| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for producing methionine stably for a long period, preventing effectively corrosion of a reaction vessel relative to both of a liquid phase part and a vapor phase part of hydrolysis solution even in the case of hydrolysis at a higher temperature, when producing methionine by hydrolyzing M-hydantoin in the presence of a basic potassium compound. <P>SOLUTION: In this method for producing methionine by hydrolyzing 5-(β-methylmercaptoethyl) hydantoin in the presence of a basic potassium compound in water, hydrolysis is performed with basic potassium concentration of ≤9.5 wt.%, at a hydrolysis temperature of ≥170°C, and in a reaction vessel whose inner surface is constituted of stainless steel having a 21.0-30.0 wt.% Cr element content, a 4.5-11.0 wt.% Ni element content, a 1.0-5.0 wt.% Mo element content, a 0.05-0.50 wt.% N element content, a ≤0.50 wt.% W element content and a ≤0.10 wt.% Cu element content. <P>COPYRIGHT: (C)2012,JPO&INPIT |
