scholarly journals Kinetic modelling for thermal decomposition of agricultural residues at different heating rates

2021 ◽  
Author(s):  
Hemant Kumar Balsora ◽  
S. Kartik ◽  
Thomas J. Rainey ◽  
Ali Abbas ◽  
Jyeshtharaj Bhalchandra Joshi ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Kinetic Modelling ◽  
Agricultural Residues ◽  
Heating Rates

Non-Isothermal Decomposition Kinetic of Polypropylene/Hydrotalcite Composite

2019 ◽  
Vol 19 (11) ◽  
pp. 7493-7501 ◽  
Author(s):  
Sheng Xu ◽  
Min Zhang ◽  
Siyu Li ◽  
Moyu Yi ◽  
Shigen Shen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Decomposition ◽  
Nitrogen Atmosphere ◽  
Heating Rates ◽  
Decomposition Reactions ◽  
Kinetic And Thermodynamic Parameters ◽  
Málek Method ◽  
Boundary Reaction ◽  
Phase Boundary Reaction ◽  
Thermal Stability Of

P3O5-10 pillared Mg/Al hydrotalcite (HTs) as a functional fire-retarding filler was successfully prepared by impregnation-reconstruction, where the HTs was used to prepare polypropylene (PP) and HTs composite (PP/HTs). Thermal decomposition was crucial for correctly identifying the thermal behavior for the PP/HTs, and studied using thermogravimetry (TG) at different heating rates. Based on single TG curves and Málek method, as well as 41 mechanism functions, the thermal decompositions of the PP/HTs composite and PP in nitrogen atmosphere were studied under non-isothermal conditions. The mechanism functions of the thermal decomposition reactions for the PP/HTs composite and PP were separately “chemical reaction F3” and “phase boundary reaction R2,” which were also in good agreement with corresponding experimental data. It was found that the addition of the HTs increased the apparent activation energy Ea of the PP/HTs comparing to the PP, which improved the thermal stability of the polypropylene. A difference in the set of kinetic and thermodynamic parameters was also observed between the PP/HTs and PP, particularly with respect to lower ΔS≠ value assigned to higher thermal stability of the PP/HTs composite.

Global Reaction Model to Describe the Kinetics of Catalytic Pyrolysis of Coffee Grounds Waste

2017 ◽  
Vol 899 ◽  
pp. 173-178 ◽  
Author(s):  
Ronydes Batista Jr. ◽  
Bruna Sene Alves Araújo ◽  
Pedro Ivo Brandão e Melo Franco ◽  
Beatriz Cristina Silvério ◽  
Sandra Cristina Danta ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Large Scale ◽  
Catalytic Pyrolysis ◽  
Petroleum Products ◽  
Reaction Model ◽  
Heating Rates ◽  
Coffee Grounds ◽  
One Step ◽  
Global Reaction ◽  
The One

In view of the constant search for new sources of renewable energy, the particulate agro-industrial waste reuse emerges as an advantageous alternative. However, despite the advantages of using the biomass as an energy source, there is still strong resistance as the large-scale replacement of petroleum products due to the lack of scientifically proven efficient conversion technologies. In this context, the pyrolysis is presented as one of the most widely used thermal decomposition processes. The knowledge of aspects of chemical kinetics, thermodynamics these will, heat and mass transfer, are so important, since influence the quality of the product. This paper presents a kinetic study of slow pyrolysis of coffee grounds waste from dynamic thermogravimetric experiments (TG), using different powder catalysts. The primary thermal decomposition was described by the one-step reaction model, which considers a single global reaction. The kinetic parameters were estimated using nonlinear regression and the differential evolution method. The coffee ground waste was dried at 105°C for 24 hours. The sample in nature was analyzed at different heating rates, being 10, 15, 20, 30 and 50 K/min. In the catalytic pyrolysis, about 5% (w/w) of catalyst were added to the sample, at a heating rate of 30 K/min. The results show that the one-step model does not accurately represent the data of weight loss (TG) and its derivative (DTG), but can do an estimative of the activation energy reaction, and can show the differences caused by the catalysts. Although no one can say anything about the products formed with the addition of the catalyst, it would be necessary to micro-pyrolysis analysis, we can say the influence of the catalyst in the samples, based on the data obtained in thermogravimetric tests.

scholarly journals Synthesis and characterization of a new conjugated polymer containing bithiazole group and its thermal decomposition kinetics

2020 ◽  
Vol 39 (2) ◽  
pp. 227
Author(s):  
Adnan Kurt ◽  
Hacer Andan ◽  
Murat Koca
Keyword(s):  
Thermal Decomposition ◽  
Heating Rate ◽  
Conjugated Polymer ◽  
Three Dimensional ◽  
Heating Rates ◽  
Diffusion Type ◽  
Optimum Heating ◽  
Rate Loss ◽  
Kinetics Of

A new conjugated polymer containing a bithiazole group is prepared by the polycondensation of 2,2'-diamino-4,4'-bithiazole and terephthaldialdehyde in the presence of glacial acetic acid. The kinetics of thermal degradation of the new polymer are investigated by thermogravimetric analysis at different heating rates. The temperature corresponding to the maximum rate loss shifts to higher temperatures with increasing heating rate. The thermal decomposition activation energies of the conjugated polymer in a conversion range of 3–15 % are 288.4 and 281.1 kJ/mol by the Flynn–Wall–Ozawa and Kissinger methods, respectively. The Horowitz–Metzger method shows that the thermodegradation mechanism of the conjugated polymer proceeds over a three-dimensional diffusion type deceleration D3 mechanism. The optimum heating rate is 20 ºC/min.

Thermal Decomposition Kinetics of Flame Retardant Polybutylene Terephthalate Matrix Composites

2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Flame Retardant ◽  
Mass Loss Rate ◽  
Decomposition Reaction ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Heating Rates ◽  
Polybutylene Terephthalate ◽  
Kinetics Of

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).

scholarly journals Hydrothermal Synthesis of Hematite Nanoparticles Decorated on Carbon Mesospheres and Their Synergetic Action on the Thermal Decomposition of Nitrocellulose

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 968 ◽  
Author(s):  
Abdenacer Benhammada ◽  
Djalal Trache ◽  
Mohamed Kesraoui ◽  
Salim Chelouche
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Analytical Techniques ◽  
Decomposition Reaction ◽  
Decomposition Temperature ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Nano Catalyst ◽  
Average Size ◽  
A Minor

In this study, carbon mesospheres (CMS) and iron oxide nanoparticles decorated on carbon mesospheres (Fe2O3-CMS) were effectively synthesized by a direct and simple hydrothermal approach. α-Fe2O3 nanoparticles have been successfully dispersed in situ on a CMS surface. The nanoparticles obtained have been characterized by employing different analytical techniques encompassing Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The produced carbon mesospheres, mostly spherical in shape, exhibited an average size of 334.5 nm, whereas that of Fe2O3 supported on CMS is at around 80 nm. The catalytic effect of the nanocatalyst on the thermal behavior of cellulose nitrate (NC) was investigated by utilizing differential scanning calorimetry (DSC). The determination of kinetic parameters has been carried out using four isoconversional kinetic methods based on DSC data obtained at various heating rates. It is demonstrated that Fe2O3-CMS have a minor influence on the decomposition temperature of NC, while a noticeable diminution of the activation energy is acquired. In contrast, pure CMS have a slight stabilizing effect with an increase of apparent activation energy. Furthermore, the decomposition reaction mechanism of NC is affected by the introduction of the nano-catalyst. Lastly, we can infer that Fe2O3-CMS may be securely employed as an effective catalyst for the thermal decomposition of NC.

Studies on the Thermal Decomposition Kinetic of an Nitrate Ester

2012 ◽  
Vol 182-183 ◽  
pp. 1575-1580 ◽  
Author(s):  
Juan Wang ◽  
Da Bin Liu ◽  
Xin Li Zhou
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Decomposition Mechanism ◽  
Thermal Decomposition Mechanism ◽  
Decomposition Kinetic ◽  
Heating Rates ◽  
Exponential Factor ◽  
Nitrate Ester ◽  
Dynamic Function ◽  
Thermal Decomposition Kinetic

The certain nitrate ester explosive has been tested by TG at the heating rates of 10, 15, 20, 25K•min-1. Basing on the TG experiment results the thermal decomposition activation energy has been calculated by the methods of Ozawa, KAS and iteration. And the thermal decomposition mechanism function of the explosive with 38 kinds of dynamic function was deduced by the method of integration. The results show that the thermal decomposition mechanism of the nitrate ester is chemical reaction mechanism. The thermal decomposition kinetic parameters such as average activation energy Ea and pre-exponential factor A are 133.23×103 J•mol-1 and 3.191×107 s-1 respectively.

Measurement of Thermal Decomposition Temperature and Rate of Sodium Hydride

2020 ◽  
Author(s):  
Munemichi Kawaguchi
Keyword(s):  
Thermal Decomposition ◽  
Mass Loss ◽  
Heating Temperature ◽  
Fission Products ◽  
Sodium Hydride ◽  
Decomposition Temperature ◽  
Cold Trap ◽  
Thermal Decomposition Temperature ◽  
Heating Rates ◽  
Fundamental Research

Abstract In decommissioning sodium-cooled fast reactors, the operators can be exposed to radiation during dismantling of cold trap equipment (C/T). The C/T is higher dose equipment because the C/T trapped tritium of fission products during the operation to purify the sodium coolant. In this study, thermal decomposition temperature and rate of sodium hydride (NaH) were measured as a fundamental research for development of “thermolysis” process prior to the dismantling. We measured the thermal decomposition temperature and rate using NaH powder (95.3%, Sigma-Aldrich) in alumina pan with ThermoGravimetry-Differential Thermal Analysis (TG-DTA) instrument (STA2500 Regulus, NETZSCH Japan). The heating rates of TG-DTA were set to β = 2.0, 5.0, 10.0 and 20.0 K/min. The DTA showed endothermic reaction and the TG showed two-steps mass-loss over 580K. This first-step mass-loss was consistent with change of chemical composition of the NaH with heating (NaH → Na+1/2H2). The thermal decomposition temperature and rate were obtained from the onset temperature of the mass-loss and the simplified Kissinger plots, respectively. Furthermore, we set to the thermal decomposition temperature of around 590K, and the mass-loss rates were measured. As a result, over 590K, the thermal decomposition occurred actively, and showed good agreement with the estimation curves obtained by the simplified Kissinger plots. The thermal decomposition rate strongly depended on the heating temperature.

scholarly journals Nonisothermal Thermogravimetric Analysis of Thai Lignite with High CaO Content

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pakamon Pintana ◽  
Nakorn Tippayawong
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermogravimetric Analysis ◽  
Combustion Kinetics ◽  
Heating Rates ◽  
Thermogravimetric Method ◽  
Degradation Behaviors ◽  
Fwo Method ◽  
Free Cao ◽  
Kinetics Of

Thermal behaviors and combustion kinetics of Thai lignite with different SO3-free CaO contents were investigated. Nonisothermal thermogravimetric method was carried out under oxygen environment at heating rates of 10, 30, and 50°C min−1from ambient up to 1300°C. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods were adopted to estimate the apparent activation energy (E) for the thermal decomposition of these coals. Different thermal degradation behaviors were observed in lignites with low (14%) and high (42%) CaO content. Activation energy of the lignite combustion was found to vary with the conversion fraction. In comparison with the KAS method, higherEvalues were obtained by the FWO method for all conversions considered. High CaO lignite was observed to have higher activation energy than the low CaO coal.

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