Preparation of aromatic polyamines

Claim 1

IN THE CONTINUOUS PROCESS FOR THE CATALYTIC HYDROGENATION OF AN AROMATIC POLYNITRO COMPOUND IN THE LIQUID PHASE IN THE PRESENCE OF A PALLADIUM CATALYST TO YIELD THE CORRESPONDING AROMATIC POLYAMINE, WHEREIN SAID AROMATIC POLYNITRO COMPOUND AND HYDROGEN ARE CONTINUOUSLY FED TO A REACTION ZONE CONTAINING AN AGITATED SLURRY OF PALLADIUM CATALYST, THE IMPROVEMENT WHICH COMPRISES SIMULTANEOUSLY AND CONTINUOUSLY (A) MAINTAINING THE REACTION ZONE SATURATED WITH HYGEN, (B) FEEDING SAID AROMATIC POLYNITRO COMPOUND FREE OF CATALYST TO THE LIQUID PHASE AT A RATE EQUIVALENT TO A CATALYST LOADING OF NO MORE THAN ABOUT 0.15 POUNDEQUIVALENT OF NITRO GROUPS PER HOUR PER POUND OF CATALYST IN THE REACTION ZONE, (C) MAINTAINING THE CONCENTRATION OF SAID AROMATIC POLYNITRO COMPOUND IN THE REACTION ZONE BELOW ABOUT 0.1 PERCENT BY WEIGHT, (D) CONTINUOUSLY WITHDRAWING FROM THE REACTION ZONE A PORTION OF THE LIQUID PHASE OF SAID SLURRY WHILE RETAINING SAID CATALYST IN THE REACTION ZONE, AND (E) MAINTAINING THE CATALYST CONCENTRATION WITHIN THE REACTION ZONE BETWEEN ABOUT 2 AND 25 PERCENT BY WEIGHT OF SAID SLURRY.