The Simulation And Study On The Oxidation Process For Liquid 1,2,4-trimethylbenzene With Air

Trimellitic acid is usually produced by liquid phase oxidation of 1,2,4-trimethylbenzene with air. The oxidation proceeds in acetic acid as solvent, with cobalt acetate,manganese acetate and bromine as catalyst, and at high temperature. In order to sufficiently understand the reaction mechanism and so as to improve the trimellitic acid producing process. The reaction kinetics and the reactor's mathematic model were studied in this paper. Firstly, for the oxidation reactions of 1,2,4-trimethylbenzene to trimellitic acid, a simplified first-order series-parallel model was proposed, and kinetic equations in constant catalyst concentration and fixed solvent ratio were set up according to the above model. Secondly, the mathematic model for the batch reactor of the above oxidation process was established on the basis of the gas-liquid reaction theory. Through computor simulation, the effects of the air flow at entrance and temperature on reaction were examined, the results between computation and measurement agree well either for laboratory reactor or pioneer one. Finally, the mathematic modeling and computing for continuous oxidation process were completed, the effects of single reactor and several reactors in series were evaluated,and the scheme of three reactors in series was recommended. The above research results can be utilized for the technological development and design of the industrial process.