Study On Hydrorefining Of Shale Oil Full Distillate

With the shortage of petroleum resources,shale oil,as one of the advantageous alternative resources of petroleum,has attracted much attention for its development and utilization.It is easy to form colloids because shale oil contains a large number of non-hydrocarbon compounds such as sulfur,nitrogen,and metals,and its high degree of unsaturation,which is very unfavorable for subsequent processing.In this experiment,shale oil was pretreated by pickling,and then treated with a combined process of hydrofining and solvent dewaxing to produce high value-added chemical products and realize the comprehensive utilization of all shale oil fractions.In the experiment,the self-made macroporous alumina was selected as the carrier,and the Mo Ni/Al₂O₃ catalyst was synthesized by the saturated impregnation method.The physical properties and microstructure information of the catalyst can be obtained through BET,SEM,TEM and other characterization techniques.The pore volume is 0.30～0.35 m L·g^-1,the specific surface area is 131～166 m~2·g^-1,and the average pore diameter is 8.4～9.1 nm;the pore height is concentrated in the regions of 10～30 nm and 30～60 nm,accounting for the total 35.11%52.74%of the pore distribution.The photo of the vulcanized catalyst characterized by TEM can clearly show the Mo₂S lamellar structure mainly composed of 4 to 7layers,indicating that the catalyst has a higher catalytic activity site,combined with good pore properties,indicating a higher activity of the catalyst.The shale oil is pretreated by pickling.After pretreatment,the nitrogen content and basic nitrogen content of shale oil were reduced by 37.93%and 96.63%,respectively.The initial boiling point is reduced from 173℃to 153℃,and the final boiling point is reduced from 518℃to 502℃,with a decrease of about 7～20℃for every 10%temperature interval.Orthogonal experiment and single factor experiment were used to optimize the hydrorefining process conditions of the whole fraction of shale oil after pretreatment.The optimal process conditions for one-stage hydrogenation were determined as follows:reaction temperature 380℃,pressure 15 MPa,volumetric space velocity 0.3 h^-1,hydrogen oil volume ratio 1500:1.Under the optimal hydrogenation conditions,the HDS rate and HDN rate reached 88.90%and 82.10%,respectively.At the same time,63.91%of the<360℃low temperature fraction and 36.0 9%of the>360℃fraction were obtained.Among them,the former undergoes two-stage hydrorefining.After the hydrogenated product is separated and treated by the urea dewaxing process,1.41%of 120^#solvent oil,87.23%of W2 series white oil and 10.77%of 7^#industrial white oil is obtained.For each product,the technical indicators of this series of products are in line with the corresponding national standards and industry standards.The>360℃fraction has a higher wax content（39.5%）.The wax product and wax oil are obtained by ketone benzene dewaxing,and the wax oil is hydrorefined to produce food-grade petrolatum.Convert the whole fraction of shale oil into high value-added chemical products to realize the comprehensive utilization of shale oil.In addition,the experiment compared the 170-310℃distillate after the second stage hydrogenation with the Fushun and Jinxi dewaxing raw materials.The results show that the content of n-alkanes in the distillate feedstock is lower than the other two reference materials,while the yields of n-alkanes after dewaxing are close to 70.35%,79.43%and 86.05%,respectively,indicating that alternative or mixed dewaxing can be used.The raw materials are used for wax production.