JP4216998B2 - Regeneration method of mixed-bed type sugar liquid purification equipment - Google Patents

Description

【００３２】
表１の結果より、本発明方法で再生を行った実施例は、処理糖液のｐＨが５〜６の範囲内で安定していることが確認された。これに対し、従来法で再生を行った比較例は、処理糖液のｐＨが酸性側に振れ、処理糖液のｐＨが５より低くなるものであった。
【００３３】
【発明の効果】
以上のように、本発明に係る混床式糖液精製装置の再生法によれば、強酸性カチオン交換樹脂と強塩基性アニオン交換樹脂を充填した混床式糖液精製装置の処理糖液のｐＨを安定させることができ、イオン交換処理の後段の濃縮工程での着色や糖の分解を防ぐことが可能である。
【図面の簡単な説明】
【図１】本発明を適用する混床式糖液精製装置の一例を示す概略構成図である。
【符号の説明】
２ 混床式糖液精製装置
４ 支持床
６ ディストリビュータ
８ 強塩基性アニオン交換樹脂
１０ 強酸性カチオン交換樹脂
１２ 分離境界面
１４ コレクタ
１６ 原糖液導入管
１８ 処理糖液排出管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for regenerating a sugar solution purification apparatus for desalting and decolorizing a sugar solution such as starch sugar solution. More specifically, the present invention relates to a mixed bed type using a strongly acidic cation exchange resin and a strongly basic anion exchange resin. The present invention relates to a method for regenerating an ion exchange resin of a sugar liquid purification apparatus.
[0002]
[Prior art]
When starch is hydrolyzed with an acid or an enzyme, various starch sugars (a general term for sugars produced using starch as a raw material) are obtained depending on the degradation conditions. The starch hydrolysis process is divided into two steps, liquefaction and saccharification, and starch saccharification is obtained by saccharification of starch, and this starch saccharification contains various impurities. Therefore, for the purpose of removing these impurities, the starch sugar solution is purified after the starch saccharification step.
[0003]
When refine | purifying starch sugar liquid, the ion exchange process is performed as post-processing of refinement | purification processes, such as powder activated carbon filtration, granular activated carbon filtration, and bone charcoal filtration. The ion exchange treatment includes an ion exchange treatment for decolorization and an ion exchange treatment for desalting.
[0004]
In general, ion exchange treatment for desalination is carried out by using a multi-bed type pre-desalting system using a strongly acidic cation exchange resin layer and a weakly basic anion exchange resin layer, a strongly acidic cation exchange resin and a type II strong base. A mixed-bed final desalination system using anionic anion exchange resin. The pre-demineralization system removes most of the salts, pigments and other impurities in the stock solution, and the final desalination system removes the final desalting system. Salt, decolorization and pH adjustment are performed. This desalting treatment is widely used industrially and is an excellent method for purifying a sugar solution in that a high-purity sugar solution can be obtained. This is because finishing desalination using a mixed bed layer works well. Recently, it has also been proposed to form a mixed bed using a type I strongly basic anion exchange resin instead of a type II strongly basic anion exchange resin.
[0005]
The regeneration of the ion exchange resin in the mixed-bed type sugar liquid refining apparatus (finishing desalination system) using the above-mentioned strongly acidic cation exchange resin and strongly basic anion exchange resin has been conventionally performed as follows. First, after the sugar solution treatment is completed in the mixed bed tower, the strong acid cation exchange resin is separated into the lower layer and the strong base anion exchange resin is separated into the upper layer in the mixed bed tower. Separation of both resins in the mixed state is performed by backwashing using the difference in specific gravity of both resins. Then, an acid regenerating agent such as an aqueous hydrochloric acid solution is passed through the lower strong acid cation exchange resin to regenerate the strong acid cation exchange resin. Similarly, an alkali regenerator such as an aqueous sodium hydroxide solution is poured into the upper strong base anion exchange resin to regenerate the strong base anion exchange resin. When medicine is passed through one resin layer, water is passed through the other resin layer, and the resin regeneration waste liquid and the water are discharged from a collector installed at the separation boundary surface between the two resins. There is also a method in which a regenerant is poured into both resin layers simultaneously. After regenerating both resins, they are mixed again to form a mixed bed.
[0006]
[Problems to be solved by the invention]
In the ion exchange treatment of the starch sugar solution described above, the pH of the treated sugar solution after the ion exchange treatment is preferably in the range of 5 to 6 in order to prevent coloring and sugar decomposition in the subsequent concentration step. The pH of the treated sugar solution is determined by a mixed-bed final desalination system using a strongly acidic cation exchange resin and a strongly basic anion exchange resin. The ratio of the resin amount of the strongly acidic cation exchange resin and the strongly basic anion exchange resin is determined so that is within the optimum range.
[0007]
However, the mixed bed type sugar liquid refining equipment (finishing desalination system) using a strong acid cation exchange resin and a strong base anion exchange resin is a conventional regeneration method, that is, a strong acid cation exchange resin with an acid regenerant and a strong base. When the regeneration treatment was performed several times by a method in which an alkaline regenerant was passed through each of the functional anion exchange resins, the pH of the treated sugar solution moved to the acidic side, and the pH of the treated sugar solution was sometimes lower than 5.
[0008]
The reason why the above phenomenon occurs is not always clear, but strong base anion exchange resins are more easily contaminated by liquid passage than strong acid cation exchange resins. The anion exchange rate by the cationic anion exchange resin is relatively lower than the cation exchange rate by the strongly acidic cation exchange resin, and as a result, the cation in the sugar solution is relatively ion exchanged compared to the anion. It is presumed that the pH of the sugar solution may move to the acidic side.
[0009]
The present invention has been made in view of the above-described circumstances, and is a regeneration method for a mixed-bed sugar solution purifier filled with a strongly acidic cation exchange resin and a strongly basic anion exchange resin, wherein the pH of the treated sugar solution is An object of the present invention is to provide a method for regenerating a mixed bed type sugar solution refining device that can prevent the acid side from shaking and stabilize the pH of the treated sugar solution.
[0010]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have first developed a strongly acidic cation in the regeneration of a mixed bed type sugar solution purification apparatus using a strongly acidic cation exchange resin and a strongly basic anion exchange resin. An alkali regenerant is brought into contact with both the exchange resin and the strongly basic anion exchange resin to regenerate the strongly basic anion exchange resin, and after making the strongly acidic cation exchange resin into a salt form, When a strongly acidic cation exchange resin is regenerated by contacting an acid regenerating agent equivalent to an ion exchange capacity less than the total ion exchange capacity of the resin, the pH of the processed sugar solution is prevented from shifting to the acidic side, and the processed sugar It was found that the pH of the liquid was stable.
[0011]
The present invention has been made on the basis of the above knowledge, and in regenerating the ion exchange resin of the mixed bed type sugar liquid purification apparatus filled with the strong acid cation exchange resin and the strongly basic anion exchange resin, the strong acid cation exchange resin And an alkali regenerator is brought into contact with the strongly basic anion exchange resin, and then an acid regenerator equivalent to an ion exchange capacity less than the total ion exchange capacity of the resin is brought into contact with the strongly acidic cation exchange resin. Provided is a method for regenerating a mixed-bed sugar solution purifier.
[0012]
As described above, in the mixed bed type sugar liquid refining apparatus using a strongly acidic cation exchange resin and a strongly basic anion exchange resin, the anion exchange rate is higher than the cation exchange rate when several cycles of liquid passing and regeneration treatment are performed. As a result, it is considered that the pH of the treated sugar solution may shift to the acidic side. On the other hand, after making a strongly acidic cation exchange resin into a salt form with an alkali regenerating agent as in the present invention, an acid regenerating agent equivalent to an ion exchange capacity less than the total ion exchange capacity is added to the strongly acidic cation exchange resin. When the strongly acidic cation exchange resin is regenerated by contacting it, the strongly acidic cation exchange resin contains an H-form salt and a salt-form after the regeneration. That is, the strongly acidic cation exchange resin after regeneration is partly in the H form and the remainder in the salt form, and the regeneration rate is intentionally reduced.
[0013]
In the present invention, the desalting performance of the strongly acidic cation exchange resin after regeneration is intentionally reduced by reducing the regeneration rate as described above, and even when several cycles of liquid passing and regeneration treatment are performed, strong basicity is achieved. It is prevented that the anion exchange rate by the anion exchange resin is relatively lower than the cation exchange rate by the strongly acidic cation exchange resin, and the balance between the cation exchange rate and the anion exchange rate is improved. It is considered that the pH is prevented from swinging to the acidic side, and the pH of the treated sugar solution can be stabilized. In the present invention, the desalting performance of the strongly acidic cation exchange resin after regeneration is lowered, but since it is a mixed bed type treatment, the amount of cation leaking from the mixed bed type sugar liquid refining device is extremely small, and the subsequent steps It does not affect.
[0014]
Hereinafter, the present invention will be described in more detail. In the present invention, first, an alkali regenerant is passed through a strongly acidic cation exchange resin and a strongly basic anion exchange resin. Although there is no limitation in the kind of alkali regenerator, sodium hydroxide aqueous solution can be used suitably. In addition, when an alkali regenerator is passed through a strongly acidic cation exchange resin and a strongly basic anion exchange resin, the alkali regenerator may be passed before separating both ion exchange resins, and the alkali regenerator after separation. The liquid may be passed through, but is usually passed after separation.
[0015]
In the present invention, next, an acid regenerant is passed through the strongly acidic cation exchange resin. Although there is no limitation in the kind of acid regenerating agent, hydrochloric acid aqueous solution can be used suitably. Further, the acid regenerating agent may be passed through the strongly acidic cation exchange resin in a state where both ion exchange resins are separated.
[0016]
In this case, in the present invention, an acid regenerant equivalent to an ion exchange capacity less than the total ion exchange capacity of the resin, preferably 30 to 30% of the total ion exchange capacity of the strong acid cation exchange resin is used. An equivalent amount of acid regenerant corresponding to an ion exchange capacity of 80% is contacted. If the above value is less than 30%, the salt-type strongly acidic cation exchange resin may increase so much that the salt may leak from the strong acid cation exchange resin. When the drug passing and the regeneration treatment are performed for several cycles due to excessive increase, the pH of the treated sugar solution may shift to the acidic side.
[0017]
There is no limitation on the type of the strongly acidic cation exchange resin and the strongly basic anion exchange resin in the mixed bed type sugar solution refining apparatus to which the present invention is applied, and it may be appropriately selected according to the purpose of the treatment. Specifically, Amberlite (registered trademark, hereinafter the same) 200CT, IR120B, IR124, IR118, Diaion (registered trademark, the same applies hereinafter) SK1B, SK102, PK208, PK212 (above, strongly acidic cation exchange resin), Amberlite IRA402BL, IRA400, IRA440B, IRA404, IRA900, IRA904, Diaion SA10A, SA11A, PA306, PA308 (above, I-type strongly basic anion exchange resin), Amberlite IRA411, IRA410, IRA910, Diaion SA20, PA418 (above, II type strongly basic anion exchange resin) can be used.
[0018]
In the mixed bed type sugar liquid refining apparatus to which the present invention is applied, the mixed bed is formed by setting the ratio of the resin amount of the strongly acidic cation exchange resin and the resin amount of the strongly basic anion exchange resin to 2: 1 to 1: 4. It is preferable. This is to make the pH of the treated sugar solution more stable. That is, if the amount of the strongly acidic cation exchange resin is larger than the above range, the pH of the treated sugar solution becomes too acidic, and if the amount of the strongly basic anion exchange resin is larger than the above range, the pH of the treated sugar solution becomes alkaline. Too side.
[0019]
In addition, the regeneration method of the present invention can be suitably applied to, for example, the mixed-bed type sugar liquid purification apparatus in the following sugar liquid purification systems (A) and (B), but is not limited thereto.
(A) Using a cation exchange apparatus using a strongly acidic cation exchange resin, an anion exchange apparatus using a weakly basic anion exchange resin, a strong acid cation exchange resin, and a strongly basic anion exchange resin of type I or II A sugar solution refining system in which the mixed-bed sugar solution refining device was installed in this order.
(B) a cation exchange apparatus using a strong acid cation exchange resin, a mixed bed type sugar liquid purification apparatus using a strong acid cation exchange resin and a weakly basic anion exchange resin, a strong acid cation exchange resin and an I form or II A sugar solution purification system in which a mixed bed type sugar solution purification apparatus using a strongly basic anion exchange resin is installed in this order. In the present system, the present invention is applied to a mixed-bed type sugar solution purification apparatus at the subsequent stage.
[0020]
The regeneration method of the present invention is preferably used as, for example, a regeneration method of a mixed bed type sugar solution refining apparatus for processing starch sugar solution, but is not limited thereto, and other mixed bed type sugar solution purification is used. It can be used as a device regeneration method.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic configuration diagram showing an example of a mixed bed type sugar liquid purification apparatus to which the present invention is applied. A support bed 4 for supporting ion exchange resins (strongly acidic cation exchange resin and strong basic anion exchange resin) is laid at the bottom of the mixed bed type sugar liquid purification apparatus 2 of this example. In addition, a distributor 6 for supplying an acid regenerant is installed in the lower part of the tower, and a separation boundary surface 12 between the strong basic anion exchange resin 8 in the upper layer and the strong acidic cation exchange resin 10 in the lower layer is A collector 14 for discharging the regeneration waste liquid of the strongly acidic cation exchange resin is installed. Further, in the figure, 16 indicates a raw sugar solution introduction tube, and 18 indicates a treated sugar solution discharge tube.
[0022]
The procedure for regenerating the mixed-bed sugar solution purifying apparatus of this example by the regenerating method of the present invention is as follows, for example.
(1) After the sugar solution treatment is completed, water is introduced into the tower from the raw sugar solution introduction pipe 16, and the sugar solution in the mixed bed layer is pushed out with this water. To discharge from. (2) After completion of the extrusion of the sugar solution, water is introduced from the distributor 6 and backwashing is performed to expand and flow the resin layer. Thereby, both ion exchange resin is isolate | separated using those specific gravity differences. After completion of backwashing, both ion exchange resins are allowed to settle.
(3) Thereafter, an alkali regenerant is introduced into the column from the raw sugar solution introduction pipe 16, and the alkali regenerator is collectively applied downward to the strong basic anion exchange resin 8 and the strong acidic cation exchange resin 10 in the lower layer. Take medicine. The regeneration waste liquid of the alkali regenerant is discharged from the treated sugar liquid discharge pipe 18. As a result, the strongly basic anion exchange resin 8 is regenerated and the strongly acidic cation exchange resin 10 is made into a salt form. A distributor may be separately installed at the top of the tower, and an alkali regenerant may be introduced into the tower from this distributor.
(4) Next, the alkali regenerator is extruded with water, and the resin layer is washed with water if necessary. Then, an acid regenerator such as a hydrochloric acid aqueous solution is applied upward from the distributor 6 to the strongly acidic cation exchange resin 10 in the lower layer. Take medicine. Specifically, an acid regenerant equivalent to an ion exchange capacity of less than the total ion exchange capacity of the strongly acidic cation exchange resin 10, preferably 30 to 80% of the total ion exchange capacity, is injected. At the same time, the pressing water is passed through the upper strong basic anion exchange resin 8 in a downward flow. Then, the resin regeneration waste liquid and the holding water are discharged from the collector 14. Thereby, regeneration of the strongly acidic cation exchange resin 10 is performed.
(5) Next, water is introduced into the tower from the distributor 6, and the acid regenerant in the strongly acidic cation exchange resin 10 is extruded with this water. At the same time, pressing water is passed through the strong base anion exchange resin 8 in the upper layer from the raw sugar solution introduction pipe 16 in a downward flow. Then, the resin regeneration waste liquid and the holding water are discharged from the collector 14.
(6) By bubbling air from the distributor 6 into the resin with an appropriate amount of water in the tower, the regenerated both resins are mixed again to form a mixed bed.
[0023]
As another regeneration method, after completion of the sugar solution treatment, an alkali regenerant is passed through the mixed bed layer of both ion exchange resins from the bottom in an upward flow, and both ion exchange resins are expanded and flown through the resin layer. After regenerating the strongly basic anion exchange resin, the strongly acidic cation exchange resin is made into a salt form, and then the inflow of the alkaline regenerant is stopped to calm both ion exchange resins, and then the lower part of the resin layer There is a method in which an acid regenerant equivalent to an ion exchange capacity less than the total ion exchange capacity is brought into contact with the strongly acidic cation exchange resin separated in (1). In this method, the above-described steps (2) and (3) can be performed simultaneously.
[0024]
【Example】
EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to the following Example.
[0025]
(Example)
Column (SC tower) packed with 3.5 L of H-form strongly acidic cation exchange resin (Amberlite IRA120B), column (WA tower) packed with 5.0 L of free base form weakly basic anion exchange resin (Amberlite XE583), Three columns of the column (MB column) packed with 1.0 L of H-form strongly acidic cation exchange resin (Amberlite 200CT) and 2.0 L of OH Form II strongly basic anion exchange resin (Amberlite 411) in this order Installed and configured a sugar liquid purification system. The ion exchange resin used is a resin that has been used for several cycles of sugar liquid purification treatment. In addition, an intermediate collector was installed in the MB tower.
[0026]
After 200 L of starch sugar solution was passed through the SC tower, WA tower, and MB tower in this order, the sugar solution in the MB tower was extruded, washed, and regenerated. Regeneration was performed according to the following procedure.
(1) First, 50% of the resin layer was developed by backwash water in an upward flow to separate the strongly acidic cation exchange resin and the strongly basic anion exchange resin.
(2) Next, 4 L of a 1.0 mol / L sodium hydroxide aqueous solution is passed downward through both resins from the top of the column to regenerate the strongly basic anion exchange resin, and at the same time, strongly acidic cation exchange resin Was in Na form.
(3) After extruding an aqueous sodium hydroxide solution with water and washing both resins, 950 mL of a 1 mol / L aqueous hydrochloric acid solution was passed upwardly into the strongly acidic cation exchange resin from the bottom of the column, and the strongly acidic cation The exchange resin was regenerated. At this time, pressing water was passed through the upper strong base anion exchange resin in a downward flow, and the resin regeneration waste liquid and pressing water were discharged from the intermediate collector.
(4) After extruding the aqueous hydrochloric acid solution with water and washing the strongly acidic cation exchange resin, air is supplied from the bottom of the column to mix the strongly acidic cation exchange resin and the strongly basic anion exchange resin, and again the mixed bed layer is formed. Formed.
[0027]
Here, the total ion exchange capacity and the acid regenerant usage amount of the strongly acidic cation exchange resin in the above example will be described. The total ion exchange capacity of the ion exchange resin is the equivalent of ions that can be adsorbed per liter of the resin, and the unit is [eq (equivalent) / L-resin]. The strongly acidic cation exchange resin Amberlite 200CT used in the MB tower of the example has a total ion exchange capacity of 1.75 eq / L-resin, so 1.75 mol of monovalent ions are adsorbed per liter of resin. Can do. Since hydrochloric acid (HCl) used as an acid regenerant in the examples is a monovalent acid, 1 mol / L = 1 eq / L. When Amberlite 200CT is regenerated using 1 mol / L hydrochloric acid, the amount of acid regenerant used (%) with respect to the total ion exchange capacity of the strongly acidic cation exchange resin is represented by the following formula (a).
[Concentration of hydrochloric acid (eq / L) × Amount of hydrochloric acid used (L)] ÷ [Amount of resin (L) × Total exchange capacity (eq / L)] × 100 (a)
Accordingly, when the case of this example is applied to the formula (a), the result is as follows. In this example, an acid regenerant equivalent to 54% of the total ion exchange capacity is brought into contact with the strongly acidic cation exchange resin. That's right.
(1 eq / L × 0.950 L) ÷ (1 L × 1.75 eq / L) × 100 = 54%
[0028]
After the regeneration step described above was completed, 200 L of starch sugar solution was passed through the SC tower, WA tower, and MB tower in this order to regenerate the resin for 5 cycles. Table 1 shows the average values of the pH and electrical conductivity of the treated sugar solution in 5 cycles.
[0029]
(Comparative example)
A sugar solution purification system similar to that of the example was constructed. After 200 L of starch sugar solution was passed through the SC tower, WA tower, and MB tower in this order, the sugar solution in the MB tower was extruded, washed, and regenerated. Regeneration was performed by the conventional method according to the following procedure.
(1) First, 50% of the resin layer was developed by backwash water in an upward flow to separate the strongly acidic cation exchange resin and the strongly basic anion exchange resin.
(2) Next, 4 L of 1.0 mol / L sodium hydroxide aqueous solution was passed through the strong basic anion exchange resin downward from the top of the column to regenerate the strong basic anion exchange resin. At this time, pressurizing water was passed upward through the strongly acidic cation exchange resin in the lower layer, and the resin regeneration waste liquid and pressurizing water were discharged from the intermediate collector.
(3) After extruding the sodium hydroxide aqueous solution with water and washing the strongly basic anion exchange resin, 1.5 L of 1 mol / L hydrochloric acid aqueous solution is passed upwardly into the strongly acidic cation exchange resin from the bottom of the column. Thus, the strongly acidic cation exchange resin was regenerated. At this time, pressing water was passed through the upper strong base anion exchange resin in a downward flow, and the resin regeneration waste liquid and pressing water were discharged from the intermediate collector.
(4) After extruding the aqueous hydrochloric acid solution with water and washing the strongly acidic cation exchange resin, air is supplied from the bottom of the column to mix the strongly acidic cation exchange resin and the strongly basic anion exchange resin, and again the mixed bed layer is formed. Formed.
[0030]
After the regeneration step, the starch sugar solution 200L was passed through the SC tower, WA tower, and MB tower in this order to regenerate the resin for 5 cycles. Table 1 shows the average values of the pH and electrical conductivity of the treated sugar solution in 5 cycles.
[0031]
[Table 1]

[0032]
From the results shown in Table 1, it was confirmed that in the examples where the regeneration was performed by the method of the present invention, the pH of the treated sugar solution was stable within the range of 5-6. On the other hand, in the comparative example in which regeneration was performed by the conventional method, the pH of the treated sugar solution was shifted to the acidic side, and the pH of the treated sugar solution was lower than 5.
[0033]
【The invention's effect】
As described above, according to the regeneration method of the mixed bed type sugar solution purifying apparatus according to the present invention, the treated sugar solution of the mixed bed type sugar solution purifying apparatus filled with the strongly acidic cation exchange resin and the strongly basic anion exchange resin is used. The pH can be stabilized, and it is possible to prevent coloration and sugar decomposition in the subsequent concentration step of the ion exchange treatment.
[Brief description of the drawings]
BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic configuration diagram showing an example of a mixed bed type sugar liquid purification apparatus to which the present invention is applied.
[Explanation of symbols]
2 Mixed bed type sugar solution refining device 4 Support bed 6 Distributor 8 Strong basic anion exchange resin 10 Strong acid cation exchange resin 12 Separation interface 14 Collector 16 Raw sugar solution introduction pipe 18 Processed sugar solution discharge pipe

Claims (5)

In regenerating the ion exchange resin of the mixed bed type sugar liquid refining apparatus filled with the strong acid cation exchange resin and the strong base anion exchange resin, the alkali regenerant is brought into contact with the strong acid cation exchange resin and the strongly basic anion exchange resin. Then, the regeneration method of the mixed bed type sugar liquid refining apparatus is characterized in that an acid regenerant equivalent to an ion exchange capacity less than the total ion exchange capacity of the resin is brought into contact with the strongly acidic cation exchange resin. The method for regenerating a mixed-bed sugar solution purifier according to claim 1, wherein an acid regenerant equivalent to an ion exchange capacity of 30 to 80% of the total ion exchange capacity of the resin is contacted with the strongly acidic cation exchange resin. The method for regenerating a mixed-bed sugar solution purifier according to claim 1 or 2, wherein a sodium hydroxide aqueous solution is used as the alkali regenerating agent. The mixed bed type sugar liquid refining apparatus forms a mixed bed by setting the ratio of the resin amount of the strongly acidic cation exchange resin and the resin amount of the strongly basic anion exchange resin to 2: 1 to 1: 4. The reproduction | regeneration method of the mixed bed type sugar-liquid refinement | purification apparatus of any one of 1-3. The method for regenerating a mixed bed type sugar liquid refining apparatus according to any one of claims 1 to 4, wherein the mixed bed type sugar liquid refining apparatus is a starch sugar liquid refining apparatus.

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