity is not sufficient. On the other hand, compared with the reverse treatment, the mixed-bed treatment is an excellent method as a purification treatment of a sugar solution in that a high-purity sugar solution is obtained although a regeneration operation of the ion exchange resin is complicated.

[0005] As a method for regenerating an ion exchange resin in a mixed-bed purifying apparatus, for example, methods described in JP-A-2-298358 and JP-A-11-76840 are known.

FIG. 3 is a schematic sectional view for explaining a regeneration method of the mixed-bed purifying apparatus disclosed in the above-mentioned JP-A-2-298358, in which a basic anion exchange resin and a weakly acidic cation exchange resin are separated. It shows the state after the acid regenerant has been consistently passed. In FIG. 3, reference numeral 31 denotes a mixed-bed refining apparatus, 35 denotes a distributor for supplying a regenerant, and a support bed 37 for supporting an ion-exchange resin is provided below the mixed-bed tower. I have. FIG.
As shown in (1), in the conventional mixed-bed type sugar liquid refining apparatus, the collector 32 is composed of a weakly acidic cation exchange resin 34 in a free acid form by passing an acid regenerant through a weakly acidic cation exchange resin and a strongly basic anion. It is provided on a separation boundary surface 36 with the exchange resin 33.

[0007] In the regeneration method described in Japanese Patent Application Laid-Open No. 2-298358, after a sugar solution treatment is completed in a mixed bed tower, a weakly acidic cation exchange resin is used by utilizing a sugar solution or a saline solution due to a specific gravity difference between the two resins. In the lower layer, the strongly basic anion exchange resin is separated into the upper layer, and an acid regenerant such as hydrochloric acid aqueous solution is passed through both the strongly basic anion exchange resin in the upper layer and the weakly acidic cation exchange resin in the lower layer consistently. After simultaneous regeneration of the strongly basic anion exchange resin and regeneration of the weakly acidic cation exchange resin, an alkaline regenerant such as aqueous sodium hydroxide solution was passed through the strong basic anion exchange resin in the upper layer, Water is allowed to flow upward from the lower part, and the regenerated wastewater is discharged from the collector provided at the separation boundary between the two resins.After regenerating the strong basic anion exchange resin in the upper layer, the two resins are mixed and mixed. Is formed.

Further, the method described in Japanese Patent Application Laid-Open No. 11-76840 discloses a method in which a weakly acidic cation exchange resin and a strongly basic anion exchange resin are separated into upper and lower layers, The acid regenerant is passed through both the weakly acidic cation exchange resin in the lower layer and the regeneration of the strongly basic anion exchange resin and the regeneration of the weakly acidic cation exchange resin are performed simultaneously by passing the acid regenerant from the lower layer. It is characterized by the following.

In such a mixed-bed type sugar solution refining apparatus, in the process of sugar solution treatment, the weakly acidic cation exchange resin undergoes ion exchange from a free acid form to a salt form such as Na form and Ca form. The acid gradually swells, but becomes a free acid form and shrinks by the acid regeneration treatment, and the swelling is eliminated. Therefore, the position of the collector in the mixed-bed type sugar refining apparatus is determined by the strong basic anion when the weak acid cation exchange resin shrinks in the free acid form by passing the acid regenerant through both resins consistently. The collector is set so as to come to the separation boundary between the exchange resin and the weakly acidic cation exchange resin, that is, the separation boundary when the weakly acidic cation exchange resin is in a free acid form.

In the above-mentioned regeneration method, the acid regenerant is passed through the strongly basic anion exchange resin every regeneration treatment, so that the strongly basic anion exchange resin is regenerated simultaneously with the regeneration treatment of the weakly acidic cation exchange resin. There are advantages.

In a conventional mixed-bed purifying apparatus, Na leaks into the treated sugar solution. For the purpose of preventing this Na leak, Japanese Patent Application Laid-Open No. 10-57100 discloses a regeneration of a mixed-bed purifying apparatus. Discloses a technique in which the position of a collector is provided above a separation boundary surface between both resins. The sugar liquid refining apparatus described in JP-A-10-57100 is
It is excellent for preventing the leakage of Na.

[0012]

However, if the processing cycle is repeated in the above-mentioned conventional mixed-bed processing system,
In some cases, the pH of the processing solution gradually shifted to the acidic side (p.
H4.5-6.0). The reason is that the deterioration of the strongly basic anion exchange resin proceeds faster than that of the weakly acidic cation exchange resin, so that the acidic component cannot be completely captured by the strongly basic anion exchange resin. When the pH of the treated sugar solution shifts to the acidic side, sucrose is likely to decompose. Therefore, in the purification of the sugar solution, it is necessary to avoid as much as possible the pH of the treated sugar solution swinging to the acidic side.

In order to prevent the pH of the processing solution from fluctuating to acidic due to the deterioration of the strongly basic anion exchange resin, it can be solved by exchanging the ion exchange resin. However, exchanging the expensive ion exchange resin requires purification cost. Therefore, a system that reduces the frequency of replacement as much as possible is desired.

The problem to be solved by the present invention is to provide a mixed-bed type sugar refining apparatus which can prevent the pH of the processing solution from gradually oscillating to an acidity as the processing cycle is repeated. It is an object of the present invention to provide a liquid refining apparatus, a method for regenerating a mixed-bed type sugar liquid refining apparatus, and a method for purifying a sugar liquid.

[0015]

As a result of intensive studies conducted by the present inventors, it has been found that the above problems can be solved by adjusting the position of a collector for discharging a regenerant waste liquid in a mixed-bed type sugar liquid refining apparatus. The present invention has been completed.

A first invention for solving the above-mentioned problems is as follows.
A mixed-bed type sugar refining apparatus filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin, wherein in the regeneration step of the ion exchange resin, the strength of the upper layer when the weakly acidic cation exchange resin is in a free acid form is increased. The present invention relates to a mixed-bed type sugar liquid refining apparatus, wherein a collector for discharging a regenerated waste liquid is provided below a separation boundary between a basic anion exchange resin and a lower layer weakly acidic cation exchange resin.

A second invention for solving the above-mentioned problem is a method for regenerating a mixed-bed type sugar liquid refining apparatus filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin,
In the regeneration step of the ion-exchange resin, the upper layer is a strongly basic anion exchange resin, and the lower layer is a regenerated free-form weakly acidic cation exchange resin. When the regenerant is passed, the wastewater of the alkaline regenerant is discharged by a collector provided below the separation boundary between the strong basic anion exchange resin in the upper layer and the free weak acidic cation exchange resin in the lower layer. And a method for regenerating a mixed-bed type sugar liquid refining apparatus.

A third aspect of the present invention for solving the above-mentioned problem is a process for purifying a sugar solution using a mixed-bed sugar solution purification apparatus filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin. When the pH of the sugar solution is lowered, in the step of regenerating the ion exchange resin, when the weakly acidic cation exchange resin is in the free acid form, separation of the upper layer strongly basic anion exchange resin from the lower layer weakly acidic cation exchange resin The present invention relates to a method for purifying a sugar solution, wherein a weak acid acidic cation exchange resin is added so that a collector for discharging a regeneration waste liquid is located below a boundary surface.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The feature of the present invention is to prevent the pH of a treated sugar solution from becoming acidic by using a mixed-bed sugar solution refining apparatus provided with a collector below a separation boundary.

The main sugar liquid to be treated in the present invention is a raw sugar liquid obtained by using sugar cane or beet as a raw material, which has been subjected to a pretreatment such as carbonation saturation, granular activated carbon filtration and bone charcoal filtration.

Referring to FIG. 1, the mixed-bed type sugar liquid refining apparatus of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing a state in which an upper layer of a strongly basic anion exchange resin and a lower layer of a regenerated free acid weakly acidic cation exchange resin are separated in a regeneration step of the mixed-bed type sugar liquid refining apparatus of the present invention. FIG. In the regeneration treatment, the mixed resin in the mixed-bed type sugar liquid apparatus 1 is separated into an upper layer strong basic anion exchange resin 3 and a lower layer free acid form weakly acidic cation exchange resin 4 by utilizing the specific gravity difference, and the separation interface 6 is separated into two layers.

As shown in FIG. 1, a mixed-bed type sugar having a collector 2 provided below a separation interface 6 between an upper layer of a strongly basic anion exchange resin and a lower layer of a free acid type weakly acidic cation exchange resin. When the alkaline regenerant, which is a regenerant for the strongly basic anion exchange resin, is passed through the distributor 5 by using the liquid refining apparatus 1, the weakly acidic cation exchange resin located above the collector 2 of the weakly acidic cation exchange resin 4 And an alkali regenerant such as an aqueous sodium hydroxide solution.

As a result, the weakly acidic cation exchange resin in contact with the alkali regenerant becomes a salt form such as Na form. Therefore, during the treatment of the sugar solution after regeneration, a very small amount of Na leaks into the treated sugar solution, thereby neutralizing acidic components that could not be captured by the strongly basic anion exchange resin, and the pH of the treated sugar solution fluctuates to acidic. Can be prevented.

The ion exchange resin used in the present invention may be a conventionally known strong basic anion exchange resin (for example, Amberlite (registered trademark, hereinafter the same)) IRA-402BL, IRA-900, XT-5007, Diaion (registered trademark, the same applies hereinafter) PA312, PA308), weakly acidic cation exchange resin (for example, Amberlite IRC-76, IRC-5)
0, Levacit (registered trademark, the same applies hereinafter) CNP-80, and Diaion WK11) can be used.

When the mixed-bed type sugar refining apparatus of the present invention is used, a trace amount of Na leaks into the treated sugar solution, but the amount of Na remaining in the treated sugar solution is 10 ^−6.0 to 10 ^−4.5 mol / L (carbonate). 0.05 to 1.6 mg CaCO ₃ / L in terms of calcium)
Therefore, there is no particular problem in the quality of the processed sugar solution.

In the present invention, the position of the collector 2 needs to be provided below the separation interface 6 between the strong basic anion exchange resin 3 and the free acid type weakly acidic cation exchange resin 4. The lower free acid type weakly acidic cation exchange resin may be provided at a lower portion of the layer height (h _c ) of 0.5 to 10%, preferably at a lower portion of 1 to 5%. When the collector 2 is provided below 10% of the layer height (h _c ) of the lower free acid form weakly acidic cation exchange resin, the weakly acidic cation exchange resin existing above the collector 2 becomes an alkaline regenerating agent during regeneration. And the amount of contact with the treated sugar solution increases.
H becomes alkaline. Further, the position where the collector 2 is provided depends on the layer height (h) of the free acid type weakly acidic cation exchange resin.
_If less than 0.5% of _c ), strongly basic anion exchange resin 3
When regenerating is used, the amount of the weakly acidic cation exchange resin that comes into contact with the alkali regenerating agent becomes small, so that the intended purpose may not be achieved.

The separation boundary surface 6 serving as a reference surface when deciding the installation position of the collector 2 is, as described above, when the strong basic anion exchange resin 3 and the weak acid cation exchange resin 4 in the form of free acid are separated. It means a surface where both resin layers are in contact with each other, and is usually determined at the stage of designing a mixed-bed type sugar liquid refining apparatus. The layer height (h _c ) of the weakly acidic cation exchange resin, which is a criterion for determining the downward distance from the separation boundary surface 6, means that the strongly basic anion exchange resin and the weakly acidic cation exchange resin are completely separated. Means the height of the layer of the weakly acidic cation exchange resin in the H form (standard form).

FIG. 2 shows an embodiment in which a sugar solution refining process and a regeneration process are performed using the mixed-bed type sugar solution refining apparatus of the present invention.

FIG. 2 (a) shows a raw sugar solution pretreated from the upper part of a mixed-bed sugar solution refining apparatus 1 filled with a mixed resin 8 of a strongly basic anion exchange resin and a weakly acidic cation exchange resin. The drawing shows a step of passing the liquid and recovering the purified sugar liquid from the lower part of the mixed-bed type sugar liquid purification device 1.

To regenerate the ion-exchange resin in the mixed-bed type sugar liquid apparatus 1 after the above purification treatment step, the mixed resin 8 is first separated from the mixed resin 8 by an operation such as specific gravity separation using a sugar liquid or a saline solution. The upper layer is separated into a strongly basic anion exchange resin 3 and a lower layer, a weakly acidic cation exchange resin 4 (FIG. 2B).

As described above, the weakly acidic cation exchange resin 4 swells due to the progress of ion exchange and increases the volume by about 50 to 100% in the process of treating the sugar solution. The separation interface between the acidic anion exchange resin and the weakly acidic cation exchange resin exists above the collector 2 as shown in FIG.

Next, as shown in FIG. 2 (c), an acid regenerant such as hydrochloric acid is passed through a distributor 5 installed on the upper part of the mixed-bed type sugar liquid refining apparatus 1, and the strong basic anion exchange in the upper layer is performed. Both the resin 3 and the lower layer weakly acidic cation exchange resin are penetrated by one penetrant and discharged from the lower part of the mixed-bed type sugar liquid refining apparatus 1. By passing the acid regenerant, the lower layer weakly acidic cation exchange resin is regenerated and becomes a free acid form, and the volume is reduced.

Even after the weakly acidic cation exchange resin shrinks, the separation interface between the two ion exchange resins is located above the collector 2. In addition, impurities such as organic acids adsorbed on the upper layer of the strongly basic anion exchange resin 3 are removed by passing the acid regenerant, and the strongly basic anion exchange resin 3 is regenerated.

Thereafter, the strongly basic anion exchange resin 3 is regenerated.
As shown in (d), an alkaline regenerant such as an aqueous sodium hydroxide solution is passed from the distributor 5 and water is simultaneously passed from the lower part of the mixed-bed type sugar liquid refining apparatus 1, and the alkaline regenerant is passed from the collector 2. And drain the water.

As shown in detail in FIG. 1, since the collector 2 is provided below the separation boundary 6 between both ion exchange resins, the collector 2 is located above the collector 2 during regeneration of the strongly basic anion exchange resin 3. The alkali regenerant contacts existing weakly acidic cation exchange resin. Thereby, a part of the weakly acidic cation exchange resin becomes a salt form such as Na form. Therefore, in the purification treatment step after regeneration, Na slightly leaks into the treated sugar liquid, so that the pH of the treated sugar liquid can be prevented from fluctuating acidic.

In the above-described embodiment, the regeneration method in which the acid regenerating agent is passed through the strongly basic anion exchange resin and the weakly acidic cation exchange resin after the separation operation is completed in the regeneration step has been described. The regeneration method of the apparatus of the present invention is not limited to this. For example, the acid regenerant may be passed through the ion exchange resin in a mixed state before performing the separation operation, and then the separation operation may be performed. After completion, the acid regenerant is passed through the lower part of the mixed-bed type sugar liquid refining apparatus 1 and the regenerated waste liquid is discharged from the collector 2 to regenerate only the weak acid acidic cation exchange resin 4 first, and then the upper distributor 5 The strongly basic anion exchange resin 3 may be regenerated by discharging the regenerated waste liquid through which the alkali regenerant passes through the collector 2.

In a conventional mixed-bed type sugar solution refining apparatus in which the collector is located at the separation boundary, even if the pH of the treated sugar solution is increased in the purification process, the regeneration process is performed. In, a weakly acidic cation exchange resin may be added so that the collector is located below the separation interface between the separated strongly basic anion exchange resin and the free acid form weakly acidic cation exchange resin.

[0038]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A strongly basic anion exchange resin (trade name "Amberlite I")
RA-402BL "(manufactured by Rohm and Haas) and 3 L of weakly acidic cation exchange resin (trade name" Amberlite IR ")
C-76 ", manufactured by Rohm and Haas Co., Ltd.) was charged into a mixed-bed type sugar liquid refining apparatus as shown in FIG. This resin has been used in actual equipment for a long time (200 cycles or more).

In the mixed-bed type sugar liquid purifying apparatus of Example 1, the position of the collector was located below the separation boundary by 1% of the layer height of the lower layer weakly acidic cation exchange resin (H type).

Table 1 shows the purity of the raw sugar solution and the processing conditions for the sugar solution treatment.

[0042]

[Table 1]

Regeneration after the treatment with the sugar solution was performed as follows.
First, the mixed resin was separated with a saturated saline solution, and 3.5% hydrochloric acid was added from a distributor at the upper part of the sugar solution refining device to 4.
The solution was passed through 5 L and discharged from the lower part of the sugar solution refining device. Subsequently, 6.0 L of a 4.0% aqueous sodium hydroxide solution was passed through the distributor, and at the same time, water was passed through the lower part of the sugar solution refining apparatus and discharged from the collector. Thereafter, washing water was passed through the upper and lower parts of the sugar liquid refining apparatus, and the washing water was discharged from the collector, thereby completing the regeneration treatment.

COMPARATIVE EXAMPLE 1 Except for using a conventional sugar liquid refining apparatus as shown in FIG. 3 in which the collector was located at the separation boundary,
Purification treatment and regeneration treatment of the sugar solution were performed according to Example 1.

Comparative Example 2 The position of the collector was set to be higher than the separation boundary by 5% of the layer height of the upper layer strong basic anion exchange resin (Cl type) according to JP-A-10-57100. Purification treatment and regeneration treatment of the sugar solution were performed according to Example 1.

Example 2 A new weakly acidic cation exchange resin was added to the apparatus of Comparative Example 2. For a new weakly acidic cation exchange resin, the collector position is lower than the layer height of the lower weakly acidic cation exchange resin (H type) by one.
The amount below the separation interface by% was added. That is, 318
Purification treatment and regeneration treatment of the sugar solution were performed according to Example 1 by adding ml of the weakly acidic cation exchange resin.

Using the mixed-bed type sugar solution purifying apparatus of Examples 1 and 2 and Comparative Examples 1 and 2, the pH of the treated sugar solution when the sugar solution was purified was measured. Table 2 shows the results.

[0048]

[Table 2]

As is clear from the results shown in Table 2, the sugar solution purifying apparatuses of Examples 1 and 2 have an acidic pH of the treated sugar solution compared to the conventional sugar solution purifying apparatuses of Comparative Examples 1 and 2. It did not shake and was found to be in the preferred pH range.

[0050]

In the mixed-bed type sugar solution refining apparatus according to the first or second aspect of the present invention, since the position of the collector is below the separation boundary, the free acid form weakly acidic cation exchange during regeneration with the alkaline regenerating agent. Since a part of the resin is in a salt form such as a Na salt form, it is possible to prevent the pH of the treated sugar solution from fluctuating toward the acidic side.

In the method for regenerating a mixed-bed type sugar liquid refining apparatus according to the third or fourth aspect, since the position of the collector is below the separation boundary, the free acid form weakly acidic cation can be obtained during the regeneration with the alkaline regenerant. Since a part of the exchange resin becomes a salt form such as a Na salt form, it is possible to prevent the pH of the treated sugar solution from fluctuating toward the acidic side.

In the method for purifying a sugar solution according to claim 5 or 6, the replenishment of the weak acidic cation exchange resin causes the position of the collector to be lower than the separation boundary, so that the regenerating by the alkali regenerating agent can be performed. Since a part of the free acid form weakly acidic cation exchange resin becomes a salt form such as a Na salt form, it is possible to prevent the pH of the treated sugar solution from fluctuating to the acidic side.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a state in which a strongly basic anion exchange resin and a weakly acidic cation exchange resin are separated in a regeneration step in a mixed-bed type sugar solution refining apparatus of the present invention.

2 (a) to 2 (d) are schematic cross-sectional views for explaining a method for regenerating a mixed-bed type sugar liquid refining apparatus of the present invention.

FIG. 3 is a schematic cross-sectional view showing a state in which a strongly basic anion exchange resin and a weakly acidic cation exchange resin are separated in a regeneration step in a conventional mixed-bed type sugar liquid refining apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixed-bed type sugar liquid refiner 2 Collector 3 Strongly basic anion exchange resin 4 Weakly acidic cation exchange resin 5 Distributor 6 Separation interface 7 Supporting bed

Claims (6)

[Claims] 1. A mixed-bed type sugar liquid refining apparatus filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin,
In the regeneration process of the ion exchange resin, when the weakly acidic cation exchange resin is in the free acid form, the regenerated waste liquid is discharged below the separation boundary between the upper layer strongly basic anion exchange resin and the lower layer weakly acidic cation exchange resin. A mixed-bed type sugar liquid refining device, comprising a collector that performs the treatment. 2. A collector having a layer height of 0.5% of the free acid form weakly acidic cation exchange resin from the separation interface between the upper layer strongly basic anion exchange resin and the lower layer free acid form weakly acidic cation exchange resin. 2. The mixed-bed type sugar solution refining device according to claim 1, wherein the device is provided below by 10%. 3. A method for regenerating a mixed-bed type sugar liquid refining apparatus filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin, wherein in the regeneration step of the ion exchange resin, the upper layer is a strongly basic anion exchange resin. When the alkali regenerant is passed through the strongly basic anion exchange resin in the upper layer of the separated ion exchange resin, in which the lower layer is a regenerated free-form weakly acidic cation exchange resin, the strongly basic anion exchange in the upper layer is performed. A method for regenerating a mixed-bed type sugar liquid refining apparatus, comprising discharging a regenerated waste liquid of an alkali regenerant by a collector provided below a separation boundary between a resin and a lower free acid cation exchange resin in a lower layer. 4. A collector having a layer height of 0.5% of the free acid form weakly acidic cation exchange resin from the separation interface between the upper layer strongly basic anion exchange resin and the lower layer free acid form weakly acidic cation exchange resin. 4. The method for regenerating a mixed-bed type sugar liquid refining apparatus according to claim 3, wherein the apparatus is installed below by 10%. 5. A method for purifying a sugar solution using a mixed-bed sugar solution purification apparatus packed with a strongly basic anion exchange resin and a weakly acidic cation exchange resin, when the pH of the treated sugar solution decreases, In the resin regeneration step, when the weakly acidic cation exchange resin is in the free acid form, a collector for discharging the regeneration waste liquid below the separation interface between the upper layer strongly basic anion exchange resin and the lower layer weakly acidic cation exchange resin A method for purifying a sugar solution, comprising adding a weak acid acidic cation exchange resin so that is located. 6. The layer height of the free acid form weakly acidic cation exchange resin from the separation interface between the upper layer strongly basic anion exchange resin and the lower layer free acid form weakly acidic cation exchange resin is 0.5.
The method for purifying a sugar solution according to claim 5, wherein the weakly acidic cation exchange resin is added so as to be located at the collector position by 10% or less.