Researchers from the Indian Institute of Technology Guwahati (IIT Guwahati) led by Prof Tamal Banerjee, Department of Chemical Engineering, IIT Guwahati, have developed a heat transfer fluid based on nanofluids, which is capable of efficiently transferring heat generated using solar power to desalination systems. This advancement promises a practical solution for producing potable water from seawater, addressing the pressing issue of global water scarcity.

Heat transfer fluids are used in ‘concentrated solar power’ plants that concentrate sunlight onto a heat transfer fluid—the heat is then transferred to water to produce steam. The challenge of using CSP for desalination lies in transferring the generated heat from CSP systems to the desalination plants. Common heat transfer fluids, such as molten salts and synthetic oils, present drawbacks, including high melting points and low heat transfer efficiencies. Additionally, India’s dependence on imported heat transfer fluids escalates capital costs. To address these issues, the IIT Guwahati researchers explored the use of nanofluids, suspensions of nanoparticles in Deep Eutectic Solvent (DES), as an efficient alternative.

The researchers leveraged the exceptional thermal conductivity and stability of graphene oxide dispersed in a DES, a safe and environmentally friendly solvent. By modifying graphene oxide with an amine functionality, they achieved enhanced dispersion stability, overcoming the tendency of nanoparticles to clump together.

Elaborating on their work, Mr Nipu Kumar Das, “We developed a nanoparticle-dispersed deep eutectic solvent (NDDES) through precise mixing, demonstrating outstanding thermal conductivity and stability. This breakthrough has immense potential for sustainable energy applications, particularly in solar energy and desalination.”