TRANSPORT EFFECTS IN PACKED-BED OXIDATION REACTORS

Three gas-phase oxidation reactors are studied: the reaction of sulfur dioxide to sulfur trioxide, o-xylene to phthalic anhydride, and n-but ane to maleic anhydride. Mathematical models are developed to account for the transport phenomena in packed-bed reactors. A software package , the Chemical Reactor Design Tool, is used to solve these models and assess the effect of transport phenomena, Phenomena studied include he at and mass transfer resistances around the catalyst particles; densit y, velocity, and pressure variations; radial dispersion; and axial dis persion. Criteria are developed and taken from the literature to estim ate the importance of these phenomena a priori. These criteria are com pared with the results of the computer simulations. In most cases, the criteria accurately predict which phenomena are important to a partic ular reactor design. When the estimate from the criterion is questiona ble or borderline, computer simulations can be used to investigate the phenomenon's significance.