Method for manufacturing aromatic amines

摘要

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].