Method for manufacturing aromatic amines

Preparation of aromatic amine (I) comprises hydrogenation of nitro aromatic compound (II) with hydrogen on a fixed catalyst; where the hydrogenation is carried out: at an absolute pressure of 1-50 bar and an initial temperature of the gas mixture by 150-400[deg]C and a maximal catalyst temperature of 600[deg]C under adiabatic conditions; the fixed catalyst is streamed with a gas mixture during the beginning of the hydrogenation; separating the hydrogen from the reaction mixture; and recycling the separated hydrogen into the hydrogenation process. Preparation of aromatic amine of formula (I) comprises hydrogenation of nitro aromatic compound of formula (II) with hydrogen on a fixed catalyst; where the hydrogenation is carried out: at an absolute pressure of 1-50 bar and an initial temperature of the gas mixture by 150-400[deg]C and a maximal catalyst temperature of 600[deg]C under adiabatic conditions; the fixed catalyst is streamed with a gas mixture containing 3-150 mol hydrogen- and 1-100 mol water per mol nitro group, during the beginning of the hydrogenation; separating the hydrogen from the reaction mixture; and recycling the separated hydrogen into the hydrogenation process. R 1>H, methyl, ethyl or amino; R 2>H (preferred for (II)), methyl or ethyl; and R 3>methyl, ethyl, nitro (all preferred) or H. [Image]. Die Erfindung betrifft ein Verfahren zur adiabaten Hydrierung von Nitroaromaten zu aromatischen Aminen in der Gasphase an ortsfesten Katalysatoren, worin der umzusetzende Nitroaromat mit Wasserstoff, Wasser, ggf. Stickstoff sowie im Wesentlichen in Abwesenheit von dem aus dem Nitroaromaten hergestellten aromatischen Amin unter Druck bei erhöhter Temperatur über den Katalysator geleitet wird.