High energy content bi- and mono-cycloalkane and iso-alkane jet blending mixtures derived from ethanol

Abstract

This study introduces two novel alcohol-to-jet catalytic pathways, both yielding a cycloalkane-rich liquid product with the potential to enhance fuel performance beyond current synthetic jet blendstocks. The process begins with ethanol-derived butene, which is converted into gasoline-range aromatics. The resulting aromatic intermediate is then upgraded into the jet-range fraction through two distinct approaches: alkylation, which produces alkyl-substituted aromatics, and hydroalkylation, which generates dual-ring cyclic compounds. Both products undergo selective hydrogenation, demonstrating minimal product loss due to undesirable cracking or ring-opening reactions. After distillation into the jet-range fraction, the alkylated and hydroalkylated products meet ASTM D7566 specifications for ethanol-to-jet blendstock, and with energy density increases of 1.5% and 4.8%, respectively, compared to a petroleum jet fuel baseline. Furthermore, both routes offer the potential for reduced hydrogen requirements compared to more established acyclic alkane pathways. While further process optimizations are necessary to improve carbon efficiency and economic feasibility, these results highlight the potential for synthetic jet blendstocks to surpass conventional petroleum fuels in energy density. Additionally, these blendstocks demonstrate favorable O-ring swelling characteristics, complementing existing ASTM D7566 synthetic paraffinic (SPK) pathways. Moreover, their higher smoke point compared to conventional jet fuel suggests improved combustion quality and reduced particulate emissions.