Preparation Of Solid Acid And Its Supported Metal Catalyst And Catalysis On The Co-hydrogenation Of Oil And Coal

Co-hydrogenation of oil and coal can make up for the lack of cycle solvent of direct coal liquefaction and effectively utilize inferior residue oil.It is of great significance for the clean and efficient utilization of energy in China.In this paper,Weiqiang coal（WC）and FCC heavy oil were used as raw materials.Firstly,the components of FCC heavy oil were separated and characterized,and the hydroliquefaction performance of WC alone was investigated.Then,the two kinds of solid acid,SO₄^2-/ZrO₂and WO₃/ZrO₂,and their metal-supported catalysts were prepared,respectively.By combination with the structure and acidity characterizations of the prepared catalysts,the catalysis of acidic site for hydrocracking and that of metal site for hydrogenation in the process of FCC/WC co-hydrogenation were discussed.Finally,the optimizd preparation conditions of two kinds of catalysts were obtained.The results show that the content of saturated components,aromatic components,gums,and asphalt in FCC heavy oil is 32.62%,58.01%,3.55%,and 4.87%,respectively.The saturated components are mainly linear alkanes,such as C₂₁H₄₄,C₂₄H₅₀,etc.The aromatic components are mainly fused ring-substituted aromatic hydrocarbons such as anthracene,phenanthrene,pyrene,etc.The liquefaction of WC in non-hydrogen-donating solvents is mainly by pyrolysis.The conversion of WC hydroliquefaction in tetralin,a hydrogen-donating solvent,is 70.56%.However,the yield of oil and gas is only 22.10%due to high yield of heavy products.Using liquid paraffin as a solvent and adding condensed aromatic hydrocarbons as hydrogen shuttles,such as phenanthrene and pyrene,can help promote the hydrogenation and liquefaction of WC,but anthracene is not conducive to the liquefaction of WC.The study of SO₄^2-/ZrO₂solid acid and its supported metal catalysts shows that SO₄^2-/ZrO₂solid acid has prominent catalytic activity for the co-hydrogenation of oil and coal.It is mainly manifested in the catalytic hydrocracking of coal and heavy products.At the same time,its catalytic activity is related to the medium-strong acid center.For WC/FCC co-hydroliquefaction,the SO₄^2-/ZrO₂solid acid prepared by roasting at 650℃for 3 hours has the highest catalytic activity,and the conversion of WC/FCC co-liquefaction reachs 87.70%.Ni and Mo loadings endow SO₄^2-/ZrO₂solid acid with different degrees of catalytic hydrogenation activity.The catalytic activity of SO₄^2-/ZrO₂solid acid is the highest when Ni-Mo bimetal is supported.The conversion and the yield of oil+gas of WC/FCC co-liquefaction reach 90.80%and69.90%,respectively.The research on WO₃/ZrO₂solid acid and its supported metal catalyst shows that WO₃modification can form medium and robust acid sites and strong acid sites on the surface of ZrO₂,improving the acidity and acid catalytic hydrocracking activity of WO₃/ZrO₂.WO₃/ZrO₂solid acid has higher thermal stability than SO₄^2-/ZrO₂does.Moreover,its acidic components are not easily lost.The number of solid acid sites and the content of Lewis acid centers on the surface of WO₃/ZrO₂are the highest when 15%WO₃is loaded.Moreover,the appropriate calcination condition of WO₃/ZrO₂solid acid are 800℃for 3 h.With the WO₃/ZrO₂solid acid prepared under optimized conditions as catalyst,the conversion and the yield of oil+gas of WC/FCC co-liquefaction reach 86.90%and 67.10%,respectively.Metal loading can form catalytic hydrogenation active centers on the surface of WO₃/ZrO₂solid acid and improve the strength of acid centers.For WC/FCC co-liquefaction,the Ni-Mo supported WO₃/ZrO₂solid acid shows the best catalytic performance,of which the conversion and the yield of oil+gas reach 90.10%and 68.90%,respectively.