Mixing and Transport Effects in Heterogeneous Chemical Reactors

13-3 MIXING AND TRANSPORT EFFECTS IN HETEROGENEOUS CHEMICAL REACTORS 

When chemical reactors have more than one phase, the problem increases in complexity because the reaction and mass transfer processes interact. The interaction is governed by the relative rates of the reaction and mass transfer. In some cases, chemical reactions are mass transfer rate controlled (very fast chemical reactions) and in others they are reaction kinetics controlled (very slow chemical reactions) however, in reality very few reactions strictly fit this classification. To understand the complex interactions and the various variables involved, the following sim-pUfied discussion and equations may be useful in explaining certain topics of interest and the relations between key variables. Thorough discussions of this 

The general mass balance on B in the continuous liquid in units of moles per time is 

In a steady-state batch liquid vessel, ACJAi and Ql are zero and the mass transfer rate equals the reaction rate. All other cases are more complicated. 

First consider the terms making up the mass transfer rate. 

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