Analysis for surface coke deposition in used Mo-Co/γ-Al₂O₃ catalyst for diesel hydrodesulfurization

ABSTRACT

The coked Mo-Co/γ-Al₂O₃ catalysts were Soxhlet extracted with the solvent of tetrahydrofuran. Experimental techniques like FT-IR, GC-MS, XPS, H₂-TPR, BET, etc. were applied for the characterization of coke and catalysts to make a comparison of their physical properties. The results showed that the active components of the catalyst were slightly less after the reaction. The specific surface area and the pore volume had recovered to some degree. These results indicated that the main cause of deactivation of Mo-Co/γ-Al₂O₃ catalysts is carbon deposit. The principal components of the soluble carbon deposit on Mo-Co/γ-Al₂O₃ catalysts were alkyl aromatics with 1–4 rings and C₁₉–C₂₉ long-chain alkane compounds.

KEYWORDS:

• characterization
• coke deposition
• diesel oil
• hydrodesulfurization
• Mo-Co/γ-Al₂O₃