Population balance and residence time distribution models for well-mixed reactor and regenerator systems

Abstract

By the use of population balance and residence time distribution models, the activity distribution and average activities in well-mixed vessels and in reactor-regenerator system are evaluated and discussed. Both methods give a same formula to evaluate the activity distribution for the catalysts in a well-mixed vessel with inlet catalysts of uniform or distributed activity. When the entrance catalysts have distributed activity and experience nonlinear deactivation or regeneration, the average activity calculated by both of these two methods, which are believed to be correct approaches, is not the same as that obtained by the average activity method currently used. Only the population balance model can be used to find the activity distribution functions and average activities in a reactor-regenerator system, in which the catalysts experience nonlinear deactivation and regeneration. For first order independent deactivation and regeneration, the average activity in each vessel of this system can be directly obtained from the moment equations without inverse transformation. Some design considerations for such a system are also presented.