Preparation And Performance Of Ni₂P On Ce-Al₂O₃ For Hydrodesulfurization

In recent years, as the over-exploitation and use of the crude oil, the quality of the oil became poorer and poorer. transition-metal phosphides became a field of research spots in hydro fining due to their stability and high activity under working conditions in recent years. Tn this thesis Ce(La)-Modified Al2O3 supports were prepared by Low temperature combustion synthesis method, Ni2P/La(Ce)-Al2O3 catalysts were synthesized by TPR with Ni(NO3)2 and (NH4)2HPO4 supported on La(Ce)-Al2O3. The as-obtained samples were characterized by X-ray diffraction FT-IR and 27Al MAS NMR. And using 0.8 wt% DBT in naphthane as reactions to evaluate their HDS activities.The 27Al MAS NMR indicated Five-complexing Al3+ions appeared on the surface of modified Al2O3 and weakened the strong interaction between the Al2O3 support and Ni2P precursors. The optimum conditions and methods of the preparation of Al2O3 supported nickel phosphide catalysts:modified Al2O3 as supports, Ni/P=1:1.2, impregnation method, the impregnated order:Ni(N03)2-(NH4)2HPO4. A series of Ni2P catalysts on Al2O3 supports were prepared. The prepared catalysts showed high HDS activity, the best supporting amount is 20 wt%. Contrary to the Ni2P supported on the SiO2 or HM, the HDS reaction path on N12P supported on Al2O3 was DDS path mainly.In addition, we simulated the industrial regeneration of the prepared catalyst. Using internal regeneration, the Nitrogen-Oxygen mixture (0.5 wt% O2) as the heat carrier, the results showed the HDS activity has been restored after regeneration. After the regeneration N112P5 appeared in the N12P phase due to the generation of the volatility P. The catalyst remained stable reactivity in the long time reaction.