Nanoparticles have added yet another string to their microscopic bows with a new study showing that the addition of alumina nanoparticles can improve the performance and combustion of biodiesel, while producing fewer emissions. In the study, a team at India's National Institute of Technology in Tiruchirappalli used nanoparticles with an average diameter of 51 billionths of a meter. The high surface-to-volume ratio of the nanoparticles means they have more reactive surfaces, which allows them to act as more efficient chemical catalysts and results in increased fuel combustion.

Study lead author R. B. Anand and co-author J. Sadhik Basha used a mechanical agitator to create an emulsion consisting of jatropha biodiesel – a biofuel derived from the crushed seeds of the jatropha plant –, water, and a surfactant, to which they blended in different proportions of alumina nanoparticles. The nanoparticle-spiked fuels were not only found to outperform regular biofuel, but they also produced significantly lower quantities of nitrogen oxide and carbon monoxide gases, and created less smoke as the presence of the particles increased fuel-air mixing in the fuel, leading to more complete burning.

The researchers are now testing other types of nanoparticles, including hollow carbon nanotubes, and investigating the effects of nano-additives to engine lubrication and cooling systems. Despite the positive results of the study, the researchers say the high cost of nanoparticle production and the risk of nanoparticles entering the human body are obstacles that must be overcome before the technology can be adopted on a wider scale.

The study by the National Institute of Technology researchers entitled, "Role of nano-additive biodiesel emulsion fuel on the working characteristics of a diesel engine," appears in the Journal of Renewable and Sustainable Energy.