(292d) Modeling of the Catalytic Oxidation Reaction Producing Terephthalic Acid

Terephthalic acid (TPA) is a commodity chemical for polyethylene terephthalate (PET). It is produced from homogeneous catalytic reaction which is the liquid phase oxidation of p-xylene using Co/Mn/Br catalyst dissolved in acetic acid solvent. For designing a cost-effective process, the acetic acid solvent should be diluted with water though the higher water content retards the desired reactions by stimulating the formation of manganese oxide, which is no longer catalyst. To overcome this limitation, zirconium is added to the catalytic reaction to prevent the formation of manganese during the p-xylene oxidation. Consequently, the optimal reaction conditions, e.g. water content and concentration of zirconium, should be determined to keep the conversion ratio at or above a desired level. For this purpose, we have developed mathematical models for this catalytic reaction system so that kinetic study on the catalytic oxidation reactions and possible side reactions has been carried out in this work. To obtain experimental data, the effect of the amount of the zirconium catalyst and the water content in the system have been experimentally investigated. Then, using the experimental data, the model parameters for the catalytic reaction system have been estimate. This developed will contribute to designing a commercial catalytic reactor performing above a desired level.