Condensation of a binary vapour mixture in the presence of an inert gas

The simultaneous heat and mass transfer process during condensation of a binary vapour mixture in the presence of a non-condensable gas is analysed using matrix formulations of the interfacial mass transfer rate relations. A film model for multicomponent mass transfer based on an exact solution to the Maxwell-Stefan equations is used to calculate the mass transfer coefficients in the ternary vapour phase. With the aid of a computational example involving condensation of methanol and water vapours in the presence of air, it is demonstrated that diffusional interactions can significantly affect condensation rates.