The following terms in the general heat balance have to be omitted for:

1. adiabatic reactors:

   • adiabatic STR,

     'cancel' : term (IIa) and (IIb) = convective term; term (IV) = heat exchange ;
     realize: * the heat 'goes into' the reaction mass via the instationary term (I)
     
     

   • adiabatic CSTR,

     'cancel': term (I) = instationary term; term (IV) = heat exchange;
     realize: * there is no strict adiabatic behaviour, as heat is transported by the convective flow: 'adiabatic' means here 'without heat exchange'. Heat 'goes' also into the reaction mass, but temperature rests constant (isothermal behaviour) when stationarity is reached.
     
     

   • adiabatic TFR,

     'cancel': term (I) = instationary term; term (IV) = heat exchange;
     realize: the balance 'convective term = reaction term' can be rewritten in a balance for a differential volume element. The convective term 'overtakes' here the role of the instationary term in the adiabatic STR.
     
     

2. not adiabatic reactors

   • continuous reactors,

     'cancel': term (I) = instationary term
     
     

   • batch STR,

     'cancel': term (II) = convective flow

see a blackbord sketch of the various possibilities for the 3 basic reactor types

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