Water desalination, Capacitive deionization, Permeating flow discharge (PFD)
Production of potable water from brackish water, generation of potable water using small, portable units during natural disasters and other emergency situations, deionization of radioactive elements in water, and semiconductor fabrication
This invention introduces a new capacitive deionization process with permeating flow discharge (PFD). The process involves the flow of saline water through a pair of high surface area, porous electrodes across which a small voltage is applied. During the flow the ions in the saline water move towards respective electrodes and consequently the water flowing out of the system is de-ionized. In the novel configuration, the waste water is permeated through porous electrodes rather than allowing the waste water to flow between the electrodes, as in the conventional axial flow discharge process. The new permeating flow discharge process is able to completely clear the electrode surfaces of all ions in a much smaller time interval, which increases the water recovery ratio and consequently the net throughput by 15-20%.
US patent filed on December 19, 2007
Barman, I., Lee, T., Heo, G., Suh, N.P., “Capacitive deionization process with decoupled charging and discharging flow schemes”, Proceedings of the Fifth International Conference on Axiomatic Design, Campus de Caparica, Lisbon, Portugal, pp. 185-192, 25-27 March, 2009.
Barman, I., Lee, T., Kim, S.-K., Suh, N.P., “Towards a low cost desalination process: Capacitive deionization with permeating flow discharge”, 2007 MIT Manufacturing Summit, September 27, 2007 (poster presentation).
Last revised:November 8, 2010
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