Catalysts and Kinetic Regularities of Oxidation Processes of Chlorotoluenes

Abstract

The article is devoted to the selection, synthesis and study of the activities of the vanadium oxide-based catalytic systems supported on SiO₂ and Al₂O₃ carriers in the oxidation process of chlorotoluenes. It was shown that V-P-O/SiO₂+Mo, V-Mo-O/SiO₂+V, V-P-O/Al₂O₃+Sb, V-Mo-O/Al₂O₃+Mo catalytic systems exhibit high activity and selectivity in the processes of selective oxidation of mono- and dichlorotoluenes in the gas phase. The oxidation processes of chlorotoluenes were studied in open-type reactors with stationary and fluidized catalyst beds. It was established that the conversion of chlorotoluenes in a reactor with a stationary bed is higher than in a fluidized bed reactor, but selectivity in stationary bed it is slightly lower. The optimal conditions ensuring high conversion (80–95 %) and selectivity of the obtained chloromaleic anhydrides (40–45 %) were determined in a wide range of changes of technological parameters T=673–773 K, τ=0.1–1.0 s, molar ratios XT:O₂=1:1–1:25. It is established that the activities of the catalytic systems were different depending on the method of preparation. Thus, it was noticed that among the catalysts obtained by the methods of precipitation, mechano-chemical impregnation and co-precipitation-impregnation, the latter has shown satisfactory results.