Direct synthesis of a jet fuel range dicycloalkane by the aqueous phase hydrodeoxygenation of polycarbonate

Abstract

For the first time, propane-2,2-diyldicyclohexane, a jet fuel range C₁₅ dicycloalkane was directly produced by the aqueous phase hydrodeoxygenation (APHDO) of polycarbonate (PC). Among the investigated catalyst systems, the mixture of Rh/C and H-USY (denoted as Rh/C + H-USY) exhibited the best performance. Over it, a high yield of propane-2,2-diyldicyclohexane (94.9%) was achieved from the APHDO of pure PC pellets after a reaction was carried out at 473 K and 3.5 MPa H₂ for 12 h. The Rh/C + H-USY catalyst was stable under the investigated conditions. No evident deactivation was observed during three repeated cycles. When we used a chopped DVD disk (a representative of real PC wastes) as the substrate, a high yield (86.9%) of propane-2,2-diyldicyclohexane was obtained under the same reaction conditions. The propane-2,2-diyldicyclohexane as obtained had a high density (0.92 g mL⁻¹) and a high volumetric net heat of combustion (39.6 MJ L⁻¹). As a potential application, it can be blended into jet fuels to improve the range and payload of airplanes.