Study On The Preparation And Evaluation Of The Unsupported Hydrotreating Catalyst Supported On The Nanocluster Modified Carrier

In recent years,the unsupported hydrotreating catalyst has better hydrotreating performance than the hydrotreating supported catalyst,but its intrinsic activity is lower than that of the supported catalyst.The main reason is that the active component content of the unsupported catalyst is high but is not fully utilized.In addition,it's difficult to further improve the performance of the catalyst only by improving its hydrogenation performance.Therefore,secondary structure unit(or zeolite nanocluster)was chosen as a new type of acid active center to modify the unsupported catalyst and its precursors,so as to improve the activity and utilization of the catalyst.In this paper,the introduction method of zeolite nanocluster has been investigated.It is found that the catalyst prepared by different introduction methods has different pore structure properties.The catalyst prepared by impregnation method has the largest BET surface area and the strongest acidity.The catalyst prepared by alumina modified method has the largest pore volume.The preparation condition of zeolite nanocluster has great influence on the catalyst,the most suitable condition was:T=120?;t=5h;Si/Al=80.The optimum introduction amount of the filter cake modification method was 0.45mL/mL and the nanocluster solid modification method was 0.25wt%.Within the scope of this experiment,the effect of the amount on the pore structure of the catalyst prepared by modified alumina method was not significant,but the acidity was increased The results showed that the activity of the modified catalysts was higher than that of the original catalyst.Among them,the catalyst cat-5 # prepared by modified alumina showed the highest HDS activity.The Ni-Mo-W composite oxide was modified by the raw materials for preparing nanoclusters.It was found that the pore structure and acidity of the catalysts prepared by the "step-by-step method" were better than those of the"mixed method”.Among the "step-by-step method",the composite oxide prepared by order B: Si + Ni ? Al + TPAOH + W ? Mo” has the largest BET surface area,pore volume and the strongest acidity.The SEM results showed that the compound oxide particles prepared by order B were uniformly dispersion.Evaluation results showed that catalyst prepared by order B has the highest HDS activity.The results showed that the addition of raw materials had great influence on the performance of the catalyst.When the amount of raw materials was 20wt%,the composite oxides and catalysts showed the largest pore structure and the strongest acidity,the corresponding catalyst cat-20 showed the highest HDS activity.The calcination temperature of the catalyst was investigated.In a certain temperature range,it was found that the crystal phase and the acidity of the catalyst changed little,but the pore structure became worse when the temperature increased.When the temperature was 350?,the catalyst had the highest HDS activity.The HDS activity of the cat-b# catalyst prepared by tail recovery method was better than that of the cat-b without tail recovery.