Pervaporation systems

Pervaporation. Vapor arbitrated pervaporation is used to remove ethanol from whiskey by selective passage of the alcohol through a membrane. Whiskey flows on one side of a membrane. A water-vapor stream flows on the other side and sweeps away the ethanol that permeates the membrane. Thus alcohol reduction and selective retention of flavor and aroma components can be achieved usiag membranes with a particular porosity. The ethanol can be recovered by condensing or scmbbiag the vapor stream. Pervaporation systems operate at or slightly above atmospheric pressure (Fig. 

In this process the addition of water vapor to the sweep stream can be controlled so that the water activity of the gas phase equals that of the beverage. When this occurs, there is no transport of water across the membrane. The water content of both the beverage feed and the sweep stream is kept constant. These conditions must be maintained for optimum alcohol reduction. The pervaporation system controls the feed, membrane, airstream moisture level, and ethanol recovery functions. An operational system has been developed (13). 

FIG. 22-80 Simplified flow schematic for a pervaporation system. Heated feed enters from left through a feed pump. Heaters in a recirculating feed loop may he required (not shown). Stripped liquid exits at the top of the pervaporation membrane. Vapor exits at the bottom to a condenser. Liquid and noncondensibles are removed under vac-imm. Cowiesif Hoechst Celanese. )... 

Pervaporation Most pervaporation systems are small so plate-and-frame systems were used in the first systems. Spiral-wound and capillary modules are being introduced. 

Pervaporation systems, 15 798 Perxenates, 17 326 Perylene Green (Yellow), colorant for plastics, 7 374t Perylene pigments, 19 443 commercial, 19 444t Perylene Red... 

The authors suggested that a combination of pervaporation with a conventional separation technique such as a hybrid distillation-pervaporation system could be useful economically to break the azeotropy. 

T0892 WRS Infrastructure Environmental, Inc., Soil Washing Process T0900 Zenon Environmental, Inc., Cross-Flow Pervaporation System... 

T0900 Zenon Environmental, Inc., Cross-Flow Pervaporation System... 

T0892 WRS Infrastructure Environmental, Inc., Soil Washing Process T0893 WRS Infrastructure Environmental, Inc., Thermal Desorption Unit T0897 Yellowstone Environmental Science, Inc. (YES), Biocat T0900 Zenon Environmental, Inc., Cross-Flow Pervaporation System... 

---