The present invention relates to a reactor (201) for preparing hydrogen cyanide by the Andrussow process, to an equipment (200) comprising said reactor and to a process for preparing hydrogen cyanide by the Andrussow process. The reactor (201) comprising at least one gas inlet (I) for reactant gases mixture, a catalyst (203), a porous support for the catalyst (204), a porous sub support (205, 206) and at least one outlet (P8) for the reaction products. According to the invention, said reactor has a cone frustum shaped metallic casing (210) and comprises inside the metallic casing, a gas distributor (202) located between the gas inlet and the catalyst, said distributor comprising at least one cone frustum element (D1, . . . Dn) having an upper base directed towards the gas inlet (I).

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.