At present, converting seawater or saltwater is employed to change to more
freshwater to help meet the problem of shortage of freshwater. Membrane
distillation is a process for desalination in which only water vapor is passed
through a porous hydrophobic membrane. The modules used in this experiment
are tubular. Vacuum membrane distillation supplemented by humid air
recirculation (RVMD) is introduced to enhance the efficiency of the vacuum
system for water productivity enhancement. This study examined the operating
conditions of the system, that affect the performance of the system which consists
of cooling water temperature hot feedwater temperature, transmembrane
pressure, and transmembrane temperature. The results showed that when
increasing feed water temperature with the increase in the water flux. The
maximum flux value was 2.97 L/m2hr at the feed water temperature of 50°C,
transmembrane pressure -60 kPa, and cooling water temperature of 30ºC.