Flynn Wall Ozawa Method Research Articles

Catalytic Degradation of Polylactic Acid over Al2O3@SiO2 Core–Shell Catalysts

Al2O3@SiO2 core–shell catalysts were synthesized by sol–gel method. The core size’control was provided by using of polyethylene glycol (PEG) and glycerol. The shell thickness was optimized by using the different amount of tetraethylorthosilicate (TEOS). The formation of core and shell structures in catalysts was seen in high resolution transmission electron microscopy (HRTEM) images. In some catalysts, the use of PEG caused to formation of a more monodisperse core structure. The particle size of catalysts was observed in the range of 8–12 nm. The BET (Brunauer–Emmett–Teller) surface area and total pore volume of catalysts ranged 440–1014 m2/g and 1.28–2.57 cm3/g, respectively. In addition, pore diameter reached up to 25 nm. The use of PEG and glycerol improved textural properties. While BET surface area and total pore volume values decreased by the increase of TEOS amount, shell thickness increased a little. Fourier transform infrared (FTIR) spectrums of the pyridine adsorbed catalysts revealed the presence of Lewis and Bronsted acid sites in the catalysts. The catalysts were tested in the degradation of polylactic acid (PLA) by using thermogravimetric analysis (TGA) technique. TGA results showed the degradation temperature of PLA decreased from 353 to 321 °C in the presence of catalysts. Activation energy values were calculated using Flynn–Wall–Ozawa method. The activation energy was reduced from 337 to 199 kJ/mol. Pore structure, particle size and acidity of catalysts significantly affected the degradation performance.

Determination of combustion characteristics and kinetic parameters of Ulva lactuca and its biochar

Utilization of macroalgae, which accumulated in the coastal area and considered as waste by municipals, for biofuel production is a good solution putting forward for both waste management and meeting the renewable energy requirement. This study aims to investigate the use of Ulva lactuca collected from the Marmara Sea coast as a raw material for solid biofuel production. Therefore, in this study, the combustion characteristics of Ulva lactuca and its biochar were investigated by the thermogravimetric method, and kinetic parameters were determined by using Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods. When the obtained thermograms are examined, it was observed that the combustion of raw seaweed occurs in three phases, while the combustion of biochars occurs in two phases. As a result of the calculations, the combustion activation energies of macroalga and its biochar were found to be approximately 261 kJ/mol and 146 kJ/mol, respectively, using the KAS method. It was found that the values calculated using the FWO method were similar to the KAS method. These data show that biochar requires less energy than raw algae during combustion.

Effect of isopropanolysis on the structure variation and pyrolysis behaviors of Wucaiwan lignite

Alkanolysis has become an effective approach for lignite extraction due to high organic oxygen content in lignite. To better understand the effect of isopropanolysis on the chemical structure and thermal degradation process of lignite, Wucaiwan lignite (WL) and isopropanolyed residue (RI) were systematically analyzed using four multiple direct tools, including Fourier transform infrared spectrometer (FTIRS), X-ray photoelectron spectrometer (XRPES), Thermogravimetric analysis (TGA), and Pyrolysis-gas chromatography/mass spectrometry (PGC/MS). Combining with the analysis of FTIRS and XRPES, much oxygen-containing species were extracted from WL during isopropanolysis process (IP), and RI has higher carbon content than WL. Kinetic parameters such as activation energy (Ea) and pre-exponential factor (A) were determined by using two model-free methods of Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO). Average Ea for WL pyrolysis was 235.4 and 235.7 kJ mol−1, respectively, obtained by KAS and FWO methods, were lower than that of RI (354.4 and 351.3 kJ mol−1). Besides, based on the obtained kinetics data, thermodynamic analysis was established to evaluate the pyrolysis complexity of WL and RI. PGC/MS results showed that the main volatile products (VPs) of RI fast pyrolysis (FP) were arenes and alkanes while formation of oxygenated compounds reduced, further confirming the extraction of oxygen-containing species from IP of WL. It is noteworthy that isopropanolysis pretreatment of WL can influence its chemical structure and thermal degradation process.

Investigation of Intumescent Flame Retardant THEIC/APP on the Thermal Behaviors of Coal Based on Thermal Oxidative Kinetics

ABSTRACT In this work, the influences of the intumescent flame retardant (IFR) composed of tri-(2-hydroxyethyl) isocyanurate (THEIC) and ammonium polyphosphate (APP) on the coal were studied in order to effectively prevent and control the coal spontaneous combustion. The effects of IFR on the thermal behaviors of the coal were investigated by Kissinger and Flynn–Wall–Ozawa methods. The results have shown that the mass ratio of THEIC/APP = 1:2 has the best effect on the coal. It has a better carbonization performance and thermal stability at high temperature. The activation energy of the treated coal with 30 wt% IFR was increased up to 283.1 kJ/mol, indicating it is more difficult to be oxidized than that of raw coal (168.4 kJ/mol). At 200°C, the inhibition rate of coal treated by IFR reached approximately 56.5%. From fire extinguishing test, it can be found that an expanded carbonization layer was formed during the combustion for the treated coal with IFR which could effectively limit the transfer of heat, oxygen and combustible volatiles from the heat source to the coal, and prevent the coal from further burning. From this work, it is hoped to provide an efficient method to effectively prevent and extinguish the coal spontaneous combustion.

TG-FTIR study on co-combustion of bituminous coal semicoke and lignite

The combustion behaviors and pollutants emission characteristics during co-combustion of bituminous coal semicoke and lignite were investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG-FTIR). Results showed the addition of lignite could lower the ignition and burnout temperature and also enhance the comprehensive combustion performance of blends. High heating rate could improve the combustion intensity and corresponding combustion characteristic indexes. The activation energy analysis by distributed activation energy model (DAEM) and Ozawa–Flynn–Wall (OFW) methods at lignite blend ratio of 40% indicated its distribution was consistent with the combustion process of blends. An obvious activation energy jump occurred at conversion rate range of 0.4–0.55 due to the poor ignition performance of semicoke. The average activation energy obtained by DAEM and OFW methods was 101.69 kJ mol−1 and 109.12 kJ mol−1, respectively. With the increase of lignite blend ratios, CO and CO2 emission gradually decreased. Meanwhile, NO emission increased, while NO2 and SO2 emission ascended after an initial decline. Semicoke had certain suppression effect on NOx and SO2 emission. The minimum NO2 and SO2 emission was obtained at lignite blend ratio of 20%.

Elucidation of Thermal Degradation Model for Low and High Density Polyethylene by Statistical Parameters

AbstractSolid state decomposition studies of Low and High Density Polyethylene (LDPE and HDPE) have been carried out in the present work. Thermo‐gravimetric analysis (TGA) is utilized to determine the degradation kinetics for pure plastic samples at different heating rates. The distribution of activation energy values and rates estimated using various Iso‐conversional methods have been selected on basis of correlation coefficients. For LDPE, isoconversional method of Friedman and for HDPE Flynn Wall Ozawa methods are used to estimate the distribution of activation energies having their mean values as 256.5 and 257.2 kJ/mol respectively. The inputs from Isoconversional methods are used to determine decomposition behavior with Criado method. Model based studies performed with Criado method identifies the solid‐state degradation follows contracting volume‐sphere (R3) model based on lower statistical parameter values. The identified decomposition model is validated by Coats Redfern method which also results in lower statistical parameter values. This is further validated through a best fit of extent of reaction profile against temperature, substantiating the solid‐state decomposition model followed by given plastic fractions.

Thermal, kinetic and thermodynamic study for co-pyrolysis of pine needles and styrofoam using thermogravimetric analysis

This study investigate the thermal decomposition behavior of pine needles (PN), styrofoam (SF) as well as their mixture at ratio of 1:1 (w/w), determine the kinetic and thermodynamic parameters for co-pyrolysis of PN and SF using thermogravimetric analysis (TGA) data. The co-pyrolysis experiments were performed in an inert environment (N2) at three variable heating rates of 5, 10 and 20 °C/min in TG analyzer from 35 to 850 °C. TGA outcomes represent that the thermal degradation of PN occurred in three stages, while SF degradation took place in a single stage and degradation of their mixture occurred in three stages. Model-free methods such as Ozawa-Flynn-Wall (OFW) and Kissinger-Akahira-Sunose (KAS) were employed to findout the activation energy (Ea) for co-pyrolysis of PN and SF. Moreover, the thermodynamic parameters (changes in enthalpy, Gibbs free energy and entropy) were also determined by OFW method. The pre-exponential factors were also evaluated by model-fitting (Coats-Redfern) method. The average of Ea for co-pyrolysis of PN and SF determined by KAS and OFW methods was 96.44 and 109.73 kJ/mol, respectively. The results of this study suggest that PN and SF mixture has potential to be used as a pyrolysis feedstocks.

Electrical investigation on Eu+3- doped copolymer composite system and conventional kinetic analysis

Poly(maleic anhydride-co-benzyl methacrylate) copolymer was prepared by using free radical polymerization (FRP) method at 70 °C. The structural characterization of the polymer was accomplished FT-IR, 1H and 13C NMR spectroscopic techniques. P(MA-co-BMA)/ EuCl3 composites were prepared rate of 2%, 5% and 10% (wt/wt). The thermal behavior of pure copolymer was investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal decomposition kinetics of poly(MA-co-BMA) carried out from Flynn–Wall–Ozawa method via TG curves for calculated apparent activation energies. According to FWO; the activation energy (Ea) was estimated as; 185.61 kJ/mol. Dielectric and electrical properties of copolymer/composite systems were investigated against frequency (range from 100 Hz to 20 kHz) at room temperature by using an impedance analyzer. The effect of EuCl3 concentration on dielectric constant, dielectric loss factors, ac conductivity, susceptance (B) and impedance (Z) was investigated. A remarkable increase was observed in dielectric and AC electrical properties were observed with the addition of Eu+3 to the polymer matrix. The B and Z parameters of poly(MA-co-BMA) and composites were investigated depending on frequency at room temperature based on the alternating current (AC).

Comparison of chemical reaction kinetic models for corn cob pyrolysis

This study used thermogravimetric analysis to investigate activation energy and pre-exponential factor of corn cob pyrolysis via various model-free methods. For applying kinetics of pyrolysis reaction in commercial simulation tools, a representative single reaction of overall pyrolysis reaction would be preferable in provided toolboxes. However, the kinetic parameters for this single reaction should be suitable to cover all the conversion range. Thus, the kinetic parameters were developed as polynomial regression models. The results showed that verification of using the quadratic regression models derived via Friedman method (Ea=−488.68X2+587.78X+64.104 and ln(A)=−106.58X2+116.71X+17.232) had very close agreement with the experiments in entire range of conversion. These regression models could be widely applied in slow pyrolysis and gasification. However, the constants derived via Ozawa–Flynn–Wall​ method (Ea=248.05 kJ mol−1 and A=3.05x1022 min−1) were simpler for use in some applications which had no effect of pyrolysis at temperature​ below 300 °C or conversion below 50%, like fluidized bed pyrolysis/gasification.

Study of pyrolysis kinetic of green corn husk

In this paper, it was suggested the use of green corn husk, which is a biomass from agro-industry, as an alternative source of energy through its pyrolysis. Green corn husk characterization was done through immediate and elemental analysis of its components: cellulose, hemicelluloses, and lignin. It was also measured its higher calorific value. The pyrolysis study of green corn husk was done by the isoconversion and the Master plots method. Thermogravimetric plots were obtained at heating rates of 5, 10, 15, and 20 °C min−1. The pyrolysis kinetics parameters were studied through the Flynn–Wall–Ozawa (FWO), Kissinger, and Friedman models. The Master plots method was used to determine the pyrolysis reaction order. The results of the reaction energy activation were found to be in the range 105.21–157.46 kJ mol−1 by the FWO method, 150.50 kJ mol−1 by the Kissinger method, and ranged 120.66–163.81 kJ mol−1 by the Friedman method. The Master plots method showed a three-way-transport diffusional kinetics for the biomass de-volatilization process. The higher calorific value found for green corn husk was 16.14 MJ kg−1. The simulation showed correlation between the experimental data and the proposed model for conversion values up to 0.8.

Catalytic effect of lithium titanate oxide doped with praseodymium on thermal decomposition of ammonium nitrate

In this work, lithium titanate oxide (Li4Ti5O12) (LTO) and praseodymium ion doped in lithium titanate oxide (Pr-LTO) were synthesized in a sol–gel simple method, and their catalytic effects on thermal decomposition of ammonium nitrate were reported using thermogravimetric analysis–differential scanning calorimetry (TGA–DSC) techniques. The X-ray powder diffraction, Brunauer–Emmett–Teller surface area measurements, particle size analysis, energy-dispersive X-ray spectroscopy, and scanning electron microscopy techniques were used to identify the structural properties and morphology of LTO and Pr-doped LTO. By doping the praseodymium ion within the LTO spinel structure, the surface area increases (from 204.2 m2 g−1 for LTO semiconductor to 318.9 m2 g−1 for Pr-doped LTO), and the catalytic activity improved. The catalytic effects of LTO and Pr-LTO on the thermal behavior of AN were studied via TG-DSC techniques. The thermal decomposition of pure AN (196–400 °C) shifted to lower temperatures, 154–280 °C, and 131–241 °C, in the presence of LTO and Pr-LTO, respectively. The results showed that the catalytic effects of LTO were improved by praseodymium doping. The Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink, and Tang methods were used to determine activation energies of all AN samples at different conversion values (α). The activation energies of pure AN values were 166 ± 3, 166 ± 2, 166 ± 2, and 162 ± 2 kJ mol−1, while AN/LTO activation energies were 145 ± 2, 144 ± 1, 144 ± 1, and 144 ± 2 kJ mol−1 and finally, those of AN/Pr-LTO were 112 ± 1, 109 ± 2, 110 ± 1, and 110 ± 1 kJ mol−1 using FWO, KAS, Starink, and Tang methods, respectively.

Thermal degradation characteristics, kinetics, thermodynamic, and reaction mechanism analysis of pistachio shell pyrolysis for its bioenergy potential

The research work aims to estimate the bioenergy potential of pistachio shell and study its degradation kinetics which is necessary for the efficient design and optimization of thermochemical processes for bioenergy generation. Initial characterizations (proximate, ultimate, higher heating value, and compositional analysis), kinetic study, and thermodynamic analysis accompanied by reaction mechanism are investigated. Physicochemical characterization results confirmed high volatile matter (~ 79.8 wt%) and high heating value (16.85 MJ/kg) of pistachio shell. Thermogravimetric analysis (TGA) is performed at four different heating rates of 10, 20, 30, and 40 °C/min under nitrogen gas flow rate from ambient temperature to 900 °C. TGA results show the three-stage pyrolysis reaction which involves removal of moisture and light volatiles, degradation of cellulose and hemicellulose, and decomposition of lignin. The result also reveals that maximum degradation occurred in the temperature range of 200–400 °C. For calculating the kinetic (activation energy and pre-exponential factor) and thermodynamic parameters (enthalpy, entropy, and Gibbs free energy), different iso-conversional models, i.e. Flynn-wall-Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), Starink, and Friedman, are employed which gives the average value of activation energy as 168.86, 165.80, 166.29, and 190.10 kJ/mol, respectively and the pre-exponential factor values lie in the range of 107-1021 s−1. The average values of Gibbs free energy calculated for FWO, KAS, Starink, and Friedman methods are 182.09, 182.15, 182.13, and 181.42 kJ/mol, respectively. Criado method and Z plot are showing complex reaction mechanism. The results of kinetics and thermodynamic study reveal pistachio shell is an efficient biomass for bioenergy production.

Lifetime Prediction Methods for Degradable Polymeric Materials-A Short Review.

The determination of the secure working life of polymeric materials is essential for their successful application in the packaging, medicine, engineering and consumer goods industries. An understanding of the chemical and physical changes in the structure of different polymers when exposed to long-term external factors (e.g., heat, ozone, oxygen, UV radiation, light radiation, chemical substances, water vapour) has provided a model for examining their ultimate lifetime by not only stabilization of the polymer, but also accelerating the degradation reactions. This paper presents an overview of the latest accounts on the impact of the most common environmental factors on the degradation processes of polymeric materials, and some examples of shelf life of rubber products are given. Additionally, the methods of lifetime prediction of degradable polymers using accelerated ageing tests and methods for extrapolation of data from induced thermal degradation are described: the Arrhenius model, time–temperature superposition (TTSP), the Williams–Landel–Ferry (WLF) model and 5 isoconversional approaches: Friedman’s, Ozawa–Flynn–Wall (OFW), the OFW method corrected by N. Sbirrazzuoli et al., the Kissinger–Akahira–Sunose (KAS) algorithm, and the advanced isoconversional method by S. Vyazovkin. Examples of applications in recent years are given.

Kinetic Analysis of Durian Rind Pyrolysis Using Model-Free Method

In this study, the thermal degradation behavior and kinetic parameters of durian rind were investigated by using the thermogravimetric analysis technique. The experiments were performed in the temperature range of 313 – 1,073 K with the heating rate of 5, 10, 20 and 40 Kmin−1. Three model-free methods namely Friedman (FR) method, Kissinger-Akahira-Sunose (KAS) method, and Flynn-Wall-Ozawa (FWO) method were used to attain the kinetic parameters. The results show that the thermal degradation of durian rind exhibits 3 stages including dehydration stage (up to 380 K), active pyrolysis stage (380 – 680 K) and passive pyrolysis stage (above 680 K). A maximum rate loss shifts to a higher temperature with an increases in the heating rate. The values of kinetic parameters obtained from FR, KAS and FWO methods are in a good agreement with the experimental results. The average activation energies calculated by FR, KAS and FWO methods are reported at 243.02, 220.38 and 218.33 kJmol−1, respectively. Combining with heating value and chemical structure of durian rind, it can be stated that durian rind can become a useful source of alternative fuels and/or chemical feedstocks.

Effects of Amino Acids on the Crystallization of Calcium Tartrate Tetrahydrate

This work assesses the effects of various amino acids, including serine, alanine, methionine, and proline, on calcium tartrate tetrahydrate (CTT) crystals. The crystallization experiments were performed in batch mode at 25 °C, pH 9 with three amino acid concentrations. The CTT crystals were characterized by XRD, FTIR, SEM, particle size and zeta poten-tial analysis. All of the amino acids used in this study were found to significantly affect the surface electrical charge, size, and morphology of the obtained crystals. In addition, the thermal decomposition of the produced crystals obtained in pure media was examined and the obtained data were used to investigate the decomposition kinetics of the crystals with the help of three different model-free kinetic methods, namely Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink. The average activation energy of the crystals for the first, second, third, and fourth stages using the FWO, KAS, and Starink methods was calculated to be 91.0, 158.0, 249.1, and 224.8 kJ/mol; 89.6, 155.9, 250.7, and 221.1 kJ/mol; 88.6, 156.8, 250.5, and 220.4 kJ/mol, respectively. Thus, the results of this work are useful for selecting CTT mor-phology modifiers and explaining the decomposition kinetics of CTT crystals.

Kinetics of Gasification and Co-gasification of Petcoke and Coal

Co-gasification of petroleum coke with other carbonaceous material is making significant inroads in the quest for efficient utilization of petroleum coke. In the present work, gasification and co-gasification of petroleum coke and low-grade Indian coal was studied by thermogravimetric analysis at three heating rates, 10, 20, 30 °C min−1 under oxygen atmosphere. Physicochemical characterization of petroleum coke revealed that it contains significantly high fixed carbon and has high calorific value with low ash content vis-a-vis coal sample. It was observed that with the increase in heating rate, the ignition and the burn out temperature also increases. Kinetic parameters were calculated by employing commonly used two model-free isoconversional methods, i.e., Kissinger–Akahira–Sunose (KAS) and Flynn–Wall–Ozawa (FWO) based on TGA data. The activation energies of petcoke and blend (petcoke + coal) calculated by KAS and FWO methods were found to be 126.75 and 109.94 kJ mol−1, and 128.3 and 111.85 kJ mol−1, respectively. Activation energy values obtained by both the methods demonstrate that the blend requires lesser energy than gasification of petcoke alone. Gasification of blend was found to follow complex multi-step nature of kinetics. Overall, the findings demonstrate that co-gasification could be a practical approach for energy recovery from the petcoke–coal mixture than gasification of petcoke alone.

Pyrolysis of garlic husk biomass: Physico-chemical characterization, thermodynamic and kinetic analyses

Non-isothermal thermogravimetric experiments pertaining to garlic husk (GH) biomass were carried out at four heating rates, namely, 5, 10, 15 and 20 °C/min. Majority of volatile components of GH biomass were found to thermally degrade in the range of 210–370 °C. Kinetic parameters were calculated by employing isoconversional model-free Kissinger-Akahira-Sunose (KAS), Flynn-Wall-Ozawa (FWO), Starink, and Kissinger methods. Thermodynamic parameters (enthalpy, entropy, and Gibbs free energy) were estimated. Average activation energy for GH pyrolysis from KAS, FWO, and Starink methods was found to be 153.95, 154.91, and 154.32 kJ/mol, respectively. The average ∆H for KAS, FWO, and Starink was found to be 149.39, 150.35, and 149.75 kJ/mol, respectively and the average ∆G was found to be 150.55, 150.49 and 150.51 kJ/mol for the respective methods. The data obtained for GH biomass pyrolysis was found to fit well with second order reaction (R2) model based on z(α) master plot.

Petroleum Coke Combustion in Fixed Fluidized Bed Mode in the Presence of Metal Catalysts.

Petroleum coke is one of the waste products generated in the oil refining industry that can be used as fuel in energetics. However, the low volatile matter content and graphite-like structure of petroleum coke are the reasons for its high ignition temperature and combustion complexity. In this research, petroleum coke combustion and oxidation kinetics in the presence of metal catalysts were investigated. To evaluate the effect of the catalyst on the ignition temperature and the apparent activation energy, a new approach of a “fixed fluidized bed” was proposed. In this mode, petroleum coke particles spaced from each other by inert quartz powder kind of “freeze” in the porous layer. This regime allows us to determine the ignition temperature of petroleum coke particles in the static mode by differential thermography and calculate the activation energy by gas analysis. Organic and inorganic salts of copper, iron, and cerium are used as catalysts for petroleum coke combustion. A series of experiments were carried out in the porous media thermo-effect cell (PMTEC) and on a thermogravimetric (TG) analyzer. The kinetics of the combustion processes was calculated by Kissinger–Akahira–Sunose and Ozawa–Flynn–Wall methods. The results obtained in the “fixed bed” mode showed that the ignition temperature and the average apparent activation energy significantly decreased in the presence of CuCl2 and FeCl3. The results obtained by the new approach were compared with the results of the thermogravimetric analysis.

A Kinetic Analysis of the Thermal Degradation Behaviours of Some Bio-Based Substrates.

In the present paper, we report on a detailed study regarding the thermal degradation behaviours of some bio-sourced substrates. These were previously identified as the base materials in the formulations for fireproofing wood plaques through our investigations. The substrates included: β-cyclodextrin, dextran, potato starch, agar-agar, tamarind kernel powder and chitosan. For deducing the Arrhenius parameters from thermograms obtained through routine thermogravimetric analyses (TGA), we used the standard Flynn–Wall–Ozawa (FWO) method and employed an in-house developed proprietary software. In the former case, five different heating rates were used, whereas in the latter case, the data from one dynamic heating regime were utilized. Given that the FWO method is essentially based on a model-free approach that also makes use of multiple heating rates, it can be considered in the present context as superior to the one that is dependent on a single heating rate. It is also relevant to note here that the values of energy of activation (Ea) obtained in each case should only be considered as apparent values at best. Furthermore, some useful, but limited, correlations were identified between the Ea values and the relevant parameters obtained earlier by us from pyrolysis combustion flow calorimetry (PCFC).

Kinetic Study of Pyrolysis of Ulin Wood Residue using Thermogravimetric Analysis

Biomass as a renewable and sustainable energy source is expected to solve the energy crisis problem. Ulin wood residues as a biomass source could be converted into bioenergy utilizing the pyrolysis process since its primary component is a hydrocarbon. Pyrolysis process has received many interests for bioenergy production from biomass, elevating the importance of the kinetic study of pyrolysis. The kinetic study of pyrolysis is related to the beginning stage behavior of gasification and combustion process. The kinetic mechanism of pyrolysis is analyzed using Thermogravimetry Analysis (TGA), by estimating the mass decomposition at solid-state that shows TG and DTG curve. The TG and DTG curves were analyzed to see the effect of heating rate on decomposition temperature. This experiment was performed by heating 10 mg of Ulin wood sawdust from ambient temperature to 1473 K utilizing 100 mL/min of nitrogen (N2) gas as carrier gas at various heating rate: 5, 10, 20, and 50 K/min. The kinetic parameters were determined by applying the iso-conversional methods, the Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods, and then compared the results with the non iso-conversional method, using Kissinger method. The average value of activation energy calculated using the KAS and FWO methods are 253.5514 and 245.2512 kJ/mol, with the average value of constant coefficient square (R2) of 0.9848 and 0.9859, respectively, whereas the calculated activation energy and R2 using the Kissinger method are 237.4478 kJ/mol and 0.8520, respectively.