KR20070015437A - Activated-carbon composition and method of decoloring liquid with the same - Google Patents

Abstract

An activated-carbon composition which is less apt to cause dusting, has satisfactory handleability, and is excellent in decoloration performance, etc. The composition is characterized by comprising activated carbon and cellulose which have been coated with chitosan. Preferably, the composition is one obtained by precipitating chitosan from a chitosan solution in the presence of activated carbon and cellulose to thereby coat the activated carbon and cellulose with the chitosan. The composition is further characterized by containing the cellulose and the chitosan in amounts of 1 to 30 pts.wt. and 0.1 to 15 pts.wt., respectively, per 100 pts.wt. of the activated carbon. ® KIPO & WIPO 2007

Description

ACTIVATED-CARBON COMPOSITION AND METHOD OF DECOLORING LIQUID WITH THE SAME}

The present invention relates to an activated carbon composition and a method for decolorizing a liquid product using the same.

As a method of decolorizing liquid foods, such as alcoholic beverages and seasonings, the method of using a decolorizing resin and a reverse osmosis membrane is known. However, the method of using them is expensive in terms of equipment cost, and is hardly spread from the trouble of maintenance, etc., and the decolorization method by powdered activated carbon is common.

Powdered activated carbon used for decolorizing carbonizes sawdust, reactivates it with steam or chemicals, and then pulverizes it.

However, conventional powdered activated carbon is vulnerable to pressure, and the surface is shaved only by individual particles rubbing each other, and pulverized coal is generated. The pulverized coal is immediately generated even if the pulverized coal is removed by a sieve. In addition, since the pulverized coal generated is fine and light in specific gravity, there is a problem that it becomes dust at the time of working and the working environment worsens.

In addition, pulverized coal contained in conventional powdered activated carbon is hard to settle, and it becomes a state floating in the supernatant liquid, and filtration leak, blockage, etc. were generated by pulverized coal at the time of diatomaceous earth filtration (primary filtration). Further, when the primary filtrate is subjected to fine filtration (secondary filtration) using a membrane filter or the like, the pulverized coal that has passed through the primary filtration clogs the eye of the microfiltration membrane, causing filtration obstruction and deteriorating filterability of the secondary filtration. The problem is that the expensive filtration membrane is excessively consumed and the cost increases.

As a countermeasure against dust, there is a wet powder activated carbon (wet carbon) to which moisture is added. However, dust generation cannot be prevented sufficiently, and fine powder is suspended in the supernatant of the liquid food, There existed a problem that clogging and the filtration blockage of secondary filtration were easy to occur. In addition, since wettan is susceptible to propagation of bacteria (microorganisms) during storage, there is also a problem that it is not preferable for food hygiene to be used for foods such as liquid food.

As activated carbon for deodorizing decolorization of surfactant, the activated carbon surface-coated with chitosan is proposed (patent document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. 10-297913

Disclosure of the Invention

However, even when activated carbon coated with chitosan is used, there is a problem that dust is liable to be generated during operation, and filtration leakage and clogging of primary filtration and filtration clogging of secondary filtration occur.

An object of the present invention is to provide an activated carbon composition which is hard to generate dust, has good workability, and has excellent decolorizing performance, and a method for decolorizing a liquid product using the same.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, it discovered that the activated carbon composition formed by coating activated carbon and cellulose with chitosan can solve the said subject, and came to complete this invention.

That is, the present invention is an activated carbon composition characterized by coating activated carbon and cellulose with chitosan.

By coating activated carbon and cellulose with chitosan, it is possible to obtain an activated carbon composition which generates less dust during handling and has better sedimentability and better filterability than conventional powdered activated carbon.

In the activated carbon composition of the present invention, it is preferable that the activated carbon and cellulose are coated with chitosan by depositing chitosan from the chitosan solution in the presence of activated carbon and cellulose.

Moreover, it is preferable that 1-30 weight part of celluloses and 0.1-15 weight part of chitosan are contained with respect to 100 weight part of activated carbons.

The activated carbon composition of this invention is especially preferable for the decolorization of liquid food.

The discoloration method of the liquid substance in this invention is characterized by performing the decolorization process of the liquid substance by making the activated carbon composition of this invention contact a liquid substance.

Moreover, in the decolorizing method of this invention, it is preferable to use together the said activated carbon composition and at least 1 sort (s) chosen from the group which consists of a silica sol, tannin, and sodium alginate. It is especially preferable to use sodium alginate together. By using these together, the activated carbon composition can be settled faster.

The activated carbon composition of the present invention is characterized by coating activated carbon and cellulose with chitosan. Chitosan is the deacetylation of chitin, and as deacetylation degree, it is preferable that it is 70% or more, More preferably, it is 85% or more.

As the usage-amount of chitosan, 0.1-15 weight part is preferable with respect to 100 weight part of activated carbon, More preferably, it is 0.5-5 weight part. When the amount of chitosan used is small, the effect of preventing the generation of dust from activated carbon may be insufficient. Moreover, when the usage-amount of chitosan is large, since the quantity of activated carbon is comparatively small, the decolorization performance of an activated carbon composition may fall.

Although the cellulose used in this invention is not specifically limited, The cellulose, the hydrolyzate of cellulose, various adducts, its salt, etc. are mentioned. In particular, it is preferable to use staple cellulose derived from pulp and cotton thread. As staple cellulose, it is especially preferable that they are 10-30 micrometers of fiber diameters, and 30-1000 micrometers of fiber lengths.

As a usage-amount of cellulose, it is preferable that it is 1-30 weight part with respect to 100 weight part of activated carbon, More preferably, it is 5-15 weight part. When the amount of cellulose used is small, the effect of preventing dust generation may not be sufficient, and when the amount of cellulose used is large, the amount of activated carbon is relatively small, so that decolorization performance may decrease.

In this invention, it is preferable that the use ratio of chitosan and cellulose is 10-5000 weight part of cellulose with respect to 100 weight part of chitosan, More preferably, it is 50-2000 weight part.

Although the kind and particle size of the activated carbon used in this invention are not specifically limited, Powdered activated carbon is used preferably. Especially when the powdered activated carbon derived from sawdust which is easy to generate | occur | produce pulverized coal, the activated carbon containing a lot of pulverized coal, and the granular activated carbon under the sieving of activated carbon are acquired, these are used suitably.

As a method for producing the activated carbon composition of the present invention, for example, by dissolving organic acids such as lactic acid, acetic acid and citric acid, chitosan is dissolved in an acid solution adjusted to pH 3.0 to 4.5 to prepare a chitosan solution, After adding cellulose and activated carbon to this, alkaline aqueous solutions, such as sodium hydroxide and potassium hydroxide, are added and pH is 8.0-9.5, and chitosan is precipitated in presence of an activated carbon and a cellulose mixture, and the film of chitosan is formed, Then, the method of filtration, water washing, and drying is mentioned.

The concentration of chitosan in the chitosan solution is preferably 0.02 to 4% by weight. Moreover, it is preferable that it is 300-1000 weight part with respect to 100 weight part of activated carbon to add as quantity of a chitosan dissolution liquid.

The activated carbon composition of this invention coat | covers activated carbon and cellulose with chitosan, and only a part of the surface of activated carbon and a cellulose should be coat | covered with chitosan.

The activated carbon composition of the present invention is suitable for the decolorizing treatment of liquids such as liquid food, and the liquids that can be used in the decolorizing method of the present invention include sake, mirin, shochu, liqueur, miscellaneous wine, wine, beer, whiskey, and shaoxing wine. , Vinegar, soy sauce, fisheries, amino acid solution, juice, honey, sugar solution, tea, extracts and fermentation solutions of various animals and plants. Moreover, it can apply to the various processes until raw material preparation, refine | purification, and waste processing of these liquid foods, etc. are reached.

In the decolorizing method of the present invention, the activated carbon composition of the present invention is brought into contact with a liquid to decolorize the liquid. As a specific treatment method, (1) a method of directly injecting and mixing the activated carbon composition of the present invention into a liquid, followed by filtration, and (2) a mixture of the activated carbon composition of the present invention directly into a liquid and allowed to settle, The method of filtration, (3) The method of laminating | stacking the activated carbon composition of this invention on a filter paper or a filter cloth, and passing it through a liquid substance, and filtering. (4) After filling the column with the activated carbon composition of this invention, it is liquid And a method of filtering through water.

As the filtration method, natural filtration, pressure filtration, centrifugal filtration and the like can be adopted.

Compared with the conventional powdered activated carbon, the activated carbon composition of the present invention has a faster sedimentation, and the supernatant is easily filtered. In addition, the activated carbon composition of the present invention can be precipitated more quickly by adding silica sol, tannin or sodium alginate in combination.

Silica sol is not particularly limited, but can be widely used, including the known ones, the SiO ₂ content among these is used to preferably about 16-50% by weight, and not more than about 10ppm Fe content in the solid content of the sol, among them Is particularly preferably used. As a specific example of these silica sol, the brand names "Corolock 300", "Corolock SA", etc. made by Otsuka Foods, Inc. are mentioned.

As tannin, tannin containing substances, such as a persimmon and a tannic acid, are mentioned generally.

As sodium alginate, the brand name "Copolac A" by Otsuka Foods, Inc. is mentioned, for example.

The amount of silica sol, tannin, and sodium alginate to be used is preferably 50 to 3000 ppm for silica sol, 50 to 3000 ppm for tannin, and 10 to 100 ppm for sodium alginate with respect to a liquid product containing 5 to 10,000 ppm of activated carbon composition. .

By using the activated carbon composition of this invention, the filtration leak and clogging by pulverized coal in diatomaceous earth filtration (primary filtration) can be prevented, and the turbidity of a filtrate can also be made favorable. In addition, in the case of further performing fine filtration (secondary filtration), filtration can be performed smoothly without causing filtration blockage in the fine filtration.

In the decolorizing method of the present invention, in addition to the activated carbon composition of the present invention, the silica sol and the like, gelatin, peptide, polypeptide, collagen, fish gelatin, egg white, wheat protein, pea protein and the like within the range that does not impair the effects of the present invention. Protein, polysaccharides such as sodium alginate, carrageenan, agar, chitosan, gelling agents such as polyacrylic acid, PVPP (polyvinylpolypyrrolidone), silica gel such as silica gel, diatomaceous earth, cellulose, calcium silicate, calcium titanate, etc. Adsorbents, such as an adjuvant, bentonite, acidic clay, talc, alum, can be used together. These may use 1 type, or 2 or more types.

In the activated carbon composition of the present invention, dust is hardly generated before packaging, after opening, during filtration, and the like, and is excellent in workability. Moreover, the activated carbon composition of this invention is excellent in filterability and sedimentation property compared with the conventional powdered activated carbon.

To practice the invention  Best form for

Hereinafter, the present invention will be described in detail with reference to specific examples, but the present invention is not limited to the following examples.

<Preparation of activated carbon composition>

To 0.05 g of chitosan (average molecular weight 75000, deacetylation degree 89%), 150 ml of water was added and stirred, while the lactic acid was gradually added and the chitosan was completely dissolved to prepare a chitosan solution. To this chitosan solution, 4.45 g of powdered activated carbon (manufactured by Nimura Chemical Co., Ltd., brand name "FCS") and pulp-derived cellulose (average fiber diameter of 20 µm, average fiber length of 200 µm) were added. After confirming that pH was 3.9 or less and stirring for 5 minutes, after adding 1 volume% sodium hydroxide aqueous solution gradually and confirming that pH was 9.0 or more, it left still for 30 minutes and precipitated chitosan. Next, the mixture was filtered, washed with water, and dried to obtain 5 g of the activated carbon composition (89% by weight of activated carbon, 10% by weight of cellulose, 1% by weight of chitosan) of the present invention.

<Comparative Activated Carbon 1>

The powder activated carbon used above was made into comparative activated carbon 1.

<Preparation of Comparative Activated Carbon 2>

In the preparation of the activated carbon composition, 4.5 g of Comparative Activated Carbon 2 (99% by weight of activated carbon, 1% by weight of chitosan) was obtained by coating only powdered activated carbon with chitosan without using pulp-derived cellulose.

<Example 1> (measurement of dust scattering)

2 g of each sample of the obtained activated carbon composition, the comparative activated carbon 1, and the comparative activated carbon 2 were taken, it was dropped at 20 cm in height, and the scattering range (maximum diameter) of the activated carbon was measured. Table 1 shows the measurement results.

Scattering range Activated carbon composition 15 cm Comparative activated carbon 1 35 cm Comparative activated carbon 2 25 cm

As is clear from the results shown in Table 1, it can be seen that the activated carbon composition according to the present invention has a smaller scattering range and less dust scattering than the comparative activated carbons 1 and 2.

Example 2 (Measurement of Turbidity by Filtration Test)

0.2 g of each sample of the activated carbon composition, Comparative Activated Carbon 1 and Comparative Activated Carbon 2 according to the present invention was added to 100 ml of sake and stirred, followed by filtration with filter paper No. 5A, and the turbidity of the filtrate was measured by a turbidimeter (Nippon Electron Color). Industrial Co., Ltd. make: NDH-20D type). In addition, 50 ml of the filtrate was collected, filtered through a 0.45 µm filter, and visually checked for leakage of carbon. Table 2 shows the turbidity of the filtrate and the presence or absence of coal leakage.

Turbidity of the filtrate Presence of leakage Activated carbon composition 0.1% radish Comparative activated carbon 1 0.7% U Comparative activated carbon 2 0.3% U

As is clear from the results shown in Table 2, it can be seen that by using the activated carbon composition according to the present invention, turbidity of the filtrate can be significantly reduced and leakage of carbon can be reduced.

Example 3 (Sedimentation)

After adding 0.2 g of each sample of the said activated carbon composition, the comparative activated carbon 1, and the comparative activated carbon 2 to 100 ml of sake, and stirring, the turbidity of the supernatant liquid after 120 minutes was measured using the same turbidimeter as mentioned above. Table 3 shows the measurement results.

Supernatant Turbidity Activated carbon composition 8.5% Comparative activated carbon 1 25.7% Comparative activated carbon 2 15.2%

As is clear from the results shown in Table 3, it is understood that the activated carbon composition of the present invention has a high sedimentation rate and the fine powdered coal is hardly suspended in the supernatant, which can significantly reduce the turbidity of the supernatant.

<Example 4> (Sedimentation promotion test by silicazol, persimmon and sodium alginate)

0.2 g of each sample of the activated carbon composition and Comparative Activated Carbon 1 was added to 100 ml of sake and stirred, followed by addition of silica sol (Otsuka Food Co., Ltd. product, trade name "CopoLock 300") to 1000 ml / kl and stirred. A thing, persimmon (Iwamoto Kametaro Store, brand name "H-1") was added and stirred so as to be 1000 ml / kl, and sodium alginate (manufactured by Kimika Co., Ltd., product name "kimika algin I-3") The thing which added and stirred so that it might become 100 g / kl was prepared, respectively, and the turbidity of the supernatant liquid after 1 hour, 5 hours, and 24 hours after each was measured with the said turbidimeter. Table 4 shows the measurement results.

additive After 1 hour 5 hours later After 24 hours No addition Activated carbon composition 14.8% 7.2% 3.4% Comparative activated carbon 1 27.2% 17.5% 10.0% Copoloc 300 1000ml / kl Activated carbon composition 7.6% 4.4% 2.1% Comparative activated carbon 1 38.2% 25.3% 14.1% Persimmon 1000ml / kl Activated carbon composition 9.2% 5.2% 2.3% Comparative activated carbon 1 38.3% 24.6% 14.0% Sodium alginate 100g / kl Activated carbon composition 6.5% 4.1% 1.4% Comparative activated carbon 1 26.2% 18.9% 13.4%

As is clear from the results shown in Table 4, by using silica sol, persimmon (tannin) or sodium alginate together in the activated carbon composition according to the present invention, the settling of the activated carbon composition can be further accelerated, and the turbidity of the supernatant can be reduced. It can be seen that.

Claims (6)

Activated carbon composition characterized by coating activated carbon and cellulose with chitosan. The method of claim 1, Activated carbon composition comprising coating activated carbon and cellulose with chitosan by depositing chitosan from chitosan solution in the presence of activated carbon and cellulose. The method according to claim 1 or 2, An activated carbon composition comprising 1 to 30 parts by weight of cellulose and 0.1 to 15 parts by weight of chitosan, based on 100 parts by weight of activated carbon. The method according to any one of claims 1 to 4, Activated carbon composition, characterized in that for the decolorization of liquid food. The decolorizing method of the liquid substance which made the liquid substance decolorize-process by making the activated carbon composition of any one of Claims 1-4 contact a liquid substance. The method of claim 5, A method for decolorizing a liquid product, comprising using an activated carbon composition and at least one selected from the group consisting of silica sol, tannin, and sodium alginate.