Nanofuels are the subject of a new feasibility study at Queen Mary, University of London, UK. The project, supported by Shell Research, has received nearly £200,000 of funding from EPSRC and could provide a more environmentally sustainable alternative to fossil fuels, say researchers.
The concept is to inject wet and dry fuels made from silicon, aluminium or iron nanoparticles (separately, as single fuels) into internal combustion engines, and measure the resulting thermal energy and work output. Scientists will examine the entire combustion process, including injection, oxidation, ignition combustion and engine performance – such as in-cylinder pressure and temperature.
Although nitric oxide will remain a by-product, lead researcher Dr Dongsheng Wen explains that the process, unlike burning fossil fuels, will not emit carbon dioxide and sulphur dioxide. The team also hopes to minimise nanoparticle emissions by capturing the resulting metal oxide particles using a combination of commercially available filters and electrostatic deposition methods, and reusing the materials in a closed loop process.
‘This could, if proven, open a window to replace fossil fuels,’ says Wen. ‘Hydrogen has been proposed as an alternative fuel, but we have still not realised this even though billions of pounds have been pumped into research. With hydrogen, there is a problem with transportation and storage, as it is a gas. But the nanoparticles are solid, and therefore easier to transport and store. There is no need for high pressure conditions to reduce volume.’
Aluminium, silicon and iron were selected as potential fuels due to their abundance in nature and high energy density (level of energy released per volume base is about twice that of fossil fuels, and only slightly lower at per weight base), as well as combustion properties. ‘Microparticles of aluminium, for example, are already used as an auxiliary fuel for rocket propulsion,’ says Wen.
Shell Research has offered to supply any liquid fuels required. A spokesperson says, ‘It is a far off concept, but we feel areas that are off centre need to be worked on. It will also generate a lot of interesting incidental science, and that in itself needs to be looked at’.