The diffusion distillation is the evaporation and diffusion process below the boiling temperature of the mixture in a gap filled with the inert gas. It can separate the azeotropic mixture of ethanol and water. The mass transfer in a differential single column can be described by the Maxwell-Stefan equations. Differential mass balances which can extend a column model from a differential single column to an integral column and heat balances were suggested. The new model considers the sensible heat transfers and develops algorithm which enables to calculate interfacial temperature more precisely at condensing liquid film and include one more iterative loop. The results are compared with the experimental data and other models.