Research tests better way to remove salt from seawater for agricultural, human needs

New research from Binghamton University could lead to a more energy-efficient desalination method to turn seawater into fresh water for human consumption or agricultural use.

Assistant Professor Cosan Daskiran — a faculty member at the Thomas J. Watson College of Engineering and Applied Science’s Department of Mechanical Engineering — will lead research funded by the U.S. Department of Energy as part of a $10 million investment into its Water Power Technologies Office’s Powering the Blue Economy Initiative.

Daskiran and his collaborators from Lehigh University and Cleveland State University received a $607,819 grant to develop, test and establish proof of concept for their integrated tidal desalination system, which creates drinkable water through renewable energy using the rotational power of hydrokinetic turbines rather than electrical energy.

The conventional desalination process mostly uses the reverse osmosis approach, in which the whole module is operated at pressures higher than the thermodynamic minimum energy required. Daskiran and his team want to develop a centrifugal reverse osmosis (CRO) system, that harnesses the rotational energy of ocean turbines to generate varying centrifugal pressure within the desalination module, optimizing operational efficiency.

“Currently, renewable energy sources generate electricity, which is then employed by conventional reverse osmosis modules to purify water. However, the process of converting mechanical energy into electricity introduces inefficiencies, reducing the overall system efficiency.” Daskiran said. “Our concept for centrifugal reverse osmosis aims to eradicate conversion losses by directly integrating the turbine with the CRO system. This approach not only enhances efficiency but also streamlines the system, making it more compact.”

Professor Emeritus William Krantz from the University of Colorado invented the technology behind centrifugal reverse osmosis, and he serves as a senior advisor to the DOE project. Daskiran plans to apply this idea to seawater desalination, believing it could significantly reduce the energy requirements compared to conventional methods.

“When we cut the energy consumption by 30%, we anticipate a corresponding decrease of approximately 6% in the cost of desalinated water,” he said. “At first glance, this may not appear significant, but when considering the sheer volume of water being produced, it becomes crucially important.”

Daskiran worked with his Cleveland State collaborator, Assistant Professor Mustafa Usta, during their time at Lehigh studying for their PhDs. While Daskiran focused on turbine power generation, Usta delved into desalination — so this new DOE project brings together both areas of expertise.

The first phase of the project will involve the design, engineering and manufacturing of the centrifugal reverse osmosis module that will be supported by computational fluid dynamics (CFD) simulations. In the second phase, the effect of the CRO module on turbine performance will be studied with high-fidelity simulations and experiments at Lehigh’s Tidal Turbulence Test Facility managed by Professor Arindam Banerjee, department chair of Lehigh’s Department of Mechanical Engineering and Mechanics.

“The primary goal is to provide drinkable water for remote communities without an electric grid,” Daskiran said. “Also, in coastal urban regions, climate change-induced disasters like floods and power outages can compromise the safety of drinking water wells. This underscores the pressing requirement for renewable energy-driven desalination systems, such as the integrated tidal desalination system being developed in this project.”