An Experimental Comparison of the Sooting Behavior of Synthetic Jet Fuels

作者：Saffaripour Meghdad; Zabeti Parham; Kholghy Mohammadreza; Thomson Murray J^*

来源：Energy & Fuels, 2011, 25(12): 5584-5593.

DOI：10.1021/ef201219v

An experimental study is conducted for the laminar, atmospheric pressure, sooting, coflow diffusion flames of prevaporized Jet A-1 and four synthetic jet fuels to compare their sooting characteristics and flame structures. Soot volume fraction, species concentration, and temperature profiles are measured, using the laser extinction measurement method, gas chromatography, and fine wire thermocouples, respectively. To evaluate the sooting tendency of the fuels, their smoke point heights are measured using the ASTM D1322 method and compared. The synthetic jet fuels under investigation are ( I) Fully SyntheticJet Fuel (FSJF), which is a coal-to-liquids (CtL) kerosene plus some coal tar derived material from Sasol, (2) Fischer-Tropsch Synthetic Paraffinic Kerosene (FT-SPK), which is a gas-to-liquids (GtL) product from Shell, (3) SPK plus naphthenic cut (50% by volume), and (4) SPK plus hexanol (20% by volume). The threshold sooting index (TSI) of the proposed surrogate mixtures for the fuels are calculated and compared to the TSI of the real fuels to evaluate the performance of the surrogates in predicting the sooting behavior of the actual fuels. The surrogate mixtures underpredict the sooting tendency of the Jet A-1, FSJF, and SPK + naphthenic cut, although they correctly capture the trend. It is shown that the soot concentration and the TSI values are strongly dependent on the aromatic content of the fuels. Fuels with the largest soot concentrations and sooting indexes, in decreasing order, are Jet A-1, FSJF, SPK + naphthenic cut, FT-SPK, and SPK + hexanol. There are minor differences between the species concentration and temperature profiles of the heavily sooting flames (Jet A-1, FSJF, and SPK + naphthenic cut) and the lightly sooting flames (FT-SPK and SPK + hexanol), caused by the lower contribution of aromatics to the formation of light aliphatic species and the higher radiative heat transfer by soot particles in the heavily sooting flames. It is demonstrated that the soot levels in flames are proportional to benzene concentrations but not to acetylene levels. Thus, only aromatic-based inception models can capture the differences in soot formation for jet fuels.

• 出版日期2011-12