Remarks on Arheotropes

The aim of this section is to show that in an open batch distillation process both gas-phase and liquid-phase mass transfer resistances have a remarkable effect on the compositions at which nonreactive arheotropes and reactive arheotropes appear. 

Both mass transfer resistances are interconnected in a rather complex manner. The structure of these interconnections was made visible by the presentation of analytical solutions which could be easily handled on a spreadsheet calculation tool, even for much more complicated VLE equations with variable relative volatilities and chemical equilibrium equations of any complexity because no integration procedure is necessary, but just finding roots. 

Both mass transfer resistances - as can be seen from the analytical solutions -act in a different way and cannot be combined to a so-called overall transfer resistance . The introduction of such a lumped parameter will hide essential physical effects, evoked by these two resistances separately. 

Eventually, there is an essential difference between batch distillation processes and column distillation processes. Whilst in most adiabatic column distillation processes Stefan fluxes are usually very small (unless inert gases are present, as in hydrogenation or oxidation processes), the batch distillation process just lives from 

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