Recent progress in membrane distillation

Membrane distillation (MD) is an emerging membrane separation technique which provides a competition for the conventional separation process such as reverse osmosis (RO) and thermal distillation. The MD process was first developed in the 1960s, but only recently garnered the interest from academics and industry due to the advancement of membrane fabrication technique. The MD is a thermal-driven process which has an ability to be integrated with renewable energy and/or waste heat. The driving force of the MD process is vapor pressure difference where the feed vapor is transported through the non-wetted hydrophobic porous membrane to the permeate regime where permeate will be collected via condensation. As such, the MD possesses a theoretical rejection rate of nearly 100%. This review addressed the recent progress of the MD process in terms of membrane fabrication, integration with renewable energy and/or other membrane separation process as well as applications of MD in various industries. This paper may serve as an update of the recent progress of MD which in some way, is able to help the researchers explore the new investigation field in MD for it to be commercially more viable