Firing Up The Tank With Nanoparticles

In an attempt to make liquid fuels more energy efficient, scientists have found that adding aluminum or aluminum oxide nanoparticles to diesel fuel improves its ignition properties (Nano Lett., DOI: 10.1021/nl080277d). In simple hot-plate experiments, Arizona State University mechanical engineer Patrick E. Phelan and coworkers found that diesel fuel containing 0.1% aluminum or aluminum oxide nanoparticles ignites more readily at lower temperatures than pure diesel. The researchers suspect that adding nanoparticles to diesel improves the fuel's radiative properties and its heat- and mass-transfer capabilities. The nanoparticles increase the probability that a single drop of the fuel will ignite at just above 700 ??C. The probability increases from about 15% for pure diesel to between 50 and 60% for nanoparticle-enriched diesel. Phelan's group also looked at two different sizes of Al2O3 particles and found that 50-nm particles were slightly better at getting diesel to ignite than 15-nm particles but only at the lower range of temperatures tested. Envirox, a cerium oxide-based catalyst nanoparticle that's reported to boost fuel efficiency, is already on the market from nanomaterials firm Oxonica.