JP3231228B2 - Regeneration method of ion exchange resin tower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an anion exchange resin tower for an apparatus for desalting and purifying sugar solutions such as sucrose, glucose, maltose, etc., a pure water production apparatus, or an ion exchange apparatus for removing impurity ions from various wastewaters. The present invention relates to a method for regenerating an ion exchange resin tower such as a cation exchange resin tower.

[0002]

2. Description of the Related Art Conventionally, for example, as a method for desalting and purifying a sucrose solution, a reverse method in which raw materials of a sucrose solution are successively passed through a strongly basic anion exchange resin tower and a weakly acidic cation exchange resin tower, or a sucrose solution. A desalination purification method in which the raw material is passed through a strongly basic anion exchange resin tower and then treated in a mixed bed tower filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin (Japanese Patent Laid-Open No. 2-295499). Etc.

The regeneration of the ion-exchange resin tower is performed by passing a regenerant through the ion-exchange resin tower.
The strong basic anion exchange resin tower is regenerated using an alkali agent such as a 0.2 to 4N sodium hydroxide solution as a regenerating agent. In addition, the weakly acidic cation exchange resin tower has 0.2
It is regenerated using an acid agent such as a ~ 4N hydrochloric acid solution. The flow rate is determined by the ion exchange capacity of the charged ion exchange resin.

Since the sucrose solution is easily denatured, if an alkali or an acid is contained in the desalted and purified sucrose solution, coloring, alteration, etc. will occur in the subsequent steps. Therefore, the remaining exchange capacity of the ion exchange resin packed in the ion exchange resin tower is accurately predicted, desalting is performed within the range, and a sucrose solution containing an alkali or acid is absolutely removed from the ion exchange resin tower. It is necessary to prevent spills.

[0005] However, the ion concentration in the sucrose solution to be desalinated and purified varies depending on the raw material, and the desalination and purification are performed at a relatively high temperature.
Since there are problems such as a decrease in the ion exchange capacity of the ion exchange resin, it is extremely difficult to accurately predict the remaining exchange capacity.

In order to avoid this problem, in the desalting treatment described above, the desalting treatment of the sucrose solution is stopped with the exchange groups remaining to some extent without using up the entire exchange capacity of each ion exchange resin used. In general, a regeneration treatment of an ion exchange resin is performed.

[0007] In practice, a fixed amount of sucrose solution raw material is set in advance within a range in which the exchange group can reliably remain irrespective of the salt concentration in the sucrose solution raw material. The regeneration process is performed using an amount of the regenerating agent capable of regenerating the entire exchange capacity irrespective of the remaining amount.

[0008] Therefore, according to this method, since a relatively large amount of the exchange group always remains, an extra regenerant is required correspondingly, which is uneconomical.

In order to solve this problem, there is a method of recovering an excessively used regenerating agent and reusing it as a regenerating agent at the next regeneration. However, after a certain amount of the regenerant is passed through the ion-exchange resin tower, a method of recovering a part of the regenerated waste liquid does not use a regenerant corresponding to the remaining exchange capacity of the ion-exchange group. The properties of the recycled waste liquid, that is, the concentration of impurity ions contained therein become unstable.
In particular, when the impurity ion concentration is high, there is a problem that when the recovered regenerated waste liquid is used as a regenerating agent, these are re-adsorbed to the ion exchange resin.

[0010]

The inventor of the present invention has conducted intensive studies in order to solve the above-mentioned problems, and as a result, has found that p
The inventors have found that the above problem can be solved by measuring H using a pH meter and controlling the amount of the regenerant passed based on the measured value, and completed the present invention. Therefore, the purpose thereof is to use a regenerant in accordance with the remaining ion exchange capacity of the ion exchange resin in the regeneration of the ion exchange resin tower, and to stably recover the regeneration waste liquid having a small impurity content as the regenerant. It is an object of the present invention to provide a method of regenerating an ion-exchange resin tower that can perform the above-mentioned steps.

[0011]

In order to achieve the above object, the present invention provides an ion-exchange resin tower by supplying an acid regenerant or an alkali regenerant to the inlet thereof and removing the regenerated waste liquid from the outlet of the ion-exchange resin tower. In the method of regenerating an ion exchange resin tower for regenerating an exchange resin tower, the regenerant is supplied to the inlet of the ion exchange resin tower, and the pH of the recycle waste liquid is measured while taking out the recycle waste liquid from the outlet, based on the pH of the regenerant. The pH of the reclaimed waste liquid falls within the predetermined range as
The method for regenerating an ion-exchange resin tower, characterized in that the supply of the regenerant is stopped when reaches, and the regeneration waste liquid is supplied from the outlet of the ion-exchange resin tower while supplying an acid regenerant or an alkali regenerant to the ion-exchange resin tower inlet. In a method for regenerating an ion-exchange resin tower in which the ion-exchange resin tower is regenerated by taking out the regenerant, the regenerant is supplied to the inlet of the ion-exchange resin tower, and the pH of the regenerant is measured while taking out the regenerate waste from the outlet. The supply of the regenerant is stopped when the pH of the regenerated waste liquid reaches a predetermined range based on the pH of the regenerated waste liquid, and then the regenerant is recovered from the ion-exchange resin tower by supplying water to the ion-exchange resin tower. The present invention proposes a method for regenerating an ion exchange resin tower, wherein the ion exchange resin tower is used for desalting and purification of a sugar solution. No.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings.

[0013] The regeneration method of the present invention is, for example, a strong basic anion exchange resin tower or a weak acid cation in a reverse method in which a sucrose solution is desalted and purified by a strongly basic anion exchange resin tower and then a weakly acidic cation exchange resin tower. Regeneration of the exchange resin tower and / or recovery of the waste liquid, desalting and purification of the sucrose solution by using a strongly basic anion exchange resin tower and then a mixed bed tower filled with a strongly basic anion exchange resin and a weakly acidic cation exchange resin Of the strongly basic anion exchange resin tower and / or recovery of the regenerated waste liquid in the above method, glucose is passed through the strongly acidic cation exchange resin tower and the strongly basic anion exchange resin tower in this order, and then treated. Acid cation exchange resin column and strong basic anion exchange in the method of desalting and purifying by passing through a mixed bed column of cation exchange resin and strong basic anion exchange resin In a pure water production apparatus for regenerating a resin tower and / or recovering a waste liquid for recycle, treating raw water such as city water and industrial water with a strongly acidic cation exchange resin tower and then a strongly basic anion exchange resin tower to obtain pure water. Regeneration of a strongly acidic cation exchange resin tower and a strongly basic anion exchange resin tower, and / or collection of regenerated waste liquid, removal of impurity ions from various wastewater to obtain recovered water, a cation exchange resin tower or an anion exchange resin tower It can be used for regeneration and / or recovery of regenerated waste liquid, but it is not so strictly required for regeneration, especially for regeneration of ion exchange resin tower of desalting and purification equipment for sugar liquid and / or recovery of regenerated waste liquid. It is suitable.

In the present invention, an acid regenerating agent or an alkali regenerating agent is supplied to the inlet of the ion exchange resin tower at the time of regeneration of the ion exchange resin tower after the liquid to be treated is passed through the ion exchange resin tower and subjected to desalination purification. While regenerating the ion-exchange resin and measuring the pH of the reclaimed waste liquid flowing out of the ion-exchange resin tower outlet, recovering the regenerant based on the measured value, and controlling the amount of the drug passed through, it is used for regeneration. The amount of the regenerating agent is made appropriate, and a regenerating waste liquid having a composition close to that of an unused regenerating agent, that is, having a low impurity content, is collected and reused.

FIG. 1 shows an example of the configuration of an ion-exchange resin column of a sugar liquid desalination and purification apparatus in which the present regeneration method is suitably carried out.

In the step of desalting and purifying the sugar solution, the sugar solution 2 is sent from the inlet 6 of the ion-exchange resin tower 4 to the ion-exchange resin tower 4, and is desalted and purified by the ion-exchange resin filled therein. Thereafter, the outlet 8 of the ion exchange resin tower, the pipe 10
Taken out through.

When a predetermined amount of the sugar solution has been desalted and purified, the supply of the sugar solution is stopped, and the process proceeds to a regeneration step.

First, a regenerant 14 is supplied to the ion-exchange resin tower 4 through the inlet 6.

When the ion exchange resin packed in the ion exchange resin tower 4 is a strongly basic anion exchange resin or a weakly basic anion exchange resin, the regenerant is an alkali such as sodium hydroxide of 0.2 to 4N. Agent is used. The recycled waste liquid taken out through the outlet 8 is sent to a pH meter 12, where its pH is measured, and then discharged to the outside through a discharge pipe 16 until a predetermined pH described later is reached.

[0020] The pH of the regeneration waste liquid changes as follows.
That is, in the early stage of the passage of the regenerant, anions such as chloride ions and sulfate ions adsorbed on the ion-exchange resin are desorbed, so that the pH of the recycle waste liquid is smaller (lower) than the pH of the regenerant. Indicates a value. However, as the amount of anions desorbed decreases as the regeneration proceeds, the pH of the regenerant gradually decreases.
Approach. The fact that the pH of the regenerating waste liquid is equal to the pH of the regenerating agent means that the anion is scarce or not present in the regenerating waste liquid at that time. It can be reused as a regenerant in the process.

In the present invention, when the pH of the regenerated waste liquid reaches a predetermined range based on the pH of the regenerant,
That is, when the pH of the regenerating waste liquid becomes almost the same as the pH of the regenerating agent, the passage of the regenerating agent 14 is stopped, and the extrusion process is started. The above-mentioned predetermined range is preferably ± 0.2 of the value of the pH of the regenerant.

In the extrusion step, extrusion water 18 is supplied to the inlet 6 of the ion exchange resin tower 4. As a result, the regenerant remaining in the ion exchange resin tower 4 is extruded from the outlet 8 and is collected in the collection tank 22 through the pH meter 12 and the collection pipe 20. These operations are automatically controlled by an instruction from the control device 24. In addition, 26 is a valve.

Explaining concretely by exemplifying the figures, when the pH of the regenerating waste liquid becomes substantially the same as the pH of the regenerating agent (for example, the pH of the regenerating agent-0.2), the drug delivery is terminated and the extrusion step is performed. And the extruded water is supplied to the ion exchange resin tower to recover the regenerant. It is also preferable to measure the pH of the extruded water at the time of recovery, and recover only the portion having a high concentration of the regenerant, that is, the portion of the regenerant having a pH of 0.5 or more.

The regenerated waste liquid recovered as described above may be used as an initial regenerant in the next regenerating step, and thereafter, the ion-exchange resin may be regenerated with an unused new regenerant.

In the above description, the reclaimed waste liquid flowing out after the pH of the regenerant has become substantially the same has been described as being collected and reused. However, the present invention is not limited to this. Includes cases in which waste is discarded without being collected.

When the ion exchange resin packed in the ion exchange resin tower 4 is a strongly acidic cation exchange resin or a weakly acidic cation exchange resin, an acid agent such as 0.2 to 4 N hydrochloric acid is used as a regenerant. You. The pH change of the regenerated waste liquid taken out through the outlet 8 is as follows. That is, in the initial stage of the passage of the regenerating agent, the state in which sodium ions, calcium ions, and the like adsorbed on the ion exchange resin are desorbed continues, so that the pH of the regenerating waste liquid shows a value larger than the pH of the regenerating agent. . Thereafter, as the regeneration of the weakly acidic cation exchange resin proceeds, the amount of ions to be desorbed becomes smaller.
H rapidly approaches the pH of the regenerant. As described above, since the regenerated waste liquid having the same pH as that of the regenerant contains almost no impurity ions such as sodium and calcium, it can be reused as the regenerant.

Explaining concretely by exemplifying the numbers, when the pH of the regenerating waste liquid becomes substantially the same as the pH of the regenerating agent (for example, the pH of the regenerating agent + 0.2), the drug delivery is terminated and the extrusion process is started. Then, extruded water is supplied to the ion exchange resin tower to recover the regenerant. At the time of recovery, the pH of the extruded water is measured, and the pH of the regenerant is high, that is, the pH of the regenerant is +
A method of recovering only a portion having a pH of 0.5 or less is preferable.

It is preferable that the recycled waste liquid recovered as described above is used as an initial regenerating agent in the next regenerating step, and thereafter, the ion-exchange resin is regenerated with a new unused regenerating agent.

Examples of the strong basic anion exchange resin include Amberlite (registered trademark) IRA-900, IRA-41
1S, XT-5007, Diaion (registered trademark) PA
-312 and the like, and examples of the weakly basic anion exchange resin include Amberlite IRA-68, IRA-93,
Examples include IRA-94. Examples of the weakly acidic cation exchange resin include Amberlite IRC-50 and Diaion WK-11. Examples of the strongly acidic cation exchange resin include Amberlite IR-120B and IR-124.
Etc. can be exemplified.

The present invention includes a case in which only the amount of the regenerant passed is controlled, or a case in which only the recovery step of the regenerant is controlled.

[0031]

【Example】

(Reference Examples 1 and 2) The following desalination tests were performed using the ion exchange resin tower of the desalination and purification apparatus shown in FIG.

The ion-exchange resin tower 4 has an OH-type strongly basic anion-exchange resin (Amberlite IRA-402BL).
Was filled with 50 ml.

The conditions for passing the sucrose solution raw material (stock solution: Bx50) were as follows: 50 ° C., 2000 ml / 200 ml / hr flow rate.
Was desalted.

The total anion content in the raw material of the sucrose solution was 100 mg-CaCO ₃ / l in Reference Example 1 and 500 in Reference Example 2.
mg-CaCO ₃ / l.

After completion of the desalting step, a regeneration step was performed as follows. That is, 1N NaOH (pH = 1
4) The pH of the regenerated waste liquid was measured by the pH meter 12 while 125 ml (2.5 l / l-R) was passed down through the ion-exchange resin tower 4 filled with a strongly basic anion exchange resin. FIG. 2 shows the relationship between the amount of the regenerant and the subsequent flow of the extruded water and the pH of the regenerated waste liquid. In addition, pure water was used for the extrusion water.

In Reference Examples 1 and 2, since the total amount of anions in the sucrose solution is different, the remaining exchange capacity of the strongly basic anion exchange resin is different. For this reason, as shown in FIG. 2, the state of the change in the pH of the regeneration waste liquid is different.

As shown in FIG. 2, in the case of Reference Example 1, the amount of drug passed through was 1 liter.
/ L-R, and in the case of Reference Example 2, the drug delivery amount is 1.5
At 1 / l-R, the pH of the regenerated waste liquid was about 13.8, respectively.
At this point, it can be determined that the regeneration of the anion exchange resin has almost ended and has returned to the initial state.

Conventionally, the flow rate of the regenerant is 2.5 l / l-R.
The regenerating step was carried out at a rate of 1 l / l- in Reference Example 1 as described above, based on the results shown in FIG.
R, in Reference Example 2, it can be seen that it is possible to reduce to 1.5 l / l-R. Further, by recovering the waste liquid after the pH reached 13.8 and reusing it as a regenerant, the amount of new regenerant used can be greatly reduced.

(Reference Examples 3 and 4) OH type strong basic anion exchange resin (Amberlite IRA-402BL)
Sucrose solution (stock solution: Bx50) treated with H-type weakly acidic cation exchange resin (Amberlite IRC-76) 50
The mixture was treated in a weakly acidic cation exchange resin tower at 50 ° C. packed with 50 ml. The desalination treatment is performed at a flow rate of 400 ml / hr and a flow rate of 400 ml / hr.
The processing volume was 0 ml. The apparatus configuration of the ion exchange resin tower was as shown in FIG.

The total cation amount of the sucrose solution was 500 mg-CaCO ₃ / l in Reference Example _{3 and} 1000 mg-CaCO ₃ / l in Reference Example 4.

200 ml of 1N HCl (pH = 0) as a regenerating agent was flowed downward into the weakly acidic cation exchange resin tower.
(4 l / l-R) was passed, the weak acid cation exchange resin tower was regenerated, and the pH of the regenerated waste liquid was measured with a pH meter 12. FIG. 3 shows the relationship between the amount of the regenerant and the subsequent pumping water and the pH of the regenerated waste liquid.

FIG. 3 shows that the pH of the regenerated waste liquid reached about 0.2 when the flow rate of the regenerant was 1.6 (Reference Example 3) and 2.7 (Reference Example 4). It can be determined that the reproduction of is almost completed and has returned to the initial state. Extrusion water used was pure water.

Conventionally, the regeneration step was carried out with a regenerating agent flow rate of 4 l / l-R. However, from the results shown in FIG. 3, the regenerating agent flow rate was 1.6 l / l in Reference Example 3. −R, and in Reference Example 4, it can be reduced to 2.7 l / l−R. Further, by collecting the regenerated waste liquid after the pH reaches 0.2, it can be reused as a regenerating agent, so that the amount of new regenerating agent used can be greatly reduced.

Example 1 An anion exchange resin tower and a cation exchange resin tower having the same structure as that shown in FIG. 1 were prepared, and the present invention was carried out as described below. That is, an OH type strongly basic anion exchange resin (Amberlite IRA-4)
02BL) an anion exchange resin tower filled with 50 ml;
H-type weakly acidic cation exchange resin (Amberlite IRC-
76) A sucrose solution (stock solution: Bx50) was passed through a cation exchange resin tower filled with 25 ml in this order, and desalted. One cycle of processing is performed at a flow rate of 200 ml / hr.
The processing volume was 2000 ml.

The total anion amount and total cation amount of the sucrose solution were 500 mg-CaCO ₃ / l, respectively.

After the above liquid-passing treatment, 1N-NaOH (pH = 14) was passed as a regenerating agent through the strongly basic anion exchange resin tower, and 1N-HCl (pH = pH) was passed through the weakly acidic cation exchange resin tower. = 0), and the strong basic anion exchange resin tower and the weakly acidic cation exchange resin tower were regenerated. In the case of an anion exchange resin tower, the regenerant is 80 m
l (1.6 l / l-R) at the time of passing the drug,
Since H reached 13.8, the passage of the regenerant was stopped, and the extrusion process was started.

In the case of the cation exchange resin tower, the pH of the regenerated waste liquid reached 0.2 at the time when 70 ml (2.8 l / l-R) of the regenerant was passed, so that the regenerant was not passed. Stopped and started the extrusion process.

After completion of the above extrusion step, pure water was passed through the anion exchange resin tower and the cation exchange resin tower to perform washing by a conventional method.

After the washing is completed, the above-mentioned sucrose solution 2000 m
1 was passed again to perform desalting treatment. As a result, a treated sugar solution having an electric conductivity of 3.0 μS / cm or less could be obtained stably.

The amount of the regenerant used is the above-mentioned amount of the conventional regenerant (that is, 2.5 in the case of the anion exchange resin tower).
l / l-R, 4.0 l for cation exchange resin tower
/ L-R), which indicates that the present invention can significantly reduce the amount of the regenerating agent used in the prior art.

In the above embodiment, by collecting the recycled waste liquid after the start of the extrusion step, it is possible to obtain a recycled waste liquid having a low impurity content, which can be reused as a regenerating agent in the next regeneration step. It is needless to say that the amount of new regenerant can be reduced correspondingly.

[0052]

According to the method of the present invention, the pH of the regeneration waste liquid discharged in the regeneration step of the ion-exchange resin tower is measured, and the amount of the regenerant used is controlled by controlling the amount of the regenerant used to an appropriate amount. The amount can be reduced. Further, it is possible to collect and reuse a recycled waste liquid having a quality equivalent to an almost unused regenerant. As a result, the amount of the regenerant used per cycle can be significantly reduced.

[Brief description of the drawings]

FIG. 1 is a flow chart showing an example of an ion-exchange resin tower of a desalination and purification device used for carrying out the present invention.

FIG. 2 is a graph showing an example of the relationship between the pH at the outlet of a strongly basic anion exchange resin tower in the regeneration step and the flow rate of the regenerant and the subsequent pumping water.

FIG. 3 is a graph showing another example of the relationship between the pH at the outlet of the weakly acidic cation exchange resin tower in the regeneration step and the flow rate of the regenerant and the subsequent pumping water.

[Explanation of symbols]

 2 sugar liquid 4 ion exchange resin tower 6 inlet 8 outlet 10 pipe 12 pH meter 14 regenerant 16 discharge pipe 18 extrusion water 20 recovery pipe 22 recovery tank 24 control device 26 valve

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B01J 49/00 B01J 47/14 C02F 1/42

Claims (3)

(57) [Claims] 1. A method for regenerating an ion-exchange resin tower in which an acid regenerant or an alkali regenerant is supplied to an inlet of the ion-exchange resin tower and a regenerated waste liquid is taken out from the outlet of the ion-exchange resin tower to regenerate the ion-exchange resin tower. Supplying the regenerant to the inlet of the ion exchange resin tower and measuring the pH of the regenerated waste liquid while taking out the regenerated waste liquid from the outlet,
The pH of the regenerated waste liquid falls within a predetermined range based on the pH of the regenerant.
A method for regenerating an ion-exchange resin tower, wherein the supply of the regenerant is stopped when H reaches. 2. A method for regenerating an ion exchange resin tower in which an acid regenerant or an alkali regenerant is supplied to an inlet of the ion exchange resin tower and a regenerated waste liquid is taken out from an outlet of the ion exchange resin tower to regenerate the ion exchange resin tower. The regenerant is supplied to the inlet of the ion exchange resin tower and the pH of the recycle waste is measured while taking out the recycle waste from the outlet. When the pH of the recycle waste reaches a predetermined range based on the pH of the regenerant, the pH of the regenerant is reduced. A method for regenerating an ion-exchange resin tower, wherein the supply is stopped, and then extruded water is supplied to the ion-exchange resin tower to recover the regenerant from the ion-exchange resin tower. 3. The method for regenerating an ion-exchange resin tower according to claim 1, wherein the ion-exchange resin tower is used for desalting and purifying a sugar solution.