Nuclei Growth Model Research Articles

Pyrolysis kinetic analysis of molten bioplastics based on the combination of real-time characterization and Guassian deconvolution: Case study of poly(lactic acid) materials

Pyrolysis remains a promising method for the utilization of biogradable plastics. However, the kinetics and mechanisms of molten polymer pyrolysis are not well understood, and the effect of additives (mainly inorganic nucleating agents) on the reaction pathway has not been widely explored. In this work, we conducted a method using the thermogravimetric analysis-Fourier transform infrared spectrometry (TG-FTIR) combined with a model-fitting method, instead of a traditional method subjectively selecting a reaction model. The FTIR curves provided information for sub-reaction determination, and the detailed parameters were determined using Gaussian deconvolution. The calculation results revealed that the whole process of poly(latic acid) (PLA) pyrolysis is the random nucleation and nuclei growth model. The introduction of inorganic nucleating agents provided nuclei for PLA decomposition, decreasing the initial activation energy (E) from approximately 136 kJ·mol−1 to 88 and 79 kJ·mol−1 at a conversion rate of 0.01. However, the nucleating agent could hinder the generation of nuclei from PLA ontology, which led to the increase of E value after the nucleating agents were occupied.

Kinetic analysis of biochar chemical looping gasification with calcium ferrite as oxygen carriers

The chemical looping gasification (CLG) kinetics of biochars with calcium ferrite as oxygen carriers and the effects of different kinds of calcium ferrite and biochars were investigated by TGA. The properties of biochars and calcium ferrite were analyzed by XRD, SEM, BET, etc. The Škvára-Šesták method was used to determine the kinetic mechanism function. The results show that the reduction reaction rate and the oxygen carrying capacity of oxygen carriers follow the sequence: Ca2Fe2O5 > CaFe2O4 > Fe2O3, and CaFe2O4 > Ca2Fe2O5 > Fe2O3, respectively. The oxygen carriers can be completely reduced to Fe and CaO by biochar. The activation energy of CaFe2O4 reduction is in the range of 167.44–600.83 kJ/mol; and the activation energy of Ca2Fe2O5 reduction is in the range of 413.62–583.51 kJ/mol. The CaFe3O5 generated during the reduction of CaFe2O4 may have a negative influence on the lattice oxygen diffusion. The reduction of CaFe2O4 can be divided into two stages: when the conversion degree α is less than 0.15, the CaFe2O4 is reduced to Ca2Fe2O5 following the random nucleation and nuclei growth model; when α is greater than 0.15, Ca2Fe2O5 is further reduced to CaO and Fe following the 3-D diffusion mechanism. The mechanism function of the reduction of Ca2Fe2O5 is the same as that of the second stage of CaFe2O4 reduction.

Pyrolysis of sulfuric acid-treated chrome-tanned leather wastes: Kinetics, mechanism and evolved gas analysis

Management and safe disposal of chrome-tanned leather wastes generated in leather industry are of great importance due to their potential health risks and environmental hazards. Herein, an integrated strategy was proposed for disposing of chrome-tanned leather scrap (CTLS). This method involves the separation of chromium salts from CTLS with sulfuric acid for recycling purpose, followed by pyrolysis of the acid-treated CTLS in an inert atmosphere. SEM/EDX analysis was employed to characterize the changes in composition and morphology of CTLS after acid treatment. CO2 and H2O are main pyrolysis gases of CTLS, while the acid treatment increases the relative content of aliphatic hydrocarbons and NH3 in evolved gases. The pyrolysis characteristics and kinetics of the acid-treated CTLS were investigated by thermogravimetric analysis (TGA) at three different heating rates. After 3 and 6 days of acid treatment, the average activation energy of CTLS (450.9 kJ/mol) obtained from the Flynn-Wall-Ozawa method decreased to 369.6 and 351.0 kJ/mol, respectively. It is assumed that the CTLS consists of two pseudocomponents: low-crosslinked collagen (LCol) and highly-crosslinked collagen (HCol). Using the generalized master plots method, random nucleation and nuclei growth model (An model) was found to be the most probable kinetic model for the pyrolysis process of LCol and HCol. The kinetic exponent for pseudocomponent pyrolysis varied between 3.00 and 3.90, and the pre-exponential factor ranged from 5.83 × 1012 to 2.93 × 1013 min−1. The results of the present study provide an alternative route and useful information for recycling and disposing of chrome-containing leather wastes.

Solid-State Redox Kinetics of CeO2 in Two-Step Solar CH4 Partial Oxidation and Thermochemical CO2 Conversion

The CeO2/CeO2−δ redox system occupies a unique position as an oxygen carrier in chemical looping processes for producing solar fuels, using concentrated solar energy. The two-step thermochemical ceria-based cycle for the production of synthesis gas from methane and solar energy, followed by CO2 splitting, was considered in this work. This topic concerns one of the emerging and most promising processes for the recycling and valorization of anthropogenic greenhouse gas emissions. The development of redox-active catalysts with enhanced efficiency for solar thermochemical fuel production and CO2 conversion is a highly demanding and challenging topic. The determination of redox reaction kinetics is crucial for process design and optimization. In this study, the solid-state redox kinetics of CeO2 in the two-step process with CH4 as the reducing agent and CO2 as the oxidizing agent was investigated in an original prototype solar thermogravimetric reactor equipped with a parabolic dish solar concentrator. In particular, the ceria reduction and re-oxidation reactions were carried out under isothermal conditions. Several solid-state kinetic models based on reaction order, nucleation, shrinking core, and diffusion were utilized for deducing the reaction mechanisms. It was observed that both ceria reduction with CH4 and re-oxidation with CO2 were best represented by a 2D nucleation and nuclei growth model under the applied conditions. The kinetic models exhibiting the best agreement with the experimental reaction data were used to estimate the kinetic parameters. The values of apparent activation energies (~80 kJ·mol−1 for reduction and ~10 kJ·mol−1 for re-oxidation) and pre-exponential factors (~2–9 s−1 for reduction and ~123–253 s−1 for re-oxidation) were obtained from the Arrhenius plots.

Effect of Sodium Tungstate Promoter on the Reduction Kinetics of CaMn0.9Fe0.1O3 for Chemical Looping – Oxidative Dehydrogenation of Ethane

Reduction kinetics of unpromoted and Na2WO4-promoted CaMn0.9Fe0.1O3 redox catalysts are measured in the context of chemical looping-oxidative dehydrogenation (CL-ODH). CL-ODH is a promising alternative for ethylene production compared to steam cracking, as it reduces the energy demand and increases the single-pass ethane conversion. The ability of a redox catalyst for selective hydrogen combustion (SHC), i.e. selectively oxidizing hydrogen co-product from ethane dehydrogenation, represents an effective strategy for CL-ODH because it can shift the reaction equilibrium and facilitate exothermic overall reaction. In this work, kinetic models and parameters of unpromoted and Na2WO4-promoted, Fe-doped CaMnO3 (CaMn0.9Fe0.1O3) under H2 and C2H4 were investigated. The reduction of unpromoted CaMn0.9Fe0.1O3 follows reaction-order models. C2H4 reduction has a higher energy barrier and a greater dependence on active lattice oxygen concentration, resulting in an order-of-magnitude decrease in the reduction rate. In comparison, the reduction of Na2WO4-promoted CaMn0.9Fe0.1O3 follows an Avrami-Erofe’ev nucleation and nuclei growth model. The addition of Na2WO4 more significantly suppressed C2H4 combustion relative to H2 oxidation. As a result, the reduction rate of Na2WO4-promoted CaMn0.9Fe0.1O3 under H2 was three orders of magnitude greater than that under C2H4, demonstrating its excellent SHC properties. The resulting redox catalyst was shown to be effective for ethane CL-ODH with measured 90.5% ethylene selectivity and 41.6% ethylene yield at 750 °C. The kinetics models and parameters provide useful information for CL-ODH reactor design and further development of the redox catalyst.

Thermal and kinetic behaviors of pyrolytic carbon black and gas coal in co-combustion

In this study, a combustion study of tire pyrolytic carbon black (CBp), gas coal (GC), and their blends was carried out by thermogravimetric analysis with four heating rates under air atmosphere. And the structure characteristics of CBp and GC were studied using particle size distribution, scanning electron microscope, X-ray diffraction, Raman spectra followed by peak deconvolution and data analysis. The results demonstrated that the structural differences between CBp and GC directly affected their thermal behavior trends. GC with low graphitization degree had more combustibility reactivity than that of CBp, while the mean reaction rate and maximum reaction rate of CBp were larger than GC due to its bigger specific surface area and higher porosity. For blends, the combustibility reactivity could be improved by blending with GC, and there was obviously synergetic effect for the co-combustion of CBp and GC. The combustion reaction mechanisms and kinetic parameters were carried out using three non-isothermal kinetic models: random nucleation nuclei growth model (RNGM), volume reaction model, and unreacted core model. The kinetic analysis demonstrated that the RNGM model had a better performance than other models for describing the thermal behavior of the selected samples. In addition, the synergetic effect between CBp and GC was observed from the kinetics data calculated by RNGM. The activation energies of CBp and GC calculated by RNGM model were 119.6 kJ mol−1 and 126.4 kJ mol−1, respectively, whereas the lowest activation energy for their blends was 104.3 kJ mol−1 when CBp ratio was 40%.

Combustion behaviors and kinetics analysis of coal, biomass and plastic

In this paper, thermal analysis method (TGA) was adopted to describe the combustion behavior of bituminous coal(GC), anthracite(LC), biomass(PS) and plastic(PVC).The structure characteristics of these samples were carried out using Raman spectroscope followed by peak deconvolution and data analysis. The kinetic parameters and combustion reaction mechanism were obtained by fitting experimental data with the random nucleation nuclei growth model (RNGM) and volume model (VM) in order to find out the kinetics characteristics responsible for the combustion of the samples. The results indicate that significant difference between combustion process of these samples are mainly attributed to their differences structures, the combustion reactivity of PS is better than GC duo to the catalysis of alkali matter in biomass ash. RNGM model is better than VM model for simulating the combustion process, and TRNGM model plays a good performance in depicting the combustion process of PVC with three reaction stages.

Characterization of Powder River Basin coal pyrolysis with cost-effective and environmentally-friendly composite Na[sbnd]Fe catalysts in a thermogravimetric analyzer and a fixed-bed reactor

The pyrolysis characteristics of PRB coal with use of NaFe composite catalysts were investigated in a thermogravimetric analyzer and a fixed bed reactor. Model-free methods developed by Friedman (FR), Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO) and Vyazovkin (VA) were compared and applied to determine the pyrolysis kinetic parameters. A Master-plot method was used to determine the reaction order and pre-exponential factors. Raw coal with the addition of 4% FeCO3 achieved the highest effect on coal conversion; specifically, 4% Na2CO3 and 1% Na2CO3–3% FeCO3 showed higher effect than 3% Na2CO3–1% FeCO3 and 2% Na2CO3–2% FeCO3. The averaged E values of raw coal with 4% FeCO3 catalyst decreased by 10% compared with that of raw coal. Compared with the individual use of 4% Na2CO3, the addition of FeCO3 can be effective in decreasing the E values of the raw coal. The nonlinear VA method appears to be superior in determining activation energies of coal pyrolysis at considered conversion range. Further, the An (random nucleation and nuclei growth model) appears to be the appropriate reaction model for raw coal pyrolysis with and without the use of NaFe composite catalysts. From the pyrolysis in the fixed bed reactor, XRD and FTIR tests for coal chars produced by PRB coal pyrolysis with use of catalysts were conducted. By combining the gas evolution and XRD/FTIR results, a reaction mechanism is proposed for coal pyrolysis with composite Na2CO3FeCO3 catalysts.

Kinetics model for the reduction of Fe2O3/Al2O3 by CO in Chemical Looping Combustion

Kinetics model which describes intrinsic characteristics of reactions involved in Chemical Looping Combustion (CLC) can be used as a basic tool for reactor design and reactor modeling. To further develop previously studied sol-gel Fe2O3/Al2O3 oxygen carrier, this work performed a detailed kinetics investigation for the reduction from Fe2O3/Al2O3 to Fe3O4/Al2O3 by CO. In order to derive a reliable kinetics model, thermodynamics calculations were first performed to identify the reaction pathways with full CO2 capture and no carbon deposition, excluding their influence. Experimental data at 673–773 K during thermogravimetric analyzer (TGA) tests was considered for kinetics analysis to attain good CLC performance. Finally, a widely used model-free method was employed to develop the kinetics model. Accordingly, a 3D nucleation and nuclei growth model with the model function g(X) = [-ln(1-X)]1/3, activation energy 270 kJ/mol and pre-exponential factor 1.6·1012s−1 was developed to describe the first half reduction from Fe2O3/Al2O3 to Fe3O4/Al2O3 by CO (0 < X≤ 0.5). Following this, the diffusion effects dominated the reduction process (0.5 < X ≤1), which can be described by a 2D diffusion model function g(X) = (1-X)·ln(1-X) + X with the activation energy and pre-exponential factor as 131 kJ/mol and 3.1·103 s−1, respectively. The whole kinetics model can be considered for the future application.

Direct numerical simulation of the thermal dehydration reaction in a TGA experiment

This work presents a detailed mathematical model of the coupled mass and heat transfer processes in salt hydrate grains in a TGA experiment. The purpose of developing this numerical model is to get a more fundamental understanding of the influence of parameters like particle size, nucleation rate and vapor pressure on the dehydration reaction in a TGA experiment. Such a model needs a detailed description of the fluid flow and water vapor distribution between the particles. The dehydration reaction of grains of TCMs is described by the nucleation and nuclei growth model presented in our earlier work. The flow around grains is solved by means of the finite volume method using OpenFOAM including heat and mass transfer. Direct numerical simulations of TGA-experiments under various conditions are performed. Such simulations provide direct insight into the physics of mass and heat transport processes coupled with detailed reaction kinetics at grain scale. The numerical results are compared to the experimental results. The developed CFD model can be a promising tool to calculate the overall kinetics for dehydration reactions under realistic heat storage conditions. To that end, the effect of buoyancy should also be included in the model to get a more accurate description of convection within the sample.

Spray-Dried Sodium Zirconate: A Rapid Absorption Powder for CO2 Capture with Enhanced Cyclic Stability.

Improved powders for capturing CO2 at high temperatures are required for H2 production using sorption‐enhanced steam reforming. Here, we examine the relationship between particle structure and carbonation rate for two types of Na2ZrO3 powders. Hollow spray‐dried microgranules with a wall thickness of 100–300 nm corresponding to the dimensions of the primary acetate‐derived particles gave about 75 wt % theoretical CO2 conversion after a process‐relevant 5 min exposure to 15 vol % CO2. A conventional powder prepared by solid‐state reaction carbonated more slowly, achieving only 50 % conversion owing to a greater proportion of the reaction requiring bulk diffusion through the densely agglomerated particles. The hollow granular structure of the spray‐dried powder was retained postcarbonation but chemical segregation resulted in islands of an amorphous Na‐rich phase (Na2CO3) within a crystalline ZrO2 particle matrix. Despite this phase separation, the reverse reaction to re‐form Na2ZrO3 could be achieved by heating each powder to 900 °C in N2 (no dwell time). This resulted in a very stable multicycle performance in 40 cycle tests using thermogravimetric analysis for both powders. Kinetic analysis of thermogravimetric data showed the carbonation process fits an Avrami–Erofeyev 2 D nucleation and nuclei growth model, consistent with microstructural evidence of a surface‐driven transformation. Thus, we demonstrate that spray drying is a viable processing route to enhance the carbon capture performance of Na2ZrO3 powder.

Kinetic study of the thermal decomposition of uranium metaphosphate, U(PO3)4, into uranium pyrophosphate, UP2O7

The thermochemical properties of uranium compounds have attracted much interest in relation to thermochemical treatments and the safe disposal of radioactive waste bearing uranium compounds. The characteristics of the thermal decomposition of uranium metaphosphate, U(PO3)4, into uranium pyrophosphate, UP2O7, have been studied from the view point of reaction kinetics and acting mechanisms. A mixture of U(PO3)4 and UP2O7 was prepared from the pyrolysis residue of uranium-bearing spent TBP. A kinetic analysis of the reaction of U(PO3)4 into UP2O7 was conducted using an isoconversional method and a master plot method on the basis of data from a non-isothermal thermogravimetric analysis. The thermal decomposition of U(PO3)4 into UP2O7 followed a single-step reaction with an activation energy of 175.29 ± 1.58 kJ mol−1. The most probable kinetic model was determined as a type of nucleation and nuclei-growth models, the Avrami-Erofeev model (A3), which describes that there are certain restrictions on nuclei growth of UP2O7 during the solid-state decomposition of U(PO3)4.

Step-wise reduction kinetics of Fe2O3 by CO/CO2 mixtures for chemical looping hydrogen generation

The reduction kinetics of iron-based oxygen carriers significantly affect the efficiency of chemical looping hydrogen generation. Based on the thermodynamics properties of the Fe–CO–CO2 system, CO/CO2 mixtures in different volume ratios can decouple the reduction of Fe2O3 into three relatively independent steps. The step-wise reduction of Fe2O3 was conducted in a thermogravimetric analyzer at 800–900 °C. To investigate the reaction mechanisms, the Hancock–Sharp method and the nonlinear fitting approach were applied to select the kinetic models. The reaction model of step 1 and 2 are geometrical contracting model; the step 3 is controlled by nucleation and nuclei growth model and diffusion model. The activation energy of the three steps including Fe2O3 → Fe3O4, Fe3O4 → FeO and FeO → Fe is estimated to be 34.92 ± 1.24, 70.13 ± 0.88 and 44.12 ± 1.44 kJ/mol, respectively. The rate equations derived from the Arrhenius law were determined to predict the reaction rate at a specific CO concentration.

Reduction kinetics of lanthanum ferrite perovskite for the production of synthesis gas by chemical-looping methane reforming

The reduction kinetics of LaFeO3 oxygen carrier for the production of synthesis gas by chemical-looping methane reforming (CLMR) is investigated in the present work. The stoichiometric relationship between oxygen carrier and methane in chemical-looping process is established by temperature programmed surface reaction (TPSR), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) characterization. The effects of reduction conditions, namely, gas to solid molar ratio, temperature and sequential redox reaction on the oxygen carrier conversion are investigated. The results from Hancock and Sharp method suggest that the phase boundary control is likely to be dominant. The power law model (PLM), shrinking core model (SCM), as well as nucleation and nuclei growth model (NNGM) are considered to interpret the reduction kinetics of LaFeO3 with methane to synthesis gas. The obtained results show that the 2-D NNGM best describes the experimental data providing parameters with adequate statistical fitting indicators. The model validity is also verified by the data from continuous flow reaction and sequential redox cycles to simulate chemical-looping methane reforming process. The apparent activation energy is estimated and compared with values from the literature data.

Direct reduction of nickel catalyst with model bio-compounds

The effects of temperature and S/C on the reduction extent and kinetics of a steam reforming NiO/α-Al2O3 catalyst were systematically investigated using five bio-compounds commonly produced during the fermentation, pyrolysis and gasification processes of biomass (acetic acid, ethanol, acetone, furfural and glucose). Reduction was also performed with methane and hydrogen for comparison. Kinetic modelling was applied to the NiO conversion range of 0–50% using the Handcock and Sharp method. The two-dimensional nuclei growth model (A2) was found to fit very well except for glucose. For all the bio-compounds, the apparent activation energy of NiO reduction was between 30 and 40kJ/mol. Their pre-exponential factors decreased in this order: CH4>ethanol≈acetone>acetic acid>furfural>glucose, probably due to the different activities of reducing species they produced. Optimal molar steam to carbon ratios for reduction kinetics were found between 1 and 2.

Devolatilization Characteristics and Kinetic Analysis of Lump Coal from China COREX3000 Under High Temperature

A devolatilization study of two lump coals used in China COREX3000 was carried out in a self-developed thermo-gravimetry at four temperature conditions [1173 K, 1273 K, 1373 K, and 1473 K (900 °C, 1000 °C, 1100 °C, and 1200 °C)] under N2. This study reveals that the working temperature has a strong impact on the devolatilization rate of the lump coal: the reaction rate increases with the increasing temperature. However, the temperature has little influence on the maximum mass loss. The conversion rate curve shows that the reaction rate of HY lump coal is higher than KG lump coal. The lump coals were analyzed by XRD, FTIR, and optical microscopy to explore the correlation between devolatilization rate and properties of lump coal. The results show that the higher reaction rate of HY lump coal attributes to its more active maceral components, less aromaticity and orientation degree of the crystallite, and more oxygenated functional groups. The random nucleation and nuclei growth model (RNGM), volume model (VM), and unreacted shrinking core model (URCM) were employed to describe the reaction behavior of lump coal. It was concluded from kinetics analysis that RNGM model was the best model for describing the devolatilization of lump coals. The apparent activation energies of isothermal devolatilization of HY lump coal and KG lump coal are 42.35 and 45.83 kJ/mol, respectively. This study has implications for the characteristics and mechanism modeling of devolatilization of lump coal in COREX gasifier.

Pretreatment of Acacia nilotica Sawdust by Catalytic Delignification and Its Fractal Kinetic Modeling

Alkaline delignification of Acacia nilotica heartwood has been carried out using 10 % Sodium hydroxide and Sodium sulphide as the cooking liquor. Delignification was carried out at 373, 393, 403 and 413 K on Acacia nilotica sawdust of particle-sizes 70, 100 and 120 mesh, for durations ranging from 1 to 3 h. The reactions were carried out in presence and in absence of Ferrous sulphate to determine its catalytic properties in delignification. Maximum delignification achieved was 82.7 %, based on Klason lignin, in 3 h at 413 K for 120 mesh feed. The activation energies for delignification were 20.9275 and 35 kJ/mol, respectively, in presence and in absence of Ferrous sulphate, indicating its significant catalytic effect. A kinetic model for delignification was developed by modification of the Nuclei Growth model. Delignification extent could be predicted from the developed model quite accurately, with R2 values ranging from 0.947 to 0.99.

Isothermal kinetic analysis on fast pyrolysis of lump coal used in COREX process

The isothermal pyrolysis characteristics of lump coal used in COREX was studied by the self-developed thermos-gravimetry analysis device varying the temperature from 900 to 1200 °C. The results indicated that pyrolysis temperature had a significant influence on the pyrolysis rate of the lump coal, but have a little influence on the weight loss ratio. The results obtained by nonlinear fitting of mechanism functions indicated that the pyrolysis process of lump coal satisfied the two-dimensional random nucleation and nuclei growth model. The pyrolysis kinetics equation is \( \frac{{{\text{d}}\alpha }}{{{\text{d}}t}} = - 1.03082\,\exp ( - \frac{46630}{8.314T})[(1 - \alpha )( - \ln (1 - \alpha ))^{0.5} ] \), and the pyrolysis activation energy is 46.63 kJ mol−1. In addition, the average activation energy calculated by iso-conversional method is 47.06 kJ mol−1, which proves that the kinetics equation determined by the master curve method is reliable.

Redox property and kinetics of copper oxygen carrier under different oxygen concentrations

Chemical looping with oxygen uncoupling and chemical looping air separation technologies all depend on the redox property of oxygen carrier. The present work investigated the redox properties of Cu/Zr oxygen carrier under different oxygen concentrations by TG technique. The durability and stability of oxygen carrier is also investigated under 1065°C reduction and 800°C oxidation temperatures. For reduction, the starting and ending temperatures and the peaks of DTG curves shift to high values with oxygen concentration increasing. The effect of oxygen concentration on oxidation is little and the regeneration of Cu/Zr oxygen carrier can be achieved in thin oxygen environment. For reduction and oxidation, times for complete conversion decrease with heating rates increasing. Kinetic models were proposed based on the nucleation and nuclei growth model. The reduction mechanism function is: and the oxidation mechanism function is: . For reduction, the values of E and A all increase as oxygen concentrations increase and heating rates decrease. For oxidation, the values of E and A are almost the same. The Cu/Zr oxygen carrier has high stability and it is a good candidate for chemical looping technologies at high temperatures. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 531–539, 2016

TG/DSC-FTIR and Py-GC investigation on pyrolysis characteristics of petrochemical wastewater sludge

The pyrolysis characteristics of petrochemical wastewater sludge (PS) were evaluated using TG/DSC-FTIR and fixed-bed reactor with GC. TGA experiments indicated that the pyrolysis of PS proceeded in three phases, and the thermographs shifted to higher temperatures with increasing heating rate. Chars FTIR showed that the absorption of O–H, C–H, CO and C–C decreased with pyrolysis temperatures increasing. Gases FTIR correspondingly showed that H2O, CO, and CH4 generated at higher temperatures. For the fixed-bed reactor tests, H2 and CO were relatively higher in the pyrolysis gases, and CH4 was negligible at 436K. The kinetic triplets of PS pyrolysis were estimated by Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, and integral master-plots method. The results suggested that the most potential kinetic models for the first and second phase were the order reaction model, while the random nucleation and nuclei growth model for the third phase.