Simulation of a phthalic anhydride production process through gaseous catalytic oxidation of o-xylene in ChemCAD simulator

Abstract

Phthalic anhydride (PA) is a key industrial compound, particularly relevant for the large-scale production of plasticizers. This study aimed to develop the conceptual design of a proposed PA production process using the ChemCAD 7.1.2 simulation software, in which maleic anhydride (MA) wasidentified as the principal byproduct. Several parameters were obtained for the heat exchangers, including heat curves, heat duty, logarithmic mean temperature difference (LMTD), and overall heat transfer coefficient. Additionally, the mass flow rate and composition of the main process streams were determined through simulation, along with their temperature, pressure, and vapor fraction. Design parameters for both distillation columns were also calculated, as well as the heat duty of the catalytic reactor.Finally, the total purchase and installation costs of selected equipment were estimated. The mass flow rate of the bottom stream from the purification column was 10,921.083 kg/h, composed primarily of PA (99.19% purity) and o-xylene (0.80%), while MA was recovered in the top stream with a mass flow rate of 973.342 kg/h and a purity of 83.36%.