Single droplet combustion of aluminum nanoparticles added to a biofuel

The present work evaluates the evaporation and combustion of single droplets of a biofuel (HVO) added with aluminum nanoparticles (n-Al). Tests were carried out in a drop tube furnace that allows the control of the wall temperature and oxygen concentration, in which the single droplets were injected downward at the top of the furnace. Droplets with a diameter of 250 μm were generated from a commercial droplet generator. Experiments were conducted with two particle sizes (40 nm and 70 nm) and two particle concentrations (0.5 wt.% and 1.0 wt.%). The effect of the size and concentration of the aluminum nanoparticles added to the biofuel was studied at 1100 °C. Detailed measurements, namely the temporal evolution of the droplet size and burning rate, were analyzed post-processing images. The combustion of aluminum nanoparticles added to a biofuel reveals micro-explosions, a disruptive burning phenomenon that appears at the end of the droplet lifetime, which is greatly influenced by the particle concentration.Fundação para a Ciência e a Tecnologia