Simulation of V2O5/TiO2 catalyst activity by central composite design for optimal operating conditions and catalyst life in phthalic anhydride production

A simple central composite design was applied to estimate the activity of V2O5/TiO2 catalyst and catalyst life in phthalic anhydride production. Using 1–3 years of simulation data, it was found that the temperature profiles along the catalyst bed and the outlet flow rates of phthalic anhydride and maleic anhydride (main by-product) were less than 8% deviation compared with the plant data. In comparing the simulated optimal conditions to the normal operating conditions, the phthalic anhydride production increased by 1,600 ton with the inlet o-xylene-air ratio (w/w) and the coolant temperature, while maleic anhydride decreased by approximately 340 ton.