Kinetic Analysis of Pyrolysis and Thermo-Oxidative Decomposition of Tennis String Nylon Wastes

Polypropylene (PP) is considered as one of six polymers representative of plastic wastes. This paper attempts to obtain information on PP polymer pyrolysis kinetics with the help of thermogravimetric analysis (TGA). TGA is used to measure the weight of the sample with temperature increases at different heating rates—5, 10, 20, 30, and 40 K min−1—in inert nitrogen. The pyrolytic kinetics have been analyzed by four model-free methods—Friedman (FR), Flynn–Wall–Qzawa (FWO), Kissinger–Akahira–Sunose (KAS) and Starnik (STK)—and by two model-fitting methods—Coats–Redfern (CR) and Criado methods. The values of activation energies of PP polymer pyrolysis at different conversions are in good agreement with the average of (141, 112, 106, 108 kJ mol−1) for FR, FWO, KAS and STK, respectively. Criado methods have been implemented with the CR method to obtain the reaction mechanism model. As per Criado’s method, the most controlling reaction mechanism has been identified as the geometrical contraction models—cylinder model.

Section: Resultsmentioning

confidence: 99%

Kinetics Study of Polypropylene Pyrolysis by Non-Isothermal Thermogravimetric Analysis

Dubdub

2023

“…It should be highlighted here that the temperature-integral function in the right-hand side of Equation (7) has no analytical solution and it might be solved numerically or approximated to different extents. As for the reaction mechanism functions available either in differential f ( a ) or in integral g ( a ), some literature can be referred to for the details [ 7 , 8 , 28 ].…”

Section: Materials and Analysis Methodsmentioning

confidence: 99%

“…Thereafter, the model-fitting efforts are made by plotting Y n against E kn over 0.05 < α < 0.95 for all g ( α ) models [ 7 , 8 , 28 ]. For simplicity, one global reaction model is assumed herein for the entire kinetic degradation process.…”

Section: Materials and Analysis Methodsmentioning

confidence: 99%

“…Therefore, pyrolysis and combustion have been extensively investigated for the purpose of sustainable disposal of various solid wastes [ 1 , 2 , 6 ]. Recently, we have made exploratory efforts on how to properly dispose of tennis wastes via inert pyrolysis, and oxidative decomposition has been thus conducted [ 7 , 8 ], where thermal characteristics and kinetic analysis have been reported in detail. In the present work, tennis ball rubber (TBR) waste has been considered for the thermal disposal purpose and then studied by means of thermogravimetric analysis (TGA).…”

Section: Introductionmentioning

confidence: 99%

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Pyrolysis and Oxidative Thermal Decomposition Investigations of Tennis Ball Rubber Wastes through Kinetic and Thermodynamic Evaluations

Wan

Huang

2023

Self Cite

Thermal decomposition of tennis ball rubber (TBR) wastes in nitrogen and air has been studied through thermogravimetric analysis. The samples were thermally decomposed from room temperature to 950 K at heating rates of 3 to 20 K/min with a purging flow of 30 cm3/min. The degradation features and specific temperatures for two purging gases are thus compared according to the nonisothermal results. Kinetic analyses of two thermal decomposition processes have been isoconversionally performed using differential or integral methods. The activation energy as a function of mass conversion has been thus obtained over the entire decomposition range, varying from 116.7 to 723.3 kJ/mol for pyrolysis and 98.2 to 383.6 kJ/mol for oxidative thermal decomposition. The iterative Flynn–Wall–Ozawa method combined with the linear compensation effect relationship has been proposed for determining the pre-exponential factor and reaction mechanism function, resulting in chemical order reaction models of f(α) = (1 − α)5.7 and f(α) = (1 − α)5.8 for describing pyrolysis and the oxidative thermal degradation of TBR wastes, respectively. With these kinetic parameters, very satisfactory matching against experimental data has been obtained for both gases. Additionally, the thermodynamic parameters, such as the changes of entropy, enthalpy and Gibbs free energy, over the whole thermal degradation processes have also been evaluated.

“…In recent years, as the demand for chemical processes and the maturity of experimental techniques for thermal analysis have increased, this method has commonly been applied to evaluate the thermal stability of organics, inorganics, and polymers. Thermodynamic analysis is mainly used to obtain the "kinetic triple factors" (pre-exponential factor (A), activation energy (E a ), and reaction mechanism function) of a reaction by means of established mechanism functions [17][18][19].…”

Section: Thermodynamic Analysismentioning

confidence: 99%

Thermal Hazard Evaluation of Tert-Butyl Peroxy-3,5,5-trimethylhexanoate (TBPTMH) Mixed with Acid-Alkali

Xia

Pan

et al. 2022

Tert-butyl peroxy-3,5,5-trimethylhexanoate (TBPTMH), a liquid ester organic peroxide, is commonly used as an initiator for polymerization reactions. During the production process, TBPTMH may be exposed to acids and alkali, which may have different effects on its thermal hazard, so it is necessary to carry out a study on the thermal hazard of TBPTMH mixed with acids and alkali. In this paper, the effects of H2SO4 and NaOH on the thermal decomposition of TBPTMH were investigated by differential scanning calorimetry (DSC) and adiabatic calorimetry (Phi-TEC II). The “kinetic triple factors” were calculated by thermodynamic analysis. The results show that the three Ea are 132.49, 116.36, and 118.24 kJ/mol, respectively; thus, the addition of H2SO4 and NaOH increased the thermal hazard of TBPTMH. In addition, the characteristic parameters (time to maximum rate under adiabatic conditions, self-accelerated decomposition temperature) of its thermal decomposition were determined, and the control temperature (45, 40, and 40 °C) of TBPTMH under the action of acid-alkali were further received. This work is expected to provide some guidance for the safe storage, handling, production, and transportation of TBPTMH in the process industry.