Showa Denko Kabushiki Kaisha

Yoshihiko Hosaki

Koichi Wada

Nobutake Mihara

Kazuo Nakayasu

A novel separation process of an iminodiacetic acid component from an aqueous glycine solution including the same is provided. In this process, sulfuric acid is added, in the presence of sodium salt, to the aqueous glycine solution in such an amount that the pH of the aqueous glycine solution becomes 1.5 or less, whereby the iminodiacetic acid is crystallized from the solution and, then, the crystallized iminodiacetic acid component is separated from the mother liquor. Thus, glycine can be efficiently recovered without causing undesirable accumulation of the iminodiacetic acid component in the mother liquor.

Process for separating iminodiacetic acid from aqueous glycine solution

A process for purifying an .alpha.-amino acid containing cyano impurities comprising heating an aqueous solution of the .alpha.-amino acid in the form of its alkali metal salt in the presence of an alkali metal hydroxide to decompose the cyano impurities.

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Yokohama, Japan

Yoshihiko Hosaki