Kinetics of p-Xylene Liquid-Phase Catalytic Oxidation to Terephthalic Acid

A fractional kinetic model for the liquid-phase oxidation of p-xylene to terephthalic acid catalyzed by cobalt acetate and manganese acetate and promoted by hydrogen bromide was proposed. The developed model parameters were determined in a nonlinear optimization, minimizing the difference between the simulated and experimental time evolution of the product composition obtained in a semibatch oxidation reactor where the gas and liquid phases were well mixed. The experiments included four values of the initial concentration of p-xylene. Further, the effects of the oxygen partial pressure, reaction temperature, catalyst concentration, and promoter concentration on the time evolution of the experimental product distribution and kinetic constants of the developed model were investigated.