Study On Catalytic Pyrolysis Characteristics And Pyrolysis Process Of Jimsar Oil Shale

With the development of economy and industry,the problem of energy shortage has become increasingly prominent.The search for alternative energy has become an important issue to promote the sustainable development of today's society.The reserve of oil shale is large,shale oil and shale gas can be obtained after low temperature pyrolysis.Shale oil,which is similar to oil;shale gas can be directly used for combustion.Therefore,oil shale is considered to be the best supplementary energy source for petroleum,which has attracted wide attention of scholars both at home and abroad.The pyrolysis process and oil production of oil shale vary greatly with the quality of shale,and the regularity of influence of catalyst are also different.The study of Chinese oil shale is focusing on Maoming,Huadian and Fushun mining areas.The oil shale reserves in Xinjiang Jimsar oil shale account for 17%of the national reserves,with an average oil conten of 8%.Therefore,thes paper takes the oil shale in Jimsar as the research object,and explores the main characteristics and laws of its pyrolysis process.Inorder to promote the productivity of shale oil and shale gas,and to study the laws which influenced by catalysts,different kinds of catalysts were added into oil shale samples.Numerical simulation of the temperature history of block oil shale was studied in this paper,to save the study time and the efficient.In this paper,CoCl₂·6H₂O,Fe₂O₃ and Fe₃O₄ was taken as catalysts to study the law of catalyst pyrolysis process of Jimsar oil shale.It was found that the average activation energy of oil shale pyrolysis was reduced from 216kJ/mol to 163kJ/mol by CoCl₂·6H₂O,and slightly increased by adding Fe₂O₃ and Fe₃O₄.Further analysis showed that iron-based catalyst could inhibit the decomposition of minerals in Jimsar oil shale to some extent.Thermogravimetric-mass spectrometry?TG-MS?analysis showed that CoCl₂·6H₂O could greatly increase the concentration of pyrolysis products and reduce the pyrolysis temperature by about 100?.The results of aluminum retort experiment showed that CoCl₂·6H₂O could increase the oil yield of shale oil about 1.5 times,Fe₂O₃ could increase the oil yield about 1.15 times,Fe₃O₄ could not increase the oil yield,but the shale gas yield increased.The composition of shale oil and shale gas in several samples shows that there is little change in the species.The variation of thermal conductivity in different bedding directions of oil shale is studied experimentally.The results show that the thermal conductivity in the direction parallel to the bed is 1.25 times that in the direction perpendicular to the bed.On this basis,a mathematical model of the pyrolysis process of oil shale with single grain is presented,which includes the kinetic parameters of each sub-reaction and the total reaction obtained by the main curve method.The model can describe the pyrolysis process and internal temperature field of oil shale more accurately.The simulation results of the pyrolysis process of Jimsar oil shale show that the temperature difference increases with the increase of equivalent diameter.When oil shale is regarded as anisotropic material,the final heating time and anisotropy are the same when the equivalent diameter is greater than 30 mm.On the basis of the difference of 45 s,the rule between pyrolysis time and equivalent diameter of Jimsar oil shale is given,which lays a foundation for simulating the catalytic pyrolysis process of oil shale.