Kinetics and thermodynamics of hydrotreating synthetic middle distillates

Middle distillates from the Tar Sands deposits in Alberta are an important component of diesel and jet fuels in the Canadian market. Commercial catalysts based on sulfided Ni-Mo and Ni-W are currently used to hydrogenate synthetic distillates to improve the cetane number and smoke point. In previous work {sup 13}C NMR was used to study the kinetics of overall hydrogenation of aromatics over sulfided Co-Mo, Ni-Mo and Ni-W catalysts. Arrhenius parameters were obtained for hydrogenation over sulfided Ni-W catalyst for a similar distillate feedstock. In the latter study, mass spectrometry was used to quantitate the three major aromatic hydrocarbon group types in the feed and products. In this study, liquid products from hydrotreating experiments with a hydrotreated distillate from delayed coking of Athabasca bitumen and sulfided Co-Mo and Ni-Mo catalysts have been analyzed by mass spectrometry. This completes a preliminary comparison of the kinetics of hydrogenation of alkylbenzenes, benzocycloparaffins and benzodicycloparaffins, the three major aromatic hydrocarbon types in these distillates.