Abstract: The invention relates to catalytically active heating elements, and to the production and use thereof in the production of hydrogen cyanide (HCN). The problem addressed by the invention is that of providing thermally stable and catalytically active heating elements with which a BMA process can be simultaneously electrically heated and chemically catalysed. In particular, the heating elements should be thermally and mechanically stable in continuous industrial operation and retain their catalytic activity. The heating element according to the invention has a layered structure (A, B, C) formed from (A) silicon carbide (SiC), (B) aluminium nitride (AlN) and (C) platinum (Pt). The silicon carbide (SiC) serves as an electric heating resistor. The platinum (Pt) serves as catalyst. Aluminium nitride (AIN) is arranged as a protective layer between platinum (Pt) and silicon carbide (SiC). It prevents platinum (Pt) and silicon carbide (SiC) from alloying during ongoing operation.

Abstract: The present invention pertains to a method for producing methionine or salts or derivatives thereof from hydrogen cyanide (HCN), the method comprising a step of producing 2-hydroxy-4-(methylthio)butyronitrile (MMP-CN), or a crude product mixture comprising MMP-CN, by contacting a hydrogen cyanide (HCN) process gas mixture prepared according to the Andrussow process from methane, ammonia and oxygen, with 3-methylmercaptopropionaldehyde (MMP), wherein the HCN process gas mixture is obtained from the crude HCN process gas mixture by adjusting the amount of ammonia to between 20% (v/v) and 60% (v/v) of the amount of the ammonia in the crude HCN process gas mixture.

Abstract: The present invention pertains to a method for producing methionine or salts or derivatives thereof from hydrogen cyanide (HCN), the method comprising a step of producing 2-hydroxy-4-(methylthio)butyronitrile (MMP-CN), or a crude product mixture comprising MMP-CN, by contacting a hydrogen cyanide (HCN) process gas mixture prepared according to the Andrussow process from methane, ammonia and oxygen, with 3-methylmercaptopropionaldehyde (MMP), wherein the HCN process gas mixture is obtained from the crude HCN process gas mixture by adjusting the amount of ammonia to between 20% (v/v) and 60% (v/v) of the amount of the ammonia in the crude HCN process gas mixture.