Selection and performance comparison of jet fuel surrogates for autothermal reforming

Three fuel mixtures were investigated as possible surrogates for low-sulfur JP-8. The selected fuel mixtures were chosen based on a desire to match hydrocarbon chemical composition classes found in real jet fuels. The surrogate fuels selected consisted of single, binary and tertiary-component mixtures of n-dodecane, decalin and toluene in liquid volume ratios of 10:0:0, 9:1:0 and 7:1:2. The hydrocarbon components selected represented the largest chemical classes within JP-8 of normal paraffin, cyclo-paraffin and aromatic. The surrogate fuels and individual surrogate fuel components were reacted in an atmospheric pressure autothermal reformer with noble metal catalysts under conditions of steam-to-carbon ratio of 2.0, fuel equivalency energy flow of 3.3 kW thermal, space velocities of 21,000-28,000 h⁻¹ and variable oxygen-to-carbon ratios of 0.8-1.2. For all fuels investigated fuel conversion of greater than 96% could be achieved. The single component n-dodecane proved to be the least reactive resulting in lower hydrogen yields, lower reforming efficiency and increased olefin products in the reformate. The binary mixture of n-dodecane and decalin resulted in a closer match with JP-8, but did not correlate well in terms of fuel conversion and hydrogen yield. Aliphatic mixtures also exhibited greater olefin production. The three-component mixture of n-dodecane/decalin/toluene provided the best correlation to JP-8 and appears to be a good three-component surrogate fuel, particularly over the operating range of oxygen to carbon ratio of 0.95-1.10.