Adsorptive distillation is a new process to separate liquid mixtures in a packed distillation column. It depends on using active packing material instead of inert packing material in a packed distillation column. The active packing material can affect the intermolecular forces among the system components and thus alter its vapor-liquid equilibrium (VLE). The VLE of the ethanol-water system at 1 atm was studied using a circulation still in the absence and in the presence of different amounts of 4 Angstrom molecular sieves. The results obtained showed that the VLE of the system was altered in the presence of the molecular sieves, the azeotropic point of the system (at 89.7 mol% ethanol in the normal case) was eliminated and considerable separation was achieved for a mixture of azeotropic composition, and the alteration in the VLE of a given binary mixture is a function of the pore size and the amount of the molecular sieves.