The development of high-energy-density (HED) liquid fuels represents a critical challenge for the sustainable advancement of aerospace vehicles. Polycyclic alkanes are considered ideal high-performance fuel components due to their high density and volumetric calorific value, which originate from their compact polycyclic structures. In this study, five polycyclic alkanes were synthesized as HED liquid fuels using biomass-derived cyclic ketones (cyclopentanone, cyclohexanone, isophorone, menthone, and nopinone) as raw materials, and their synthesis routes and fuel properties were studied. An optimized McMurry coupling reaction was used to synthesize fuel intermediates, affording a maximum yield of 89.4%. Subsequent hydrodeoxygenation (HDO) reaction afforded the target polycyclic alkanes with yields of up to 96.2%. Fuel performance evaluations revealed that the densities of the five polycyclic alkanes ranged from 0.867 to 0.911 g/mL, and the volumetric net heat of combustion (NHOC) ranged between 36.78 and 39.22 MJ/L. Notably, the best-performing polycyclic alkanes in terms of overall fuel performance have high density (0.874 g/mL), low freezing point (−77.2 °C), and high volumetric NHOC (39.22 MJ/L) and show superior or close performance to Jet A, JP-10, and RJ-4 in key fuel aspects. This work provides an efficient and sustainable synthetic pathway toward biomass-based HED liquid fuels, showing significant potential for application in aerospace vehicles.
Huang et al. (Thu,) studied this question.