Simultaneous Hydrogenation of Multiring Aromatic Compounds over NiMo Catalyst

Abstract

Hydrogenation of six model feeds containing three-, two- and one-ring aromatic compounds was investigated to gain insights into the aromatic hydrogenation reaction chemistry over a commercial NiMo catalyst under practical reaction conditions. The hydrogenation reactivity of the aromatic compounds followed the following order: phenanthrene ~ two-ring aromatics >> one-ring aromatic. Comparison with previous studies revealed that the relative reactivity of the aromatic compounds is strongly influenced by the nature of the catalyst. Multiple component feed studies showed that phenanthrene and naphthalene strongly inhibited the tetralin hydrogenation rate, however naphthalene and tetralin had no appreciable effect on phenanthrene conversion. Langmuir-Hinshelwood type rate equations were used to describe the reaction kinetics with physically meaningful and well identified parameter values. The inhibition was attributed to competitive adsorption and was described in the kinetic model by adsorption terms which were obtained from the multicomponent feed experiments.