ABSTRACT

In this work the mass transfer analysis of the pervaporative separation of dichloromethane from aqueous solutions in hollow fiber devices has been performed. Experimental results were obtained at 40°C working at different flow rate values (0.02 − 0.105 l/min) and using modules with different thickness of membrane (148 − 433 µm).
In the pervaporation of dichloromethane from dilute aqueous solutions using polydimethylsiloxane hollow fibers, the rate of separation is strongly influenced by the mass transfer resistance in the feed phase. In the laminar flow regime, the resistance of the membrane is not dominant, although it may become significant at higher Reynolds numbers.
A mathematical model resulting from the solution of the continuity equation of the feed phase flowing in laminar regime through the hollow fiber module has been proposed. The analysis by means of the fundamental equations separates the effects of the operation variables such as the hydrodynamic conditions and the geometry of the system from the mass transfer properties of the system, described by the diffusion coefficient in the aqueous phase and the membrane permeability.