JP3205251B2 - Method for decolorizing melanoidin coloring liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decolorizing a melanoidin coloring solution, and more particularly to a method for decolorizing a melanoidin coloring solution using activated carbon fibers, in which regeneration with ozone water and regeneration with alkali are combined. The present invention relates to a method for decolorizing a melanoidin colored liquid.

[0002]

2. Description of the Related Art Hitherto, since a melanoidin-based coloring component is produced in the production process of sake, soy sauce, and lactic acid beverages, decolorization has been performed using powdered activated carbon. However, there is a problem that this used activated carbon powder is difficult to regenerate and cannot be reused, and must be discarded after one use. For this reason, recently activated carbon fibers (hereinafter ACF)
(Japanese Patent Publication No. 7-2213 and Japanese Patent Publication No. 7-2).
No. 214). Also, a method by ozone treatment has been proposed as a method for regenerating activated carbon (Matsumoto et al .: Research on microbial decomposition and rotation of pesticides (Part 1), Shizuoka Prefectural Shizuoka Industrial Technology Center Research Report, No. 39, p. 71). )

[0003]

When sake is decolorized using ACF, a large amount of washing water is required in the regeneration step using an alkaline aqueous solution, and thus a problem of wastewater treatment has arisen. In addition, the regeneration treatment of activated carbon by ozone treatment does not sufficiently recover the adsorptivity, and has not been practically used for the regeneration of ACF.

[0004]

In order to solve the above-mentioned problems, the present inventors have proposed a method for combining a regeneration process with ozone water and a regeneration process with an alkaline solution when decolorizing a melanoidin coloring solution using ACF. The invention method has been found.

The ACF used in the present invention is obtained by activating a polyacrylonitrile fiber, a pitch fiber, a phenol fiber and a rayon fiber by a known method to obtain an ACF. In particular, the surface area of the polyacrylonitrile-based 300 to 2 in terms of the adsorption rate of the melanoidin-based coloring component and the handleability.
ACF of 000 m ² / g is suitable. If the surface area is small, the decolorization rate becomes small and it is not practical. If the surface area is too large, the strength of the ACF becomes small and the ACF is damaged during handling, and fine powder is generated, which is unsuitable.

The form of the ACF used in the present invention is not particularly limited, and continuous fibers or short (discontinuous) fibers cut to a certain length are used. The fiber 2
Use in dimensional, woven or felt form is preferred in terms of handling. Fiber filled into blocks, woven or felt ACF laminated, columnar,
It is used in the shape of a prism or a cylinder.

[0007] The ACF used in the decoloring step of sake or the like and having reduced adsorption performance is recovered in the regeneration step and used again for decolorization. In the present invention, as the regeneration step, regeneration with ozone water and regeneration with an alkaline solution are used in an appropriate combination. The flow of sake in the decolorization (adsorption) step and the flow of washing water and the like in the regeneration step are preferably reversed from the viewpoint of the distribution of adsorbed substances and the desorption efficiency.

[0008] Regeneration with an alkaline solution has a high rate of recovery of adsorption capacity and can be used repeatedly. However, the amount of water used in the regeneration step becomes large, causing a problem of an increase in the size of wastewater treatment equipment. Regeneration with ozone water is slightly inferior in terms of recovery of the adsorption rate, but it has been found that the amount of washing water used in the regeneration step can be reduced to about １ ／ to １ ／ of that in alkali regeneration, As a result of intensive studies on the regeneration conditions, a practical method of the present invention was achieved by combining two types of regeneration.

The regeneration process using ozone water used in the present invention comprises water washing, ozone water washing, and second water washing.
Preferably, it comprises each of water washing, warm water washing, ozone water washing, second warm water washing, and second water washing. In order to reduce the amount of water in the water washing treatment, it is preferable to use warm water.

Water washing is performed by washing water at room temperature with an SV value of 200 to 300.
ACF by flowing at 0 ml / g · hr for 15-30 minutes
This is a process for removing impurities such as proteins attached to the surface. In order to remove the deposits more efficiently, it is preferable to wash with warm water at 50 to 80 ° C.

The washing with ozone is performed at an ozone concentration of 0.5 to 10 m.
g / l of water. Processing conditions are practically SV value 2
It is performed for about 15 to 30 minutes at 00 to 3000 ml / g · hr. Ozone water is prepared by blowing ozone gas into water.

To remove residual ozone after washing with ozone, it is necessary to perform a washing treatment. In order to reduce the amount of water used, it is preferable to perform a hot water washing treatment.

The regeneration step using an alkaline solution used in the present invention comprises each of washing, washing with an alkaline solution, washing with an acid, and washing with water. In order to reduce the amount of water to be treated, it is preferable to carry out water washing, warm water washing, alkali solution washing, water washing, acid water washing, warm water washing, and water washing.

[0014] Washing with an alkaline solution is carried out at an alkali concentration of 0.1 such as sodium hydroxide, potassium hydroxide and barium hydroxide.
SV solution of 200 to 3000 ml / g
-The adsorbate is desorbed by flowing for 15 to 30 minutes at hr. When the alkali concentration is high, the strength of the single fiber of the ACF decreases during the repetition of several tens of times, and fine powder is generated, which is not preferable. When the alkali concentration is low, it takes a long time for the regeneration, and the recovery rate of the adsorption ability is not sufficient.

After the treatment with the alkaline solution, the substrate is treated with an acidic aqueous solution in order to remove residual alkali by washing with water.
As the type of the acidic aqueous solution, an aqueous solution of hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, or the like is used. The concentration of the processing solution is suitably from 0.1 to 3.0% by weight. If the concentration of the treatment liquid exceeds 3.0% by weight, a large amount of washing water is required in the subsequent washing step. When the concentration of the treatment liquid is less than 0.1% by weight, the alkali remaining in the ACF after the treatment with the alkaline liquid is not sufficiently removed or it takes a long time to remove it. The preferred range is 0.2-2.0% by weight
It is.

The regeneration with ozone water and the regeneration with an alkali solution can be appropriately combined depending on the recovery state of the adsorption capacity by the regeneration and the capacity of the wastewater treatment equipment. Alkaline solution regeneration 1
It is preferable to repeatedly perform the decolorization (adsorption) step and the regeneration step in combination. In the decolorization of sake, it is particularly preferable to combine about four times of ozone regeneration with one alkali solution regeneration in order to maintain a practically used decolorization rate of about 50%. During the regeneration step, it is also possible to combine the ozone water washing and the alkaline liquid washing to form the regeneration step. Further, in order to recover the adsorptivity, it is also possible to appropriately combine a general gas treatment (activation). The gas used at this time is steam, carbon dioxide,
Carbon monoxide, ammonia and the like can be used, and activation by steam is generally preferred.

[0017]

EXAMPLE About 0.2 g of polyacrylonitrile-based ACF having a specific surface area of 1600 m ² / g (Fine Guard FW510 manufactured by Toho Rayon Co., Ltd.) was packed in a glass column having an inner diameter of 1 cm so as to have a layer height of 1 cm. An ACF having a packing density of 0.18 g / cm 3, which is a commercially available sake that has been colored yellow by heat treatment (about 0.1 ABS)
(430 nm, 5 cm cell)). The bleaching test is
Colored liquor (400 ml) was passed through the column at 3.3 ml / min (SV value 1000 ml / g · hr, passing time 120 minutes,
The temperature was 25 ° C), and the change in absorbance at that time was measured. The absorbances of the original sake and the processing solution were measured by Shimadzu self-recording spectrophotometer (UV-26
Measured in 5). In the regeneration test, after the decolorization step and the regeneration step with ozone water (1-2 mg / l) were repeated four times,
FIG. 1 shows the relationship between the number of repetitions (cycles: the number of repetitions of the decoloring step and the regenerating step) and the decoloring rate. The bleaching ratio is obtained by the following equation (1).

[0018]

(Equation 1)

Table 1 shows the conditions for alkali regeneration. Table 2 shows the conditions for regeneration with the ozone liquid.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Comparative Example] A decolorization test was performed using the same ACF as in the example. As a regeneration test, a change in the decolorization rate was measured when alkali regeneration was repeated and ozone regeneration was repeated. Shown for. In the case of ozone water regeneration alone, the decolorization rate decreases significantly from about 15 times.

[0023]

According to the method for decolorizing a melanoidin coloring liquid in which activated carbon fibers are regenerated and used repeatedly, the decolorization rate does not decrease even if the decolorization and regeneration steps are repeated, and the use of washing water in the regeneration step. The amount of the melanoidin coloring liquid can be efficiently reduced with a small amount.

[0024]

[Brief description of the drawings]

FIG. 1 shows the change in the sake decolorization rate. Specifically, an example (combination of ozone water regeneration and alkali regeneration)
7 is a comparison of the cycle changes of Comparative Examples 1 and 2 (only alkali regeneration or ozone water regeneration).

Continued on the front page (72) Inventor Takuo Inui 2078 Makigaya, Shizuoka City, Shizuoka Prefecture Inside of the Shizuoka Industrial Technology Center (56) References JP-A-53-72794 (JP, A) JP-A-4-200743 (JP, A) JP-A-48-95067 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) C02F 1/28 B01J 20/20-20/34 A23L 1/27

Claims (4)

(57) [Claims] 1. A method for decolorizing a melanoidin coloring liquid using activated carbon fibers and then regenerating the activated carbon fibers to repeatedly use the melanoidin coloring liquid, wherein the following steps (1) and (2) are combined. A method for decolorizing a melanoidin coloring liquid, comprising: (1) Decolorization step and regeneration step with ozone water (2) Decolorization step and regeneration step with alkaline solution 2. A method for decolorizing a melanoidin coloring liquid using activated carbon fibers and then regenerating the activated carbon fibers to repeatedly use the melanoidin coloring liquid, wherein (1) is repeated a plurality of times and then (2) A method for decolorizing a melanoidin colored liquid, comprising the steps of: (1) Decolorization step and regeneration step with ozone water (2) Decolorization step and regeneration step with alkaline solution 3. The regeneration step using ozone water includes washing with water, washing with warm water,
The method for decolorizing a melanoidin colored liquid according to any one of claims (1) and (2), comprising a treatment of ozone water washing, warm water washing, and water washing. 4. The regeneration with an alkaline solution includes washing with water, washing with warm water,
The method according to any one of claims (1) and (2), wherein each of the treatments comprises an alkaline liquid washing, a water washing, an acid washing, a warm water washing and a water washing.
The method for decolorizing a melanoidin colored liquid according to the above-mentioned item.