PROCESS FOR THE PREPARATION OF METHIONINE

The present invention relates to a process for the preparation of methionine comprising the step of contacting a solution or suspension comprising 2-amino-4-(methylthio)butanenitrile and/or 2-amino- 4-(methylthio)butaneamide with water in the presence of a catalyst to give a methionine comprising mixture, wherein the catalyst comprises CeO2 comprising particles, wherein the CeO2 comprising particles have a BET surface area of from 175 to 300 +/- 10% m2/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter xFmax, mean of from 3 +/- 10% to 40 +/- 10% nm and a mean minimum Feret diameter xFmin, mean of from 2 +/- 10% to 30 +/- 10% nm, both measured according to DIN ISO 9276-6 (2012). 本发明涉及一种制备甲硫氨酸的方法，其包括在催化剂存在下，使包含2-氨基-4-(甲硫基)丁腈和/或2-氨基-4-(甲硫基)丁酰胺的溶液或悬浮液与水接触以得到包含甲硫氨酸的混合物，其中所述催化剂包含含CeO2的颗粒，其中根据DIN ISO 9277-5(2003)测量，所述含CeO2的颗粒的BET表面积为175至300±10％m2/g，平均最大Feret直径xF最大,平均为3±10％至40±10％nm，且平均最小Feret直径xF最小,平均为2±10％至30±10％nm，平均最大Feret直径xF最大,平均和平均最小Feret直径xF最小,平均二者均根据DIN ISO 9276-6(2012)测量。