Study On High Temperature Rapid Pyrolysis And High Temperature Catalytic Gasification Of Coal And Petroleum Coke

Due to the low gasification activity of petroleum coke,it is often co-gasification with coal or adding some catalyst to improve the gasification activity.As the gasification temperature of coal and petroleum coke industry large-scale gasification gradually rises,common catalysts have problems of volatilization,deactivation,fly ash generation and melting and slagging in the high temperature section.At the same time,the existing research on pyrolysis and gasification characteristics of coal and petroleum coke at high temperature is not enough,so how to realize the efficient catalytic utilization of coal and petroleum coke at high temperature has important research significance.Firstly,the pyrolysis experiments of Shilin bituminous coal,Sihe anthracite and Qingdao petroleum coke were carried out in a high temperature fixed bed,and the release of pyrolysis gas and the pore structure and chemical characteristics of the pyrolysis char were studied.The results show that the main products of pyrolysis gas are H₂ and CO.With the increase of pyrolysis temperature,the relative content of H₂ and CO,the order of carbon microcrystalline structure and the degree of graphitization are increased.The gasification activity of pyrolysis char of bituminous coal and anthracite decreased continuously with the increase of pyrolysis temperature,while that of petroleum coke increased slightly after 1300?.In addition,high temperature pyrolysis has a significant effect on the desulfurization of high sulfur petroleum coke,and the desulfurization rate can reach 81.34%at 1500?.Then,the catalytic gasification effect of different catalysts on high-temperature pyrolysis char of petroleum coke was studied by TGA,and the kinetic calculation of TGA data was carried out.The results show that Na Al O₂ has a good catalytic effect on the pyrolysis char of petroleum coke,and the gasification activity of the pyrolysis char can be gradually increased by increasing the proportion of Na Al O₂ loaded on the pyrolysis char,and the melting and volatilization of Na Al O₂ are not occurred at high temperature due to its low volatility and high melting point.In addition,it is found that the gasification reaction activity of the sample is very high when the pyrolysis coke of petroleum coke and bituminous coal is first mixed with1:2 and then loaded with 1.0%Na Al O₂.The kinetic calculation shows that the activation energy of the sample is 95.54 k J·mol^-1,which is significantly lower than that of petroleum coke(214.27 k J·mol^-1).At the same time,the mixing ratio of 1:2 can ensure the utilization of high proportion of petroleum coke.Therefore,catalytic gasification of the mixture of petroleum coke and bituminous coal is an excellent way for the efficient utilization of petroleum coke.Finally,the high temperature gasification experiments of coal and petroleum coke in different atmosphere were carried out by high temperature fixed bed.The low heating value of the gasified gas from the pyrolysis char of bituminous coal and the mixture coke of petroleum coke and bituminous coal loaded with Na Al O₂ is more than 10 MJ/m³ at high temperatures.The study on the structure evolution of semi-coke gasified in different atmosphere by acid-washed anthracite pyrolytic char shows that the reaction rate of coal char gasification in CO₂/H₂O is the fastest,followed by H₂O,and CO₂ is the slowest.In high temperature gasification,CO₂ mainly etches the surface of coal char and generates micropores,while H₂O can etch the interior of coal char and form micropores and mesopores.The mesopores produced after H₂O gasification can promote the formation of micropores CO₂penetrates into the interior of coal char and forms more abundant pores,so the two gasification agents have synergistic effect and can effectively increase the gasification reaction activity of pyrolysis char.