Particle Temperature Rise Research Articles

DEM analysis of heat generation and transfer during granular flow in a rotating drum

In many granular material handling processes, heat generation, and subsequent temperature rise, due to contacts between particles and surfaces is common. Aiming to explore this phenomenon, friction-induced heat generation and heat transfer models are developed and implemented into a Discrete Element Method (DEM) in this paper. The DEM models are validated qualitatively for the temperature distribution pattern and quantitatively for the evolution of particle temperature rise using data obtained experimentally. Moreover, the temperature distribution of the drum end plates obtained in the simulations shows the same annulus pattern observed in experiments. It is also found that increasing the rotation speed of the drum leads to an increase in the annular heated region of drum and in the net heat that particles obtain. In addition, a higher rotation speed leads to higher absolute fluctuations and lower relative variability of particle temperature.

The effect of cavity shape on critical high-temperature regions formation pattern and structural evolution difference in explosive particle bed

The occurrence of critical high-temperature regions within explosives is a crucial factor in initiating combustion and explosion. The primary causes of hot regions in cavity-containing explosives are dissipative processes occurring inside the explosive or at its interface, such as shear, friction, viscosity, plasticity, and heat transfer. Currently, there is limited research on the generation and dissipation mechanisms of critical high-temperature regions in cavity-containing explosives during impacts, based on the mesoscale analysis that describes particle motion. In this study, a model based on the discrete element method is employed allowing for an accurate analysis of the dynamic and thermodynamic processes among particles, which systematically considers the shear history between particles, elastoplastic collisions, and heat transfer between particles. The temporal evolution of particle temperature and dissipated work contours during the impact process of explosives with different cavity shapes is analyzed. Explosives with cavities undergo three stages during the impact process: the formation of the trapezoidal high-temperature region, cavity collapse, and dispersion of the particle bed, ultimately leading to the formation of two main critical high-temperature regions: near the cavity and near the wall. The temperature rise of hot particles near the wall can be roughly divided into two stages, and the temperature rise mechanisms are different. Initially, the temperature rise is primarily attributed to plastic dissipation of hot particles, and the same initial impact velocity results in the same temperature rise. During the cavity collapsing, continuous momentum transfer occurs between the hot particles near the wall and the particles in the high-temperature shear bands, deeply influencing the development of the high-temperature shear bands through the movement of the hot particles near the cavity. Therefore, the different collapse modes of hot particles near cavities of different shapes lead to differences in the later temperature evolution of the hot particles near the wall. The unique aggregation processes of hot particles near cavities of various shapes result in distinct high-temperature region morphologies: circular cavity exhibits approximate “——” shape, triangular cavity displays arch shape, and inverted triangular cavity presents “M” shape. Significantly, a new mechanism resulting from the interaction of two opposing “jet “flows for the formation of higher-temperature hot regions near the circular cavity has been discovered.

Temperature Prediction of Icy Lunar Soil Sampling Based on the Discrete Element Method

This study is part of the preliminary research for the Chang’e 7 project in China. The Chang’e 7 project plans to drill to penetrate the lunar polar soil and collect lunar soil samples using a spiral groove structure. Ice in the cold environment of the lunar polar region is one of the important targets for sampling. In the vacuum environment of the lunar surface, icy soil samples are sensitive to ambient temperature and prone to solid–gas phase change as the temperature increases. To predict the temperature range of lunar soil samples, this study analyzed the effect of thermal parameters on the temperature rise of lunar soil particles and the drill using discrete element simulation. The parameters included in the thermal effect analysis included the thermal conductivity and specific heat capacity of the drilling tools and lunar soil particles. The simulation showed that the temperature of the icy lunar soil sample in the spiral groove ranged from −127.89 to −160.16 °C within the thermal parameter settings. The magnitude of the value was negatively correlated with the thermal conductivity and specific heat capacity of the lunar soil particles, and it was positively correlated with those of the drilling tools. The temperature variation in the drill bit ranged from −51.21 to −132 °C. The magnitude of the value was positively correlated with the thermal conductivity and specific heat capacity of the lunar soil particles and the thermal conductivity of the drilling tool.

Numerical study of aeration flow angle on powder flow and thermal behaviors in fluidized bed particle solar receivers

The particle flow and thermal characteristics in fluidized bed particle solar receivers with different aeration flow angles were numerically investigated by employing the Eulerian-Eulerian two-fluid model. The filtered drag correlation was utilized to characterize the interaction between SiC particles of Geldart-A classification and gas. The model underwent validation using experimental data from the literature, confirming that the simulated solid holdup and local heat transfer rate agreed well with the experimental measurements. Simulation results show that the particle volume fraction was higher along the walls in the bottom section. In both +45° and + 60°, the particles returned to the aeration flow region. The aeration had a relatively small impact on the particle distribution at the center, whereas the other two regions (x / D = 0.5 and 0.95) exhibited a significant decrease in particle volume fraction at the height of aeration injection. For different aeration injection structures, the equilibrium temperature rise reached approximately 51% of the difference between the wall and inlet temperatures. The temperature rise of particles in FBPSR was attributed to the direct heat transfer from the heating wall to particles and he return of hot particles.

Identifying the enhancement mechanism of Al/MoO3 reactive multilayered films on the ignition ability of semiconductor bridge using a one-dimensional gas-solid two-phase flow model

Energetic Semiconductor bridge (ESCB) based on reactive multilayered films (RMFs) has a promising application in the miniature and intelligence of initiator and pyrotechnics device. Understanding the ignition enhancement mechanism of RMFs on semiconductor bridge (SCB) during the ignition process is crucial for the engineering and practical application of advanced initiator and pyrotechnics devices. In this study, a one-dimensional (1D) gas-solid two-phase flow ignition model was established to study the ignition process of ESCB to charge particles based on the reactivity of Al/MoO3 RMFs. In order to fully consider the coupled exothermic between the RMFs and the SCB plasma during the ignition process, the heat release of chemical reaction in RMFs was used as an internal heat source in this model. It is found that the exothermal reaction in RMFs improved the ignition performance of SCB. In the process of plasma rapid condensation with heat release, the product of RMFs enhanced the heat transfer process between the gas phase and the solid charge particle, which accelerated the expansion of hot plasma, and heated the solid charge particle as well as gas phase region with low temperature. In addition, it made up for pressure loss in the gas phase. During the plasma dissipation process, the exothermal chemical reaction in RMFs acted as the main heating source to heat the charge particle, making the surface temperature of the charge particle, gas pressure, and gas temperature rise continuously. This result may yield significant advantages in providing a universal ignition model for miniaturized ignition devices.

Numerical simulation and solidification characteristics for laser cladding of Inconel 718

During the laser cladding process, the interaction between laser beam and materials (substrate and conveyed powder) results in melting deposition. The thermal behavior and solidification characteristics significantly influence the cladding geometry and the solidified microstructure. In this paper, a three-dimensional numerical model of heat-flow multiphysics is established to investigate the non-isothermal flow and solidification characteristics in laser cladding of Inconel 718 on a substrate. The theoretical analysis of laser-powder interaction is carried out to obtain the laser energy attenuation and temperature rise of powder particles. Based on the apparent heat capacity and the moving mesh methods, the solid-liquid phase transition and material addition are handled. Subsequently, the transient evolution of the temperature and velocity fields is discussed, meanwhile the variations of solidification characteristics (including temperature gradients (G) and solidification rates (R)) on the curved solidification front are analyzed. The results indicate that the temperature gradient and solidification rate at the top of the solidification interface, compared to that at the bottom, undergo a maximum twofold and thirtyfold decrease, respectively. Supplementary, the reliability of the model was verified by comparing the simulated cladding geometry (width and height) with the experimental measurements. The simulation is found to have a relatively good agreement with the experiments. Research in this paper is instructive for understanding the thermal behavior in the melt pool and the evolutionary laws of the solidification microstructure, while reducing the cost of cladding process optimization.

Simultaneous two-phase flame velocity measurement using laser-induced incandescence particle image velocimetry (LII-PIV)

In a previous study we demonstrated a novel two-phase PIV technique based on the laser-induced incandescence (LII) signal from black submicron tungsten carbide particles (WC), which achieved velocity measurements for both dispersed-form (large water droplet) and continuous-form (gas). Submicron WC particles are intentionally seeded into a two-phase flow, and heated by a light sheet generated by a double-pulsed PIV laser running at high energy. The 200 nm diameter, light absorbing WC particles are heated to several thousand degrees to emit strong incandescence signals, whilst the temperature rise in liquid droplets or large particles remains negligible. The small particles follow the gas phase flow, unlike the droplets which may have a different velocity. Droplets are detected via the Mie scatter signal at the same incident wavelength, whereas the LII signal from small WC particles is detected at a suitably different wavelength within the LII emission spectrum, thus allowing discrimination of velocities between phases. The LII-PIV technique had been implemented with a low-speed CCD PIV camera in non-reacting flows. In flames, the strong flame luminosity saturated the second frame due to the long exposure time as the characteristics of the device. To solve this problem, in the present study, we synchronized two high-speed CMOS cameras to a low speed laser. One records the LII signal and the other records the Mie scatter signal from 36.6 µm water droplets. The scattering from WC particles appears only as a weak background signal in the Mie image, which can be easily removed by applying a high-pass filter. Simultaneous velocity measurements for both gas and liquid phase are demonstrated in an air jet, a cold impinging flow, and finally in a Bunsen flame. The last two cases are repeated using the traditional two-phase PIV technique based on image segmentation so as to conduct a fair comparison of both techniques. We show that LII-PIV can achieve the same level of accuracy as the segmentation method in non-reacting flows, and can be applied to measure in flames with two-phase flows with less stringent requirements regarding seeding quality.

Oxidation mechanism of pyrite concentrates (PCs) under typical circulating fluidized bed (CFB) roasting conditions and design principles of PCs’ CFB roaster

The circulating fluidized bed (CFB) roasting process is a promising way to utilize pyrite concentrates (PCs) which are byproducts in nonferrous metal production processes. The oxidation mechanism of PCs was investigated under typical CFB roasting conditions with the temperature of 850 °C and oxygen concentration of 1–21% on a drop tube furnace. The oxidation reaction pathway and products of PCs are strongly coupled with particle morphology evolution, which affects the oxygen diffusion from the particle surface to the core. A reaction path model of PC oxidation coupled with particle morphology evolution under CFB roasting conditions was proposed. The initial relatively slow oxidation of the porous particle structure followed by the relatively fast oxidation for complete oxidation was demonstrated to be the ideal reaction path for the CFB roasting operation of PCs. The critical issue for PCs roasting in the CFB reactor is to inhibit the particle temperature rise in dense phase region to avoid the formation of compact solid spheres. The flow and reaction behaviors of PC particles in CFB reactor naturally follow the ideal reaction path and make the CFB roasting technology feasible. Finally, the design principles of PCs CFB roasting process were suggested.

The shock-induced chemical reaction behaviour of Al/Ni composites by cold rolling and powder compaction

Al/Ni composites are typical structural energetic materials, which have dual functions of structural and energetic characteristics. In order to investigate the influence of manufacturing methods on shock-induced chemical reaction (SICR) behaviour of Al/Ni composites, Al/Ni multi-layered composites with 3–5 cold-rolling passes and Al/Ni powder composites were obtained. Microstructural observation using scanning electron microscopy (SEM) and two-step impact initiation experiments were performed on the four Al/Ni composites. Furthermore, mesoscale simulations, through importing SEM images into the finite element analysis to reflect the real microstructures of the composites, were performed to analyse the particle deformation and temperature rise under shock compression conditions. The experimental results showed the distinct differences on the SICR characteristics among the four Al/Ni composites (i.e. by 3, 4 and 5 cold-rolling passes and powder compaction). The manufacturing methods provided the control of the particle sizes, particle distribution and the content of the interfacial intermetallics at scale of different microstructures, which ultimately affected the temperature distribution, as well as the contact between Al and Ni in Al/Ni composites under shock loading. As a result, the Al/Ni powder composites showed the highest energy release capacity among the four composites, while the energy release capability of Al/Ni multi-layered composites decreased with the growth of rolling passes.

On-Sun Performance Evaluation of Alternative High-Temperature Falling Particle Receiver Designs

This paper evaluates the on-sun performance of a 1 MW falling particle receiver. Two particle receiver designs were investigated: obstructed flow particle receiver versus free-falling particle receiver. The intent of the tests was to investigate the impact of particle mass flow rate, irradiance, and particle temperature on the particle temperature rise and thermal efficiency of the receiver for each design. Results indicate that the obstructed flow design increased the residence time of the particles in the concentrated flux, thereby increasing the particle temperature and thermal efficiency for a given mass flow rate. The obstructions, a staggered array of chevron-shaped mesh structures, also provided more stability to the falling particles, which were prone to instabilities caused by convective currents in the free-fall design. Challenges encountered during the tests included nonuniform mass flow rates, wind impacts, and oxidation/deterioration of the mesh structures. Alternative materials, designs, and methods are presented to overcome these challenges.

Non-intrusive temperature measurement of particles in a fluidised bed heated by well-characterised radiation

We report an important step towards the in-situ measurement of heat transfer in particle-laden flows via direct measurement of the temperatures of fluidised particles. Laser-induced phosphorescence (LIP) was employed to provide non-intrusive, temporally resolved and in-situ measurement of suspended particles as a function of heat flux and radiation attenuation. Excitation was performed at 355 nm with a repetition rate of 1.67 Hz. Particles were transported with dry air within an optically-accessible fluidised bed and heated with a well-defined source of high-flux radiation from a 3 kW solid-state solar thermal simulator radiation to achieve heating rates in order 23,000°/s. Particle and gas temperatures were measured simultaneously with the former determined from thermo-phosphorescent emissions following excitation at 355 nm. Irradiation flux and mass loading were found to play important roles in particle and gas temperature rise. Confidence in the method was obtained by verifying internal consistency between the energy absorbed by the particles and the temperature rise of the gas phase, taking into account the variability of particle mass loading.

Experiment study of a quartz tube falling particle receiver

This paper presents an experimental evaluation of a specially designed falling particle receiver. A quartz tube was used in the design, with which the particles would not be blown away by wind. Concentrated solar radiation was absorbed and converted into thermal energy by the solid particles flowed inside the quartz tube. Several experiments were conducted to test the dynamic thermal performance of the receiver on solar furnace system. During the experiments, the maximum particle temperature rise is 212°C, with an efficiency of 61.2%, which shows a good thermal performance with a falling distance of 0.2 m in a small scale particle receiver. The average outlet particle temperature is affected by direct normal irradiance (DNI) and other factors such as wind speed. The solid particles obtain a larger viscosity with a higher temperature while smaller solid particles are easier to get stuck in the helix quartz tube. The heat capacity of the silicon carbide gets larger with the rise of particle temperature, because as the temperature of solid particles increases, the temperature rise of the silicon carbide decreases.

A combined experimental and modeling study of thermodynamics and kinetics of mechanochemical treatment for synthesis of Ni0.5Co0.5Fe2O4

A combined experimental and modeling approach has been used to explain thermodynamic and kinetic aspects of mechanochemical treatment to synthesizeNi0.5Co0.5Fe2O4. After obtaining the desired phase from Fe2O3, Co3O4 and NiO as precursors via continuous and interrupted mechanochemical routs, the contributions of microstructure changes and temperature rise to total input energy were calculated. The fraction for the former was less than 1% and the remaining energy was lost mostly in the form of heat. Then, a theoretical model for calculation of temperature rise in particles at the point of collision was proposed. Based on the model results, the temperature rise during the continuous condition was higher than the interrupted one's which was verified by lower amount of microstrain, larger grain and particle size of the interrupted milled samples. To evaluate the amount of formed phase as a result of the simultaneous effects of temperature rise and microstructure changes, a phenomenological kinetic model was developed. The fairly good agreement between this model results and new experimental findings gives a strong support to the validity of the model. For instance, in the case of a sample which was milled continuously for 180ks, the model prediction and experimental results were 41.7 and 40.2, respectively.

Contact temperature under three-body dry friction conditions

Particles (wear debris, particle contaminants, or abrasive particles) are often present at contact interfaces. These particles affect the contact temperature and the real contact area between two rough surfaces. In this paper, we used a three-body micro-contact model and contact temperature theory to evaluate particle-to-surface and surface-to-surface contact temperatures between two surfaces with different particle sizes, particle densities, surface roughnesses, relative speeds, and applied loads.The results show that the values of the particle-to-surface and surface-to-surface temperature rise parameters are highly dependent on the contact load ratio, i.e., the proportion of the total load borne by the contact between the two surfaces. For a given relative speed and applied load, the particle temperature rise parameter value increases with increasing particle size and particle density and with decreasing surface roughness. On the other hand, for a given relative speed, the surface temperature rise parameter value decreases with decreasing applied load and surface roughness and with increasing particle density and particle diameter. For hybrid friction contact conditions, the particle temperature rise parameter value increases almost linearly with an increasing ratio of particle size to surface roughness, xa/σ, for a given surface roughness and contact load. For a given surface roughness and contact load, the surface temperature rise parameter value remains almost unchanged under hybrid friction contact conditions when xa/σ is less than 1.0, whereas at xa/σ values greater than 1.0, the surface temperature rise parameter value decreases as the ratio of particle size to surface roughness increases. The results also show that even for a relatively low load, the particle temperature may be higher than the surface temperature for large debris sizes or high particle densities, suggesting an abnormal wear process. High particle temperatures are believed to play an important role in fatigue, wear, and failure mechanisms. The results indicate that to reduce the interfacial temperature, the larger the contact load is, the smaller the surface roughness value must be. Under hybrid friction contact conditions, the difference between the surface and particle contact temperatures is relatively small.

A model for calculating the temperature of aluminium particles ejected from overhead low-voltage lines owing to a short-circuit

Wildfires, which are uncontrolled fires spreading readily over vast areas, are usually the result of human negligence, arson or lightning. There are cases of fires close to electrical distribution lines for which the network has been blamed. In the present paper, the risk of a wildfire breaking out owing to the temperature of molten metal particles that are possibly created on bare conductors of low-voltage networks in short-circuit faults (unless they are interrupted by the protection systems) is examined. Thus, a mathematical model is proposed for the estimated temperature rise of those molten metal particles ejected from bare conductors of low-voltage overhead lines. Moreover, this model can be applied to medium- or high-voltage networks. The model takes into account the weather conditions and particles’ height above the ground. Further, an arithmetic example for an incandescent particle ejected from aluminium conductors of a low-voltage network is given. According to this example, there is no risk of dead leaves or wood catching fire owing to this particle.

Non-Fourier heat transport in metal-dielectric core-shell nanoparticles under ultrafast laser pulse excitation

Relaxation dynamics of embedded metal nanoparticles after ultrafast laser pulse excitation is driven by thermal phenomena of different origins, the accurate description of which is crucial for interpreting experimental results: hot electron-gas generation, electron-phonon coupling, heat transfer to the particle environment, and heat propagation in the latter. Regarding this last mechanism, it is well known that heat transport in nanoscale structures and/or at ultrashort timescales may deviate from the predictions of the Fourier law. In these cases heat transport may rather be described by the Boltzmann transport equation. We present a numerical model allowing to determine the electron and lattice temperature dynamics in a spherical gold nanoparticle core under subpicosecond pulsed excitation as well as that in the surrounding shell dielectric medium. For this, we have used the electron-phonon coupling equation in the particle with a source term linked with the laser pulse absorption and the ballistic-diffusive equations for heat conduction in the host medium. Either thermalizing or adiabatic boundary conditions have been considered at the shell external surface. Our results show that the heat transfer rate from the particle to the matrix can be significantly smaller than the prediction of Fourier's law. Consequently, the particle-temperature rise is larger and its cooling dynamics might be slower than that obtained by using Fourier's law. This difference is attributed to the nonlocal and nonequilibrium heat conductions in the vicinity of the core nanoparticle. These results are expected to be of great importance for analyzing pump-probe experiments performed on single nanoparticles or nanocomposite media.

Optical and infrared study of individual reacting metallocene catalyst particles

AbstractPolymer particle agglomeration and melting causing sheet formation in fluidized bed reactors have been reported to occur during olefin polymerization. The cause of this deleterious sheet formation has not yet been established. Infrared and optical imaging were used to study the temporal temperature and size during polymerization of individual commercially active catalyst particles supported on a nylon mesh. Experiments conducted at 2100 kPa confirmed theoretical predictions that the temporal temperature rapidly attains a maximum after the start of the reaction. The magnitude of the temperature rise increases upon an increase of either reactor temperature, initial catalyst particle diameter, catalyst loading, or addition of hydrogen to the feed. The maximum transient temperature rise of single commercial catalyst particle during ethylene polymerization (7.5°C) is lower than that which can lead to local melting and polymer sheet formation. The temperature rise of particle clusters is much higher than that of individual particles, as the cluster acts as a particle with an effective diameter much larger than that of an individual particle. Thus, to circumvent polymer melting it is essential to avoid catalyst particles clustering, which may be caused by electrostatic attraction. The addition of hydrogen to the feed, often used to control polymer properties, significantly increased the initial particle temperature rise (almost double in some cases). © 2008 American Institute of Chemical Engineers AIChE J, 2008

EFFECTS OF HYDROCARBON LIQUID FEED IN POLYETHYLENE POLYMERIZATION PROCESS ON PARTICLE SURFACE TEMPERATURE

In the fluidized bed gas phase polymerization of polyethylene (PE), the heat generated by the exothermic polymerization process is dissipated into the gas mixture flowing past the polymer particles. The polymer particle temperature is determined by the extent of convective heat transfer and other mechanisms of heat removal. In addition to the heat removal by convective heat transfer, liquid hydrocarbon (HC) is often injected into the reactor to further remove heat by evaporation but without partaking in the reaction. The effects of adding this liquid HC on the particle surface temperature have been investigated numerically by means of a one-dimensional polar model. Results indicate that the primary mechanism for removal of the heat of polymerization from the particles is by means of convective heat transfer to the bulk gas, which amounts to 99.5% removal of total heat of polymerization. The PE particle temperature rises only by 1–2°C above the surrounding bed gas mixture. The addition of liquid HC to the feed, however, has a pronounced effect on controlling the reactor gas temperature as most of this liquid is evaporated to the gaseous phase before it reaches the polymer particles. To state it clearly, heat of polymerization is transferred from the particles to the reactor bulk gas predominantly by convection, and part of this heat is subsequently absorbed by evaporation of the fresh liquid HC in the feed. Comparison with a detailed computational fluid dynamic (CFD) model of polymerization in a generic gas phase reactor has also been conducted. The results confirm that the particle temperature rise above the reactor gas temperature is consistent with the one-dimensional model. However, local gas temperature variations are present in the reactor due to the unsteady gas-solid hydrodynamics. Hence, there are some zones that are a few degrees hotter/colder than the bulk reactor temperature with corresponding increase/decrease in particle temperature in these zones.

Numerical simulation of heat transfer and fluid flow in coaxial laser cladding process for direct metal deposition

The coaxial laser cladding process is the heart of direct metal deposition (DMD). Rapid materials processing, such as DMD, is steadily becoming a tool for synthesis of materials, as well as rapid manufacturing. Mathematical models to develop the fundamental understanding of the physical phenomena associated with the coaxial laser cladding process are essential to further develop the science base. A three-dimensional transient model was developed for a coaxial powder injection laser cladding process. Physical phenomena including heat transfer, melting and solidification phase changes, mass addition, and fluid flow in the melt pool, were modeled in a self-consistent manner. Interactions between the laser beam and the coaxial powder flow, including the attenuation of beam intensity and temperature rise of powder particles before reaching the melt pool were modeled with a simple heat balance equation. The level-set method was implemented to track the free surface movement of the melt pool, in a continuous laser cladding process. The governing equations were discretized using the finite volume approach. Temperature and fluid velocity were solved for in a coupled manner. Simulation results such as the melt pool width and length, and the height of solidified cladding track were compared with experimental results and found to be reasonably matched.

Devolatilization characteristics of large particles of tyre rubber under combustion conditions

A systematic experimental study has been performed in order to investigate the effect of particle size and temperature on the devolatilization rate of large tyre rubber particles. Cylindrical tyre particles with diameters between 7.5 and 22 mm were devolatilised in a macro-TGA reactor, at temperatures between 490 and 840 °C in an inert atmosphere. The effect of particle size and surrounding temperature on the rate of devolatilization was observed to be significant, i.e. larger particle diameters and lower temperatures increased the devolatilization time. A detailed mathematical model for the devolatilization process including internal and external heat transfer, three parallel independent devolatilization reactions and reaction enthalpy effects has been developed and solved using an implicit finite difference method. Comparison of the model predictions with experimental data, reveals that the devolatilization process of large tyre rubber particles at temperatures above 490 °C can be considered to be controlled mainly by heat transfer and reaction kinetics. The model analysis further shows that exothermic devolatilization reaction enthalpy effects cannot be neglected in the prediction of the intra particle temperature rise. A sensitivity analysis of the model parameters, demonstrates that the specific heat capacity of the virgin fuel and the activation energies of the devolatilization reactions is the most important model parameters in the prediction of devolatilization times of large tyre rubber particles.