Low Temperature Dechlorination of Densified Refuse Derived Fuel in Pyrolysis

Study on behavior of chlorine contained in oval-shaped densified refuse derived fuel (d-RDF) prepared from municipal solid waste in pyrolysis was carried out by means of temperature-programmed electrical furnace, and the gas evolving from pyrolysis was investigated by FTIR. De-HCl rate was calculated by determining the emission fraction of HCl in the flue gas and the fraction of Cl left in the pyrolysis residue. The results show that Cl in the d-RDF releases primarily in the form of HCl during the pyrolysis, and the initial releasing temperature of HCl enhances with the increase of heating rate. Meanwhile, the higher the end temperature of pyrolysis, the more the Cl released. De-HCl rate is about 70% when the end temperature of pyrolysis is around 600℃. Besides, mechanism of Cl release is dis-cussed.

Relationship between hydrogenation degree and pyrolysis performance of jet fuel

Understanding the relationship between the chemical composition and pyrolysis performance of endothermic hydrocarbon fuel(EHF) is of great significance for the design and optimization of advanced EHFs. In this work, the effect of deep hydrogenation on the pyrolysis of commercial RP-3 is investigated.Fuels with different hydrogenation degrees were obtained by the partially and completely catalytic hydrogenation and their pyrolysis performances were investigated using an apparatus equipped with an electrically heated tubular reactor. The results show that with the increase of hydrogenation degree, fuel conversion almost remains constant during the pyrolysis process(500-650°C, 4 MPa);however, the heat sink increases slightly, and the anti-coking performance significantly improves, which are highly related to their H/C ratios. Detailed characterisations reveal that the difference of the pyrolysis performance can be ascribed to the content of aromatics and cycloalkanes: the former are prone to initiate secondary reactions to form coking precursors, while the latter could act as the hydrogen donor and release hydrogen, which will terminate the radical propagation reactions and suppress the coke deposition. This work should provide the guidance for upgrading EHFs by modulating the composition of EHFs.

The nitrogen transformation behavior based on the pyrolysis products of wheat stra

In order to provide basic design parameters for the industrial pyrolysis process,the transformation behavior of nitrogen was investigated using wheat straw as raw material.The distributions of nitrogen in pyrolysis char,oil,and gas were obtained and the nitrogenous components in the products were analyzed systematically by X-ray photoelectron spectroscopy(XPS),pyrolysis-gas chromatography/mass spectrometry(Py-GC/MS)and thermogravimetric-Fourier transform infrared spectrometry(TG-FTIR).The nitrogen distribution ranges of the pyrolysis char,oil,and gas were 37.34%–54.82%,32.87%–40.94%and 10.20%–28.83%,respectively.More nitrogen was retained in char at lower pyrolysis temperature and the nitrogen distribution of oil was from rise to decline with increasing temperature.The most abundant N-containing compounds in three-phase products were pyrrole-N,amines,and HCN,respectively.In addition,the transformation mechanism of nitrogen from wheat straw to pyrolysis products was concluded.

Study of Pyrolysis Characteristics and Kinetic Analysis of Shenmu Coal at a High Heating Rate Using TG-FTIR

Coal pyrolysis is a fundamental reaction in the thermal processing and utilization of coal.Investigating the behavior and kinetics of coal pyrolysis is crucial for optimizing,designing,and developing a composite riser for the staged pyrolysis gasification process of pulverized coal.In this study,the non-isothermal pyrolysis behavior and kinetics of coal were examined at different heating rates(30,50,100,300,500,700,and 900℃/min)using thermogravimetry(TG)coupled with Fourier-transform infrared spectroscopy.Analysis of the TG/derivative TG(TG/DTG)curves indicated that coal pyrolysis mainly occurred between 300℃ and 700℃.Higher heating rates led to more volatiles being released from the coal,and a higher temperature was required to achieve rapid pyrolysis.Kinetic analysis showed that both the model-free methods(Friedman,Flynn-Wall-Ozawa,and Kissinger-Akahira-Sunose)and the model-based method(Coats-Redfern)effectively describe the coal pyrolysis process.The change in the Ea values between the two kinetic models was consistent throughout the pyrolysis process,and the most probable mechanism was the F2 model(secondary chemical reaction).In addition,the heating rate did not change the overall reaction order of the pyrolysis process;however,a higher heating rate resulted in a decrease in the Ea value during the initial pyrolysis stage.

Effect of long reaction distance on gas composition from organic-rich shale pyrolysis under high-temperature steam environment

When high-temperature steam is used as a medium to pyrolyze organic-rich shale,water steam not only acts as heat transfer but also participates in the chemical reaction of organic matter pyrolysis,thus affecting the generation law and release characteristics of gas products.In this study,based on a long-distance reaction system of organic-rich shale pyrolysis via steam injection,the effects of steam temperature and reaction distance on gas product composition are analyzed in depth and compared with other pyrolysis processes.The advantages of organic-rich shale pyrolysis via steam injection are then evaluated.The volume concentration of hydrogen in the gas product obtained via the steam injection pyrolysis of organic-rich shale is the highest,which is more than 60%.The hydrogen content increases as the reaction distance is extended;however,the rate of increase changes gradually.Increasing the reaction distance from 800 to 4000 mm increases the hydrogen content from 34.91%to 69.68%and from 63.13%to 78.61%when the steam temperature is 500°C and 555°C,respectively.However,the higher the heat injection temperature,the smaller the reaction distance required to form a high concentration hydrogen pyrolysis environment(hydrogen concentration>60%).When the steam pyrolysis temperature is increased from 500°C to 555°C,the reaction distance required to form a high concentration of hydrogen is reduced from 3800 to 800 mm.Compared with the direct retorting process,the volume concentration of hydrogen obtained from high-temperature steam pyrolysis of organic-rich shale is 8.82 and 10.72 times that of the commonly used Fushun and Kivite furnaces,respectively.The pyrolysis of organic-rich shale via steam injection is a pyrolysis process in a hydrogen-rich environment.

Importance of oxygen-containing functionalities and pore structures of biochar in catalyzing pyrolysis of homologous poplar

Biochar and bio-oil are produced simultaneously in one pyrolysis process,and they inevitably contact and may interact,influencing the composition of bio-oil and modifying the structure of biochar.In this sense,biochar is an inherent catalyst for pyrolysis.In this study,in order to investigate the influence of functionalities and pore structures of biochar on its capability for catalyzing the conversion of homologous volatiles in bio-oil,three char catalysts(600C,800C,and 800AC)produced via pyrolysis of poplar wood at 600 or 800℃or activated at 800℃,were used for catalyzing pyrolysis of homologous poplar wood at 600℃,respectively.The results indicated that the 600C catalyst was more active than 800C and 800AC for catalyzing cracking of volatiles to form more gas(yield increase by 40.2%)and aromatization of volatiles to form more light or heavy phenolics,due to its abundant oxygen-containing functionalities acting as active sites.The developed pores of the 800AC showed no such catalytic effect but could trap some volatiles and allow their further conversion via sufficient aromatization.Nevertheless,the interaction with the volatiles consumed oxygen on 600C(decrease by 50%),enhancing the aromatic degree and increasing thermal stability.The dominance of deposition of carbonaceous material of a very aromatic nature over 800C and 800AC resulted in net weight gain and blocked micropores but formed additional macropores.The in situ diffuse reflectance infrared Fourier transform spectroscopy characterization of the catalytic pyrolysis indicated superior activity of 600C for removal of -OH,while conversion of the intermediates bearing C=O was enhanced over all the char catalysts.

Computational fluid dynamics modeling of rapid pyrolysis of solid waste magnesium nitrate hydrate under different injection methods

This study developed a numerical model to efficiently treat solid waste magnesium nitrate hydrate through multi-step chemical reactions.The model simulates two-phase flow,heat,and mass transfer processes in a pyrolysis furnace to improve the decomposition rate of magnesium nitrate.The performance of multi-nozzle and single-nozzle injection methods was evaluated,and the effects of primary and secondary nozzle flow ratios,velocity ratios,and secondary nozzle inclination angles on the decomposition rate were investigated.Results indicate that multi-nozzle injection has a higher conversion efficiency and decomposition rate than single-nozzle injection,with a 10.3%higher conversion rate under the design parameters.The decomposition rate is primarily dependent on the average residence time of particles,which can be increased by decreasing flow rate and velocity ratios and increasing the inclination angle of secondary nozzles.The optimal parameters are injection flow ratio of 40%,injection velocity ratio of 0.6,and secondary nozzle inclination of 30°,corresponding to a maximum decomposition rate of 99.33%.

Sustainable Biofuel Production from Brown and Green Macroalgae through the Pyrolysis

The escalating demand for energy coupled with environmental concerns necessitates exploring sustainable alternatives to fossil fuels.The study explores the viability of using large ocean-based seaweeds as a source of thirdgeneration biomass,specifically focusing on their conversion to biofuel via the process of pyrolysis.Sargassum plagiophyllum and Ulva lactuca represent prevalent forms of macroalgae,posing significant discharge challenges for coastal regions globally.However,the exploration of their potential for bio-oil generation via pyrolysis remains limited.This study investigates the pyrolysis process of S.plagiophyllum and U.lactuca for biofuel production,aiming to provide valuable insights into their utilization and optimization.Pyrolysis experiments were conducted within temperature ranges of 400°C to 600°C and durations of 10 to 50 min using a batch reactor.The chemical analysis of the synthesized bio-oil indicated it contains critical compounds such as organic acid derivatives,furans,nitrogenous aromatics,and aliphatic hydrocarbons.The effectiveness of converting the initial biomass into bio-oil is significantly influenced by the pace at which the biomass undergoes decomposition,underscoring the importance of comprehending the kinetic aspects of this conversion.By applying the Arrhenius formula,we calculated the activation energies and frequency factors,with the findings for S.plagiophyllum being 15.27 kJ/mol and 0.477 s^(-1),and for U.lactuca,the values were 43.17 kJ/mol and 0.351 s^(-1),correspondingly.These findings underscore the potential of brown and green macroalgae as sustainable sources for biofuel production via pyrolysis,offering insights for further optimization and valorization efforts in the quest for renewable energy solutions.

Chemical looping reforming of the micromolecular component from biomass pyrolysis via Fe_(2)O_(3)@SBA-16

To solve the problems of low gasification efficiency and high tar content caused by solid–solid contact between biomass and oxygen carrier in traditional biomass chemical looping gasification process.The decoupling strategy was adopted to decouple the biomass gasification process,and the composite oxygen carrier was prepared by embedding Fe_(2)O_(3) in molecular sieve SBA-16 for the chemical looping reforming process of pyrolysis micromolecular model compound methane,which was expected to realize the directional reforming of pyrolysis volatiles to prepare hydrogen-rich syngas.Thermodynamic analysis of the reaction system was carried out based on the Gibbs free energy minimization method,and the reforming performance was evaluated by a fixed bed reactor,and the kinetic parameters were solved based on the gas–solid reaction model.Thermodynamic analysis verified the feasibility of the reaction and provided theoretical guidance for experimental design.The experimental results showed that the reaction performance of Fe_(2)O_(3)@SBA-16 was compared with that of pure Fe_(2)O_(3) and Fe_(2)O_(3)@SBA-15,and the syngas yield was increased by 55.3%and 20.7%respectively,and it had good cycle stability.Kinetic analysis showed that the kinetic model changed from three-dimensional diffusion to first-order reaction with the increase of temperature.The activation energy was 192.79 kJ/mol by fitting.This paper provides basic data for the directional preparation of hydrogen-rich syngas from biomass and the design of oxygen carriers for pyrolysis of all-component chemical looping reforming.

Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin

This work investigated the pyrolysis reaction of waste resin in a fluidized bed reactor.It was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and defluidization.Adding kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical reaction.On the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of resin.On the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

Cross-upgrading of biomass hydrothermal carbonization and pyrolysis for high quality blast furnace injection fuel production:Physicochemical characteristics and gasification kinetics analysis

The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion.

Micro-aluminum powder with bi-or tri-component alloy coating as a promising catalyst:Boosting pyrolysis and combustion of ammonium perchlorate

A novel design of micro-aluminum(μAl)powder coated with bi-/tri-component alloy layer,such as:Ni-P and Ni-P-Cu(namely,Al@Ni-P,Al@Ni-P-Cu,respectively),as combustion catalysts,were introduced to release its huge energy inside Al-core and promote rapid pyrolysis of ammonium perchlorate(AP)at a lower temperature in aluminized propellants.The microstructure of Al@Ni-P-Cu demonstrates that a three-layer Ni-P-Cu shell,with the thickness of~100 nm,is uniformly supported byμAl carrier(fuel unit),which has an amorphous surface with a thickness of~2.3 nm(catalytic unit).The peak temperature of AP with the addition of Al@Ni-P-Cu(3.5%)could significantly drop to 316.2℃ at high-temperature thermal decomposition,reduced by 124.3℃,in comparison to that of pure AP with 440.5℃.It illustrated that the introduction of Al@Ni-P-Cu could weaken or even eliminate the obstacle of AP pyrolysis due to its reduction of activation energy with 118.28 kJ/mol.The laser ignition results showed that the ignition delay time of Al@Ni-P-Cu/AP mixture with 78 ms in air is shorter than that of Al@Ni-P/AP(118 ms),decreased by 33.90%.Those astonishing breakthroughs were attributed to the synergistic effects of adequate active sites on amorphous surface and oxidation exothermic reactions(7597.7 J/g)of Al@Ni-P-Cu,resulting in accelerated mass and/or heat transfer rate to catalyze AP pyrolysis and combustion.Moreover,it is believed to provide an alternative Al-based combustion catalyst for propellant designer,to promote the development the propellants toward a higher energy.

Coconut Fiber Pyrolysis: Bio-Oil Characterization for Potential Application as an Alternative Energy Source and Production of Bio-Degradable Plastics

The current energy crisis could be alleviated by enhancing energy generation using the abundant biomass waste resources. Agricultural and forest wastes are the leading organic waste streams that can be transformed into useful alternative energy resources. Pyrolysis is one of the technologies for converting biomass into more valuable products, such as bio-oil, bio-char, and syngas. This work investigated the production of bio-oil through batch pyrolysis technology. A fixed bed pyrolyzer was designed and fabricated for bio-oil production. The major components of the system include a fixed bed reactor, a condenser, and a bio-oil collector. The reactor was heated using a cylindrical biomass external heater. The pyrolysis process was carried out in a reactor at a pressure of 1atm and a varying operating temperature of 150˚C, 250˚C, 350˚C to 450˚C for 120 minutes. The mass of 1kg of coconut fiber was used with particle sizes between 2.36 mm - 4.75 mm. The results show that the higher the temperature, the more volume of bio-oil produced, with the highest yield being 39.2%, at 450˚C with a heating rate of 10˚C/min. The Fourier transformation Infrared (FTIR) Spectroscopy analysis was used to analyze the bio-oil components. The obtained bio-oil has a pH of 2.4, a density of 1019.385 kg/m3, and a calorific value of 17.5 MJ/kg. The analysis also showed the presence of high-oxygenated compounds;carboxylic acids, phenols, alcohols, and branched oxygenated hydrocarbons as the main compounds present in the bio-oil. The results inferred that the liquid product could be bestowed as an alternative resource for polycarbonate material production.

Effect of demineralization on pyrolysis characteristics of LPS coal based on its chemical structure

The critical issue in developing mature Oxy-Coal Combustion Steam System technology could be the reactivity of deminer-alized coal which,is closely related to its chemical structure.The chemical structures of Liupanshui raw coal(LPS-R)and Liupanshui demineralized coal(LPS-D)were analyzed by FTIR and solid-state 13C-NMR.The pyrolysis experiments were carried out by TG,and the pyrolysis kinetics was analyzed by three iso-conversional methods.FTIR and 13C-NMR results suggested that the carbon structure of LPS coal was not altered greatly,while demineralization promoted the maturity of coal and the condensation degree of the aromatic ring,making the chemical structure of coal more stable.The oxygen-containing functional groups with low bond energy were reduced,and the ratio of aromatic carbon with high bond energy was increased,decreasing the pyrolysis reactivity.DTG curve-fitting results revealed that the thermal weight loss of LPS coal mainly came from the cleavage of aliphatic covalent bonds.By pyrolysis kinetics analysis of LPS-R and LPS-D,the apparent activation energies were 76±4 to 463±5 kJ/mol and 84±2 to 758±12 kJ/mol,respectively,under different conversion rates.The reactivity of the demineralized coal was inhibited to some extent,as the apparent activation energy of pyrolysis for LPS-D increased by acid treatment.

Preparation of aromatic hydrocarbons from catalytic pyrolysis of digestate

Catalytic pyrolysis of digestate to produce aromatic hydrocarbons can be combined with anaerobic fermentation to effectively transform and utilize all biomass components,which can achieve the meaningful purpose of transforming waste into high-value products.This study explored whether catalytic pyrolysis of digestate is feasible to prepare aromatic hydrocarbons by analyzing the thermogravimetric characteristics,pyrolysis characteristics,and catalytic pyrolysis characteristics of digestate.For digestate pyrolysis,an increase in temperature was found to elevate the CO,CH_4,and monocyclic aromatic hydrocarbon(benzene,toluene,and xylene;BTX)content,whereas it decreased the contents of phenols,acids,aldehydes,and other oxygenates.Furthermore,the catalytic pyrolysis process effectively inhibited the acids,phenols,and furans in the liquid,whereas the yield of BTX increased from 25.45%to 45.99%,and the selectivity of xylene was also increased from 10.32%to 28.72%after adding ZSM-5.ZSM-5 also inhibited the production of nitrogenous compounds.

Pyrometallurgical recycling of spent lithium-ion batteries from conventional roasting to synergistic pyrolysis with organic wastes

The synergistic pyrolysis has been increasingly used for recycling spent lithium-ion batteries(LIBs)and organic wastes(hydrogen and carbon sources),which are in-situ transformed into various reducing agents such as H_(2),CO,and char via carbothermal and/or gas thermal reduction.Compared with the conventional roasting methods,this“killing two birds with one stone”strategy can not only reduce the cost and energy consumption,but also realize the valorization of organic wastes.This paper concluded the research progress in synergistic pyrolysis recycling of spent LIBs and organic wastes.On the one hand,valued metals such as Li,Co,Ni,and Mn can be recovered through the pyrolysis of the cathode materials with inherent organic materials(e.g.,separator,electrolyte)or graphite anode.During the pyrolysis process,the organic materials are decomposed into char and gases(e.g.,CO,H_(2),and CH_(4))as reducing agents,while the cathode material is decomposed and then converted into Li_(2)CO_(3) and low-valent transition metals or their oxides via in-situ thermal reduction.The formed Li_(2)CO_(3) can be easily recovered by the water leaching process,while the formed transition metals or their oxides(e.g.,Co,CoO,Ni,MnO,etc.)can be recovered by the reductant-free acid leaching or magnetic separation process.On the other hand,organic wastes(e.g.,biomass,plastics,etc.)as abundant hydrogen and carbon sources can be converted into gas(e.g.,H_(2),CO,etc.)and char via pyrolysis.The cathode materials are decomposed and subsequently reduced by the pyrolysis gas and char.In addition,the pyrolysis oil and gas can be upgraded by catalytic reforming with the active metals derived from cathode material.Finally,great challenges are proposed to promote this promising technology in the industrial applications.

Wax from Pyrolysis of Waste Plastics as a Potential Source of Phase Change Material for Thermal Energy Storage

Over the past half-century, plastic consumption has grown rapidly due to its versatility, low cost, and unrivaled functional properties. Among the diff erent implemented strategies for recycling waste plastics, pyrolysis is deemed the most economical option. Currently, the wax obtained from the pyrolysis of waste plastics is mainly used as a feedstock to manufacture chemicals and fuels or added to asphalt for pavement construction, with no other applications of wax being reported. Herein, the thermal pyrolysis of three common waste polyolefin plastics: high-density polyethylene(HDPE), low-density polyethylene(LDPE), and polypropylene(PP), was conducted at 450 ℃. The waste plastics-derived waxes were characterized and studied for a potential new application: phase change materials(PCMs) for thermal energy storage(TES). Gas chromatography–mass spectrometry analysis showed that paraffin makes up most of the composition of HDPE and LDPE waxes, whereas PP wax contains a mixture of naphthene, isoparaffin, olefin, and paraffin. Diff erential scanning calorimetry(DSC) analysis indicated that HDPE and LDPE waxes have a peak melting temperature of 33.8 ℃ and 40.3 ℃, with a relatively high latent heat of 103.2 J/g and 88.3 J/g, respectively, whereas the PP wax was found to have almost negligible latent heat. Fourier transform infrared spectroscopy and DSC results revealed good chemical and thermal stability of HDPE and LDPE waxes after 100 cycles of thermal cycling. Performance evaluation of the waxes was also conducted using a thermal storage pad to understand their thermoregulation characteristics for TES applications.

Catalyst for Increasing Ethylene and Propylene Production and Its Industrial Application in a Catalytic Pyrolysis Unit

Light olefins,particularly ethylene and propylene,are the most important building blocks for the petrochemical industry,and demand for their production has been increasing.The catalytic pyrolysis process(CPP)and the corresponding catalyst,developed by SINOPEC Research Institute of Petroleum Processing Co.,Ltd.,are designed to maximize the light olefin yield from catalytic cracking of heavy feedstocks.However,owing to the continuing degradation of feedstocks,the original catalyst can no longer maintain its activity.Herein,we describe the rational design of the new catalyst,Epylene,from a new metal-modified hierarchical ZSM-5 zeolite and matrix.Epylene was tested in the CPP unit of Shaanxi Yanchang Coal Yulin Energy and Chemical Company.A test run and base run were conducted to demonstrate the better performance of Epylene compared with the original catalyst.The properties of the feedstocks and the operating conditions in both runs were similar.The light olefin yield was increased from 33.95%to 36.50%and the coke yield was only 9.58%in the test run,which was lower than that in the base run.

Insight into the key kinetic steps in the pyrolysis of coking and non-coking coals,characterization of the pyrolysis products

The chemical composition,structural and plastometric properties of different-ranked coals from Mongolia deposits were studied.The non-isothermal iso-conversion Ozawa-Flynn-Wall and Friedman model-free methods were used to assess kinetic parameters and to differentiate decomposition steps.Key peculiarities of the pyrolysis kinetics of brown and bituminous coals were revealed and discussed in terms of the composition and plastometric properties.Brown coal was shown to undergo three decomposition steps with ever increasing activation energy as temperature increased because of the decomposition of thermally more and more stable molecular fragments.The pyrolysis of bituminous coals occurred in four steps,the activation energy having extreme mode of temperature dependence.An important new finding was that the temperature range of the second,major pyrolysis step well corresponded to that between the softening and re-solidification temperatures according to Gieseler plastometry.The yield and composition of the pyrolysis products obtained under isothermal conditions were also characterized depending on coal rank and temperature,and the ways for qualified utilizations were offered.

Insight into pyrolysis of hydrophobic silica aerogels:Kinetics,reaction mechanism and effect on the aerogels

Silica aerogels have promising applications in thermal insulation,but their flammability and reaction mechanisms have rarely been investigated.The pyrolysis kinetics and thermodynamics of hydrophobic silica aerogels under N_(2) environment were studied.The kinetic and thermodynamic parameters were obtained by three model-free methods.Based on the calculated kinetic parameters,the pyrolysis mechanism of silica aerogels was discussed by the master plots method.The results indicate that the reactions of the whole pyrolysis phase can be characterized by a random nuclear model.In addition,FTIR test results show that the volatile products of silica aerogel pyrolysis are mainly hydrocarbons generated by the decomposition of hydrophobic groups(methyl groups)on the surface.Finally,the effects of pyrolysis on the properties of silica aerogels Finally,the effects of pyrolysis on the properties of silica aerogels were investigated based on the analysis results of SEM,specific surface area,pore size distribution,X-ray diffraction,XPS and infrared spectroscopy.