A simplified mass transfer analysis for multicomponent condensation

Abstract

This paper considers the problem of calculating the condensation fluxes N_i for n-component vapour mixtures, taking account of diffusional interactions in the vapour phase. A simplified method for the flux calculation is suggested requiring the assumption that the matrix of multicomponent mass transfer coefficients [W], defined by the n-1 dimensional matrix relation (N) = [W](Δx), is constant along the diffusion path. This assumption allows the calculation of the steady-state fluxes N_i in an explicit manner without iterations. For conditions of equimolar diffusion, the simplified method developed here coincides with the linearized theory development of Toor and Stewart and Prober. For other cases involving diffusion through an inert gas, for example, the method suggested here is simpler than the Toor-Stewart-Prober approach. The accuracy of the simplified method is demonstrated with a few typical examples involving mass transfer in a ternary gas phase. Though condensation in the presence of an inert gas has been treated explicitly here, the developed simplified method should find application in other mass transfer processes such as distillation, absorption and extraction.