Range Of Heating Rates Research Articles

Pyrolysis characteristics and kinetic study of coal in a novel concentrating photothermal thermogravimetric analyzer: Effect of heating rate

Coal pyrolysis is the initial reaction of vast utilization technologies, and the quantitative description of pyrolysis characteristics and accurate kinetic parameters under the wide range of heating rates are of significant challenges. The effect of heating rate from 5 ℃/min to 1000 ℃/min on coal pyrolysis in a novel concentrating photothermal thermogravimetric analyzer was systematically investigated. A new temperature control scheme especially for the ultra-fast heating process was proposed, guaranteeing the absolute temperature control error was less than 4 ℃ throughout the whole heating process. As the heating rate increased from 5 ℃/min to 1000 ℃/min, the absolute value of maximum mass loss rate increased linearly from 4.18 wt%/min to 66.06 wt%/min, and the specific reaction rate for coal conversion at 20% and 50% also increased linearly by 15.4 times and 16.4 times, respectively. The mean activation energies exhibited the exponential decrease tendency from 235.41 kJ/mol to 28.37 kJ/mol. The transformation rates for functional groups of chars were accelerated with the heating rate, and the char with same conversion rate would be more condensed. The activation energy of coal during pyrolysis under heating rate of 1000 ℃/min was binomially correlated with the ratio of small aromatic rings to large ones in char.

Feasibility study on co-processing of automobile shredder residue in coal-fired power plants via pyrolysis

Facing the challenges of organic industrial solid waste (OISW) disposal, co-processing of OISW by power plants has become a developing trend. In order to avoid feeding problems of OISW and enhance the combustion adaptability of the furnace, pyrolysis coupled with incineration technology is proposed as a potential method. Among various OISW, automobile shredder residue (ASR) is regarded as a promising fuel due to its high heating value. In view of engineering application, the researches focused on the products’ properties and economic evaluation under a wide range of heating rates which are insufficient. In this study, regarding the rapid pyrolysis by conducting the high-temperature flue gas as heating source in power plants, the pyrolysis behavior of ASR was correspondingly studied under a wide range of heating rates. The formation of volatiles and property’s improvement were further investigated for generating high-valued oil. Results showed that the high heating rate is not only beneficial to the homogenization of pyrolytic products but also the aromatization in oil and radical generation in gases. Importantly, it also contributed to the cleavage of the single bond connected to the benzene ring and carbon-oxygen single bond for esters. By conducting the enhanced cracking of volatiles, the wax-like fraction was significantly reduced. In addition, the deoxygenation in oil (oxygen content decreased by 20 wt%) and high heating value of gases (increased by 73%) were improved. Our findings demonstrated the feasibility and economic efficiency for the co-processing of ASR in coal-fired power plants via pyrolysis and thus provide guidance for future commercial application.

Transformation behavior and fate of chlorine in polychloroprene (PCP) during its pyrolysis

Polychloroprene (PCP) rubber is mostly mixed in industrial solid waste (ISW) as the main source of chlorine element. Whereas, the products formation and chlorine behavior during the pyrolysis are insufficiently illustrated for this typical chlorinated polymer, which is not conducive to the chlorine regulation of ISW pyrolytic products. In order to investigate the chlorine transformation behavior, the PCP pyrolysis under the influence of a wide range of heating rates (3–600 °C/min) was conducted to explore the chlorine distribution properties as well as its migration mechanism in the present study. Importantly, 30–65 wt% chlorine was found to be migrated to gas and tar, respectively. Compared with PVC, the differences of chlorine distribution between PCP and PVC may be attributed to the easier cyclization with a longer molecular chain. Also, the release temperature of HCl acted as main component determines its availability for the subsequent formation of chlorinated hydrocarbons. In details, the conversion pathway from chlorinated limonene to Cl-aromatic hydrocarbons was confirmed and the reaction was found to be enhanced at higher temperature and heating rate. By analyzing the content of tar components (especially at low heating rate), it was found that the major formation pathway of aromatic hydrocarbons was supposed to be the direct Diels-Alder reaction of monomer rather than the dechlorination of intermediate chlorinated limonene. Our findings discussed the effect mechanism of heating rate and temperature on chlorine behavior during PCP pyrolysis, providing guidance for the chlorine regulation of ISW pyrolytic products.

Kinetic modelling of pyrolysis of cellulose using CPD model: effect of salt

In this work, effect of salt on cellulose pyrolysis behaviour using chemical percolation devolatilization (CPD) model has been investigated. The distributed activation energy model (DAEM) has been used to determine the kinetics of pure and NaCl-loaded cellulose pyrolysis in a thermogravimetric analyser (TGA). A number of these experiments were performed for a range of heating rates (5–100 °C min−1) and for different concentrations of NaCl in cellulose (0.25–2 mass/%) which showed a pronounced effect of salt on the primary pyrolysis reactions of cellulose. These data were then used in a two-component DAEM to calculate the kinetic parameters for the chemical percolation devolatilization model (CPD) for both pure and NaCl-loaded cellulose. The optimized kinetic parameters for the pure and NaCl-loaded cellulose were used in the CPD model, and the product yield was predicted. The CPD predictions showed that the fraction of gases and char in the pyrolysis products increased in the presence of salt. The amount of char for pure cellulose was 6.97% which increased to 16.4% in the presence of 0.25% NaCl. The amount of gases produced as a result of pure cellulose pyrolysis was 9.63% and this amount increased with addition of NaCl to 22.85% and then further increases with an increase in NaCl concentration. Amount of tar produced for pure cellulose was 83.4%, and this amount reduced to 60.7% with addition of 0.25% NaCl. The presence of NaCl accelerates cellulose decomposition and favours the formation of gases and char.

Experimental and Kinetic Studies on Tobacco Pyrolysis under a Wide Range of Heating Rates.

In the present work, experimental and kinetic studies are conducted to explore and model tobacco pyrolysis characteristics under a wide range of heating conditions. First, thermal decomposition processes of a tobacco sample were investigated using thermogravimetric analysis/difference thermogravimetry (TGA/DTG) experiments under a wide range of heating rates (10–500 K/min), and the TGA/DTG profiles were compared to highlight the effect of heating rate on the pyrolysis characteristics. The results showed that the tobacco sample was sufficiently devolatilized at 1173.15 K (900 °C) and the final volatiles yields were not sensitive to the heating rate. Moreover, it was illustrated that the DTG curve presents a polymerization trend with the increase in heating rate. Then, kinetic parameters, including total component mass fraction, preexponential factor, and activation energy, were derived by deconvolution from TG/DTG profiles for each component with a one-step kinetic framework, and the correlations between kinetic parameters and heating rates were further explored and modeled. The results illustrated that four subpeaks can be found in the deconvolution, indicating the four components (volatile components, hemicellulose, cellulose, and lignin). In addition, the activation energy of each component was found to be insensitive with heating rate (with standard deviation less than 20%). Therefore, an average activation energy was used for each component to avoid the compensation effect and a power correlation between the heating rate and the preexponential factor could be found. A posteriori analysis also confirmed the validity of this correlation.

Waste-tyre pyrolysis and gasification via the reverse boudouard reaction: derivation of empirical kinetics from TGA data

The pyrolysis of scrap tyre rubber crumbs under nitrogen and treatment with pure carbon dioxide was investigated both isothermally and dynamically up to 1100 °C, at heating rates up to 20 °C min−1. The rubber sample was a mixture of industrially representative tread and sidewall material. Workable, but not definitive, models could be derived from the isothermal analysis: Jander D3 diffusion for the first pyrolysis event under nitrogen up to 550 °C; the Mampel mechanism for high-temperature pyrolysis above 550 °C; and shrinking-particle chemical-reaction control as the rate limiting step for the reverse Boudouard reaction. The isothermally derived pre-exponential factors and activation energies were further refined by non-linear fitting to the dynamic data of all heating rates, and by making both parameters functions of the degree of conversion. In addition, the Sestak-Berggren equation was directly fitted to the full data set, i.e., for all heating rates, also using pre-exponential factors and activation energies that are dependent on degree of conversion. Both the approaches yielded workable engineering kinetics, with the Sestak-Berggren performing worse. With single-value pre-exponential factors and activation energies, the models fitted the data less satisfactorily across the range of heating rates. The required numerical analysis is fully implementable on a commercial spreadsheet.

Modeling Coal Swelling during Pyrolysis at Elevated Pressure by Using a Single Bubble Model: Validation and Application

ABSTRACT Pressurized oxy-coal combustion technologies are attracting more attention of researchers because of their advantages of carbon capture. While the ambient pressure could significantly influence the coal pyrolysis behavior. In this study, Yulin coal was used for the pyrolysis experiment in a pressurized drop tube furnace. Pyrolysis temperature of 1273 K, and pressures of 1, 4, 7, 10 atm were considered. The swelling behavior of produced char was analyzed by the scanning electron microscope (SEM). The char evolution process during pyrolysis at elevated pressure was simulated by a revised single bubble model, in which the volatile releasing rate and yield by residence time can be obtained from the CPD (chemical percolation devolatilization) model. Results show that the revised single bubble model is suitable for predicting the char evolution over a wide range of pressure and heating rate. Optimum pressure is present in the range of 7–15 atm, where the swelling ratio and porosity reach the maximum value. This model can predict the two regimes of coal swelling in varied heating rates, which is more obvious at high pressure. The porosity development by time can also be output, and the variation trends are similar to the swelling ratio.

Thermogravimetric kinetic analysis of in-situ catalytic pyrolysis of palm oil wastes with the presence of palm oil wastes ash catalyst

The thermal degradation and kinetic analysis for oil palm frond (OPF) and oil palm trunk (OPT) with its ashes were investigated using thermogravimetric approach (TGA). OPF ash, OPT ash and its mixtures are used as a natural source of catalysts in the pyrolytic conversion of the palm oil wastes to bioenergy. The TGA experiments were conducted in a range of heating rates of 10-100 K/min from the temperature of 323 K to 1173 K. Coats-Redfern model is applied in this study to evaluate the activation energy (EA ) and pre-exponential factor (A). The average EA values ranged 24.27-32.36 kJ.mol−1 and 41.42-46.10 kJ.mol−1 for pyrolysis of OPF and OPT respectively. Meanwhile, the average EA values ranged 24.27-31.06 kJ.mol−1 and 31.77-43.45 kJ.mol−1 for catalytic pyrolysis of OPF and OPT respectively.

Development of a pyrolysis model for poly(vinylidene fluoride-co-hexafluoropropylene) and its application in predicting combustion behaviors

Pyrolysis and combustion behaviors of poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), a promising polymer matrix in lithium-ion polymer battery, are experimentally and numerically investigated. A pyrolysis reaction scheme consisting of three high order consecutive reactions was established based on the thermogravimetric analysis (TGA) measurements and parameterized combining a modified numerical model and Genetic Algorithm (GA). The results show that in the heating rate range of 5–20 K min−1 the peak temperature of pyrolysis increases from 739 to 770 K. After deriving the pyrolysis kinetics, the thermodynamics was further determined by inversely modeling the measured mass loss rate in cone calorimeter tests. By fitting the measured heat release rate, the effective heat of combustion of each gaseous component, the global effective heat of combustion (9.56 MJ kg−1) and the flame heat flux (15 kW m−2) were quantitatively estimated. Reliability of the fully developed model was validated by alternative experimental results which were not utilized in parameterization, and good agreement was found. The collected ignition times in cone calorimeter tests were well predicted by the numerical model employing the measured critical mass flux, 2.87±0.32 g m−2 s−1. By invoking the ignition theory proposed for thermally intermediate solid and the measured ignition data, thermal diffusivity of PVDF-HFP, critical heat flux and critical temperature were assessed to be 3.00 × 10−7 m−2 s−1, 17.13–24.34 kW m−2 and 763.34–794.13 K, respectively.

Magma Ocean Evolution of the TRAPPIST-1 Planets

Recent observations of the potentially habitable planets TRAPPIST-1 e, f, and g suggest that they possess large water mass fractions of possibly several tens of weight percent of water, even though the host star's activity should drive rapid atmospheric escape. These processes can photolyze water, generating free oxygen and possibly desiccating the planet. After the planets formed, their mantles were likely completely molten with volatiles dissolving and exsolving from the melt. To understand these planets and prepare for future observations, the magma ocean phase of these worlds must be understood. To simulate these planets, we have combined existing models of stellar evolution, atmospheric escape, tidal heating, radiogenic heating, magma-ocean cooling, planetary radiation, and water-oxygen-iron geochemistry. We present , a versatile magma-ocean evolution model, validated against the rocky super-Earth GJ 1132b and early Earth. We simulate the coupled magma-ocean atmospheric evolution of TRAPPIST-1 e, f, and g for a range of tidal and radiogenic heating rates, as well as initial water contents between 1 and 100 Earth oceans. We also reanalyze the structures of these planets and find they have water mass fractions of 0-0.23, 0.01-0.21, and 0.11-0.24 for planets e, f, and g, respectively. Our model does not make a strong prediction about the water and oxygen content of the atmosphere of TRAPPIST-1 e at the time of mantle solidification. In contrast, the model predicts that TRAPPIST-1 f and g would have a thick steam atmosphere with a small amount of oxygen at that stage. For all planets that we investigated, we find that only 3-5% of the initial water will be locked in the mantle after the magma ocean solidified.

Crystallization mechanism of Zr55Cu30Al10Ni5 metallic glass in an extended range of heating rates

The crystallization mechanisms of Zr55Cu30Al10Ni5 (Zr55) amorphous alloys from slow continuous heating to rapid laser heating are investigated. The multiphase nanocrystalline structures such as CuZr2-type, NiZr2-type and Al2Zr3-type phases with various compositions are observed at heating rates lower than 50 K/s, while the CuZr2-type/ZrCu-type eutectic dendrites are produced at heating rates higher than 50 K/s. A numerical model is established to calculate the onset crystallization temperatures as a function of the heating rates. This model indicates that in addition to rapid dendritic growth from a certain number of quenched-in nuclei, the non-Arrhenius behavior of high diffusion coefficient in the supercooled liquid region contribute to the serious crystallization during rapid heating process. The activation energy of dendritic crystallization is obviously smaller than that of multiphase nanocrystallization, which is due to a much smaller scale of diffusion distance and larger atomic diffusivity during dendritic growth.

Identifying Synergistic Effects between Biomass Components during Pyrolysis and Pointers Concerning Experiment Design

A review of existing data has shown that “char yield deficits” develop during the pyrolysis of lignocellulosic biomass, relative to char yields expected from pyrolyzing chemically isolated lignins and the proportion of lignin in the particular biomass. This paper describes two sets of pyrolysis experiments. The work done in a thermogravimetric (TG) balance was initiated to probe whether diminishing heating rates might reduce, or even wipe out, the “char yield deficits” identified in previous work, where a wide range of heating rates had been used. Experiments were performed at 2 °C min–¹, a lower heating rate than that has hitherto been used to investigate char deficits. The effect was confirmed at this slow heating rate, using samples of birchwood and almond shells. A parallel set of differential scanning calorimetry (DSC) experiments provided evidence that mechanisms by which biomass samples pyrolyze are distinct from those of biomass components pyrolyzing in isolation. Moreover, the observed effects could not be replicated by simply mixing the three biomass components in appropriate proportions. The “lignin char deficit” is consistent with chemical interactions between intermeshed biomass components during pyrolysis altering reaction pathways and product distributions relative to the pyrolysis of biomass components pyrolyzed in isolation. The present work also shows that sample mass loss in TG balances is affected by altering sample loading, leading to potential errors. The design of pyrolysis experiments is discussed and approaches are suggested to prevent masking of key pyrolysis phenomena, viz. synergistic effects between biomass components or onset-of-pyrolysis temperatures, through the appropriate selection of experimental parameters.

Performance of fire protective coatings on structural steel member exposed to high temperature

The purpose of this study is to investigate the performance of fire protective materials in protecting steel section. A new indexing system is introduced, named as fire endurance index (FEI), which can be used to evaluate the performance of fire protective materials.,In this study, experiments were carried out using W4 × 13 steel section. Eight samples were prepared; one was a bare steel section without any coating material, and seven were prepared using four types of materials such as vermiculite-gypsum plaster, gypsum plaster, concrete cover and glass wool-concrete cover for fireproofing of the sections. An enclosed electric coiled furnace was used for heating the samples for a certain period. The duration of protection was determined, and the FEI of the materials was calculated. The higher the index value is, the better the performance.,The results demonstrate that the glass-wool-concrete cover offered the best performance at high temperature among the four types of materials. In the experiment with glass-wool-concrete cover, the furnace temperature reached 750°C, whereas the steel temperature reached only 100°C. The FEI of the coatings were calculated. Among the eight samples, glass wool-concrete cover also achieved the highest index value.,The experimental work was performed using a limited number of specimens. Furthermore, the robustness of the indexing system needs to be evaluated with other materials and a wide range of heating rate and temperature. This study sets the foundation for future work.,The findings of this research may contribute to a better understanding of the performance of the materials used as fire protective coatings. This might be helpful for the researchers and practitioners in their design and implementation of legislation of fire safety codes.,Understanding the performance of the fire protective coatings will help in evaluating the fire resistance capabilities of the materials to use for the structural steel members, which may protect collapses and disasters of buildings.,This paper deals with the performance of four types of materials, that can be used as fire protective coatings for structural steel members. Furthermore, the FEI explicitly indicated their performance with numerical values. In this study, the heating of the specimens was performed using a non-standard fire curve based on the concept that naturally occurring incidents of fire do not follow the standard fire curves.

Multi-alloying of nanomet: conception and implementation of homogeneous nanocrystallization in high-flux density soft magnetic alloys

This study demonstrates how multi-alloying the Fe-Si–B–P–Cu (Nanomet®) can avoid the strict requirements on the annealing scheme in terms of high heating rate and narrow annealing temperature range in order to grow a homogeneous ultrafine nanocrystalline structure. The rather restricted amorphization capability sets a low limit of the maximum thickness of the amorphous precursor. These shortcomings have their origin in the existence of detrimental pre-existing nuclei in the amorphous precursors, which in turn potentially lead to a heterogeneous crystallization. Here, we have multialloyed Nanomet with CoCNi- and CoCMo- to avoid the creation of these pre-existing nuclei. This leads to improved amorphization capability and changes a potentially heterogeneous crystallization to a homogeneous nanocrystallization over a much broader temperature range than for unalloyed Nanomet. Thus, the requirements for the annealing are much relaxed. This work encompasses quenching the amorphous precursors using melt-spinning, investigating the crystallization temperatures by calorimetry, showing the depletion of pre-existing nuclei by magneto-thermo-gravimetry, conceptualizing the crystallization dynamics using isothermal calorimetry, and finally revealing the excellent soft magnetic properties over a broad annealing temperature interval (390–490 °C for the substituted alloys compared to 410–470 °C for unalloyed Nanomet). The multi-elemental substitution of Fe with CoCMo and CoCNi in Nanomet alloy nearly maintains the saturation magnetization and the coercivity. We believe the substituted alloys provide a better alternative to Nanomet with improved amorphization capability and homogeneous nanocrystallization without any special heat treatment scheme.

Comparison of Conventional and Flash Spark Plasma Sintering of Cu–Cr Pseudo-Alloys: Kinetics, Structure, Properties

Spark plasma sintering (SPS) is widely used for the consolidation of different materials. Copper-based pseudo alloys have found a variety of applications including as electrodes in vacuum interrupters of high-voltage electric circuits. How does the kinetics of SPS consolidation for such alloys depend on the heating rate? Do SPS kinetics depend on the microstructure of the media to be sintered? These questions were addressed by the investigation of SPS kinetics in the heating rate range of 0.1 to 50 K/s. The latter conditions were achieved through flash spark plasma sintering (FSPS). We also compared the sintering kinetics for the conventional copper–chromium mixture and for the mechanically induced copper/chromium nanostructured particles. It was shown that, under FSPS conditions, the observed maximum consolidation rates were 20–30 times higher than that for conventional SPS with a heating rate of 100 K/min. Under the investigated conditions, the sintering rate for mechanically induced composite Cu/Cr particles was 2–4 times higher compared to the conventional Cu + Cr mixtures. The apparent sintering activation energy for the Cu/Cr powder was twice less than that for Cu–Cr mixture. It was concluded that the FSPS of nanostructured powders is an efficient approach for the fabrication of pseudo-alloys.

Temperature deformation characteristics of acrylic windows used for tide embankments

<abstract> <p>Tide-embankment walls protecting coastal roads frequently contain numerous windows so that pedestrians and drivers can view the scenery without experiencing reduced sunlight. Tide-embankment windows must withstand extreme climatic conditions. However, the effects of temperature extremes on acrylic boards have rarely been studied. This paper proposes a simple method for constructing a high-temperature environment and a method for measuring strain on an acrylic plate. The deformation and strain of a 40-mm-thick acrylic tide-embankment window were determined experimentally and numerically in this study in a high-temperature environment, obtaining similar results; additionally, the numerical method was subsequently used to simulate a low-temperature environment. Because thermal conductivity was low, the internal temperature of the thick acrylic board did not immediately change with the temperature of the surface, and thermal expansion and contraction of the board were restrained. Temperature-induced deformation effects were low across the entire range of temperatures and heating rates recorded in coastal Japan.</p> </abstract>

Release of potassium in association with structural evolution during biomass combustion

A mechanistic understanding of potassium release is essential to mitigate the potassium-induced ash problems during biomass combustion. This work studies the effects of operational condition on the potassium release and transition during the combustion of wheat straw, and elucidate the release potential of potassium associated with the structural change of biomass particles. The combustion tests were carried out in a laboratory-scale reactor, working in a wide range of temperatures and heating rates. It was found that the combustion of biomass sample at a temperature up to 1000 °C results in a release of over 60% of its initial potassium content. Raising the heating rate from 8 °C/min to 25 °C/min could lead to an additional release of up to 20% of the initial amount of potassium. A three-stage potassium release mechanism has been concluded from this work: the initial-step release stage (below 400 °C), the holding stage (400–700 °C) and the second-step release stage (above 700 °C). Comprehensive morphology analysis with elemental (i.e. K, S, O, Si) distribution was carried out; the results further confirmed that potassium is likely to exist inside the stem-like tunnel of biomass particles, mainly in forms of inorganic salts. During the heating-up process, the breakdown and collapse of biomass particle structure could expose the internally located potassium and thus accelerate the release of potassium and the transform of its existing forms. Lastly, a detailed temperature-dependent release mechanism of potassium was proposed, which could be used as the guidance to mitigate the release of detrimental potassium compounds by optimising the combustion process.

Investigation of Heat Transfer Characteristics in a Rotating Convection System With Bi-Directional Thermal Gradients

Abstract A series of rotating convection experiments have been conducted in a novel configuration, which comprises a cylindrical annulus with spot heating on the bottom outer edge and uniform cooling on the inner surface. Such a system provides bi-directional thermal gradients in both radial and vertical directions, thereby reenacting the thermal gradient patterns encountered in the atmosphere. Bulk heat transfer characteristics are studied by quantifying the overall Nusselt number, Nu, for a range of Taylor number, Ta, heating rate, Q, and Rayleigh number, Ra. Temperature measurements are carried out at different locations with the help of thermocouples. The Nusselt number is found to be quite sensitive to the buoyancy and relatively insensitive to the rotation rate. The correlation for Nu as a function of Ra revealed different power law exponents for low and high Ta values. The varying exponent is attributed to the presence of baroclinic eddies at high Ta, which in turn is verified with the help of flow visualization. The heat transfer characteristics in this new configuration are significantly different compared to other conventional rotational convection systems, where thermal gradients are present in only one direction.

Insights into pyrolytic feedstock potential of date palm industry wastes: Kinetic study and product characterization

This paper aims to study the pyrolysis characteristics of primary residues from industrial date palm processing, namely Fruit stalks pruning (FSP) and Date Palm petiole (DPP) biomasses, and evaluate their potential as a raw material for the pyrolysis process. TG-DTG analyses were performed on the raw material FSP and DPP to inspect the thermal degradation of samples at a range of heating rates within an inert atmosphere. Kinetic parameters, such as activation energy and pre-exponential factor for pyrolysis of (FSP) and (DPP), were calculated by the Distributed Activation Energy Model. As for the kinematic parameters obtained, the activation energy ranged from 110.92 to 120.08 kJ/mol for FSP and from 113.90 to 132.39 kJ/mol for DPP. Pyrolysis experiments were performed using a fixed bed reactor at a heating rate of 15 °C/min−1. The maximum liquid product yield was acquired at 500 °C. For the syngas production, the highest yield was obtained at 600 °C. The highest production of bio-char at a low temperature of 450 °C, and it decreased considerably with rising temperature. Evaluation of the kinetic parameters with physicochemical analysis illustrates the promising bio-energy potential of the two studied biomasses.

Response of PETN detonators to elevated temperatures

In the present study, commercially available detonators with pentaerythritol tetranitrate (PETN) were subjected to elevated temperatures. The detonators were thermally ignited over a range of heating rates to measure ignition delay time and assess detonator violence. The violence of the detonator was quantified by measuring the velocity of the detonator closure disc (or “flyer”). The maximum flyer velocity of a thermally ignited detonator was comparable in magnitude to that obtained by initiating a room temperature pristine detonator with an exploding bridge wire (under the same confinement); however, the high flyer velocity was not an indication of deflagration to detonation transition (DDT) in the thermally ignited detonator. The detonator responded more violently than a thermally ignited detonator when initiated at 95% of the ignition delay time. Inoperability thresholds were also measured by varying the detonator temperature and the threshold was found to be sensitive at detonator temperatures below the melting point of PETN.