HYDROGENATION OF AROMATICS OVER HYDRODENITROGENATION-SELECTIVE AND HYDRODESULFURIZATION-SELECTIVE CATALYSTS

A denitrogenation-selective FeMo sulfide is evaluated against a commercial desulfurization-selective CoMo catalyst to understand better the effects of catalyst selectivity for heteroatom removal on aromatics hydrogenation. The experiments were done in an upflow fixed-bed reactor with an uncracked gas oil. Combined clay-gel separation and mass spectrometry were used to follow the saturate make and the distributions of aromatic compound classes as functions of the extent of heteroatom removal. The FeMo catalyst, despite its low desulfurization activity, shows a higher volumetric activity for total aromatics reduction than the conventional CoMo catalyst of much higher surface area. The behaviorial differences between the two catalysts in aromatics hydrogenation are discussed.