Production of Sustainable Aviation Fuel by Hydrocracking of n-Heptadecane Using Pt-Supported Y-Zeolite-Al2O3 Composite Catalysts

Abstract

Hydrocracking of fat or Fischer-Tropsch (FT) wax from biomass to produce the jet fuel of sustainable aviation fuel has been one of the key reactions. n-Heptadecane, which is one of the model diesel fractions produced from fat or FT wax, has hardly been used for hydrocracking of hydrocarbon for jet fuel production, while n-hexadecane has often been used as one of the model compounds for this reaction. In the present study, a HY-zeolite (50 wt %, SiO2/Al2O3 = 100)-Al2O3 (50 wt %) composite-supported Pt (0.5 wt %) catalyst [0.5Pt/Y(100)35A] was tested for hydrocracking of n-heptadecane using a fixed-bed flow reactor at a H2 pressure of 0.5 MPa, H2 flow rate of 300 mL/min, WHSV of 2.3 h-1, and a catalyst weight of 2 g. Fine-tuning of the temperature to 295 °C achieved the highest selectivity of 74% for the jet fuel fraction C8-C15 with the high conversion of 99%. The jet fuel yield reached 73%, which was almost an ideal maximum yield of 75%. Similar hydrocracking of n-hexadecane has just reported the maximum yield of 51% for jet fuel fraction. Further, 0.5Pt/Z(110)35A, which has a composition similar to that of 0.5Pt/Y(100)35A except for the type of zeolite, could not give as high yield of jet fuel as 0.5Pt/Y(100)35A because the rapid conversion to lighter fractions than the jet fuel occurred by the slight increase in the reaction temperature even at a lower temperature range.