Hydrocracking of Iron-Catalyzed Fischer−Tropsch Waxes

Sasol iron-catalyzed Fischer−Tropsch (FT) reactor waxes were hydrocracked at 3.5 and 7.0 MPa hydrogen pressure to fuels using a NiMo on SiO 2 /Al 2 O 3 catalyst. The aim was to predominantly produce diesel. The effects of feed carbon number distribution, reaction variables, and process configurations have been investigated. High hydrogen-to-wax ratios led to improved C 23+ conversion and increased diesel yields. Increasing the liquid hourly space velocities decreased C 23+ conversion and increased diesel selectivity. Prehydrogenation of FT reactor wax prior to the hydrocracking reaction improved C 23+ conversion; however, it negatively influenced diesel selectivity. The apparent n -paraffin reactivity was found to be chain length dependent increasing with pressure.