Determination of Critical Properties (T_c, P_c) of Some Jet Fuels

The critical temperatures of some petroleum- and coal-derived jet fuels were measured with good reproducibility, using a rapid heating sealed tube method. A critical property estimation method was used to calculate the critical temperatures and pressures of the jet fuel samples. Five other methods were also used to estimate the critical temperatures of the fuels. While most of the estimation methods give satisfactory predictions of the critical temperatures of the petroleum-derived jet fuels, they all fail to give acceptable results for the coal-derived jet fuels. The larger differences between the measured and estimated critical temperatures for the coal-derived fuels are attributed to the different composition of these fuels, dominated by cycloalkanes. On the basis of properties of the compounds found in the coal-derived jet fuels, a new correlation is proposed to calculate the critical temperatures of the coal-derived jet fuels.