Researchers at NYU Tandon School of Engineering achieved a breakthrough in redox flow desalination (RFD). This emerging electrochemical technique can turn seawater into potable drinking water and store affordable renewable energy.
In a paper published in Cell Reports Physical Science, the NYU Tandon team increased the RFD system’s salt removal rate by approximately 20 per cent. It also lowered its energy demand by optimizing fluid flow rates. The project was led by Dr André Taylor, professor of chemical and biomolecular engineering and director of DC-MUSE (Decarbonizing Chemical Manufacturing Using Sustainable Electrification),
RFD offers multiple benefits. These systems provide a scalable and flexible approach to energy storage. It enables the efficient utilization of intermittent renewable energy sources such as solar and wind. RFD also promises an entirely new solution to the global water crisis.
“By seamlessly integrating energy storage and desalination, our vision is to create a sustainable and efficient solution. It will not only meet the growing demand for freshwater but also champion environmental conservation and renewable energy integration,” said Taylor.
RFD can both reduce reliance on conventional power grids and also foster the transition towards a carbon-neutral and eco-friendly water desalination process. Furthermore, integrating redox flow batteries with desalination technologies enhances system efficiency and reliability.
The inherent ability of redox flow batteries to store excess energy during periods of abundance and discharge it during peak demand aligns seamlessly with the fluctuating energy requirements of desalination processes.
“The success of this project is attributed to the ingenuity and perseverance of Stephen Akwei Maclean. He is the paper’s first author and an NYU Tandon Ph.D. candidate in chemical and biomolecular engineering,” said Taylor. “He demonstrated exceptional skill by designing the system architecture using advanced 3D printing technology available at the NYU Maker Space.”
What is redox flow desalination?
The system’s intricacies involve dividing incoming seawater into two streams. One is the salinating stream, and the other is the desalinating stream. Two additional channels house the electrolyte and redox molecule. These channels are effectively separated by a cation exchange membrane (CEM) or an anion exchange membrane (AEM).
In CH4, electrons are supplied from the cathode to the redox molecule, extracting Na+ that diffuses from CH3. The redox molecule and Na+ are then transported to CH4. Here, electrons are supplied to the anode from the redox molecules, and Na+ is allowed to diffuse into CH2. Under this overall potential, Cl- ions move from CH3 through the AEM to CH2, forming the concentrated brine stream. Consequently, CH3 generates the freshwater stream.
“We can control the incoming seawater residence time to produce drinkable water by operating the system in a single pass or batch mode,” said Maclean.
In the reverse operation, the brine and freshwater are mixed. The stored chemical energy can be converted into renewable electricity. In essence, RFD systems can serve as a unique form of “battery,” capturing excess energy stored from solar and wind sources.
This stored energy can be released on demand, providing a versatile and sustainable supplement to other electricity sources when needed. The RFD system’s dual functionality showcases its potential in desalination and as an innovative contributor to renewable energy solutions.
The future of the findings around redox flow desalination
While further research is warranted, the findings from the NYU Tandon team signal a promising avenue towards a more cost-effective RFD process. Thus, it is a critical advancement in the global quest for increased potable water. As climate change and population growth intensify, more regions grapple with water shortages. This underscores the significance of innovative and efficient desalination methods.
This research aligns seamlessly with the mission of DC-MUSE (Decarbonizing Chemical Manufacturing Using Sustainable Electrification), a collaborative initiative established at NYU Tandon. DC-MUSE is committed to advancing research activities that diminish the environmental impact of chemical processes through using renewable energy. The current study builds upon Taylor’s extensive work in renewable energy, with a recent emphasis on storing sustainably produced energy for utilization during off-peak hours.
An exceptional milestone, this publication marks the 100th from Taylor’s Transformative Materials & Devices Lab. Originally established at Yale University in 2008 and subsequently relocated to NYU Tandon in 2018, the lab focuses on developing innovative materials and devices for energy conversion and storage, reflecting Taylor’s enduring commitment to transformative research in the field.
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