A new desalination process consisting of air humidification by pervaporation through hydrophilic or microporous hydrophobic hollow fibers followed by dehumidification by cooling water was investigated. In this system hot water is passed through hollow fibers in a recycled air-sweep pervaporation process. The water is heated by waste heat or solar energy or by any other cheap source of energy. The flux of water through the hollow fibers is in the range of 1.5–3.0 l/m2h, when water temperature is 45–65°C. The energy requirement for recycling hot water depends on water temperature as well as on the diameter and length of the hollow fibers. The energy requirement for air recycling depends on the air temperature and on the pressure drop of the system. The calculated energy requirement for pumping air and water in a pilot plant unit of a capacity of 6.3 l/h with 4 m2 of anion-exchange hollow fibers was about 2 kWh/m3, when hot water temperature was 60°C.
- Hollow fibers
- Water desalination