Energy and Materials Technology Available for Licensing

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.

Efficient Humidification-Dehumidification Water Desalination

Keywords:
HDH desalination process

Applications:
Production of freshwater from seawater, groundwater or brackish water

Problem:

Poor energy efficiency of conventional humidification-dehumidification desalination

Lack of technology for small-scale, decentralized, off-grid desalination systems.

Advantages:

Significant enhancement of the productivity of freshwater

Practical and simple solution for the system to be working under varied sub-atmospheric pressure

Improvement of energy efficiency

Inventors:

Professor John H. Lienhard(Department of Mechanical Engineering, MIT)

Dr. Mostafa H. El Sharqawy (Department of Mechanical Engineering, MIT)

Prakash N. Govindan (Department of Mechanical Engineering, MIT)

Syed M. Zubair (King Fahd University of Petroleum and Minerals, Saudi Arabia)

Intellectual Property:
US Patent filed on September 4, 2009 and October 5, 2009

Efficient Humidification-Dehumidification Water Desalination

Keywords: HDH desalination process

Applications: Production of freshwater from seawater, groundwater or brackish water

Problem: Poor energy efficiency of conventional humidification-dehumidification desalination Lack of technology for small-scale, decentralized, off-grid desalination systems.

Advantages: Significant enhancement of the productivity of freshwater Practical and simple solution for the system to be working under varied sub-atmospheric pressure Improvement of energy efficiency

Inventors: Professor John H. Lienhard(Department of Mechanical Engineering, MIT) Dr. Mostafa H. El Sharqawy (Department of Mechanical Engineering, MIT) Prakash N. Govindan (Department of Mechanical Engineering, MIT) Syed M. Zubair (King Fahd University of Petroleum and Minerals, Saudi Arabia)