Effect of different heavy feedstocks on the deactivation of a commercial hydrotreating catalyst

Different feedstocks (7–21°API gravity, 300–450 ppm Ni + V) were hydrotreated in a bench-scale reactor at moderate reaction conditions (70 kg/cm2, 5000 ft3/bbl H2/oil ratio, 0.5 h−1 LHSV) to study the deactivation of a NiMo/γ–Al2O3 commercial catalyst. The experiments were carried out at three temperatures (380, 400 and 420 °C) and samples were taken every 10 h during 240 h of time-on-stream and characterized for sulfur, metals and asphaltenes contents. The conversion of impurities resulted higher as the temperature was increased. The properties of the feed and of their asphaltenes were found to have a great impact on catalyst deactivation. A deactivation model considering both metals and carbon depositions was used to fit the data. Good agreement of the overall trend of experimental and predicted deactivation curves was observed.

► Different heavy feedstocks were hydrotreated at moderate reaction conditions to study NiMo/γ-Al2O3 catalyst deactivation.
► Different effect of the type of feedstock on catalyst deactivation was observed depending on reaction temperature.
► A deactivation model has been used to predict experimental deactivation curves.