(560iv) Studying Heterogeneous Cobalt Catalysts for Sulfite Oxidation to Compare with Theoretical Models

The sulfite oxidation reaction, where air is bubbled into a stirred liquid tank with dissolved sodium sulfite, can be used to determine liquid side volumetric mass transfer coefficients. Many of the assumptions that go into the calculations rely on appropriate reaction kinetics. Therefore, a catalyst can be used to appropriately use theoretical models. In this study, cobalt was immobilized on heterogeneous supports and compared with homogeneous analogs of cobalt as well as the theoretical models. It was determined that some of the key assumptions broke down when operated at various conditions, which should be avoided. This was especially true if comparing with uncatalyzed reactions. In this study we approached the reaction as a tool to teach undergraduate students the importance of assumptions as well as various techniques for analyzing gas/liquid reactions including using the effluent gas oxygen content to measure reaction progress. By using a heterogeneous catalyst, this experiment lends itself as an excellent opportunity to reinforce concepts learned in the classroom with real world applications which include concepts such as mass transfer, catalysis, and reaction engineering. After the reaction, the catalyst can be recovered and reused thus reducing waste disposal and catalyst loss compared to homogeneous catalyst use.