MONITORING THE STOCHIOMETRIC RATIO WHEN CONVERTING NITROAROMATICS WITH HYDROGEN

摘要

The present invention relates to a continuous method for producing at least one aromatic amine by hydrogenation of at least one nitroaromatic with hydrogen, wherein a liquid phase containing at least the aromatic amine and a gaseous phase containing at least hydrogen are present, in the presence of a catalyst suspended in the liquid phase, at a temperature of 50-250°C and a pressure of 5-0 bar. The pressure in the reactor is held substantially constant by continuously adjusting the quantity of hydrogen supplied to the reactor, the total amount of hydrogen supplied to the reactor is monitored and the supply of the at least one nitroaromatic is interrupted if the hydrogen uptake of the reactor does not amount to at least 50 mol% of the hydrogen quantity required for stoichiometric reaction of the at least one nitroaromatic to form the at least one aromatic amine.