Preliminary Study On Upgrading Coal-derived Oil To High-density Fuel By Hydrogenation

Nowadays,China is greatly dependent on foreign oil.The production and supply of conventional petroleum-based jet fuel are usually constrained by global market and international situation.Besides,coal storage in China is relatively high,and Chinese technology of producting liquid oils from coal has been already in the forefront of the world.Coal-based jet fuel helps meet the need for high density,high energy per unit mass,stability,and low freezing point.The development of coal-based jet fuels can not only expand the source of military jet fuel,but also meet the requirements of high-performance jet fuel,which holds important research value and application prospects.In this paper,Shenhua direct liquefied oil was selected as the raw oil.Based on the analysis of oil properties,the procedure of oil processing has been determined,that is,alkali eluting phenol,hydrodesulfurization and hydrogenation saturation.The commercial Ni Mo W/Al₂O₃ catalyst was used to remove sulfur.Sulfur content of the product after HDS was～12 ppm,and the fraction between 170-280°C was collected by distillation to obtain a high-density coal-based aviation fuel component with 5 ppm S.Furthermore,in order to develop hydrodesulfurization catalysts with higher performance,a series of new catalysts were prepared by a solvothermal method using carbon nanotubes（CNTs）,H-Beta and SBA-15 as supports and Mo,Co and Ni as active components.Dibenzothiophene（DBT）was used as the model compound to evaluate hydrodesulfurization（HDS）performance of the catalysts.The results show that Mo S₂prepared in the solvothermol thermal method condition of ethanol and glycerin,has the highest HDS activity.By introducing Co,the conversion of DBT（Co Mo S/H-Beta）was increased to 97%.Finally,to further improve the quality of coal-based oil,Pt-based catalysts for hydrogenation were also investigated.A joint experimental and theoretical study has been conducted to investigate the role of capping molecules on Pt NPs for hydrogenation.By DFT and Kinetic calculation,a volcano plot is obtained between the adsorption energy of 4-NP on various Pt NPs against reaction rate constant（k）.Moreover,Pt/r GO with 1 wt%Pt loading posseses excellent activity for the hydrogenation of 4-NP and naphthalene.At room temperature,0.4 MPa,Pt/r GO can catalyze the complete conversion of p-nitrophenol in 2 min.At 250 ^oC,4 MPa,the conversion of naphthalene was 62.3%,and the selectivity of tetrahydronaphthalene was100%.When the loading of Pt was 5 wt%,the conversion of naphthalene was 100%.Among that,the selectivity of tetrahydronaphthalene was 21.4%,the selectivity of cis-decahydronaphthalene was 37.6%,and the selectivity of trans-decahydronaphthalene was 41.0%.