Modeling ethane oxy-dehydrogenation over monolithic combustion catalysts

A numerical approach is used to investigate the role of a combustion catalyst in the oxidative dehydrogenation of ethane at short contact times for ethylene production. A two-dimensional (2-D) model, with mass and energy equations coupled with the Navier-Stokes equations, is applied to show that an oxidation catalyst can beneficially affect the formation of ethylene, by optimizing the sacrifice of ethane for producing heat with a larger selectivity to CO2 than a purely homogeneous process. Simulations also showed that for exceedingly high catalyst activity hot spots are formed on the catalyst walls, as the characteristic times of heat production become comparable with those of heat transfer. This may result into the formation of byproducts that reduce ethylene selectivity. (C) 2004 American Institute of Chemical Engineers.