Experimental and numerical study of palm oil and castor oil biodiesel droplet evaporation

Abstract

The vaporization characteristics of Palm and Castor oil biodiesel (Ricinus comunis) droplets were studied. An experimental set-up for measuring the evaporation rate of fuel droplets at atmospheric pressure and variable temperatures was developed. The droplets were suspended on a quartz fiber with initial droplet diameters ranging from 0.9 mm to 1.3 mm. The D2 law model for droplet evaporation was used to predict the evaporation rate of the fuels. Biodiesel physical properties were estimated using group contribution methods and empirical mixing rules. Numerical results accurately predict the evaporation rate of biodiesel when compared to experimental results, with maximum deviations of the evaporation of  15.2%. Results show that Castor oil biodiesel evaporation rate is 48% lower than that for Palm oil biodiesel at the studied temperatures. This is explained by its higher density and vaporization enthalpy, which can be traced back to the structure of the fuel components.