Deactivation Analysis of Industrial Spent Catalysts Applied to Lube Oil Hydrotreating in a Pilot Plant

Industrial spent catalysts taken from different beds of industrial lube oil hydrotreating reactors were investigated in a pilot plant. Experiments to quantify the catalytic activity loss for hydrodesulfurization, hydrodenitrogenation, and aromatic hydrogenation reactions were carried out using an industrial feedstock under operational conditions similar to the industrial ones. Characterization of the spent catalysts was performed to demonstrate the relative influence of different possible deactivation causes. Depending on the position of the catalyst inside the industrial reactor, different deactivation causes were evaluated. At the top of the reactor, poisoning by silicon, arsenic, and iron was the main cause, while at the bottom, coke deposition was predominant. Industrial spent catalyst evaluation tests revealed a nonlinear deactivation through a hydrotreating reactor. Different main deactivation causes were determined depending on the location of the industrial spent catalyst samples. Poisoning by silicon, arsenic, and iron was the main cause at the top of the reactor, while coke deposition at the reactor bottom.