New magnetic liquids to convert waste heat into energy
EU-funded researchers are developing new liquid magnetic materials that convert waste heat into electricity. The long-term aim for these materials, which are both affordable and environmentally friendly, is to use them to harness waste thermal energy to reduce energy consumption and help tackle the global energy crisis.
© viperagp #54958920, 2019 source: stock.adobe.com
Current global energy use is extremely inefficient. Across industrial sectors, 20-50 % of energy consumed is lost through heat. For gasoline- and diesel-powered vehicles, this figure rises to 60-70 %. Huge savings could be made to reduce the impact of the global energy crisis if even a portion of this waste heat could be converted into useful energy.
To achieve this, the EU-funded MAGENTA project has brought together experts from around Europe and across a range of disciplines to develop prototype liquids which will be used to produce thermo-cells. These liquids known as an ionic-based ferrofluids are made from new magnetic materials that can convert waste thermal energy into electricity. They contain magnetic nanoparticles dispersed in a sea of charged ions.
Importantly, the ionic-liquid based ferrofluids used in the thermo-cells are made of non-toxic raw materials which are easily and cheaply available, such as carbon, hydrogen, nitrogen, phosphorus and iron. This means that their development is both environmentally friendly and affordable.
The liquids are paving the way for technology to replace expensive and toxic solid, semiconductor-based thermoelectric technology, which is currently used to convert waste heat into useful energy. In addition, they are versatile in terms of shape and stable at relatively high temperatures, increasing their potential for many possible applications.
The project focus is on their application in the microelectronics and automotive industries. MAGENTA is developing breakthrough thermoelectric materials that will assist in an economic and environmentally sustainable energy transition in Europe, says project coordinator Sawako Nakamae of the French Alternative Energies and Atomic Energy Commission.
Theory becomes reality
Theoretical simulations and models to support the experimental findings are enabling the MAGENTA team to identify the best combinations of materials for effective waste-heat conversion. From this research, they have synthesised a few promising liquids and are scaling up their production to create large volumes for use in active thermo-cells, which they are currently developing in parallel. Meanwhile, work on second-generation ferrofluids continues.
The project is working with several industrial partners to transform fundamental knowledge into technological applications for their research. Once developed, the teams prototype energy converters will be used in microelectronic devices to act as a portable power source, as well as in the automotive industry to reduce fuel consumption.
However, their new magnetic liquid materials may have many uses as thermal-to-electrical energy converters beyond these industries. One of the ionic-liquid-based ferrofluids already created by MAGENTA has been taken up by an external group for further research and development.
In addition to creating and developing the new liquid thermoelectric materials, the MAGENTA project is also pioneering a new area of research into understanding these materials. MAGENTA is creating a seed community that is laying out the fundamental principles for understanding nano-liquids. This knowledge will nucleate out from the project, forming the foundations of innovation for future renewable energy science and technology, says Nakamae.
The MAGENTA team is creating a demonstration model thermo-cell that will be exhibited at science fairs and events to raise public awareness about thermoelectric materials and devices. Furthermore, together with UNESCO, the project is co-organising an international conference on new materials for thermoelectricity to be held in 2019. To date, the researchers have also published a number of peer-reviewed papers and trained seven young researchers.