SIMULATED REGENERATION OF AN INDUSTRIAL COMO-GAMMA-AL2O3 CATALYST - INFLUENCE OF THE REGENERATION TEMPERATURE

An industrial CoMo/Al//2O//3 hydrotreating catalyst has been subjected to regeneration temperatures between 300 and 700 degree C. Catalytic activities for hydrodesulfurization (HDS) of thiophene and hydrogenation (HYD) of cyclohexene were largely influenced by these pretreatments. Infrared spectroscopy of the NO-probe, sulfur analyses and X-ray photoelectron measurements were used to interpret the changes brought about during regeneration. At temperature above 500 degree C the sulfur content, octahedrally coordinated Co species, and HDS (or HYD) activities markedly decreased, while Mo** delta ** plus species increased.