Deactivation of Ni–Mo/Al2O3 catalysts aged in a commercial reactor during the hydrotreating of deasphalted vacuum residuum Original Research Article

A series of Ni–Mo/Al2O3 catalysts for the hydrotreating of deasphalted vacuum bottoms has been investigated as fresh catalysts and after aging in an industrial reactor during a typical commercial run. Several structural parameters have been varied in the catalyst series. In particular, pore size, surface area, active metal loading and pellet size were changed to investigate the role of kinetic and diffusional phenomena present in this process. The samples were placed in different locations along the industrial reactor allowing for a comparative analysis of the different samples under varying environments, since along the reactor, quality, temperature, and H2 partial pressure continuously change.Fresh and aged samples were analyzed by a variety of techniques, which include atomic adsorption, scanning electron microscopy, X-ray microanalysis, BET, thermogravimetry and temperature-programmed oxidation. In addition, a laboratory trickle-bed reactor was used to compare the catalytic activity of fresh samples with the residual activity retained by the aged samples after the commercial run.