Vaporization and oxidation of liquid fuel droplets at high temperature and high pressure:: Application to N-alkanes and vegetable oil methyl esters

Vaporization and oxidation of liquid fuel droplets are basic mechanisms in spray combustion for various industrial applications. In this work, coupled effects of temperature and pressure on n -alkane droplet vaporization are investigated in experiments conducted in a high-pressure and high-temperature gasification facility equipped with the fiber-suspended droplet technique. The influence of temperature and pressure on n -heptane and n -decane vaporization rates is particularly emphasized with regard to critical conditions of the liquid fuel. Characteristics of n -alkane droplet vaporization, and heating and vaporization times are compared with those of vegetable oil methyl esters--biofuels used in diesel engines. Finally, chemical species formed during the oxidation of these biofuels are identified by gas chromatography in oxidation experiments performed in a jet-stirred reactor. The influence of temperature, pressure, and equivalence ratio on regulated and unregulated pollutants is discussed. Emissions of pollutants obtained during biofuels oxidation are compared with those identified during the oxidation of a synthetic diesel fuel.