ABSTRACT
The intermediates necessary for producing these products are often unstable and require great care in their handling. Traditional techniques used to concentrate these intermediates include distillation, evaporation, crystallization, and centrifugation. The membrane process known as pervaporation has been recognized as a potentially valuable new way of concentrating pharmaceutical intermediates and products. Pervaporation is a membrane separation process for miscible liquids. The factors that affect pervaporation membrane performance are as follows: feed flow rate over the membrane surface, feed composition and temperature, membrane type and downstream pressure. A range of polymer membranes have been studied for removal of organics from water. Plate and frame systems consist of flat sheets of membrane sealed onto porous permeate plates by O-rings that are compressed onto membrane surface. Spiral wound modules consist of a flat sheet of membrane that is folded so that the two free ends are glued onto a porous tubular permeate collection pipe, the membrane then is wound around the central pipe.
