Advanced Membrane Distillation and Pervaporation

Membrane distillation is a membrane separation/concentration process which has vapor pressure (temperature) gradient/ difference between the feed and the permeate side of a hydrophobic membrane as the driving force for the process, in other words, Membrane distillation is a thermally driven separation process in which separation is enabled due to phase change. A hydrophobic membrane acts as a barrier for the liquid phase, letting the vapor phase (e.g. water vapor) pass through the membrane's pores. In simple terms, heated salt water (feed) flows across one side and chilled salt free water (permeate) flows across the other side of a hydrophobic membrane at pressures less than the breakthrough pressure of the membrane. Liquid Water does not penetrate the pores of the membrane since it is hydrophobic. The vapor pressure of salt water is lower than the vapor pressure of salt free water. This vapor pressure differential encourages salt water to vaporize. Pure water vapor diffuses across the hydrophobic membrane from the feed to the permeate side and condenses into the chilled permeate stream. The PMI Membrane distillation machine is capable of measuring rate of increase in volume of the permeate stream under a wide variety of experimental conditions including pressure, circulation flow rate and temperature. Quality of feed and permeate can be compared using conductivity measurements of both streams. Clean permeate may be collected in flowing water, in flowing gas or under vacuum.

The major advantage of MD in desalination is the ability to achieve high rejection factors which cannot be accomplished by RO at high permeate fluxes. Production of high purity water is well established with rejection factors of almost 100% of non-volatile compounds
Food industry
• Fruit Juice concentration (Orange, Blackcurrant, pineapple, kiwi, sugarcane, camu-camu and cherry)
• Removing ethanol from fermentation broth
• Concentration of food colorants
• Dealcoholization of wine
• Concentration of herbal and plant extracts
Chemical Industry
• Concentration of nonvolatile acids
• Recovery of volatile compounds from aqueous solutions Water industry applications
• Semiconductor grade water (100% rejection)
• Pharmaceutical grade water
• Pure Drinking water
• Treatment of water with nanoparticles
• Purification of High Salinity water
• Nuclear Membrane distillation (waste heat from reactor is used)
Environmental applications
• Landfill leachate treatment
• Heavy metal concentration

  • Membrane area: 100cm2
    What can PMI Membrane Distillation/Pervaporation machines work with?
    Feed Characteristics
    • Temperature Range: 20-90°C
    • Recirculation Flow Rate: 0.1 - 1 gallon/min (Up to 10 gallons/min can be made)
    • Pressure Range: 1 - 120 psi
    • Maximum concentration: 200,000 ppm of NaCl equivalent
    • pH Range: 1.5-13 (may vary based on membrane used)
    • Feed Tank Volume: 5 liter standard (Up to 50 Liter possible)
    Feed Characteristics
    • Temperature Range: 5 – 30°C
    • Recirculation Flow Rate: 0.1-1 gallon/min (Upto 10 gallons/min can be made)
    • Pressure Range: Up to 120 psi (Vacuum or Sweeping gas optional)
    • Recommended Maximum Concentration: 1000 ppm of NaCl equivalent
    • pH Range: 5-9 (may vary based on membrane used)
    • Permeate Tank Volume: 5 liter standard (Up to 50 Liter possible)