Membrane contactor applications

In a membrane contactor the membrane separation is completely integrated with an extraction or absorption operation in order to exploit the benefits of both technologies fully. Membrane contactor applications that have been developed can be found in both water and gas treatment. Several recently developed applications that have been introduced in industry — selective removal of heavy metals from a galvanic process bath, organic component recovery from a process water in chemical industry and ammonia recovery from an off gas stream — will be discussed technically and economically to show the wide scope of the technology.

Unique features from membrane technology and conventional phase contacting processes form the basis of the new membrane contactor technology. Properties like the modular concept with high specific surface area from membrane technology are combined with the selectivity from conventional separation processes like extraction or absorption. This creates a new generation of highly efficient, compact and flexible separation technologies. Applications for membrane contactors are in gas–liquid and liquid–liquid contacting operations. The first full-scale membrane contactor installations are in successful operation in industry now. The success of these applications depends on the unique advantages of membrane contactors (flexible capacity, no phase separation, low volume, low weight, extreme phase ratios etc.). With these installations the long term reliability of membrane contactors can be demonstrated under industrial conditions. This will give more confidence in the membrane contactor technology for other end users and can lead to a whole new world of membrane contactor applications.