Liquid Phase Ammoxidation of Monoalkylbenzene under Normal Pressure

Abstract

A study of liquid phase ammoxidation of ethylbenzene and various monoalkylbenzenes was carried out in order to examine the effects of reactions conditions on the formation of benzonitrile, and acetophenone.1. In case of ammoxidation of ethylbenzene, the best yield of benzonitrile was obtained under such reaction condions as to give a low yield of acetophenone. That is, 19.7mol% of ethylbenzene was converted and 19.5mol% of benzonitrile was obtained under the following conditions; reaction temperature 150°C, oxygen flow rate 0.5l/hr, ammonia flow rate 4.5l/hr, the reaction time of 10 hours, using Mn-acetate (0.023, molar ratio on the basis of ethylbenzene used), and NH4Br (0.029, molar ratio on the basis of ethylbenzene used) as the catalysts, and benzonitrile as the solvent.2. The order in the selectivity of benzonitrile formation at the same conditions was as follows: isopropylbenzene<toluene<ethylbenzene. 99.2mol% of the selectivity and 19.7mol% of the conversion were obtained in the case of ethylbenzene.3. In the liquid phase ammoxidation, we confirmed that the main reaction did not pass through the states of acetophenone and carbinol.