Reactions, where the 'conversion related' optimization of the space
time alone doesn't work
All reactions where the product formation is not
obviously and steadily related to the conversion. That are reaction networks
with competitive paths, reactions with fraction term kinetics, many 'not
isothermal' reactions and so on. Here a few simple examples:
- competitive parallel reactions of different
order
- consecutive reactions (intermediate
product!!)
- autocatalytic reactions
- reactions with Hougen-Watson or Michaelis-Menten
microkinetics
- polymerization reactions (radical, initiator): e.g.
styrene polymerization
- and there is a quite a different matter too: thermal
effects: see example
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*But you have to pay attention:
some of these reactions exhibit a noticeable different function course in the
1/r(U) - plot, as for instance the autocatalytic reaction, - but others, as for
example the consecutive or parallel reaction don't do so, - the reason is that
'normally' the 1/r(U)-function is plotted for the educt consumption.
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* Example: for the
consecutive reaction you can reach a high conversion, but you don't
realize from the 1/r(U) - plot that you get more and more 'end product C' for
higher space times (in other terms: reaction times, likewise conversions) !!
see: snapshot of batch kinetics
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