Study On The Production Of Needle Coke Raw Materials By FCC Oil Slurry Pretreatment

Needle coke is a new type of carbon material with excellent properties such as highly graphitizable and good thermal shock resistance.It is widely used in the field of graphite electrodes and lithium ion battery anode materials.The catalytic oil slurry is rich in aromatic hydrocarbons with short side chains,has a narrow molecular weight distribution,and has a low content of colloidal asphaltenes.After pretreatment and hydrodesulfurization,it is used as a raw material for the production of needle coke and has good economic benefits.A 6L real boiling point distillation device is used to cut wide and narrow fractions of a certain enterprise’s catalytic oil slurry.As the fraction yield increases,the sulfur and nitrogen content increases,and the aromatic fraction first increases and then decreases.When the fraction yield is 60%,the aromatic fraction The highest content;in every 10%narrow cut,as the cut becomes heavier,the content of tricyclic aromatic hydrocarbons decreases,and the content of tetracyclic aromatic compounds first increases and then decreases.After 50%-60%of the cut,the content of tetracyclic aromatic hydrocarbons decreases significantly,meeting the requirements.The suitable fraction required for the raw coke is the initial fraction-60%.Two series of CoMo/Al₂O₃ catalysts with different Co/Moratio and different CoO/MoO₃content prepared with industrial alumina as the carrier were analyzed and characterized by BET,XRD,Py-IR,TEM and other analytical methods.On a 100m L hydrogenation evaluation device,the catalytic oil slurry（high aromatic oil）of a certain enterprise vacuum distillation-solvent extraction was used as the raw material to evaluate the hydrogenation activity.The results showed that the active components of the CoMo/Al₂O₃ catalysts with different Co/Moratios It is uniformly dispersed.With the increase of Co/Moratio,the specific surface area and pore diameter are slightly reduced,and the pore volume is basically unchanged.The number of stacks of MoS₂ wafers in the sulfided catalyst increases,and the wafers with a Co/Moratio of 0.23 The length is concentrated in 2-5nm,the number of stacked layers is 2-4,and the suitable Co/Moratio is 0.23.CoMo/Al₂O₃ catalysts with different cobalt and molybdenum loadings,with the increase of the active metal cobalt and molybdenum loading,the specific surface area,pore volume and pore diameter gradually decrease,and the MoS₂ wafer length and the number of wafer stacking layers in the sulfided catalyst increase;With the increase of the component content,the desulfurization and denitrification rate will increase.The suitable active component content is 14%MoO₃ loading and 2.7%CoO loading.The optimized CoMo/Al₂O₃ catalyst and the industrial NiMo/Al₂O₃ catalyst are graded.Under the same process conditions,the desulfurization and denitrification performance of the graded catalyst is better than that of a single CoMo/Al₂O₃ catalyst;with the increase of the ratio of NiMo/CoMocatalyst,The hydrodesulfurization rate of high aromatic oil shows a trend of first increasing and then decreasing.When the NiMo-CoMogradation ratio is 3:9,the desulfurization effect is the best,and the aromatics loss of the hydrogenated product is the smallest.In the NiMo/CoMocatalyst gradation ratio 3:9,reaction temperature 360℃,reaction pressure 3.0～4.0MPa,space velocity 1.5～1.75h^-1,the sulfur content of the hydrogenated product is less than 2000ppm,and the aromatic component loss is less than 5 percentage points.