JP3465291B2 - Method for producing water for beverage and food production - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention produces pure water used in the production of soft drinks such as carbonated drinks, fruit drinks, coffee drinks, tea drinks and water drinks and foods such as alcoholic drinks and confectionery. It concerns the improvement of the method. More specifically, the present invention comprises a cation tower packed with a strongly acidic cation exchange resin (hereinafter abbreviated as strong acid resin) and an anion tower packed with a strongly basic anion exchange resin (hereinafter abbreviated as strong basic resin). The present invention relates to improvement of a method for producing pure water used for producing beverages and foods by a multi-bed type pure water producing apparatus.

[0002]

2. Description of the Related Art Conventionally, water for manufacturing beverages and foods naturally complies with the water quality standards specified by the Ordinance of the Ministry of Health and Welfare, but industry groups and manufacturers have also established their own water quality standards. For example, the general conditions for water in the soft drink field are colorless and transparent, tasteless and odorless, free of microbial stains, containing almost no iron or manganese, and containing no residual chlorine. Is required to have low alkalinity and hardness. Although tap water and groundwater are used as the water source for soft drinks,
Treatments depending on the water quality of the raw water or the required water quality, such as aeration, filtration with sand or activated carbon, and coagulation sedimentation, are carried out individually or in combination. In recent years, examples of introducing a desalting step from the viewpoint of quality control when manufacturing drinking water have been increasing, and examples of the method for that purpose include an ion exchange method, an electrodialysis method, and a reverse osmosis membrane method. Among them, the ion exchange method is being widely used because it can remove almost all dissolved ions. Ion exchange method has many treatment methods using various ion exchange resins in combination depending on the purpose, but for water for producing beverages and foods, strong acidic resin and strong basic resin were mixed in the same tower. A mixed bed type in which raw water is passed later is generally adopted. Since the mixed bed type is a single tower type, the manufacturing cost of the device is relatively low, but the regeneration process is complicated and time-consuming. Of strong basic resin and a large amount of regenerant. This weakness has the drawback that the larger the device, the more difficult it becomes to neglect. Therefore, in recent years, a multiple bed type has been adopted in which raw water is passed in series through a cation tower filled with a strongly acidic resin and an anion tower filled with a strongly basic resin.
Since the decarbonation tower can be installed between the cation tower and the anion tower in the multiple bed type, in that case, the carbonic acid component in the raw water can be removed, the load on the anion tower is reduced, and the strong basic resin is used. And the amount of regenerant can be reduced. Furthermore, if both the cation tower and the anion tower adopt a countercurrent regeneration method in which the flow direction of the raw water and the flow direction of the regenerant are reversed, pure water of extremely high purity can be obtained, and the regeneration efficiency can be improved. Also, since the operating cost is significantly improved, the operating cost can be reduced.

[0003]

However, when the multi-bed type is adopted, there is an unpleasant odor even if a large amount of high-purity pure water having a low residual inorganic ion concentration is obtained, and beverages and foods are manufactured. It is difficult to collect water immediately as water for use, and there has been a demand for a manufacturing method capable of obtaining pure water having no odor immediately after passing through a pure water device. The cause of the unpleasant odor is considered to be the eluate from the ion exchange resin, especially the amine eluted from the strongly basic resin. Strongly basic resins are known to be of type I and type II due to the difference in the exchange groups, but since type II resins have a large flow-through exchange capacity, a large amount of pure water can be obtained, but the amine odor is more pronounced. It has the drawback of For example, in a pure water production apparatus using such a resin, an offensive odor may remain in pure water even after 6 months have passed during continuous operation. On the other hand, although the type I resin has a smaller amine odor than the type II resin, it may still have an offensive odor even after 5 days to 1 month.
Therefore, for strongly basic resins, it is possible to regenerate it with an aqueous solution of sodium hydroxide, wash it with an extremely large amount of water, and then collect water.However, washing with a large amount of water is not recommended. However, this is an irrational method that causes an increase in operating cost, a time hindrance in operation, etc., and leads to a decrease in productivity. The present inventors have taken measures to further reduce the odor from the I-type resin, which has a relatively small odor leakage, and have conducted an investigation for the purpose of obtaining tasteless and odorless treated water immediately after the test operation of the pure water production apparatus.

On the other hand, it has long been known that amines are the main eluate from strongly basic resins, but some qualitative references have been made regarding the relationship with odor intensity. However, it is not known whether it is quantitative or to a lesser extent suitable for drinking and food production. It is said that the odor component from the type I resin is trimethylamine, but since trimethylamine is also contained in seafood, it can be said that the toxicity risk is low if the concentration is low, but as a malodorous substance under the Malodor Control Law. Well known. The present inventors have diligently studied the correlation between trimethylamine concentration and odor, and by conducting a sensory test together, the trimethylamine concentration in pure water should be 20 ppb or less, which is a much lower concentration than conventionally considered. It was discovered that human beings do not feel tasteless and odorless. Further, a method of preliminarily pre-treating the type I resin to reduce trimethylamine in the treated water to 20 ppb or less was found, and a method for producing water for food production using the type I strong basic resin was established, which led to the present invention.

[0005] The present invention provides a multi-bed water purifying apparatus constructed a cation column and a strongly basic resin filled with strongly acidic resin from the anion column filled, a type I resin as strongly basic resins , And wash with polar organic solvent, or
Is heat treatment at 80 ℃ or higher in alkaline aqueous solution
To reduce the elution amount of trimethylamine
The use, resides in the production method of food preparation water, characterized by the following 20ppb trimethylamine concentration in water after the ion exchange treatment. The present invention will be described in detail below.

The method of the present invention is applied to a so-called multiple bed type pure water producing apparatus using a strongly acidic cation exchange resin tower and a strongly basic anion exchange resin tower. As the multi-bed apparatus, a two-bed two-column system in which a cation resin tower and an anion resin tower are connected in series, and a two-bed three tower system in which a decarbonation tower is further provided can be adopted. Furthermore, an apparatus using a weakly basic resin or a weakly acidic resin together can be used. The raw water to be used is not particularly limited as long as it can be treated with natural water, tap water or the like to obtain water suitable for drinking. The raw water is subjected to a pretreatment such as dechlorination as necessary, and then the method of the present invention is applied.

The ion exchange resin used is a strongly acidic cation exchange resin or a type I strong basic anion exchange resin, that is, an ion exchange group.

[0008]

[Chemical 1]

There is no particular limitation as long as the resin is Trimethylamine, which is an offensive odor component from the type I strong basic resin, is considered to be partly due to trimethylamine remaining in the resin particles during resin production. Therefore, it is necessary to forcibly remove it before use. Is also effective. As a method for removing the resin, a method of washing the resin can be mentioned. If the amount of trimethylamine eluted from the type I strong basic resin is washed with several thousand times the volume of the resin, clean water is used.
It has been known for a long time that it can be reduced to the level that a normal person feels tasteless and odorless, but it is not efficient.

Washing with a polar organic solvent is one of the efficient methods for reducing the elution amount of trimethylamine provided by the present invention. As the polar organic solvent used, methanol, ethanol, which has a strong affinity with the resin to be washed and has a high solubility in trimethylamine,
Acetone or the like is suitable. In washing, a column system with high washing efficiency is desirable, and in this case, the amount of the polar organic solvent used is 0.2 times the volume of the resin or more, preferably 0.
5 times or more is required and a contact time of 15 minutes or more is required.

Another efficient method for reducing the amount of trimethylamine eluted is heat treatment in the presence of an alkaline aqueous solution. The type of the alkaline aqueous solution is not limited, but usually an aqueous solution of caustic alkali, alkali carbonate or the like is used, and the temperature is 80 ° C. or higher under the condition of pH 10 or higher, preferably pH 12 or higher, preferably the reflux atmosphere of the aqueous solution, ie, 10
Heat treatment at 0 ° C. for 1 hour or more is required.

By carrying out the above-mentioned pretreatment, the regenerated strong basic anion exchange resin after regeneration is washed with water, but the amount of washing water is within 20 times the volume of the regenerated resin, and the concentration of trimethylamine in the treated water is reduced. Can be set to 20 ppb or less, and when the actual device is filled with a new resin, it is not necessary to significantly reduce the amount of rinsing water after the initial regeneration and to worry about the operational trouble.

[0013]

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. In the present invention, the trimethylamine concentration is measured by a gas chromatograph GC with a surface ionization detector manufactured by Shimadzu Corporation.
-14 APSI, and the sensory test was conducted by 6 testers by a three-level evaluation of smell and taste of treated water.

[Comparative Example] 100 ml of a commercially available styrene-based strongly acidic resin DIAION SK1B (registered trademark: manufactured by Mitsubishi Kasei Co., Ltd.) and the same strong basic resin DIAION SA12A (registered trademark: Mitsubishi Chemical ( 100)
Each ml was weighed and packed in two cylindrical glass columns each having an inner diameter of 14 mm. 2N-HC for strongly acidic resin
500 ml and 1N-NaO for strongly basic resin
After 500 ml of H was passed through each of the columns at a space velocity (SV) of 2 h ⁻¹ from the upper part of the column, 100 ml of ultrapure water was passed at the same flow rate. Next, Yokohama water was treated with sodium sulfite in advance to remove residual chlorine from the regenerated resin, and then a downward flow rate SV = 10 was sequentially applied to the cation tower and then the anion tower.
The solution was passed at h ^-1 , and the treated water was periodically sampled in a glass flask with a ground stopper. Table 1 shows the results of the trimethylamine concentration measurement and the sensory test performed on each sample.

Example 1 A glass column having a diameter of 45 mm and a length of 300 mm was filled with 200 ml of the same strongly basic anion exchange resin SA12A as in the comparative example, and 200 ml of reagent grade methanol was passed through for 1 hour. , Demineralized water 10
00 ml was poured for 2.5 hours and washed with water. 100 ml of the resin that had been washed with water was taken, Yokohama water was treated in the same manner as in Comparative Example, and trimethylamine concentration measurement and sensory test were carried out. The results are shown in Table 2.

[Example 2] 200 ml of the same strongly basic anion exchange resin SA12A as in the comparative example was weighed in a water-wet state, and 400 ml of demineralized water and 25 ml of 2N caustic soda were attached to four glass-made stirrers. Place in a neck flask. After heat treatment for 4 hours while stirring using an oil bath heated to 130 ° C., the resin was transferred to a glass column having a diameter of 45 mm and a length of 300 mm,
1000 ml of demineralized water was flowed for 2.5 hours and washed with water. 100 ml of the resin that had been washed with water was taken, Yokohama water was treated by the same method as in the comparative example, and trimethylamine concentration measurement and sensory test were carried out. The results are shown in Table 3.

[0017]

According to the method of the present invention, it is possible to obtain tasteless and odorless treated water promptly after the start of operation in which a new resin is filled, by using a multiple bed type deionized water apparatus using a strongly acidic resin and a strongly basic resin. Is possible.

[0018]

[Table 1]

[0019]

[Table 2]

[0020]

[Table 3]

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junji Fukuda 1000 Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Mitsubishi Kasei Co., Ltd. (56) Reference JP-A-63-97236 (JP, A) JP-A 5-92183 (JP, A) JP 64-66598 (JP, A) JP 54-112380 (JP, A) JP 60-102950 (JP, A) JP 63-97286 (JP, A) JP 54-34545 (JP, A) JP 5-49950 (JP, A) JP 48-18706 (JP, B1) Shozo Miyahara Takazo Omagari Shigeo Sakai, Ion Exchange, Japan, Ltd. Chemical Industry, October 15, 1976, 12 (58) Fields investigated (Int.Cl. ⁷ , DB name) C02F 1/42 B01J 39/00-49/02

Claims (4)

(57) [Claims] 1. A multi-bed type pure water producing apparatus comprising a cation tower filled with a strongly acidic cation exchange resin and an anion tower filled with a strongly basic anion exchange resin, and a beverage or a food product. The concentration of trimethylamine used as water for manufacturing
A method for producing pure water of ppb or less, wherein the strongly basic anion exchange resin is an I type resin and is polar.
Wash with organic solvent or in alkaline water
By heat-treating above ℃,
Those who are characterized by using a reduced elution amount
Law. 2. Washing with a polar organic solvent is performed using methanol.
A pole selected from the group consisting of
The basic organic solvent and the strongly basic anion exchange resin for 15 minutes or more.
Claims characterized by being made by contacting up
The method according to Item 1. 3. The heat treatment in an alkaline aqueous solution is 8
Characterized by being performed at 0 ° C to 100 ° C for 1 hour or more
The method of claim 1, wherein 4. The heat treatment in an alkaline aqueous solution is performed at pH
Characterized by being carried out in 12 or more alkaline aqueous solutions
The method according to claim 1 or 3, wherein