College of Computer Science and Engineering

Systems Engineering Department

Presents Public Seminar

Potential of Capacitive Deionization and Hydro-Magnetic Desalination Technologies for the Mena Region

Date: Wednesday, Jan 23, 2019

Time:  03:00 pm – 04:00 pm

Location: Building 24, Room 127

Speaker:

Dr. Moustafa Elshafei

Adjunct Professor

Systems Engineering Department

King Fahd University of Petroleum and Minerals

Abstract:

Freshwater scarcity is one of the most challenging problems facing the world today. Rivers, lakes, and surface ice represent only 1.2% of the fresh water sources on earth. The MENA region accounts for over 95% of the installed desalination plants. As such, there is a growing need in the MENA countries to explore desalination technologies to meet their growing need for fresh water. This talk provides an overview of two emerging desalination technologies; Capacitive De-Ionization (CDI) technology, and Hydro-Magnetic Desalination (HMD) technology. While the traditional techniques as thermal desalination and Reverse osmosis are based on removing water from salt, the two emerging technologies are based on removing salt from water.

In capacitive de-ionization systems, saline water is made to pass between a pair of porous electrodes connected to a voltage source. CDI is a two-step process; the first step is ion adsorption or charging that results in a pure permeate stream where ions are adsorbed in porous charged electrodes. Due to the presence of electrostatic field between the electrodes, there is movement of ions such that the positive ions, cations move to the cathode and anions towards the anode. Two layers of opposite polarity are formed at the electrode-solution interface which is referred to as electrical double layer (EDL) and ions are stored in these EDL’s. In the next step, voltage is reversed so that the ions get desorbed and flows out of the CDI cell as a brine stream and thus cause regeneration of electrodes. The problem of membrane fouling is not present in CDI. CDI has the potential to be energy efficient, robust technology for water desalination.

Hydro-magnetic desalination (HMD) techniques is based on ion separation by electromagnetic forces. While CDI is a two step process, HMD is a continuous process. CDI is suitable for desalination of brackish water with salt concentration less than 5000 ppm. HMD can be used over a wide range of salt concentration. Both techniques can be driven by solar energy.

HMD forces the positive salt ions to one chamber, and forces the negative salt ions to go to a second chamber. When these two charged chambers are electrically connected the chloride ions in the anion chamber loses two electrons, forming chlorine gas, which can be collected and sold as a byproduct. On the other hand, when the cation chamber receives two electrons the water dissociate forming hydrogen gas, and react with the sodium ions forming sodium hydroxide solution. As a result, the process produces no brine. Instead it produces Hydrogen gas and sodium hydroxide in one chamber, and Chlorine gas in the second chamber, in addition to the fresh water.

The revenues from selling these byproducts would also reduce the net cost of the produced fresh water. The technology not only eliminate the negative impact of discharging brine into the environment but could also contribute positively to improve the environment through the use of solar energy and conversion of CO2 to synthetic gas.

Speaker Bio:

Prof. Moustafa Elshafei acquired both his MS degree and PhD from McGill University, Montreal, PQ, Canada in 1978 and 1982, respectively; and joined the Systems Engineering Department at King Fahd University of Petroleum Minerals, Saudi Arabia as Professor of Control and Instrumentation Systems Engineering in 1987.  Some of his Research Interests include Intelligent Instrumentation and Control, Process Control and Industrial Automation, Application of Al in Oil and Gas Exploration and Industries, and Signal and Speech Processing of Arabic Language.

Prof. Elshafei is currently working as Adjunct Professor in the same department.

All faculty, researchers and graduate students are invited to attend.

Systems Engineering Department, College of Computer Sciences and Engineering

Telephone: +966 (13) 860 2988, Email: c-se@kfupm.edu.sa, Website: www.kfupm.edu.sa/departments/se/

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