Mixing or Residence Time

To go from volume element models to reactor models the macro flow patterns in the reactor need to be considered. For stirred tank reactors this can be quite simple, in those cases where volume elements in the stirred tank can be described in terms of average conditions. This is not so when macro mixing or residence time distribution are scale dependent, see Chapter 7. When the reactor is tubular, with two countercurrent or parallel flows, the volume element models have to be combined with reactor flow models, including axial mixing. Also this is treated in Chapter 7, for various cases. 

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