Study On Catalytic Pyrolysis Characteristics Of Combustible Solid Waste Based On Modified HZSM-5 Zeolite Catalyst

The rapid growth of urban solid waste generation in China has seriously endangered the environment and residents'living conditions.It is an important issue related to ecological civilization and environmental protection to explore ways of reducing,recycling and harmless treatment.Pyrolysis technology is increasingly being widely studied because it can achieve full reuse of valuable products and maximum energy recovery,and has high environmental and economic benefits.Biomass has a high oxygen content and a low carbon content,so pyrolysis of biomass alone makes it difficult for pyrolysis oil to meet the requirements as a liquid fuel.In order to obtain higher quality liquid products,the research of biomass pyrolysis alone is developing in the direction of catalytic pyrolysis mixed with other hydrogen-rich materials such as waste tires or waste plastics.To this end,this paper takes kitchen waste and waste tires,typical components of municipal solid waste,as research objects,studies the mixed pyrolysis and catalytic pyrolysis of kitchen waste and waste tires to produce liquid fuel,and discusses the heat under different mixing ratios and catalyst The decomposition reaction process and the distribution law of pyrolysis products provide ideas and reference basis for the comprehensive utilization of kitchen waste and waste tire resources.In this paper,a variety of experimental techniques and methods are used to study the reaction characteristics of the waste pyrolysis process of kitchen waste and waste tires and the law of precipitation of pyrolysis products,as follows:?1?The thermogravimetric synchronous analyzer was used to study the catalytic pyrolysis characteristics and anti-coking performance of kitchen waste,waste tires and their mixed samples.The research results show that the pyrolysis weightlessness process of kitchen waste and waste tires can be divided into three stages and there is a main weightlessness peak.The pyrolysis starting temperature,maximum weight loss rate and corresponding temperature of the waste tires are all higher than kitchen waste,and the pyrolysis quality residual rate is lower than kitchen waste.When the blending ratio of waste tires is 50%,the pyrolysis mass residual rate and initial pyrolysis temperature are the lowest.The 1Fe2Ni catalyst showed the best promotion effect in reducing the residual rate of pyrolysis mass.The graded HZSM-5exhibits the best anti-coking performance.?2?The pyrolysis-gas chromatography/mass spectrometry experiment was used to study the distribution of catalytic pyrolysis products of kitchen waste,waste tires and their mixed samples.The research results show that the optimal blending ratio of waste tires is 75%,which significantly promotes the formation of volatile products and hydrocarbon products and inhibits the formation of non-hydrocarbon products.2Fe1Ni catalyst showed the best catalytic effect in promoting the formation of volatile products and monocyclic aromatic hydrocarbon products.?3?Fourier transform infrared spectrometer was used to detect the gas-phase products generated during the pyrolysis process of kitchen waste and waste tires.The results show that the mixed pyrolysis of kitchen waste and waste tires promotes the production of hydrocarbons?C-H?to a certain extent and inhibits the production of NO and NH₃.?4?The physical and chemical characteristics of HZSM-5 zeolite catalyst treated with alkali and loaded with iron and nickel were analyzed by nitrogen physical adsorption,scanning electron microscope,X-ray diffraction and other methods.The results show that both the original HZSM-5 and the modified HZSM-5 have a certain mesoporous structure,and the 2Fe1Ni catalyst has more mesoporous structures.After modification,the total specific surface area and pore volume of HZSM-5 decreased to a large extent,and the external specific surface area and average pore diameter increased significantly.The modified HZSM-5 still retains the skeleton structure of the original HZSM-5.?5?Using the equal conversion rate Ozawa-Flynn-Wall method and Kissinger-Akahira-Sunose method to establish a mixed catalytic pyrolysis kinetic model of kitchen waste and waste tires.The results of the study show that the best ratio for mixing pyrolysis of kitchen waste and waste tires to reduce the apparent activation energy is 1:1.Alkali treatment HZSM-5 showed better catalytic performance in reducing the average apparent activation energy of the catalytic pyrolysis process.In summary,mixed catalytic pyrolysis comprehensively uses kitchen waste and waste tires,which improves the yield of hydrocarbon products and enhances the energy value of pyrolysis oil,making it possible to upgrade to gasoline and diesel fuel.Better application prospects.