Preparation Of NiMo/MCM-41 Catalyst And Study On Hydrogenation Of Phenanthrene

With the increasingly strict environmental protection laws and regulations,the cleaning of oil products has become a top priority;At the same time,because of the continuous decrease of crude oil resources and heavier crude oil,coal-based oil as a supplementary source of petroleum,how to reduce the content of aromatic hydrocarbons in coal-based oil is more urgent.Therefore,it is of great significance to improve the comprehensive economic benefit of coal tar processing to convert the heavy components of coal tar into light chemical raw materials or fuels.In this paper,NiMo/MCM-41 and Ni W/MCM-41catalysts with high activity were successfully prepared by equal-volume impregnation method,and the hydrogenation of phenylene was studied on these catalysts.The catalytic performance of NiMo/MCM-41 was better than Ni W/MCM-41 in the reaction time of 1-5 h.XRD,SEM,EDS,TEM,BET,H2-TPR,XPS and FTIR characterization technology have been carried on the exploration of the performance of the catalyst.Nitrogen adsorption stripping curve shows that the catalyst is the mesoporous materials,has high specific surface area and small particle size,about 10 nm,H2-TPR and XPS characterization results show that the interaction of moderate intensity can promote the high dispersion of active component,avoid Ni and Mo reunion phenomenon appeared in the process of reduction.The results show that the NiMo/MCM-41 catalyst shows excellent hydrogenation activity under 300℃.By the thermodynamic calculation of phenanthrene hydrogenation system network,it is obtained that the response curve of phenanthrene hydrogenation system along with the change of temperature and the reaction of y（the equilibrium conversion）,the change of temperature or pressure curve.The results of y decreases with the increase of temperature prove the phenanthrene hydrogenation system of each reaction is exothermic reaction.These results offer guiding significance for subsequent phenanthrene hydrogenation conditions optimization on the NiMo/MCM-41.The conversion and product selectivity with the types of solvent,catalyst dosage,reaction time,reaction temperature and hydrogen pressure and catalyst reuse during phenanthrene hydrogenation on NiMo/MCM-41 catalyst in micro-autoclave were explored.The results show that hydrogenation products is relatively complicated,there are dihydrophenanthrene（DHP）,trihydrophenanthrene（THP）,asymmetric octahydrophenanthrene（as-OHP）,symmetric octahydrophenanthrene（s-OHP）and perhydrophenanthrene（PHP）.Under the reaction conditions of reaction pressure of 5 MPa,300℃,5 h,the selectivity of phenanthrene hydrogenation products of s-OHP（34.79%）,as-OHP（16.59%）and of PHP（18.06%）are obtained,with totally 69.43%.The selectivity of THP is 30.56%and no THP appears.Reaction kinetic calculation shows that the phenanthrene hydrogenation at 275～300℃ for 1-5 h is a pseudo-first-order reaction.The calculated activation energy is 22.28 k J·mol^-1,lower than that of reported value,indicating that the prepared catalyst has good hydrogenation reaction characteristics.