Hydrogenated Orange Oil: a Waste Derived Drop-in Biojet Fuel

Orange oil was extracted by steam distillation from the peels of oranges produced as waste in the orange juice factories. This raw orange oil, a potential source for biojet fuel, was analysed by FT-IR and GC-MS, and compared with distilled orange oil and pure d-limonene, which is its main chemical constituent. Both distilled orange oil and d-limonene were hydrogenated under reaction conditions (from 3 to 18 bar) which are mild enough to be industrially feasible, to improve its properties, especially to reduce their sooting tendency. Some important properties such as density, viscosity, heating values, lubricity, flash point, crystallization onset temperature, and smoke point were measured for hydrogenated orange oil and d-limonene (as a reference for comparison) at different conversions. These hydro-biofuels were blended with Jet A1 to check their suitability as biobased blending components for aviation. Based on the results obtained for the main aviation fuel properties, it is concluded that up to 15 vol% of partially hydrogenated orange oil could be blended with Jet A1 without any significant drawback for the performance of the actual airplanes. Flammability reduction systems would be needed to further increase the blend proportion of this drop-in biofuel in Jet A1.