A method for simultaneous heat and multicomponent mass transfer incorporated with the volume of fluid surface tracking method was developed in a two-dimensional inclined channel. The process in the channel includes direct contact condensation of hydrocarbon mixtures with and without noncondensable gas, and distillation effect is also considered. Interfacial transport was performed by a multicomponent phase change model in kinetic forms considering the assumption of thermodynamic equilibrium at the vapor-liquid or vapor/gas-liquid interface using Peng-Robinson equations. The shear-stress transport k-omega turbulence model damped near the vapor-liquid or vapor/gas-liquid interface was used. The hydrocarbon mixtures in both phases were described by five pseudo-components, and Stefan-Maxwell equations were used to describe diffusional interactions in the multicomponent system. Parametric studies were performed to investigate further the model with various boundary conditions. Simulations for a binary system were also performed for a preliminary validation. For the liquid phase, similar trends of the Sherwood numbers were found between the results by simulations and predicted by the Penetration Theory. For the vapor phase, good agreement was observed between the results by empirical correlation and simulations. (C) 2012 Elsevier Ltd. All rights reserved.