Development And Optimization Of The Catalysts For Hydrorefining Of Crude Benzene

This paper mainly focused on the development and optimization of the main catalyst for hydrodesulfurization of crude benzene. The preparation methods of catalysts, the effect of phosphor and metal modifiers on the performances of these catalysts for hydrosulfurization of crude benzene were studied.The experimental results showed that when nCo/n(Co+Mo) ratio was0.35, the mass fractions of CoO and MoO3relative to the carrier were4.9%and17.4%, and the mass ratio of P to MoO3was0.11, the hydrodesulfurization activity of the catalyst prepared by Co-Mo-P coimpregnation method was the highest, meanwhile BTX retention rate maintained a high level. The results of orthogonal experiments showed that the optimum preparation conditions of catalysts are as follow:impregnation temperature is10℃, drying temperature is110℃, calcination temperature is500℃.In this paper, CoMoP/γ-Al2O3catalysts modified with the metal modifier such as Fe, Cu, K, Mg, X were prepared. The effect of modifying methods and modifier types on the hydrodesulfurization activity and selectivity of catalysts were studied. The research results showed that CoMoP-X/γ-Al2O3catalyst prepared by co-impregnation can improve the activity for hydrodesulfurization of crude benzene obviously. And CoMoP-X/γ-Al2O3catalyst has the highest activity and the suitable selectivity when the mass capacity of X relative to the carrier is1.0%. Comparison with CoMoP/γ-Al2O3catalyst, thiophene residues of CoMoP-X/γ-Al2O3catalyst went down respectivily from0.71ppm and0.50ppm to0.45ppm and0.15ppm under the low reaction conditions and high reaction conditions.In order to evaluate the carbon deposition on BASF catalyst and CoMoP-X/γ-Al2O3catalyst after reacting under the same reaction conditions and the same time, we made TG analysis for the two different catalysts. The analysis results showed that the lost weight of carbon species on the two catalysts were both around3.22%, which indicated that the CoMoP-X/γ-Al2O3catalyst showed a good ability of resistance to coking as BASF catalyst.