The effect of the surface tension gradient on froth stabilization and distillation tray efficiency is investigated experimentally in an Oldershaw column. Six binary mixtures with a wide range of physical properties are selected for this study. A point efficiency model is proposed, which takes into account the surface tension gradient effect that gives rise to froth stabilization in gas-liquid dispersion. The model satisfactorily predicts the trend and magnitude of point efficiency with respect to concentration for different systems, especially for the surface tension positive systems where enhanced point efficiency accompanied by a sharp decline at the high concentration region is observed.