Thermochemical Conversion of Bovine Fleshings into Jet Fuel-Range Hydrocarbons: Reaction Study and Proposed Mechanism

This study investigates the thermochemical conversion of bovine fleshings, a low-value by-product of the leather industry, into hydrocarbons within the aviation fuel range. Fat extracted through wet processing was rendered and than transesterified to determine its composition. The samples were characterized and quantified by gas chromatography coupled with mass spectrometry (GC–MS), revealing a predominance of saturated and mostly monoun-saturated hydrocarbon chains. In parallel, a thermal cracking reaction was performed to determine the operational conditions required for producing hydrocarbons in the aviation kerosene range. Six fractions were evaluated, yielding approximately 70–80% bio-oil composed mainly of medium-chain alkanes and alkenes (C9–C17), along with oxygenated compounds. Fractions collected between 290–310 °C exhibited chemical profiles closely resembling commercial aviation kerosene (Jet-A). Notably, Sample 6 contained about 76% hydrocarbons in the C9–C14 range (vs. 85% in Jet-A) and 23% in the C15–C17 range (vs. 15% in Jet-A), confirming its similarity to sustainable aviation fuel (SAF). Unlike previous studies that employed refined bovine tallow or residual oils, this work utilizes fat rendered directly from fleshings as feedstock. The explicit comparison of hydrocarbon fractions with Jet-A underscores the potential of tannery residues for SAF production. Defining optimal parameters for thermal cracking demonstrated the dual benefits of waste valorization and renewable fuel generation, establishing bovine fleshings as a promising source of low-carbon aviation fuels and contributing to the diversification and sustainability of the energy matrix.