Optimized introduction of the starting materials for a process for preparing aromatic amines by hydrogenation of nitroaromatics

A process for preparing aromatic amines by hydrogenation of nitroaromatics by means of hydrogen in the presence of a suspended catalyst in the liquid phase

• in a reactor (1),
• at one end of which, preferably the upper end, there is a driving jet nozzle (2) via which the reaction mixture taken off from the bottom region of the reactor is injected via an external loop (3) into this region of the reactor (1),
• with introduction of the nitroaromatic at one end, preferably the upper end, of the reactor (1) and
• introduction of hydrogen,
• wherein
• at the correct fill height of the reactor, no direct physical contact between the inlet for the nitroaromatic and the liquid phase, preferably comprising the desired aromatic amine, water and catalyst, can occur in the reactor and/or in the pumped circuit either in the operating state or on shutting down and
• partial or complete blocking of the inlet for the nitroaromatic after improper contact between the inlet for the nitroaromatic and the liquid phase in the reactor can be detected by means of measuring instruments.