A film model analysis of non-equimolar distillation of multicomponent mixtures

Abstract

Differences in the molar heats of vaporizations of component species in a multicomponent mixture lead to non-equimolar mass transfers during distillation separations. The interphase mass transfer process is analysed using a film model and a procedure developed for calculating multicomponent transfer coefficients and transfer rates from information on binary transport coeffficients and partial molar enthalpies of the constituent species in either fluid phase. It is shown with the aid of a numetical example that the commmonly made assumption of equimolar transfer during distillation may leade to signidicant errors in the calculation of constituent species transfers.