Simulation and Optimization of the Production of Phthalic Anhydride from O-Xylene

Phthalic anhydride is the organic compound whose applications are mainly in the manufacture of phthalate plasticizers, phthalocyanine dyes, polyester resins and numerous fine chemicals. It is an anhydride of phthalic acid with a colorless nature. This colorless solid is an important industrial chemical, especially for the large scale production of plasticizers for plastics. Its major outlets are phthalate plasticizers, unsaturated polyesters and alkyd resins for surface coatings while its smaller volume applications include polyester polyols, pigments, dyes, sweeteners and flame retardants

The present study illustrates a way of producing phthalic anhydride (PA) in a continuous plant, with 99.8 % wt purity, through the oxidation of o-xylene. Maleic anhydride is also obtained as a by-product of the process with 99.5% wt purity. The process was simulated using the process simulator software ASPEN Plus and improving the purity of Phthalic anhydride obtained by introduction of suitable equipments. Simulation and optimization of the process is done using the new pathway.