(73d) Strategy for Commercial Scale-up of Partial Oxidation Reactions in Microchemical Reactors

Chemical synthesis in microreactors, a novel concept few years ago, is now well-known process of achieving improved yields. The enhanced productivity of microreactors is due to their high intrinsic heat and mass transfer rates. Successful commercialization of the microreactors will depend on several other factors. In this work, we explore the role of catalyst activity on reactor design. For moderately fast reactions such as the Fischer-Tropsch reaction, it has been shown that a packed bed microchemical reactor approach is a viable approach for commercialization. However, reactions such as partial oxidation that are both fast and have very exothermic side reactions require a different approach. CFD modeling of the partial oxidation of methanol over a V-Mo/TiO2 catalyst in a packed bed microchannel indicates that hot spots will occur leading to significant loss of yield. One promising response to the challenge of eliminating the hot spot while maintaining high volumetric productivity of the reactor is the use of a structured wall catalyst. Experiments using this structured wall reactor have shown significant improvements in the selectivity and yield of formaldehyde in the methanol partial oxidation. It is thus shown that the catalyst activity is an important parameter in the design of a commercial microchemical reactor.