Study On Pyrolysis Characteristics Of Transition Metal Oxide Supported USY Zeolites To Shendong Coal In Hydrogen Rich Atmosphere

In this paper,on the basis of commercial USY zeolite catalyst,single component and two-component transition metal oxides were introduced to modify the catalyst by equal volume impregnation,Through the characterization of catalyst,we found that equal volume impregnation can effectively pass the single/two components.The loading of transition metal oxide on USY support changed the acid distribution of catalyst,decreased the total pore volume and total specific surface area,and did not cause obvious damage to the crystal form and structure of catalyst.The effect of the catalysts on the pyrolysis products of Shendong coal in hydrogen rich atmosphere was investigated by using the powder-particle fluidized bed.The experimental results show;USY molecular sieve,because of it’s strong acid position,reduces the yield of tar,increases the yield of pyrolysis gas,and accumulates Carbon increase.The content of naphthalene aromatics in tar increased obviously,while the content of aliphatic hydrocarbon,phenolic compound and monocyclic aromatics decreased.The loading of NiO increased the total yield of gas products,the content of CO and CH₄increased,while the content of C₂and C₃decreased.The loading of Co₃O₄and WO₃reduced the content of CH₄,C₂and C₃in the gas products of catalytic pyrolysis.The results of TG simulation GC-MS showed that USY could promote the tar lightening.When NiO and Co₃O₄were introduced into W-USY,the gas yield increased,the carbon deposition rate decreased.Under the action of Ni/W-USY,the contents of CO,CH₄and H₂in the gas products increased obviously.In the tar products,the contents of naphthalene compounds,polycyclic aromatic hydrocarbons,oxygen-containing compounds,monocyclic aromatic hydrocarbons and aliphatic hydrocarbons decreased.Under the action of Co/W-USY the contents of CO and CH₄in the gas products increased,the contents of H₂decreased,and the contents of aliphatic hydrocarbons,polycyclic aromatic hydrocarbons and biphenyl compounds in the tar products increased,The content of oxygen compounds and phenols decreased.After loading NiO and Co₃O₄on W-USY,the thermal weight loss of tar atlower than that of USY and W-USY,and higher than that of tar without catalyst.When NiO and Co₃O₄were introduced into Mo-USY,the yields of gas products increased,the yields of liquid products decreased,and the carbon deposition decreased.The yields of CO,CO₂and CH₄in the gas products from the pyrolysis of Ni/W-USY catalyst increased obviously,while the yields of C₂and C₃decreased,the contents of naphthalene aromatics,polycyclic aromatics and biphenyls in the tar products increased,and those of aliphatic phenols containing oxygen compounds decreased,The content decreased.Under the action of CO/W-USY,the content of CO in gas products increased obviously,the content of biphenyls,phenols and aliphatic hydrocarbons in tar products increased,while the content of naphthalene compounds decreased.After NiO is introduced into the support catalyst,the weight loss rate of tar obtained by catalytic pyrolysis atlower than that of tar under USY and Mo-USY catalytic pyrolysis,higher than that without catalyst,and the weight loss rate of tar under CO/Mo-USY catalyst is lower than that under USY catalytic,higher than that without catalyst.