Abstract: 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).

Abstract: 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 comprise from 50 to 100 wt.-% of CeO2, have a BET surface area of from 35 to 65 m2/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter xFmax, mean of from 10 to 40 nm and a mean minimum Feret diameter xFmin, mean of from 5 to 30 nm, both measured according to DIN ISO 9276-6 (2012).

Abstract: 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).

Abstract: The invention refers to the use of a particulate catalyst containing 60.0 to 99.5 wt. % ZrO2 stabilised with an oxide of the element Hf and at least one oxide of the element M, wherein M=Ce, Si, Ti, or Y, for the hydrolysis reaction of methionine amide to methionine, wherein the median particle size x50 of the particulate catalyst is in the range of from 0.8 to 9.0 mm, preferably of from 1.0 to 7.0 mm. The invention also refers to a process for preparing methionine comprising a step of contacting a solution or suspension comprising methionine amide and water with said particulate catalyst to provide a reaction mixture comprising methionine and/or its ammonium salt from which methionine can be isolated.

Abstract: 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 comprise from 50 to 100 wt.-% of CeO2, have a BET surface area of from 35 to 65 m2/g measured according to DIN ISO 9277-5 (2003), a mean maximum Feret diameter xFmax, mean of from 10 to 40 nm and a mean minimum Feret diameter xFmin, mean of from 5 to 30 nm, both measured according to DIN ISO 9276-6 (2012).

Abstract: The hearing system (1) comprises at least one hearing device which comprises an operability control unit (3) and, operationally connectable thereto, a storage unit (4) in which operability data (5) are stored. The operability control unit (3) is structured and configured to either disable or not disable the hearing device (2) from functioning as a hearing device in dependence of the operability data (5), and the hearing system comprises no means for modifying the operability data (5), more particularly comprises no means for modifying the operability data stored in the storage unit (4). The method for operating a hearing system (1) comprises providing a hearing system (1) comprising at least one hearing device (2) comprising an operability control unit (3) and, operationally connected thereto a storage unit (4) in which operability data (5) are stored, wherein the hearing system comprises no means for modifying the operability data.

Abstract: The hearing system (1) comprises at least one hearing device which comprises an operability control unit (3) and, operationally connectable thereto, a storage unit (4) in which operability data (5) are stored. The operability control unit (3) is structured and configured to either disable or not disable the hearing device (2) from functioning as a hearing device in dependence of the operability data (5), and the hearing system comprises no means for modifying the operability data (5), more particularly comprises no means for modifying the operability data stored in the storage unit (4). The method for operating a hearing system (1) comprises providing a hearing system (1) comprising at least one hearing device (2) comprising an operability control unit (3) and, operationally connected thereto a storage unit (4) in which operability data (5) are stored, wherein the hearing system comprises no means for modifying the operability data.