关键词: 超深度加氢脱硫柴油, 催化剂失活, 多环芳烃

Abstract: The effect of polycyclic aromatic hydrocarbons (PAHs) on the stability of the hydrogenation catalyst for production of ultra-low sulfur diesel was studied in a pilot plant using Ni-Mo-W/γ-Al2O3 catalyst. The mechanisms of catalyst deactivation were analyzed by the methods of elemental analysis, nitrogen adsorption-desorption, thermogravimetry-mass spectrometry (TG-MS) technology, X-ray photoelectron spectroscopy (XPS) and high resolution transmission electron microscopy (HRTEM). The results demonstrated that PAHs had little effect on the activity of catalyst at the beginning of operation, during which the reaction temperature was increased by only 1 — 4 ℃. However, the existence of PAHs significantly accelerated the deactivation of catalyst and weakened the stability of catalyst. This phenomenon could be explained by that the catalyst deactivation is not only related to the formation of carbon deposit, but also is closely related to the loss of pore volume and the decrease of Ni-W-S phase ratio after adding PAHs.

Key words: ultra-low sulfur diesel, catalyst deactivation, polycyclic aromatic hydrocarbons