Preparation And Performance Evaluation Study Of Residue Hydrodemetallization Catalysts

Hydrodemetallization process is an important part of hydrotreating process,and the development and utilization of hydrodemetallization catalyst is an important means to improve the quality of resid hydrotreating.In view of the current high cost,low activity and poor stability of industrial resid hydrodemetalliza-tion catalysts.Therefore,this paper aims to improve the performance of hydrodemetallization catalyst by adding a second auxiliary agent and an organic ligand complexing agent,and obtain the structure-activity relationship applicable to the hydrodemetallization catalyst.In this paper,different Z/Mo series,different Z impregnation mode series,different C-Z series and different E-Z series hydrodemetallization catalysts were prepared.Secondly,the catalysts were characterized by BET,XRD,H₂-TPR,NH₃-TPD,Py-IR and HRTEM.The different Z/Mo,different Z impregnation methods and the addition of organic complexing agent to the hydrodemetallization catalyst channel were investigated.The influence of the structure,the surface crystal type,the surface acidity,the acid type distribution,the interaction between the active component and the carrier,and the microscopic morphology of the active phase of the nanocluster.Research indicates:The second additive Z weakens the interaction between the active component and the carrier;modulates the acidity of the surface of the catalyst and increases the acidity of the B acid;the number of layers of the active layer of the nanocluster gradually increases to the second and second layers.The above distribution,and the Z/Mo=3a（C4）,Z/Mo=4a（C5）type catalysts have a shorter average sheet length and a suitable number of stacking layers.Compared with the step impregnation,the interaction between the co-impregnated active component and the carrier is the weakest;the weak acid amount is moderate and the B acid amount is the most;the nano-cluster active phase stacking layer is concentrated in the second layer,and the average sheet length is more short.After adding C,the interaction between the active component and the carrier is further weakened;the total acid amount is increased;the nano-cluster active phase stacking layer is further transitioned to the second layer,which is more capable of regulating the residue hydrodemetallization catalyst.The required nanocluster active phase structure.After the addition of E,the interaction between the active component and the carrier is strengthened,and it is difficult to form a type II"Ni-Mo-S"active phase structure with slightly higher hydrogenation activity;the total acid amount is reduced,and the amount of each acid acid is also reduced.The single layer of the nano-cluster active phase stacking layer is increased,and the second layer and above are reduced,which can not reach the slightly higher stacking layer distribution required for the active phase of the residue hydrodemetallization catalyst.The results of catalyst hydrogenation performance evaluation showed that with the increase of Z/Mo,the V removal rate of each oil sample increased first and then decreased,and the Z/Mo=3a catalyst had the best V performance,reaching 93.1%.The removal rate first increased gradually and then decreased slightly.Z/Mo=4a catalyst had the best denitrification performance,reaching 42.1%,and the degree of pore loss was moderate after the reaction.The C complex series catalysts have little difference in V performance compared with the former,which is about 93.0%,The performance of denitrification is obviously improved,and the law of increasing slightly increases with the increase of C,among which-COOH:Ni=b+3c（the CA4catalyst）has the highest denitrification performance,reaching 52.0%After the CA4 reaction,the pores were slightly lost compared with C4,considering that the ability to remove Ni was the highest.Therefore,CA4 is considered to be suitable as an HDM catalyst.