Advance, challenge, and outlook of carbon-increasing strategies for producing sustainable high-energy-density jet fuels from lignocellulosic derivatives

<p>High-energy-density jet fuels (HEDJFs) are advanced synthetic liquid hydrocarbons designed to enhance the performance of aerospace vehicles. Compared to conventional jet fuels, HEDJFs have higher density, volume net heat of combustion, and lower freezing points. With diminishing fossil resources and growing environmental concerns, biomass-derived HEDJFs have attracted significant attention. This review highlights recent advancements in synthesizing HEDJFs from lignocellulosic derivatives, focusing on key C-C coupling reactions such as aldol condensation, alkylation/hydroxyl alkylation, Diels-Alder reaction, oligomerization, rearrangement, cyclopropanation, and photocatalytic cycloaddition. Approaches to producing petroleum-based HEDJFs (e.g., JP-10, RJ-4) from lignocellulosic derivatives are also summarized. Additionally, the performance characteristics of various multi-ring HEDJFs are analyzed, emphasizing the influence of molecular structure and composition. Furthermore, the combustion characteristics and engine adaptability of bio-HEDJFs were also summarized. Finally, challenges in the biomass-to-HEDJF synthesis process, such as reaction efficiency, catalyst activity, cost, etc., are outlined. Meanwhile, future research directions are proposed, which show that fuel molecules with fused rings, branched chains, and low symmetry structures are the future direction. This review aims to advance the development of efficient synthesis methods for HEDJFs.</p>