KAUST solar powered desalination prototype plant nearing commercial stage
King Abdullah University of Science and Technology (KAUST) is committed to four globally significant areas of research: energy, food, water, and the environment. In line with this commitment, University scientists are looking to utilize Saudi Arabia's year-round solar radiation to provide another element essential to all life: potable water.
Professor Kim Choon Ng and his team at the University's Water Desalination and Reuse Center (WDRC) are working to introduce solar-powered water desalination technology in Saudi Arabia.He is a visiting professor in the WDRC from the National University of Singapore (NUS).
The technology is adapted from his adsorption desalination (AD) project at NUS, where he has a prototype water plant built for cooling applications such as air conditioning.
From Singapore to Saudi Arabia
In March 2008, a team of KAUST executives visiting NUS experienced a live demonstration of Prof. Ng's prototype plant. Impressed with the project, the team suggested that the technology be used in joint collaboration with KAUST and extend the technology to desalination.
In March 2009, Prof. Ng began working with engineers from HOK, the firm that designed the University campus, on the plans for the prototype plant to be built at the University. Two years later, the prototype is fully automated and operational. It is being used for research purposes only.
This year Prof. Ng's two Postdoctoral Fellows, Young Deuk Kim and Kyaw Thu, joined him at the University to work on the project.
"The idea is to bring AD technology to KAUST and eventually have it being used in Saudi Arabia. This is something we are actively working towards achieving," Prof. Ng said. "The Kingdom is a country that receives a lot of solar radiation, so the project fits well with the country's environment and needs."
Elemental innovation
The plant desalinates water at a low energy consumption of 1.38 kWh/m3, which is around twice the thermodynamic limit of 0.78 kWh/m3 – the lowest possible energy needed to extract water. Conventional desalination technologies such as multistage flash or reverse osmosis consume energy at rates five to ten times higher than the thermodynamic limit.
Solar panels placed on the WDRC roof collect heat and transfer this heat to seawater stored in the prototype plant. Two things then happen: adsorption-triggered evaporation of the water, which cools the water at between 5 and 20 ºC, and desorption-activated condensation, where solar or waste heat (from 55 to 85 ºC) desalinates the seawater through a mesoporous adsorbant into a potable form with a pH of between 7.4 and 7.8.
"We are now entering the commercial prototype stage and with help from KAUST Economic Development, we are in talks with a Saudi company to take up the license from the University," explained Prof. Ng.
The technology can be efficiently driven by solar power or by harnessing waste that can be obtained from industrial processes like factories, plants, or other major facilities. With very few moving parts, the plant requires low maintenance and can be built vertically or horizontally, making the technology adaptable for application throughout the Middle East and the world.
"In principle the technology can be run from anywhere—it can extract heat from turbines or other industrial processes. Desert areas like Saudi Arabia get a lot of sunlight, so it's hugely beneficial for the Kingdom," Prof. Ng explained.