JPS58210027A - Recovering method for amino acid - Google Patents

Abstract

PURPOSE:To obtain a free amino acid from a mineral acid salt thereof with a high efficiency, by treating the mineral acid salt of the amino acid with an alkali (earth) metallic salt type strongly acidic cation exchange resin, and regenerating the above-mentioned resin with an aqueous solution of the above-mentioned metallic hydroxide. CONSTITUTION:An aqueous solution of a mineral acid salt of an amino acid is passed through a packed column of an alkali metallic salt type or alkaline earth metallic salt type strongly acidic cation exchange resin and adsorbed in the above-mentioned resin. An aqueous solution consisting of an alkali metallic or alkaline earth metallic hydroxide is passed through the column to regenerate the above-mentioned resin and recover the amino acid as an aqueous solution. Thus, the free amino acid, particularly gamma-aminobutyric acid, is obtained efficiently from the mineral acid salt of the amino acid, particularly the amino acid hydrochloride. The above-mentioned alkali metal is preferably sodium.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recovering amino acids, and more particularly, to a method for recovering free amino acids from an aqueous solution of an amino acid mineral salt.

Since amino acids are usually water-soluble, it is difficult to efficiently recover free amino acids from amino acid mineral salts, for example. For example, when producing γ-aminobutyric acid, a method is known in which copyrrolidone is subjected to a hydrolysis reaction in the presence of a mineral acid catalyst. It will be collected.

Therefore, in this case as well, it is necessary to separate free r-aminobutyric acid from the γ-aminobutyric acid mineral salt, but no satisfactory treatment method has been found so far. For example, by passing an aqueous solution of γ-aminobutyric acid hydrochloride through a column packed with a weakly acidic anion exchange resin, the chlorine ions in the hydrochloride are adsorbed onto the anion exchange resin, and free γ-amino A method for recovering butyric acid is known, but with this method, free γ-aminobutyric acid can be recovered alone when the solution is passed through, but γ-aminobutyric acid can be recovered alone.
-The time for recovering aminobutyric acid alone is extremely short;
As a result, a mixture of γ-aminobutyric acid and its hydrochloride is immediately discharged, and γ-aminobutyric acid cannot be efficiently isolated.

In view of the above-mentioned circumstances, the present inventors have thoroughly investigated a method for efficiently recovering free amino acids from amino acid mineral salts, and as a result, they have developed a method for treating an aqueous solution of amino acid mineral salts using a specific ion exchange resin. Next, they discovered that by regenerating the ion exchange resin using a specific method, amino acids could be immediately released very efficiently, and the present invention was completed.

That is, the gist of the present invention is to provide a method for recovering amino acids from amino acid mineral salts, in which an aqueous solution of amino acid mineral salts is passed through a column packed with an alkali metal salt type or alkaline earth metal salt type strongly acidic cation exchange resin. The amino acids are adsorbed onto the cation exchange resin, and then an aqueous solution of an alkali metal or alkaline earth metal hydroxide is passed through to regenerate the cation exchange resin, and the amino acids are recovered as an aqueous solution. A method for recovering amino acids is provided.

The present invention will be explained in detail below.

The amino acids targeted by the present invention may be water-soluble, and usually aliphatic or aromatic monoaminomonocarboxylic acids, monoaminodicarboxylic acids, diaminomonocarboxylic acids, money-making amino acids, and oxyamino acids are used. Moreover, any of α-amino acids, β-amino acids, and γ-amino acids can be used. Specific examples of amino acids include α-1β- or r-amine acetic acid,
Examples include glycine, alanine, leucine, isoleucine, phenylalanine, tyrosine, methionine, cystine, cysteine, aspartic acid, glutamic acid, lysine, droxylidine, arginine, valine, proline, serine, threonine, oxyproline, and the like.

In the present invention, mineral acid salts of amino acids as described above are treated, and the types of mineral acid salts are usually hydrochlorides, sulfates, or nitrates. Amino acid mineral salts are used as aqueous solutions, and the concentration is usually between about 0.1 and 30 parts by volume.

An example of an aqueous solution of an amino acid mineral salt is, for example, when the target amino acid is γ-aminobutyric acid, a γ-amino acid salt obtained by hydrolyzing nypyrrolidone in an aqueous medium in the presence of a mineral acid is used. Mention may be made of mixtures containing mineral acid salts of butyric acid.

This hydrolysis reaction is usually carried out at a temperature of go~/10''(:, for about y~IO hours. If a mineral acid is present, for example, The amount of the aqueous medium used is 3 to 20 times the amount by weight of neepyrrolidone.

In the present invention, first, an aqueous solution of an amino acid mineral salt is passed through a packed tower of an alkali metal salt type or alkaline earth metal salt type strongly acidic cation exchange resin. Usually, a sulfonic acid type polymer whose base material is a particulate polymer 7 made of a copolymer of styrene and divinylbenzene is used. Further, examples of the alkali metal salt or alkaline earth metal include sodium salt, potassium salt, barium salt, and the like. However, if the target amino acid mineral salt is a sulfate, using a barium salt type cation exchange resin is not recommended because water-insoluble barium sulfate is generated, which may clog the inside of the packed column. none.

The cation exchange resin may be passed through the packed column either downwardly or upwardly, and the processing conditions are usually such that the processing temperature is s-so'c, and the liquid passing rate is 0. !
; -, about 2ψr.

Through this liquid passage treatment, the amino acid component of the amino acid mineral salt is adsorbed onto the cation exchange resin, and on the other hand, the alkali metal or alkaline earth metal liberated by this adsorption forms a salt with the mineral acid component of the amino acid mineral salt, This salt is recovered as an aqueous solution from the outlet of the packed tower. Since this adsorption treatment usually results in the inclusion of amino acid mineral salts, the determination can be made by analyzing this.

After the adsorption treatment, an aqueous solution of an alkali metal or alkaline earth metal hydroxide is passed through the packed column of the cation exchange resin to convert the cation exchange resin into an alkali metal or alkaline earth metal type. At the same time, free amino acids are recovered as an aqueous solution from the outlet of the packed tower.

As for the type of alkali metal or alkaline earth metal hydroxide, the same metal hydroxide as the metal salt of the cation exchange resin used in the adsorption treatment is usually used. The concentration of the metal hydroxide in the aqueous solution is usually 10 to 10% by weight. The liquid passage is usually carried out at a temperature of 5 to 50° C. and at a rate of 0.5 to φr. The amount of alkali metal or alkaline earth metal hydroxide supplied to the packed column may be approximately equivalent to the amount of amino acid adsorbed on the cation exchange resin.

Through this liquid flow treatment, the amino acid components adsorbed on the cation exchange resin are ion-exchanged with alkali metals or alkaline earth metals, so the cation exchange resin is regenerated, and free amino acids are released from the outlet of the packed tower. can be recovered as an aqueous solution. This amino acid recovery process is usually
The process is continued until the aqueous solution discharged from the cation exchange resin packed column contains an alkali metal or alkaline earth metal hydroxide. That is, in this treatment, the amino acids adsorbed on the cation exchange resin are desorbed and the free amino acids are recovered alone, but in the later stages of the treatment, the amino acids cannot be recovered alone and are recovered as a mixture with the hydroxide. Therefore, it is necessary to stop the amino acid recovery process. Amino acids can be easily isolated from the single aqueous solution of amino acids recovered here by a known method such as concentration crystallization.

Furthermore, after recovering the single amino acid component, it is desirable to further pass the aqueous solution of the hydroxide through a cation exchange resin packed column to discharge substantially all of the amino acid component remaining in the packed column. . Since the aqueous solution recovered here is a mixture of the hydroxide and amino acid, this aqueous solution can usually be used as the aqueous solution of the hydroxide used in the next step.

Since it is produced in a raw form, it can be repeatedly used for the adsorption treatment of the above-mentioned amino acid iron jH salt.

Furthermore, in the present invention, it is even more convenient to wash the inside of the cation exchange resin packed column by passing water through the cation exchange resin packed column between each treatment step.

According to the present invention, the amino acid component in the amino acid mineral salt can be efficiently adsorbed onto the cation exchange resin during the adsorption treatment, and when the adsorbed amino acid component is desorbed, the adsorption About 1fOMfji% or more of the amino acids collected can be recovered alone without mixing with other cross-reagents.

Therefore, the present invention is an industrially extremely advantageous method for recovering free amino acids from various amino acid mineral salts.

Next, the present invention will be explained in more detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example / <Production of γ-aminobutyric acid hydrochloride> In a reactor equipped with a stirrer and a temperature controller, 5 g of copyrolidone, 30 g of water, and 10 g of concentrated hydrochloric acid were charged, and heated under stirring to reflux conditions. The reaction was carried out for 6 hours at a lower temperature.

Analysis of the mixture after the reaction revealed that it was an aqueous solution containing 6% by weight of γ-aminobutyric acid hydrochloride and 0.3 weight percent of hydrochloric acid.

<Recovery of γ-aminobutyric acid> Sθθml of a sodium salt-type strongly acidic cation exchange resin (Mitsubishi Chemical Industries, Ltd., trademark Diaion EIK-/B) was packed into a packed column (diameter qo%, height 1000), and then A solution was passed through this packed tower for 3'1 minute until the γ-aminobutyric acid hydrochloride was contained in the aqueous solution produced above. In addition, by this liquid passage treatment, the amino acid component was adsorbed to 70% of the total exchange capacity of the cation exchange resin.

Continue to fill the packed tower with water? ! ; After washing with Oml, add g heavy [J'% caustic soda aqueous solution to 2 S
0 at a temperature of 'C. ! ; Liquid is passed at a speed of m, /'hr,
γ-aminobutyric acid was recovered by passing through the solution until caustic soda was contained in the aqueous solution discharged from the packed tower.

In such a method, it was recovered as a recovered r-a liquid.

Example In the method of Example 1, a barium salt type strongly acidic cation exchange resin was used in the recovery step of γ-aminobutyric acid, and a 3% barium hydroxide aqueous solution was used as the regenerating solution in the same manner. When adsorption and regeneration were performed, the amount of γ-aminobutyric acid adsorbed and the amount of a single solution of γ-aminobutyric acid recovered during desorption were as shown in Tables 1 and 7.

Examples 3 to S In the method of Example/, instead of r-aminobutyric acid as the amino acid, adsorption and regeneration were carried out in the same manner using a 75% by weight aqueous solution of the water-soluble amino acid moiety "1" shown in Table 7. As a result, the amount of amino acid adsorbed and the amount of amino acid alone solution recovered during desorption were as shown in the table.

Fang / Table note /) Amount of amino acid adsorbed When an aqueous solution of an amino acid mineral salt is passed through a cation exchange resin packed tower, the ratio of exchange groups adsorbing amino acids to the total exchange capacity is shown.

Note: Amino acid recovery' - Shows the ratio of amino acids recovered as a single amino acid solution to the total amount of amino acids adsorbed in the amino acid desorption process.

Sender: Mitsubishi Chemical Industries, Ltd. Representative Patent attorney required - (7 others)

Claims (1)

[Claims] (11. In a method for recovering amino acids from amino acid mineral salts, an aqueous solution of amino acid mineral salts is passed through a packed tower of an alkali metal salt type or alkaline earth metal salt type strongly acidic cation exchange resin. The amino acid is adsorbed onto the cation exchange resin, and then an aqueous solution of an alkali metal or alkaline earth metal hydroxide is passed through it to regenerate the cation exchange resin and recover the amino acid as an aqueous solution. (2) The method for recovering amino acids according to claim (1), characterized in that the alkali metal is sodium. (3) The amino acid mineral salt is amino acid hydrochloric acid. A method for recovering an amino acid according to claim (1), characterized in that the amino acid is a salt. (4) A method for recovering an amino acid according to claim (1), characterized in that the amino acid is γ-aminobutyric acid. Method for recovering amino acids.