Hydrodenitrogenation of Aleksinac shale oil distillates in a pilot trickle-bed reactor

Hydrodenitrogenation (HDN) of the Aleksinac shale oil distillates was studied in a pilot trickle-bed reactor at 340–435°C, 8.0 MPa, 1–4.57 h−1 liquid hourly space velocity (LHSV) and 500 cm3 (STP) of H2/cm3 oil. The commercial CoMoAl2O3 and NiMoAl2O3 presulfided catalysts were evaluated for the HDN of three different shale oil distillates. The initial HDN catalyst deactivation was followed using a linear catalyst deactivation model. The NiMoAl2O3 catalyst showed somewhat higher initial HDN activity and lower initial deactivation rate than the CoMoAl2O3 catalyst for the first 30–45 h on shale oil feedstock. Nitriles in shale oil first undergo HDN reaction at mild operating conditions, much faster than five- and six-membered nitrogen heterocyclic compounds. The overall HDN kinetics of refractive nitrogen in shale oil was analyzed using a modified pseudo-first-order behavior. The on-line measured hydrogen consumption was in the range 200–300 cm3 (STP)/cm3 for HDN > 80% regardless of the catalyst type and feedstock.