Study On New Hydrodesulfurization Catalyst For The Coke Benzene

Coking benzol is an important product in coking coal chemical industry, and also an important source of pure benzene. Catalytic hydrogenation is the main method in removing sulfur compounds in the coking benzol,and CoMo catalyst is widely used.γ-Al2O3 can strongly interacts with MoO3 and Co3O4 active phases in the calcination,which makes Mo and Co phase handly be completely sulfured,and decreases the catalyst performance.Chelating agent as a new addtive,can chelate with Co2+ in the impregnating solution and decreases the interraction with support,while in the sulfured process it can promote Co-Mo-S phase formation and increases the catalyst's active.This paper examines the effects of different chelating agents such as EDTA(n=6), CA (n=3)and OA(n=2) on the structure and performance of Co-Mo catalyst, and researches the mechanism of chelating agents effecting on Co-Mo catalyst,so as to choose a better one to apply in industry.By doping Fe,Ni(groupⅧelements) to modified CoMo catalyst and researches the cictric acid effecting on the performances of Fe-Co-Mo catalyst and Ni-Mo catalyst.At last,uses TiO2-Al2O3 composite support to replace Al2O3 support,and researches the mechanism of TiO2 effecting on the Fe-Co-Mo catalyst and Ni-Mo catalyst.Through the experiments, the paper gets the following conclusions:1.Adding chelating agents in the impregnating solution can avoid the form of CoAl2O4 phase, decreaes the interraction with support,and promotes the dispersion of active phase.As the increase of CA/Co ratio, MoS2 gradually become incomplete Mo3S4 sulfide phase, Co9S8 phase become complete CoS sulfide phase,and the active of catalyst is decreased.2.Compared with different coordination number of chelating agents effecting on the structure and performance of catalyst,it is found that the catalyst's performance is the best when the coordination number is 3 (citric acid), MoS2 phase and Co9S8 is the main phase in the catalyst.3. The performances of the catalyst prepared in accordance with the order of Fe