Non-isothermal Thermogravimetric Analysis Research Articles

TGA and elemental analysis of type II kerogen from the Bakken supported by HRTEM

In this study, non-isothermal thermogravimetric analysis was conducted on three samples taken from the Bakken Formation at one heating rate (10 °C/min). Based on the TGA thermograms, various intervals of weight loss were identified. The differences in weight loss, peak positions, and shapes of the samples’ thermograms were attributed to the variations in the composition (quantities of silicates and clay minerals), TOC content, and thermal maturity of the kerogen. Moreover, it was observed that the sample with the highest thermal maturity had the highest number of aromatic rings in its structure. XRD analysis demonstrated that the sample with the lowest silicate concentration and the highest clay mineral content lost the most weight during TGA analysis. Furthermore, CHNS elemental analysis indicated that samples with higher thermal maturity levels have higher amounts of C and H elements and lower content of N and S heteroatoms. Ultimately, our results were corroborated by HRTEM (High Resolution Transmission Electron Microscopy) analysis of p-kerogens, thus confirming the abundance of aromatic rings in the samples and delineating the relationship between aromaticity and thermal maturity.

Effect of torrefaction on thermal oxidative degradation kinetics of lignite using multi-distributed activation energy model

Torrefaction treatment is a promising method for lignite upgrading. However, its effect on the combustion characteristics has not been fully evaluated. In this study, the combustion characteristics of lignite and its upgrading samples by torrefaction were studied via non-isothermal thermogravimetric analysis. Results show that increasing the torrefication temperature decreases the volatile content while increasing the fixed-carbon in the fuels. The mole ratios of both H/C and O/C in the samples decreases as the torrefaction temperature increases. Torrefaction treatment significantly improves the combustion performance of lignite with a higher reactivity index S, and the optimum torrefaction temperature was determined to be 200 °C. The upgrading lignite by torrefaction at 200 °C has the lowest temperatures of Tf and Tp as well as the maximum corresponding DTG value. Furthermore, the results of three-parallel-DAEM model analysis results show that the activation energies corresponding to the three peaks are 176.1 kJ/mol, 186.5 kJ/mol and 221.7 kJ/mol, respectively, and that increasing torrefaction temperature had no significant effects on activation energies. With the torrefaction temperature increasing, the first standard deviation decreased while the third standard deviation increased.

Tucumã endocarp pyrolysis kinetics: A comparative analysis between independent parallel and consecutive reactions schemes

This study investigates the thermal decomposition kinetics of tucumã endocarp pyrolysis by non-isothermal thermogravimetric analysis in a nitrogen atmosphere applying global (isoconversional methods) and multiple reactions model. The experiments were conducted using a particle diameter of 0.13 mm and three heating rates (2.5, 5.0 and 10 °C/min). Thermal decomposition stages were outlined according to each reaction model. The differential (Friedman), integral (Ozawa-Flynn-Wall/modified Coats Redfern) and advanced (Vyazovkin) methods were used for an initial guess of activation energies (190.83–272.07 kJ/mol, 0.05 < α < 0.85). The kinetic triplets of independent parallel and consecutive reactions schemes were obtained considering three first-order reactions, activation energies of 39.89–168.42 kJ/mol and 39.99–152.65 kJ/mol, and pre-exponential factor logarithms of −0.41–11.84 1/s and −0.41–10.46 1/s, respectively, as well as volatilization fractions of 0.22–0.43 for IPRS and stoichiometric constants of 0.01–1.00 for CRS. Finally, the theoretical conversions and conversion rates were akin to experimental data, providing average deviations <5.0% between 150 and 900 °C.

A Thermic Effect on Degradation Kinetics of Sugar Cane Bagasse Polypropylene Composites

In this study, thermal degradation mechanisms and the kinetics of PP (Polypropylene) composites containing alkali and saline treated SC (Sugar cane bagasse) have been evaluated using a non-isothermal thermogravimetric analysis under consistent nitrogen atmosphere. The study indicates dynamics of kinetics that need to be considered should the composites be applied in high temperature applications. NaOH treated composites revealed a reduced fiber size compared to the other composites. The presence of SC generally reduced the functional group intensities of FTIR peaks, however some peaks re-emerged after the treatments. The composites indicated higher thermal stability and char content than the pristine polymer. In fact, NaOH treated composite is more thermally stable, while the saline is the least stable of the rest. Well known reliable degradation kinetics methods were employed in order to unpack thermal degradation behavior and possible metaphors. Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) thermal degradation kinetic models are in agreement that the presence of both SC and those in the PP matrix that have been treated lead to increased activation energy values with the competing reactions in the degradation process. Nonetheless, the linear relation is not absolutely perfect and the competing reactions seem complex at lower temperatures as there are overlying inconsistencies in activation energies. Interestingly, bagasse indicated some effect on the mechanism that included the hindering of free radicals that emanated from the first cleavage of PP.

Understanding pyrolysis mechanisms of corn and cotton stalks via kinetics and thermodynamics

The kinetics and thermodynamics of biomass pyrolysis are crucial in its design, optimization and industrial application. The physicochemical characterization, kinetic and thermodynamic analyses of corn and cotton stalks pyrolysis are performed. Nonisothermal thermogravimetric analysis (TGA) with four heating rates (4, 8, 16 and 32 K min−1) is employed to experimentally investigate their pyrolysis kinetic behaviors. The effective activation energy values obtained by isoconversional kinetic analysis vary significantly with the reacted fraction and the average values are 206.2 and 207.4 kJ mol−1 for the pyrolysis of corn and cotton stalks, respectively. The changes in Gibbs free energy, enthalpy and entropy for them are evaluated and the results indicate that corn and cotton stalks pyrolysis is nonspontaneous processes and requires external energy to be thermally decomposed and that their endothermicity and reactivity increase as their pyrolysis processes proceed. The results can be helpful in better understanding the reaction mechanisms and extending the application of corn and cotton stalk pyrolysis.

Thermal Kinetics of Monocationic and Dicationic Pyrrolidinium-Based Ionic Liquids.

This work presents an in-depth kinetic thermal degradation comparison between traditional monocationic and the newly developed dicationic ionic liquid (IL), both coupled with a bromide (Br−) anion by using non-isothermal thermogravimetric analysis. Thermal analyses of 1-butyl-1-methylpyrrolidinium bromide [C4MPyr][Br] and 1,4-bis(1-methylpyrrolidinium-1-yl)butane dibromide [BisC4MPyr][Br2] were conducted at a temperature range of 50–650 °C and subjected to various heating rates, which are 5, 10, 15, 20 and 25 °C/min. Thermogravimetric analysis revealed that dicationic IL, [BisC4MPyr][Br2] is less thermally stable compared to monocationic [C4MPyr][Br]. A detailed analysis of kinetic parameters, which are the activation energy (Ea) and pre-exponential factor (log A), was calculated by using Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO) and Starink. This study revealed that the average Ea and log A of [BisC4MPyr][Br2] are lower than [C4MPyr][Br], which may be contributed to by its low thermal stability. Conclusively, it proved that the Ea and log A of ILs are strongly related to the thermal stability of ILs.

Thermodynamics and Kinetic Modeling of the ZnSO4·H2O Thermal Decomposition in the Presence of a Pd/Al2O3 Catalyst

The sulfur–iodine thermochemical water-splitting cycle is a promising route proposed for hydrogen production. The decomposition temperature remains a challenge in the process. Catalysts, such as Pd supported on Al2O3, are being considered to decrease reaction temperatures. However, little is known regarding the kinetic behavior of such systems. In this work, zinc sulfate thermal decomposition was studied through non-isothermal thermogravimetric analysis to understand the effect of a catalyst within the sulfur–iodine reaction system context. The findings of this analysis were also related to a thermodynamic assessment. It was observed that the presence of Pd/Al2O3 modified the reaction mechanism, possibly with some intermediate reactions that were suppressed or remarkably accelerated. The proposed model suggests that zinc sulfate transformation occurred in two sequential stages without the Pd-based material. Activation energy values of 238 and 368 kJ·mol−1 were calculated. In the presence of Pd/Al2O3, an activation energy value of 204 kJ·mol−1 was calculated, which is lower than observed previously.

Synthesis and Study of Thermal Degradation Process of 2,4-Dihydroxyacetophenone-Guanidine-Formaldehyde Copolymer

The resin DAPGF-III, in a molar ratio of 3: 1: 5 was made by heating in the presence of 2M hydrochloric acid for 5h by polycondensation of Guanidine hydrochloride and 2,4-Dihydroxyacetophenone in the presence of formaldehyde. The preliminary structure of the copolymer was evaluated by spectral methods such as elemental analysis, 1H-NMR, FTIR and UV-Visible techniques. The molecular weight of the copolymer was determined by non-aqueous conductivity titration performed by using alcoholic KOH. TGA analysis of the synthesized copolymer is carried out by non-isothermal thermogravimetric analysis, where the sample is exposed to continuous temperature rise at a heating rate of 20°C / min in an air atmosphere and is used to study the rate, decomposition and thermal stability analysis of newly synthesized copolymer at which it was executed. Thermal parameters such as apparent entropy (ΔS), frequency factor (A), change in free energy (ΔG), and rate of reaction were determined according to the methods of Freeman Carroll (FC) and Sharp Wentworth (SW). The activation energy measured by the FC method was confirmed by the SW method.

Determination of the Thermodynamic Parameters of the Pyrolysis Process of Post-Consumption Thermoplastics by Non-Isothermal Thermogravimetric Analysis.

Currently, the pyrolysis process is an important technology for the final treatment of plastic waste worldwide. For this reason, knowing in detail the chemical process and the thermodynamics that accompany cracking reactions is of utmost importance. The present study aims to determine the thermodynamic parameters of the degradation process of conventional thermoplastics (polystyrene (PS), polyethylene terephthalate (PET), high-density polyethylene (HDPE), polypropylene (PP) and polyvinyl chloride (PVC)) from the study of their chemical kinetics by thermogravimetric analysis (TG). Non-isothermal thermogravimetry was performed at three heating rates from room temperature to 550 °C with an inert nitrogen atmosphere with a flow of 20 mL min−1. Once the TG data is obtained, an analysis is carried out with the isoconversional models of Friedman (FR), Kissinger–Akahira–Sunose (KAS), and Flynn–Wall–Ozawa (FWO) in order to determine the one that best fits the experimental data, and with this, the calculation of the activation energy and the pre-exponential factor is performed. The validation of the model was carried out using the correlation factor, determining that the KAS model is the one that best adjusts for the post-consumer thermoplastic degradation process at the three heating rates. With the use of the kinetic parameters, the variation of the Gibbs free energy is determined in each of the cases, where it is necessary that for structures containing aromatic groups a lower energy is presented, which implies a relative ease of degradation compared to the linear structures.

Investigation of the synergistic effect and kinetic behavior of anthracite and biochar during co-combustion process in pure oxygen atmosphere

The non-isothermal thermogravimetric analysis was conducted to evaluate the combustion characteristics and kinetic behavior of Anthracite (AN), Robinia pseudoacacia char (RPC) and their blends. The physical and chemical characteristics of AN and RPC were also studied systematically to explore the contribution to fuel combustion performance. And the synergistic effects of RPC and AN were quantitatively discussed by using an interaction factor. The investigation has shown that, compared to AN, RPC has better combustion reactivity due to the lower ordering degree and the higher defecting degree and more developed porous structures. The combustion reactivity of AN can be enhanced after adding RPC, and the combustion reactivity gradually increased with increasing heating rate. The synergistic effect can be obvious observed during co-combustion process of AN and RPC. When the mass ratio of RPC at 20 ∼ 80 wt % and the heating rate at less than or equal to 15 °C/min, interaction factors (IF) were greater than 1.15, which has a positive burning effect. The apparent activation energies and pre-exponential factors were determined by using the methods of Coats-Redfern (CR), Madhusudanan-Krishan-Ninan (MKN), Zavkovic (ZK) and Flynn-Wall-Ozawa (FWO). The accuracy of the kinetic results and calculated methods were evaluated by using kinetic compensation effect (KCE) from iso-conversion and iso-heating rate methods. As a result, the applicability of the four calculation methods during co-combustion process of AN and RPC is FWO = ZK > MKN > CR. The mean of apparent activation energies of AN and RPC from FWO/ZK methods were 149.76 kJ/mol and 97.13 kJ/mol, respectively.

Pyrolysis and combustion kinetics of thermally treated globe artichoke leaves

There are no data in the literature on the energy valorization of globe artichoke (GA) leaves. Thus, an extensive lab-scale experimental torrefaction, carbonization, and coking study was performed. Operative temperatures of 200 °C–1000 °C with 30–120 min residence times were considered. Nonisothermal thermogravimetric analysis was performed at 10, 20, and 40 °C/min heating rates. Pyrolysis and combustion kinetics of raw and thermally treated samples using the Ozawa–Flynn–Wall (OFW) isoconversional method were investigated. All samples exhibited three-stage thermal decomposition behavior: first, moisture and light volatiles evolution common under air and nitrogen; second, carbohydrate fraction decomposition under nitrogen and volatiles combustion; third, lignin decomposition under nitrogen and char combustion. Average activation energy ranges are 54–223 kJ/mol and 223–503 kJ/mol for combustion and pyrolysis, respectively. Some irregular trends appeared when carbonization exceeded 500 °C due to the occurrence of secondary reactions between residual char and evolved gas and the decomposition of some ash components at temperatures reaching 1000 °C. Negative temperature kinetic coefficient appeared at 800–1000 °C as the temperature approached ash softening/fusing temperatures. SEM images indicated amorphous nature and increased porosity from 600 °C, which explains the pyrolysis and oxidation behavior observed in biochar samples produced over this range. Samples pyrolyzed for 30 min showed better elemental and energy results compared to longer times.

An investigation into the pyrolysis and oxidation of bio-oil from sugarcane bagasse: Kinetics and evolved gases using TGA-FTIR

Bio-oil produced from the pyrolysis of sugarcane bagasse has the potential to be used as a sustainable and renewable energy source. In the present study, a non-isothermal thermo-gravimetric analysis (TGA) of the pyrolysis (in N2 atmosphere) and combustion (in the air) of bio-oil from sugarcane bagasse was investigated at three heating rates: 5, 10, and 20 °C/min. The sample was heated from room temperature up to 900 °C and the evolved gases in the TG furnace were carried to a Fourier transform infrared (FTIR) cell where the composition of the gases and the functional groups present there were analyzed. A global kinetic analysis was performed to obtain the Arrhenius kinetic parameters for the pyrolysis and oxidation of the bio-oil using the distributed activation energy model. Three distinct stages, namely; low-temperature oxidation (LTO), fuel decomposition (FD), and high-temperature oxidation (HTO) were observed during the oxidation of bio-oil. The initial devolatilization of the oxygenated compounds observed during pyrolysis was similar to the LTO stage observed during combustion. The intensity of the CO2 FTIR peaks seen during the bio-oil combustion was 10 times the intensity of the CO2 peaks attained during pyrolysis. The TGA-FTIR analysis of the sugarcane bagasse bio-oil sheds new light on its thermal degradation/oxidation characteristics.

Lifetime predictions of non-ionic and ionic biopolymers: kinetic studies by non-isothermal thermogravimetric analysis

In this paper, films based on sustainable polymers with variable charge have been investigated by non-isothermal thermogravimetry in order to predict their lifetime, which is a key parameter for their potential use in numerous technological and biomedical applications. Specifically, chitosan has been selected as positively charged biopolymer, while alginate has been chosen as negatively charged biopolymer. Among non-ionic polymers, methylcellulose has been investigated. Thermogravimetric measurements at variable heating rates (5, 10, 15 and 20 °C min−1) have been performed for all the polymers to study their degradation kinetics by using isoconversional procedures combined with ‘Master plot’ analyses. Both integral (KAS and Starink methods) and differential (Friedman method) isoconversional procedures have shown that chitosan possesses the highest energetic barrier to decomposition. Based on the Master plot analysis, the decomposition of ionic polymers can be described by the R2 kinetic model (contracted cylindrical geometry), while the degradation of methylcellulose reflects the D2 mechanism (two-dimensional diffusion). The determination of both the decomposition mechanism and the kinetic parameters (activation energy and pre-exponential factor) has been used to determine the decay time functions of the several biopolymers. The obtained insights can be helpful for the development of durable films based on sustainable polymers with variable electrostatic characteristics.Graphical abstract

Analysis of mixed cattle manure: Kinetics and thermodynamic comparison of pyrolysis and combustion processes

The study investigates the non-isothermal thermogravimetric analysis of cattle manure at varied heating rates to compare the kinetic and thermodynamic behaviors of cattle manure in N2 and air atmospheres. The Thermogravimetric (TG) curves indicated that the decomposition of the manure can be divided into three different regions. Exclusive of stage I (dehydration), the activation energy (Ea) values of stage II (devolatilization) for all model-free methods varied between 144 - 270 and 32–227 kJ/mol in pyrolysis and combustion respectively. While in stage III, Ea values varied in ranges of 49–336 kJ/mol and 71–136 kJ/mol for pyrolysis (carbonation) and combustion (char burning), respectively. The overall average Ea for the pyrolysis (≈146 kJ/mol) is higher than the combustion process (≈127 kJ/mol). The variation in the values of frequency factor “A” also indicated the complexity of both processes. Pyrolysis followed overall 2-Diffusion (D2) reaction models, while combustion followed 3-Power law (P3) and reaction Order-1 (O1) in stage II and III respectively. The thermodynamic study was also conducted to evaluate the important parameters, change in Enthalpy change (ΔH), Gibbs free energy (ΔG), and Entropy (ΔS).

Thermal Stability and Decomposition Kinetics of 1-Alkyl-2,3-Dimethylimidazolium Nitrate Ionic Liquids: TGA and DFT Study.

The thermal stability and decomposition kinetics analysis of 1-alkyl-2,3-dimethylimidazole nitrate ionic liquids with different alkyl chains (ethyl, butyl, hexyl, octyl and decyl) were investigated by using isothermal and nonisothermal thermogravimetric analysis combined with thermoanalytical kinetics calculations (Kissinger, Friedman and Flynn-Wall-Ozawa) and density functional theory (DFT) calculations. Isothermal experiments were performed in a nitrogen atmosphere at 240, 250, 260 and 270 °C. In addition, the nonisothermal experiments were carried out in nitrogen and air atmospheres from 30 to 600 °C with heating rates of 5, 10, 15, 20 and 25 °C/min. The results of two heating modes, three activation energy calculations and density functional theory calculations consistently showed that the thermal stability of 1-alkyl-2,3-dimethylimidazolium nitrate ionic liquids decreases with the increasing length of the alkyl chain of the substituent on the cation, and then the thermal hazard increases. This study could provide some guidance for the safety design and use of imidazolium nitrate ionic liquids for engineering.

A comprehensive insight into devolatilization thermo-kinetics for an agricultural residue: Towards a cleaner and sustainable energy

Stubble burning is a widely implemented agricultural malpractice that poses a serious environmental threat along with air pollution and global warming as the major consequences. This study aims to investigate an alternate conversion of the rice stubble feedstock to the thermochemical route by detailed kinetic and thermodynamic analysis. Initial assessment about the feedstock was made through physical and chemical characterization which indicated its energy potential with the high carbon content 47.61% along with 14.43 MJ kg−1 heating value. Subsequently, devolatilization kinetics was studied through a series of non-isothermal thermogravimetric analysis which showed the dependence on the plant cell wall component with overall conversion in active pyrolysis zone was 50.30%. Reaction pathways suggested a chain initiation and propagation mechanism associated with each constituent macromolecule. Friedman and simplified distributed activation energy methods were employed and the average apparent activation energy was estimated as 261.47 and 251.08 kJ mol−1 with corresponding pre-exponential factor as 7.85 × 1036 and 1.74 × 1021 s−1 respectively. Kinetic compensation effect was also observed within these parameters with its constants as 0.070 mol kJ−1 s−1 and 22.24 s−1. Master plots indicated that nuclei growth starts in the initial part of the reaction which exponentially increases to random nucleation and finally diffusion effects are dominant at the end of devolatilization. The empirical model mathematically showed an excellent correlation with the experimental data with a fitting percentage of 69.34%. Finally, thermodynamic parameters indicated an endothermic, non-spontaneous and high degree of randomness in the reaction. Altogether, the thermo-kinetic study suggested the energy feasibility of the overall process.

Thermogravimetric characteristics and kinetics of herb residues catalyzed by potassium carbonate

Thermal conversion technology of Chinese herb residues (CHR) becomes one of the most promising technologies in the large-scale clean utilization of herb residues due to its short process and high efficiency. In this study, non-isothermal thermogravimetric analysis of CHR samples without and with K2CO3 (5%K- 9%K) was implemented at 300−1125 K and the heating rates of 10−40 K/min. A model-free Starink method was applied to evaluate the thermal decomposition behavior and apparent activation energy (Eα) values. The estimated average activation energy decreases from 206.3 kJ/mol of raw CHR to 143.8–160.6 kJ/mol of CHR with K2CO3. K2CO3 catalysts significantly promote the catalytic pyrolysis reaction of the hemicellulose and cellulose of CHR samples at the main devolatilization stage from 425 K to 700 K with over 82.02 % mass loss. The pyrolysis temperature of the raw CHR is higher than traditional lignocellulosic biomass without decoction. By using the generalized master-plots method, it was found that the CHR pyrolysis could be described by a modified Dn-Jader model, but values of n and A tend to change measurably with heating rates for the CHR samples with catalysts due to the remarkably catalytic effect of K2CO3.

Non-isothermal thermogravimetry as an accelerated tool for the shelf-life prediction of paracetamol formulations

In this work, non-isothermal thermogravimetric studies have been carried out on several paracetamol formulations with the aim to predict their shelf-lives under variable storage conditions. Specifically, paracetamol tablets of different brands have been investigated allowing to estimate their pharmaceutical quality by considering the specific drug stability. The proposed protocol is based on the kinetic study of thermogravimetric data by the combination of isoconversional procedures (Friedman and Kissinger-Akahira-Sunose (KAS) methods) and “Master plot” analysis. Accordingly, the kinetics of the paracetamol degradation is totally explored in terms of activation energy, pre-exponential factor and reaction mechanism of the drug decomposition. The obtained insights drive to simulate the decay time functions of paracetamol amount for the several pharmaceutical formulations. Interestingly, these simulations can be easily adapted to variable isothermal conditions providing the shelf-lives of the paracetamol tablets at different temperatures. The kinetic characteristics of the paracetamol degradation as well as the corresponding shelf-life values evidenced that the expiration date of the pharmaceutical products are significantly affected by the composition of the excipients. In conclusion, this work demonstrates that non-isothermal thermogravimetric analysis can be used as efficient and sensitive tool for the prediction of the shelf-lives of paracetamol formulations.

Physicochemical characterization and pyrolysis kinetic analysis of Moutai-flavored dried distiller’s grains towards its thermochemical conversion for potential applications

The physicochemical properties of dried distiller’s grains (DDGs) were measured and the pyrolysis kinetics analysis was experimentally investigated by the non-isothermal thermogravimetric analysis (TGA) at four heating rates of 10, 20, 30 and 40 K min−1. The results of proximate and elemental analysis showed that DDGs contained relatively high contents of volatile organic components (VOCs, 89.4 wt.%) and carbon (47.0 wt.%), and a higher value of heat content (20.4 MJ kg−1), compared with some other typical agricultural residues feedstocks. The pyrolysis kinetics of DDGs sample were analyzed using the Friedman isoconversional method. The obtained effective activation energies vary with the degree of conversion: 151.2-176.3 kJ mol−1 (α: 0.05−0.10, T: 383–506 K), 176.3-206.4 kJ mol−1 (α: 0.10−0.60, T: 506–653 K), 206.4-320.5 kJ mol−1 (α: 0.60−0.95, T: > 653 K), which correspond to the thermal decomposition of hemicellulose, cellulose and part of lignin, and remaining lignin. And the decomposition temperatures of DDGs components shift to lower temperature, compared with those of typical lignocellulosic biomass, which is caused by the presence of high activity degraded enzymes during brewing process. The physicochemical properties and pyrolysis kinetic results have shown that DDGs has great thermochemical conversion potential for bioenergy. We anticipate these findings will contribute to the industrial application of DDGs pyrolysis to produce biofuel or high-value chemicals and materials.

COMPARATIVE STUDY OF VARIOUS APPROACHES IN ANALYSIS OF TGA DATA OF DEVOLATILIZATION OF HIGH ASH INDIAN COAL

ABSTRACT Thermo gravimetric analysis (TGA) has been regularly employed for the estimation of devolatilization rates and measurement of char reactivity of coal. In general, TGA studies may be classified as isothermal or non-isothermal. In the first case temperature of the sample is kept constant whereas in case of latter the rate of temperature increase is kept constant. The current research work deals with the non-isothermal TGA study and kinetic analysis of three typical pulverized high-ash Indian coal samples each weighing around 15 mg. TGA experiments were carried out for four different heating rates (5, 10, 15, 20 K/min) and weight loss curves have been obtained. Out of the various methods proposed to analyze the TGA data, the following methods have been evaluated i) Friedman method, ii) Flynn-Wall-Ozawa method (FWO), iii) Kissinger method, iv) Kissinger-Akahira-Sunose (KAS) method, and v) Miura-Maki method. Activation energy and frequency factor to be used in the Arrhenius equation is calculated using all the above methods. The most accurate method for analyzing TGA data for high-ash Indian coal is FWO as per studies carried out in this research work.