Study On Catalytic Pyrolysis Of Shendong Coal Based On Transition Metal Oxide/USY Catalysts

Coal in China’s energy consumption accounted for more than 60%,indicating that coal is very important in China’s energy status.The pyrolysis of coal is not only the key link to realize efficient and clean conversion of coal,but also a kind of routine coal utilization with the highest heat conversion efficiency.In this paper,USY were modified by the same volume impregnation method using Fe₂O₃,Co₃O₄,NiO,MoO₃ respectively to prepare one-component transition metal oxide supported Me_xO_y/USY catalysts and two-component transition metal oxide supported MeMo/USY catalysts,and characterized by ICP,XRD,BET,NH₃-TPD,TG,et al.A series of pyrolysis and catalytic pyrolysis experiments of Shendong coal were carried out in a powder-particle fluidized bed.The effects of the type and loading of transition metal oxides on the USY and its effects on the pyrolysis products were investigated.The results show that the loading of transition metal oxide didn’t change the phase structure of USY.However,the larger the loading of transition metal oxides,the smaller the pore volume and specific surface area and the larger the increase in the amount of acid.The magnitude of which was proportional to the loading;the yield of char remained at around 65%;the USY had the effect of "phenol reduction and naphthalene reduction",the content of naphthalene compounds in tar up to 79.81%;Me_xO_y/USY increased the contents of phenols,oxygenates and aliphatic hydrocarbons in tar,while the content of naphthalenes and the yields of H₂ and C₂ decreased.Fe₂O₃/USY,Co₃O₄/USY and MoO₃/USY increased the yield of CH₄,CO₂ and CO and the total yield of gas,respectively,while the yield of C₃ decreased.After Fe₂O₃,Co₃O₄ and NiO modified Mo/USY,the content of monocyclic aromatic hydrocarbons and poly-benzene compounds in tar and the yield of CH₄,CO₂,C₂ and C₃ and the total gas yield increased,respectively,and the catalysts carbon deposition decreased significantly.FeMo/USY and CoMo/USY decreased the content of phenols and aliphatic hydrocarbons in tar,and increased the content of oxygenated compounds and the yield of CO,respectively.CoMo/USY and NiMo/USY reduced the polycyclic aromatic hydrocarbons aromatics and naphthalenes,but increased the yield of H₂.