Thermal Decomposition Process Research Articles

Non‐isothermal kinetic study of high‐grade magnesite thermal decomposition and morphological evolution of MgO

AbstractThermal decomposition was the prerequisite and basis for the utilization of magnesite resources. However, the calcination of magnesite was usually accompanied by high energy consumption, which not only caused serious waste of magnesite resources, but also restricted its high value‐added utilization. Therefore, calcination conditions were the key to controlling thermal decomposition process of magnesite. The kinetics of high‐grade magnesite thermal decomposition was elaborated by non‐isothermal thermogravimetric analysis, and meanwhile the effect of heating rate on the magnesite thermal decomposition reaction and morphology of MgO particles were characterized. Both Doyle and Gorbatchev approximate functions were used to simulate the magnesite thermal decomposition process, where the experimental data (correlation coefficient) fitted by the latter could obtain more acceptable kinetic parameters of the magnesite thermal decomposition. The good linear relationship between the activation energy and the pre‐finger factor allowed for a kinetic compensation of the thermal decomposition of magnesite. Furthermore, higher heating rate induced the formation of terraced grains, grain network group, cubic grains, and spherical grains for the samples sintered at 1200°C. The heating rate largely affected the magnesite particle morphology, grain size distribution and activity, and also provided important technical indicators in the actual production of magnesia refractory raw materials.

Thermal Stability of Ionic Liquids: Current Status and Prospects for Future Development

Ionic liquids (ILs) are the safest solvent in various high-temperature applications due to their non-flammable properties. In order to obtain their thermal stability properties, thermogravimetric analysis (TGA) is extensively used to analyze the kinetics of the thermal decomposition process. This review summarizes the different kinetics analysis methods and finds the isoconversional methods are superior to the Arrhenius methods in calculating the activation energy, and two tools—the compensation effect and master plots—are suggested for the calculation of the pre-exponential factor. With both parameters, the maximum operating temperature (MOT) can be calculated to predict the thermal stability in long-term runnings. The collection of thermal stability data of ILs with divergent cations and anions shows the structure of cations such as alkyl side chains, functional groups, and alkyl substituents will affect the thermal stability, but their influence is less than that of anions. To develop ILs with superior thermal stability, dicationic ILs (DILs) are recommended, and typically, [C4(MIM)2][NTf2]2 has a decomposition temperature as high as 468.1 °C. For the convenience of application, thermal stability on the decomposition temperature and thermal decomposition activation energy of 130 ILs are summarized at the end of this manuscript.

Eggshells as a sustainable source for acetone production

Everyday, tons of food wastes are thrown to the environment constantly by people in the cities, which contain many beneficial substances. One of these beneficial wastes of unknown value is eggshells. Although the eggshells are considered negligible and not valuable material, however, the many researches that dealt with this substance proved its high potential to turn into many useful substances such as a catalyst in biodiesel preparation or as a media for adsorption of heavy metals and dyes or soil fertilizer and others. The current study highlighted the benefit possibility of white chicken eggshells (WCES) from another side, considering it as a raw material for preparing acetone one of the most important industrial solvents. The results obtained showed that this worthless raw material has a high effectiveness for acetone production by containing 94.519% by weight of calcium carbonate. The process of converting WCES to acetone was carried out in two steps, the first one were producing calcium acetate by treating it with glacial acetic acid in a batch mode reaction unit at room temperature and agitation speed, acid % excess and contact time of 200 rpm, 20% and 2 h respectively. Whereas, the next step involved conducting the process of thermal decomposition of the prepared calcium acetate at 380 °C to produce acetone in a stainless steel reactor. The results of testing the samples by the gas chromatography (GC) showed that the maximum yield of acetone is 96.395%. With these experimental results, this study presents a new idea in food waste management as one of the solid waste types by utilizing it in a useful manner to produce important materials in an economical, beneficial and environmentally friendly way, reaching to the concept of zero residue level (ZRL).

Mechanistic study of the gas-phase chemistry during the spray deposition of Zn(O,S) films by mass spectrometry

The mass spectrometer, is a powerful tool to identify species and investigate reactions in the gas phase. In this work, the mechanism of aerosol assisted chemical vapor deposition (AACVD) of Zn(O,S) films prepared from H2S and zinc acetylacetonate (Zn(acac)2) precursor solutions is elucidated by mass spectrometry. The thermochemical behavior of Zn(acac)2 is investigated by characterizing the influence of the solvent (H2O or ethanol), the pH value of the precursor solution and the effect of the reactant H2S, and by tracking gaseous intermediate products using mass spectrometry. Based on these results, a proton-promoted thermolysis mechanism for the AACVD Zn(O,S) film formation is then proposed, which is initiated by the hydrolysis with H2O as the first stage, followed either by the rearrangement with an intramolecular proton or by the reaction with an extramolecular proton to produce ZnO or Zn(O,S). A real time mass tracking of the AACVD process reveals that only an adequate amount of H2S promotes the chemical gas-phase decomposition and sulfurization process, while an excess of H2S depletes the gaseous Zn(acac)2 concentration and consequently reduces the film growth rate. The knowledge of the thermal decomposition process helps to optimize synthesis conditions and to adjust film properties to meet the requirement of the application in chalcopyrite or kesterite thin film solar cells.

Experimental study of the processes of reducing the formation of sulfur oxides during the co-combustion of particles of metalignitous coal and wood processing waste

This paper presents results of experimental research on thermal decomposition processes of a rather common D grade steam coal (metalignitous coal) and wood. The research aims to substantiate the previously formulated hypothesis on the mechanism of sulfur oxide sequestration in the combustion products of such mixtures. The elemental composition of the reference coal and wood biomass (pine sawdust) and the ash remaining after complete thermal decomposition of the studied mixtures was analyzed. The obtained results, along with results of the X-ray phase analysis of the ash composition, showed an increase in the proportion of calcium and aluminum sulfates in solid pyrolysis products. The performed experiments substantiate that the use wood as an additive for mixed metalignitous coal fuels reduces sulfur oxide yield during their combustion in power boilers in large-scale and small-scale power generation systems. It was established that pyrolysis of two-component fuels based on the D grade coal mixed with dispersed wood biomass contributes to reducing sulfur oxide concentration in gaseous products of their thermal decomposition. This effect can be attributed to formation of calcium and aluminum sulfates in the mixed fuel ash. They are formed as a result of reactions between the coal and wood pyrolysis products that occur if the content of wood components in the mixture is from 10% to 50%.

Eco-friendly flame retardant and dripping-resistant of polyester/cotton blend fabrics through layer-by-layer assembly fully bio-based chitosan/phytic acid coating

Polyester/cotton blend fabrics are widely used in clothing and household textiles which combine the comfort of cotton and excellent mechanical strength of polyester. However, their high flammability due to the special “wick effect” resulting from the different thermal decomposition process of cotton and polyester causes greatly potential fire hazards. In this study, fully bio-based intumescent flame retardant (IFR) coating of chitosan/phytic acid (CS/PA) was layer-by-layer (LBL) assembly constructed on polyester/cotton blend fabrics. The LOI value of polyester/cotton blend fabric which was LBL assembly coated by 20 bilayers CS/PA reached 29.2%. And the dripping of coated fabric was eliminated. The results of cone calorimetry test confirmed CS/PA coating greatly improved the flame retardancy of polyester/cotton blend fabrics. Thermogravimetric analysis (TGA) results showed CS/PA coating changed the thermal decomposition process to promote the char formation of polyester/cotton blend fabrics. CS/PA coating on fabric could form the IFR system which acts through both condensed phase action by the catalysis dehydration reaction to forming stable char and gas phase action by the blowing effect. This research provides a new strategy to eco-friendly flame retardant and dripping-resistant for polyester/cotton blend fabrics by bio-based IFR system through facile LBL assembly method.

Effects of the Composition and Molecular Structure of Heavy Oil Asphaltenes on Their Reactivity in Thermal Decomposition Processes

Effects of the Composition and Molecular Structure of Heavy Oil Asphaltenes on Their Reactivity in Thermal Decomposition Processes

Thermal reduction of graphite oxide in the presence of nitrogen-containing dyes

Thermal reduction of graphite oxide (GO) is considered as a prospective method for the preparation of high-performance graphene-based materials. However, this method has certain limitations, and the major is that this exothermic process is difficult to control. In this research, we focused on the kinetic studies of the reduction of graphite oxide using non-isothermal differential calorimetry (DSC) method. Six GO nanocomposites with dyes were tested to study the shift in kinetic parameters. The apparent reaction order is determined to be ca 0.7 for the thermal decomposition of pure GO, while in the presence of dye molecules it increases sometimes reaching a value of 2.0 for higher dye concentrations. Decisively, the thermal decomposition of pure GO can be presented as an intermediate between a zero- and first-order reaction, while the introduction of dye molecules turns a certain part of the energy consumption via the bimolecular pathway. Our research revealed that the process of GO thermal decomposition can be operated and properties of the final product (reduced graphene oxide (rGO) and its derivatives) can be adjusted more precisely using additive molecules, which interact with GO sheets.

Kinetic modeling and analysis of pyrolysis of polymethyl methacrylate using isoconversional methods

Pyrolysis the waste plastic into fuel is a promising way to protect the environment. In this study, we study the thermal decomposition processes of polymer Poly (methyl methacrylate) PMMA. This work used the microscale combustion calorimeter (MCC) as a tool to study the degradation. MCC is an applicable method to calculate the material combustion parameters by using milligram samples. The experiments were carried out at four heating rates 0.25, 0.5, 0.75, and 1 K/s. The temperature range in which the pyrolysis reaction occurs is « 300-470 oC. We applied several isoconversional methods such as Friedman, Ozawa, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) to estimate the apparent activation energy of thermal degradation of Poly(methyl methacrylate). Determine the activation energy from each method evaluated against the experimental data. With investigation, the FWO method shown much higher values for activation energy for PMMA polymer more than the other two methods, and the average value much higher than the Friedman and KAS methods. On the other hand, as a differential method, Friedman showed more accurate results Ea=216.65kJ/mol, and KAS method 228.61 kJ/mol. Our investigation may give a few experiences to how to more readily portray trial results with hypothetical expectations and essential data for calculating the activation energy of potential pyrolysis reactors.

High-performance methylammonium-free ideal-band-gap perovskite solar cells

Summary The development of mixed tin-lead (Sn-Pb)-based perovskite solar cells (PSCs) with low band gap (1.2–1.4 eV) has become critical not only for pushing single-junction devices toward the maximum efficiency given by the Shockley-Queisser limit, but also for enabling all-perovskite tandem devices beyond this limit. However, achieving high power-conversion efficiency (PCE) and long-term device operation stability simultaneously remains a significant challenge for Sn-Pb-based PSCs. Here, we demonstrate near ideal-band-gap (∼1.34 eV) methylammonium-free Sn-Pb-based PSCs with high efficiency (∼20%) and promising operational stability of maintaining >80% of initial PCE over 750 h under maximum-power-point tracking. The key to this success is the use of a SnCl2⋅3FACl complex additive that improves the microstructure and reduces the development of residual stress in the Sn-Pb perovskite thin films, which in turn enhances the efficiency and stability of the Sn-Pb-based ideal-band-gap PSCs.

The in-situ XAS study on the formation of Pd nanoparticles via thermal decomposition of palladium (II) acetate in hydroxyl functionalized ionic liquids

The formation of palladium nanoparticles (NPs) via thermal decomposition of palladium (II) acetate in hydroxyl functionalized ionic liquid (IL) [C2OHmim]+[NTf2]− was studied using in-situ energy dispersive x-ray absorption fine structure spectroscopy (DXAFS) and complementary methods such as transmission electron microscopy (TEM) and inductively coupled plasma mass spectrometry. Detailed XAFS spectra analysis unraveled that the palladium acetate trimer precursor underwent dissociation after being dispersed in ILs, which accelerated the thermal decomposition compared with other organic solvents. Based on the reaction kinetics, extened x-ray absorption fine structure spectroscopy fitting and TEM characterization results, the thermal decomposition process can be divided three successive stages namely the explosive nucleation, autocatalytic surface growth and NP attachment growth.

Investigation of pyrolysis kinetics and gaseous compounds emitted during charcoal production from woods commonly used in the Eastern Mediterranean

AbstractAir pollution caused by the traditional charcoal production industry is an environmental problem for developing countries. Avocado (Persea americana) and Lemon (Citrus limon) trees that are commonly used in the charcoal industry in the Eastern Mediterranean were chosen as representatives of charcoal raw material in a wood pyrolysis kinetic study that was conducted using a thermogravimetric analyzer (TGA). The weight loss was measured in a nitrogen atmosphere with a heating rate of 10 °C.min−1 at a temperature range from 30 °C to 700 °C. Four main stages, denoted as dehydration, initial decomposition and both active and final decomposition, were registered in the wood thermal decomposition. The main gases produced were identified in the active decomposition stage for lemonwood and avocado wood, respectively, in the temperature range of 255 to 355 °C and 246 to 340 °C. The released gases in the biomass pyrolysis were measured on‐line using Fourier transform infrared (FTIR) spectroscopy. Main gas products of avocado and lemonwood pyrolysis were similar and included CO2, CO, H2O, CH4, and several organic compounds including methanol, formic acid, acetic acid, and furan. Charcoal production thermogravimetric analysis validated that the wood biomass thermal decomposition process has four stages: (1) water evaporation; (2) initial decomposition; (3) active decomposition, and (4) final decomposition. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Global refinery catalysts markets, 2014-2019: 2020-2025 - increasing adoption of zeolites as an effective refinery catalyst driving market growth

We investigated the adsorption and decomposition of formaldehyde (HCHO) molecule on stoichiometric rutile TiO2(110) surface using first principles-calculations. By comparing the adsorption energy of one bidentate and two monodentate configurations, we found the bidentate configuration is the most stable one because of an additional C-O bond formation. The monodentate configuration can change into the bidentate configuration by overcoming a small barrier less than 0.1 eV. Then, we investigated the decomposition of HCHO which involves two deprotonation processes starting from different adsorption structures. The energy barrier of the first deprotonation is 1.3 eV and 1.1 eV for bidentate and monodentate configurations. After the first deprotonation, an adsorbed formate HCOO specie is formed. The second deprotonation needs 1.74 eV and 1.64 eV for bidentate and monodentate configurations, respectively. After that, an adsorbed CO2 is formed. It can desorb from the surface after overcoming a small barrier of 0.12 eV. In principle, it is also possible to obtain a CO molecule from the surface. Yet a large energy barrier higher than 1.74 eV needs to be overcome. By analyzing the energy level alignment of molecular orbitals with TiO2 energy band edges, we discussed the photocatalytic activity of the reactants and intermediates during the decomposition process. Our results give a clear description of the adsorption structure and thermal decomposition process of HCHO on rutile TiO2(110) surface. The discussion of photocatalytic reactivity based on energy level alignment provides valuable insights to understand the combined photocatalytic and thermally catalytic reactions.

Inhibiting effect of inhibitors on ignition sensitivity of wood dust

Wood products are easy to produce dust in the production and processing process, and have a serious explosion risk. In order to improve the safety of wood products production, the inhibiting effects of magnesium hydroxide (MTH), SiO2, melamine polyphosphate (MPP) on the minimum ignition energy (MIE) and minimum ignition temperature (MIT) of wood dust were experimentally studied. The results showed that the inhibiting effects of inhibitors on the MIE of wood dust show the order of MPP > SiO2>MTH. The order of the inhibiting effects on the MIT of wood dust was MPP > MTH > SiO2. When 10% MPP was added to wood dust, the time when the flame appears (Tappear) and the time when the flame reaches the top of the glass tube (Ttop) obviously rose to 80, 140 ms. Therefore, MPP had the best inhibiting effect on the ignition sensitivity of wood dust.According to thermogravimetry (TG), differential scanning calorimetry (DSC) tests, the introduction of MPP leaded to lower maximum mass loss rate (MMLR), higher temperature corresponding to mass loss of 90% (T0.1), residual mass and heat absorption. In addition, thermogravimetric analysis/infrared spectrometry (TG-IR) results showed that MPP produced H2O (g) and NH3 (g) during the thermal decomposition process, which diluted the oxygen.

Experimental and theoretical study of the effect of typical halides on thermal decomposition products and energy release of ammonium nitrate based on microcalorimetry and FTIR

Ammonium nitrate (AN) is widely used as a raw material in industry and agriculture. However, the Beirut explosion in Lebanon once again shows that AN has a risk of thermal runaway during storage, especially long-term storage or when some possible substances are mixed therein. This paper focuses on the effect of halides additives, such as sodium fluoride, sodium chloride, sodium bromide and sodium iodide, on the thermal decomposition products and energy release of AN. Especially, the thermal decomposition of AN added with 5% sodium halide and the evolved gases in the thermal decomposition process are investigated by C80 microcalorimetry and FTIR. The results show that all kinds of sodium halides have an effect on the thermal decomposition of AN, although these effects are different. The addition of the halide not only changes the timing of the formation of the AN thermal decomposition characteristic product, but also reduces the heat of the reaction. Combined with optimized kinetic parameters, the engineering prediction of thermal safety was carried out for each type of sample. It is found that sodium iodide is beneficial to the safety of large-scale storage of AN. The research results can provide a reference and guidance for revealing the thermal decomposition mechanism of halide-containing AN and thermal decomposition simulation of AN with additives.

Experimental Study on Thermal and Catalytic Decomposition of a Dual-Mode Ionic Liquid Propellant

With the increasing of space activities and people’s awareness of environmental protection, it is necessary to develop a new non-toxic space propulsion system with high performance. Hydroxylammonium nitrate (HAN)/1-ethyl-3-methyl-imidazolium ethylsulfate([Emim][EtSO4]) blend ionic liquid propellant is a potential replacement with non-toxic and high-performance characteristics for hydrazine type liquid propellants, which can be used in both chemical and electrical propulsion system. This paper introduced the thermogravimetric experimental analysis (TGA-DSC) results of HAN/[Emim][EtSO4] ionic liquid propellant with the thermal decomposition and catalytic decomposition process. Its mass-loss process and exothermic process under different reaction conditions at a heating rate of 5K/min~15K/min were studied. Generally, the mass-loss results showed that there were four characteristic stages during the decomposition process of the HAN/[Emim][EtSO4] ionic liquids, which were the evaporation of the water solvent, decomposition of the HAN component, further decomposition of the [Emim][EtSO4], and slow loss of the residual substances. At the same time, two exothermic peaks were observed, which respectively corresponded to the decomposition of HAN and the further decomposition of [Emim][EtSO4]. Using catalyst can significantly reduce the decomposition temperature of the propellant and the residual mass. The contents in this paper proved that this propellant had a good application prospect within the catalytic ignition aerospace thruster.

Study of Burning Behaviors and Fire Risk of Flame Retardant Plywood by Cone Calorimeter and TG Test

A flame retardant composition was prepared by using phosphoguanidine, guanidine sulfamate, disodium octaborate tetrahydrate and dodecyl dimethyl benzyl ammonium chloride. Veneers were immersed in such flame retardant mixture to prepare plywood. The combustion characteristics and thermal stability of plywood were assessed using a cone calorimeter and TG. Results showed that: (1) High concentration and loading of flame retardant were beneficial for the fire resistance of the plywood. (2) The limiting oxygen index (LOI) and residual mass of plywood processed using the flame retardant was increased by 87.52% and 58.66% compared to those of the untreated plywood, while the average heat release rate (av-HRR), total heat release (THR), effective heat of combustion (EHC), total smoke release (TSR), CO yield (COY), CO2 yield (CO2Y) and oxygen consumption were decreased by 44.3%, 82.9%, 47.0%, 86.0%, 89.9%, 50.1% and 83.1%, respectively. (3) Treated plywood which had a low fire growth index (FGI) displayed a later combustion heat release rate peak and slower flame spread than observed for the untreated material. Combustion of treated plywood displayed a higher fire performance index (FPI), indicating a longer time to ignition. This suggests that burning structures from this material would be subject to a longer time for escape from the structure and would present lower fire risk than similar structures containing treated plywood. (4) TG results demonstrated that the presence of the flame retardant can decrease the pyrolysis temperature for hemicellulose and cellulose, change the decomposition and reaction progress for plywood degradation and promote dehydration carbonization and accelerated charformation. Moreover, the formed char was more stable than that combustion of untreated plywood. (5) The flame retardant contains nitrogen (N), phosphorus (P), boron (B), chlorine (Cl) and guanidine (Gu) compounds. The adhesive also contains N and P compounds. These substances display flame resistance and supplement each other to generate flame retardance than any one used alone. By changing the thermolysis and thermal decomposition processes, the heat release and smoke release from plywood, undergoing combustion was reduced. This controlled generation of combustible substances and promoted dehydration and carbonization to form char. As a result, the flame resistance of plywood was improved significantly. The probability of smoke asphyxia or poisoning death of those trapped in structures containing treated plywood during fire accidents can be decreased dramatically.

Thermal behavior of Mongolian low-rank coals during pyrolysis

Low temperature pyrolysis behavior of four low-rank coals from the biggest deposits of Mongolia were studied using a fixed-bed reactor and Gray-King retort. The coal samples and resultant chars were analyzed using Fourier transform infrared spectroscopy (FTIR), 13C nuclear magnetic resonance (13C NMR) to explore the structure changes and thermogravimetric analyzer coupled with mass spectrometry (TG-MS) was used to investigate the pyrolysis reactivity of coal during thermal decomposition process. The results showed that the aliphatic structure in coal was significantly reduced and the carboxyl groups almost completely decomposed during pyrolysis process at 600 °C. The tar yield of Gray-king test is higher than that obtained from the fixed-bed reactor. The gaseous evolution measured by TG-MS during pyrolysis showed that the maximum peaks of evolution of CH4, H2, C2H2, C2H5, CO, and CO2 gases were well corresponded to the maximum rate of weight loss in the range 428–445 °C.

Calculation of Pyrolysis Zone in Installation of Activated Carbon Production

Activated carbon can be obtained in a variety of ways. The most promising in terms of resource conservation and economic benefits is the method of producing activated carbon from organic waste. The production of activated carbon by this method is based on the process of pyrogenetic decomposition of pre-crushed and dried waste. As a result of thermochemical processing, activated carbon and pyrolysis gas are formed. Conductive waste pyrolysis is a high-temperature process that runs without oxygen. The temperature regimes of the pyrolysis process are described by the differential heat transfer equation. The calculation of the specific masses of the waste, coal and steam-gas mixture formed during the decomposition is carried out according to the differential equations of mass transfer by complicated ongoing chemical reactions. The hardware design of the pyrolysis process is a set of complex design and technological solutions. When developing equipment designed for the pyrolysis of crushed waste, it is necessary to carry out calculations related to the optimization of the hardware design and operating parameters of the process of thermal decomposition of waste particles, which make it possible to obtain a high-quality product. A pyrolysis zone of crushed waste has been developed for an energy- and resource-saving continuously operating unit for the production of activated carbon. Heating of waste to a temperature of 450-550 ° C is carried out by non-condensing combustible gases obtained during the separation of the steam-gas mixture. Waste flue gases enter a recuperative heat exchanger, and then serve as a heat carrier for drying a new batch of waste. The paper describes a method for calculating the pyrolysis zone in an activated carbon production unit. A mathematical model of the pyrolysis process is presented, by which it is possible to determine the optimal height of the layer of waste particles and the specific mass of the formed coal and gases during the decomposition of organic waste. An algorithm for calculating the pyrolysis zone has been developed. The following characteristics are shown: the dependence of the heating temperature of the layer of wood particles in the pyrolysis chamber on the layer thickness and the kinetic dependence of the specific mass of the solid residue of wood particles during pyrolysis. The calculation of the coal pyrolysis zone for the activated carbon production unit is presented.

Evaluation of Synergistic Effect During Co-Pyrolysis of Imbat Coal and Rice Straw by Using Multistep Kinetic Analysis and Instantaneous Pyrolysis Index

Pyrolysis is considered as an effective thermal decomposition process for the utilization of solid fuels. Moreover, co-pyrolysis of coal and biomass offers the possibility to increase the process efficiency and to reduce the economic and environmental disadvantages of mono-utilization. Thermogravimetric analysis (TGA) provides a feasible way to obtain valuable thermal and kinetic data on the co-pyrolysis process. Kinetic analysis is critical for sizing, design, yield control, and optimization of thermochemical processes such as pyrolysis. In this study, the kinetic characterization was evaluated using the TGA data of Imbat coal, rice straw and their blends at heating rates of 5, 10 and 20 °C/min. The activation energy (Ea) and pre-exponential factor (A) were determined by Doyle's method (model fitting) and the multistep analysis based on a new pyrolysis model for the co-pyrolysis of Imbat coal and rice straw. The correlation coefficient (R2) results for the pyrolysis model were greater than 0.99, and the thermal behaviors of the pseudocomponents were simulated, and the TG curves were estimated at the additional heating rate (40°C/min). In addition, a new Instantaneous Pyrolysis Index (IPI) was introduced in this study. The IPI value provided important information about the severity of pyrolysis at different temperature ranges.