pervaporáció

Pervaporation is a membrane separation process used to separate liquid mixtures. It involves passing a liquid mixture across one side of a non-porous membrane, while a vacuum or a sweep gas is applied to the other side. The driving force for the separation is the difference in partial pressure of the components across the membrane. The more volatile components of the liquid mixture preferentially permeate through the membrane and are removed as vapor.

The selectivity of the membrane is crucial for effective pervaporation. Membranes are typically made of polymeric materials that are chosen based on their affinity for certain components in the mixture. For example, hydrophilic membranes are used to remove water from organic solvents, while hydrophobic membranes can be used for dehydrating organic liquids.

Pervaporation is an energy-efficient separation technique, especially for breaking azeotropes or separating components with similar boiling points where traditional distillation methods are not feasible or efficient. Its applications are diverse, including dehydration of alcohols, solvents, and gases, as well as the removal of organic compounds from wastewater and the recovery of valuable solvents. The process can be operated at low temperatures, which is beneficial for heat-sensitive substances. Key parameters influencing pervaporation performance include membrane properties, operating temperature, pressure difference, and feed concentration.