Impact of cabon nanotube suspensions on the hotplate ignition of liquid fuels

The fuels mixed with combustible liquids and nanoparticle suspensions, sometimes called “nanofuels” following “nanofluids”, may have better ignition and combustion properties compared to the pure combustible liquids. In this paper, we measured the hot-plate ignition probabilities of a nanofuel made from alcohol and carbon nanotubes (CNTs) with variable tube diameters (10nm, 20nm-100nm) and tube concentrations (50ppmw, 100ppmw and 500ppmw). We found that the ignition probability of the fuel can be significantly improved with the introduction of CNTs from the beginning and then the probability drops when the CNT concentration is too high. These findings may result from the conjugated impacts of CNT suspensions on the thermal conductivity and viscosity of the liquid fuel, which lead to better and worse heat transfer between the fuel droplets and the hot-plate. Most energy efficient ignition can be achieved with an optimized CNT concentration.