Effect of Doped CeO₂ Nanoparticles on Evaporation Characteristics of BioDiesel Droplets

Objective In order to explore clean energy sources for engines, the evaporation characteristics of fuels need to be investigated.

Method Nanofluidic fuels were prepared by adding CeO₂ nanoparticles with different concentrations to methyl palmitate (MP) and methyl oleate (MO), and the effects of CeO₂ doping (mass fraction of 0～500×10⁻⁶) on the evaporation characteristics of the MP and MO blended droplets were investigated by single-droplet evaporation experiments at 773 and 973 K. The results were summarized as follows.

Result The results show that at 773 K, the evaporation of MP20MO80 and MP20MO80+50CeO₂ droplets is dominated by fluctuating evaporation stage, but with the further increase of CeO₂ concentration, the evaporation stage of mixed droplets gradually changes to steady evaporation stage, and the evaporation process of droplets is dominated by fluctuating evaporation stage at 973 K; At 773 K, the proportion of transient evaporation phase time of biodiesel droplets with CeO₂ nanoparticles is less than that of droplets without nanoparticles, and the proportion of fluctuating evaporation phase time of droplets at 973 K is greatly improved compared with that at 773 K; At 773 K and 973 K, the evaporation rate of droplets increases first and then decreases with the increase of CeO₂ concentration. When the mass fraction of CeO₂ is 50×10⁻⁶, the evaporation rate of droplets reaches the maximum, which is 0.125 mm²/s and 0.373 mm²/s respectively. The evaporation rate of droplets at 973 K is higher than that at 773 K, because the temperature increase promotes the evaporation of droplets and the occurrence of micro-explosion.

Conclusion The results of the study can provide valuable references for the practical application of CeO₂ nanoparticles in engine fuels.