Experimental study on sooting characteristics of a direct coal liquefaction derived jet fuel and its blend with RP-3 jet fuel

Abstract Alternative jet fuel from direct coal liquefaction (DCL) process is of critical importance to meet the energy goals of both military and civil aviation. Soot emission is a critical issue for the promotion of airworthiness certification process of jet fuels. In this work, a systematic evaluation of sooting characteristics is conducted for the DCL derived jet fuel together with RP-3 jet fuel and their 50/50 blend. Experiments are performed in a shock tube facility at conditions of 3.0 bar, 1700 to 2300 K and equivalence ratios of 5, 20, and infinity (pyrolysis) diluted in argon. The effect of pressure on sooting characteristics of the DCL derived jet fuel is also investigated. Soot induction time and soot yield are obtained by measuring the soot-induced laser extinction signal. The effects of temperature, pressure and equivalence ratio on soot induction times and soot yields are then systematically analyzed. Detailed comparisons of the soot induction times and soot yields are performed. This work provides quantitative experimental data set of soot formation properties for alternative jet fuels that can be used for combustion kinetic model development and validation. The experimental data is also valuable for the airworthiness certification process of the DCL derived jet fuels.