Credit: © 2008 ACS

Nanoparticles can improve the performance of solid fuels but little is known about the influence of adding nanoparticles to liquid fuels. Now, researchers have shown that adding aluminum nanoparticles to liquid diesel fuel can cause them to ignite more easily.

Patrick Phelan and co-workers at Arizona State University in the US and Agder University College in Norway1 released droplets of diesel containing aluminum and aluminum oxide nanoparticles onto a temperature-controlled hot plate. The ignition time was recorded for different hot-plate temperatures, different nanoparticle sizes (15 or 50 nm), and different volume fractions of nanoparticles (0%, 0.1% and 0.5%). The team found that the ignition probability for a fuel mixture containing nanoparticles was significantly higher than that for pure diesel.

The team propose that the high surface-area-to-volume ratio and small interparticle distances between nanoparticles can significantly improve radiative and heat/mass transfer, thereby reducing the time it takes the fuel to ignite. Optimizing ignition of fuel can improve the efficiency and performance of diesel engines.