Mass transfer efficiency multicomponent systems

In fact, through use of matrix models of mass transfer in multicomponent systems (as opposed to effective diffusivity methods) it is possible to develop methods for estimating point and tray efficiencies in multicomponent systems that, when combined with an equilibrium stage model, overcome some of the limitations of conventional design methods. The purpose of this chapter is to develop these methods. We look briefly at ways of solving the set of equations that model an entire distillation column and close with a review of experimental and simulation studies that have been carried out with a view to testing multicomponent efficiency models. 

In any event, we hope it is now well understood that mass transfer in multicomponent systems is described better by the full set of Maxwell-Stefan or generalized Fick s law equations than by a pseudobinary method. A pseudobinary method cannot be capable of superior predictions of efficiency. For a simpler method to provide consistently better predictions of efficiency than a more rigorous method could mean that an inappropriate model of point or tray efficiency is being employed. In addition, uncertainties in the estimation of the necessary transport and thermodynamic properties could easily mask more subtle diffusional interaction effects in the estimation of multicomponent tray efficiencies. It should also be borne in mind that a pseudobinary approach to the prediction of efficiency requires the a priori selection of the pair of components that are representative of the... 

Design Methods. Improvements ia the ability to predict multicomponent equilibrium and mass-transfer rate performance will allow significant improvements ia the design of new adsorption systems and ia the energy efficiency of existing systems. 

Toor, H. L., Prediction of Efficiencies and Mass Transfer on a Stage with Multicomponent Systems, AIChE J, 10, 545-547 (1964b). 

Model calculations were carried out by the example of a parabohc dependence of the interdiffusion coefficient for a binary system. The efficiency of the method was demonstrated for significant perturbations of the model experimental concentration profile up to 10% with respect to the exact values. The additional smoothing component of the discrepancy functional expressed as squared entropy production can be set to solve any inverse problems of heat and mass transfer. The suggested method, unlike the Matano-Boltzmann method, can be generalized to multicomponent systems with arbitrary sample configurations. 

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