The pervaporation technology is a separation method that combines thermally driven distillation and membrane process. The driving force for the separation is the difference in the partial pressures of the components on the two sides and the absorption and diffusion through the membrane.

    During the separation process of pervaporation membrane, the feed solvent is placed in contact with the feed side of the membrane, and the vapor penetrant is removed from the permeate side. The low pressure of the permeate side is maintained by the use of a vacuum pump. Water molecules are preferentially adsorbed on the surface of the membrane, and then permeate through NaA zeolite membrane layer. The driving force of the process is the difference in the partial pressures of components across the membrane. After separation, the dehydrated product can be achieved.

     Inorganic NaA zeolite membraneswith uniform small pore size (~ 0.42 nm) were synthesized on the surface of a porous support by hydrothermal synthesis. Owing to the molecular sieving properties and strong hydrophilicity of NaA zeolite membranes, water could be preferentially separated from organic solvents by pervaporation with high perm-selectivity. Compared to organic pervaporation membranes, NaA zeolite membranes show higher selectivity as well as permeation flux, higher mechanical strength, and better thermal/chemical stability.