HDH desalination process
Production of freshwater from seawater, groundwater or brackish water
This invention introduces a water desalination process that uses the principle of humidification-dehumidification of air. In this process, air (or a carrier gas) is circulated between the humidifier and dehumidifier in a closed loop system. The air is humidified in the humidifier using the hot saline water, and then dehumidified using the cold inlet saline water. Therefore, the water vapor in the air condenses and is collected as potable water. The heating of the saline water or the humidified carrier gas may be carried out by using solar collectors or any waste heat source in which the maximum water temperature should not exceed 900C. In this novel technology, the pressure inside the humidifier and dehumidifier is lower than the atmospheric pressure during the system operation. Moreover, the moisture laden low pressure gas can be compressed to a higher pressure in an additional compression device and then sent to the dehumidification device. The dehumidification process also results in the heating up of the liquid mixture that is eventually used to irrigate the humidification device.
US Patent filed on September 4, 2009 and October 5, 2009
G.P. Narayan, M.H. Sharqawy, J.H. Lienhard V, and S.M. Zubair, “Thermodynamic analysis of humidification-dehumidification desalination cycles,” Desalination and Water Treatment, 16, 2010.
G.P. Narayan, M.H. Sharqawy, E.K. Summers, J.H. Lienhard V, S.M. Zubair, and M.A. Antar, “The potential of solar-driven humidification-dehumidification desalination for small-scale decentralized water production,” Renewable and Sustainable Energy Reviews, Vol. 14, No. 4, pp.1187-1201, May 2010
Last revised:November 8, 2010
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