Synthesis of Decaline-Type Thermal-Stable Jet Fuel Additives with Cycloketones

Abstract

Decalin is a jet fuel additive with high thermal stability and energy density. Herein, we reported a novel method for the preparation of decalin from cyclopentanone, a hemicellulose derived cycloketone. Ethanolamine acetate (EAOAc), an ionic liquid catalyst which can be derived from biomass, was first applied to the self-aldol condensation of cyclopentanone and demonstrated good activity for this reaction. After the optimization of reaction conditions, ∼83.5% carbon yield of 2-cyclopentylidenecyclopentanone was achieved over the EAOAc catalyst. The hydrodeoxygenation of 2-cyclopentylidenecyclopentanone over a physical mixture of Ru/C and H-β zeolite afforded bi(cyclopentane) which could be further isomerized to decalin. Among the screened catalysts, La-Y zeolite exhibited excellent performance for the isomerization process. According to the characterization results, the high activity of La-Y was rationalized by its large medium-strong acid amount and the appropriate ratio of Brønsted acid to Lewis acid. Analogously, branched decalins were synthesized with cyclohexanone using the same procedure.

Bio‐Based Cycloalkanes: The Missing Link to High‐Performance Sustainable Jet Fuels

“…Self‐aldol condensation of these cyclic ketones was achieved with the ionic liquid EAOAc [189,190] at 100 °C, resulting in good conversion (82.2 %) and yield (83.5 %) of coupled products (Scheme 17). In comparison to traditional catalysts used in aldol condensations, EAOAc required less heat and a lower catalyst loading [188] . HDO of the condensation products over a mixture of Ru/C and acidic zeolites displayed the following activity sequence: Ru/C+(H‐ β >H−ZSM‐5>H−SAPO‐34).…”

“…In comparison to traditional catalysts used in aldol condensations, EAOAc required less heat and a lower catalyst loading. [188] HDO of the condensation products over a mixture of Ru/C and acidic zeolites displayed the following activity sequence: Ru/C + (H-β > HÀ ZSM-5 > HÀ SAPO-34). Zeolites with larger pore sizes exhibited higher activity.…”

“…To develop a bio‐based route to endothermic fuels, Li and coworkers [188] investigated the synthesis of decalin and branched decalins from cyclopentanone and cyclohexanone, respectively. Self‐aldol condensation of these cyclic ketones was achieved with the ionic liquid EAOAc [189,190] at 100 °C, resulting in good conversion (82.2 %) and yield (83.5 %) of coupled products (Scheme 17).…”

Pore Size Engineering Enabled Selectivity Control in Tandem Catalytic Upgrading of Cyclopentanone on Zeolite-Encapsulated Pt Nanoparticles

“…In particular, the synthesis of jet fuel range polycyclic alkanes from lignocellulose-derived platform chemicals has drawn much attention. − Compared with aliphatic alkanes, polycyclic hydrocarbons have higher densities and volumetric heating values owing to strong ring strain . Cyclopentanone (CPO) can be produced from furfural, a hemicellulose-derived platform compound, in one step and high yields. − CPO has been recognized as a potential feedstock in the production of C 10 cyclic hydrocarbons such as bicyclopentane and decalin. ,,, Bicyclopentane has been proposed as promising biojet fuels, ,, and decalin is the main component of JP-900, which is a coal-derived high-energy-density jet fuel. ,, CPO can be converted into bicyclopentane and decalin via multiple sequential reactions catalyzed by metal and acid sites. ,,, However, one-step or one-pot synthesis of C 10 cyclic hydrocarbons from CPO has not been achieved to date.…”

“…36−38 CPO has been recognized as a potential feedstock in the production of C 10 cyclic hydrocarbons such as bicyclopentane and decalin. 28,31,34,39 Bicyclopentane has been proposed as promising biojet fuels, 28,31,34 and decalin is the main component of JP-900, which is a coal-derived high-energydensity jet fuel. 30,39,40 CPO can be converted into bicyclopentane and decalin via multiple sequential reactions catalyzed by metal and acid sites.…”