High-density jet fuels are advanced fuel synthesized to improve the performance of aerospace vehicles. As response to the sustainable development, the development of high-density biofuels becomes extremly necessary, which can also extend the sources of fuels. Herein, the progress in synthesis of high-density jet fuels using biomass-derived feedstock has been reviewed. Biofuels with different structure, such as paraffins, branched monocycloalkanes, and polycycloalkanes, and the feedstock including pinenes and lignocellulose-derived platform molecules such as cyclic ketones/alcohols, furanic aldehydes/alcohols, aromatic oxygenates, etc. are covered. The propulsion performance of the engine is deeply dependent on the properties of the applied fuel, for which the most important features are density and low-temperature properties. Specially, the properties of typical biofuels are summarized to discuss the effect of molecular structure. Increasing the number of the ring in fuel molecular improves the fuel density, with undesirable variation in low-temperature properties. Fortunately, introducing the branched chain will improve the low-temperature properties. And several reactions such as alkylation, condensation, cyclic addition, and hydrodeoxygenation are discussed from the aspects of catalyst and reaction condition. An outlook on further development of high-density biofuels is also given. This review will be helpful to explore and develop better approach and process for high-density biofuel synthesis and upgrade for advanced aerospace vehicles.
Contents
1 Introduction
2 Synthesis of paraffin biofuels
3 Synthesis of branched monocycloalkane biofuels
4 Synthesis of polycycloalkane biofuels
4.1 Terpene-derived biofuels
4.2 Lignocellulose-derived polycycloalkane biofuels
4.3 Lignocellulose-derived fused-ring biofuels
5 Conclusion