| 摘要 |
Process for preparing piperazine of the formula I by reacting diethanolamine (DEOA) of the formula II with ammonia (NH3) in the presence of hydrogen and a supported, metal-containing catalyst, wherein the catalytically active mass of the catalyst, prior to its reduction with hydrogen, comprises 20 to 85% by weight of oxygen-containing compounds of zirconium, calculated as ZrO2, 1 to 30% by weight of oxygen-containing compounds of copper, calculated as CuO, 14 to 70% by weight of oxygen-containing compounds of nickel, calculated as NiO, and 0 to 5% by weight of oxygen-containing compounds of molybdenum, calculated as MoO3, and the reaction is carried out in the liquid phase at an absolute pressure in the range from 160 to 220 bar, a temperature in the range from 180 to 220° C., using ammonia in a molar ratio to DEOA used of from 5 to 20 and in the presence of 0.2 to 9.0% by weight of hydrogen, based on the total amount of DEOA used and ammonia. |
