Supply of solar energy in vacuum membrane distillation

Membrane distillation (MD) is a novel process introduced to overcome the disadvantages of the conventional distillation process. MD has gained much interest, principally, for its lower energy demand and higher rejection factors. This thermal process has the advantage of being able to be associated with solar energy to produce drinking water at low energy costs. A theoretical modelling of several compounds of VMD seawater desalination unit coupled with solar energy was carried. The solar flux increases until reaching 900 W/m² at solar noon. The variation of the temperature of the heat transfer fluid at the outlet of the cascades of solar collectors with plates increases gradually until reaching 80°C. A good approach has been shown between the theoretical and experimental values of the temperature of the coolant at the outlet of the solar collectors. For a pressure equal to 2500 Pa have shown that the permeate flow is equal to 7 kg/m²h when the system is coupled with solar energy while it does not exceed 3 kg/m²h without coupling with solar energy at noon. An increase of the pressure from 2000 to 10,000 Pa increases the flux of permeate up to 8 kg/m²h. The variation of the wind speed does not affect the flux of permeate. An increase in temperature for a constant pressure value of 2500 Pa and a wind speed equal to 1 m/s gives an increase in permeate flow. The same result has been shown with room temperature.