| 摘要 |
A process for producing methionine advantageously in view of cost, while efficiently recovering useful components, is provided including the following steps: (1) hydrolyzing 5-[2-(methylthio)ethyl]imidazolidine-2,4-dione in the presence of a basic potassium compound; (2) introducing carbon dioxide into the reaction solution obtained in the step (1) to thereby precipitate methionine, and separating the resulting slurry into a precipitate and a mother liquor; (3) concentrating the mother liquor obtained in the step (2), mixing the resulting concentrate with a lower alcohol, introducing carbon dioxide into the resulting mixture to thereby precipitate methionine and potassium hydrogencarbonate, and separating the resulting slurry into a precipitate and a mother liquor; and (4) concentrating the mother liquor obtained in the step (3), treating the resulting concentrate by heating at a temperature of from 150 to 200° C., and recycling the treated solution for use in step (2). |
