Pyrolysis kinetics of polypropylene

The degradation kinetics of Juglans regia shell, scrap tyre and their blends were investigated using a thermogravimetric analysis method. Experiments were performed under dynamic conditions and a nitrogen atmosphere in the range 293 to 973 K at different heating rates. During pyrolysis of J. regia shell three mass loss zones were specified as removal of water, decomposition of hemicelluloses and cellulose, and decomposition of lignin. The degradation curves of scrap tyre showed merely one stage which was due to decomposition of styrene butadiene rubber. The kinetic parameters were calculated using both Arrhenius and Coats-Redfern methods. By adopting the Arrhenius method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blends were found to be 69.22, 71.48 and 47.03 kJ mol(-1), respectively. Additionally, by using the Coats-Redfern method, the average value of activation energies of J. regia shell, scrap tyre and their 1 : 1 blend were determined as 99.85, 78.72 and 63.81 kJ mol(-1), respectively. The addition of J. regia shell to scrap tyre caused a reduction in the activation energies. The difference of weight loss was measured to examine interactions between raw materials. The maximum difference between experimental and theoretical mass loss was 5% at about 648 K with a heating rate of 20 K min(-1). These results indicated a significant synergistic effect was available during co-pyrolysis of J. regia shell and scrap tyre in the high temperature region.

show abstract

“…The decomposition of a solid in a non-isothermal mode can be represented by the following reaction (Aboulkas et al, 2007):…”

Section: Kinetic Modellingmentioning

confidence: 99%

Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis

Uzun

Yaman

2014

Waste Manag Res

View full text Add to dashboard Cite

show abstract

“…It is well known that TG and DTG can be used for thermal dynamic analysis. 19, 20 According to the Arrhenius equation, the pyrolysis reaction rate of an asphalt binder can be written as follows: where k is reaction rate constant, A is the pseudo frequency factor or pseudo pre‐exponential factor (s −1 ), E is the pseudo activation energy (kJ/mol), R is the universal gas constant (kJ mol −1 K −1 ), t is the time of the pyrolysis process (s), T is the pyrolysis temperature at time t (K), α is the residue matter mass (kg), and f (α) is the function related to the reaction rate and α.…”

Section: Resultsmentioning

confidence: 99%

“…Some previous studies also used TG curves for thermal dynamic analysis. 21, 22 The Coats–Redfern method was used to solve the kinetic equations in this study. It deduces the approximate integral‐type equation and can be described as follows: …”

Section: Resultsmentioning

confidence: 99%

Pyrolysis properties and kinetic model of an asphalt binder containing a flame retardant

Huang

2010

J of Applied Polymer Sci

View full text Add to dashboard Cite

In this study, thermogravimetry (TG) experiments were employed to study the influence of magnesium hydroxide (MH) on the pyrolysis characteristics of an asphalt binder. Pyrolysis models of the asphalt binder were developed to reveal the flame-retarding mechanism of MH. The TG experimental results showed that the pyrolysis process of the asphalt binder in N 2 was a one-stage reaction. The asphalt binder containing MH had a higher residue yield ratio at a high temperature, and TG and differential TG curves showed a dramatic shift toward higher temperatures with an increase in the MH concentration; this indicated that MH inhibited the thermal decomposition of the asphalt binder. By optimal identification of the pyrolysis mechanism function, the pyrolysis reaction of the asphalt binder was found to follow the model of one-dimensional diffusion (parabolic law), whereas that of the flame-retarding asphalt binder followed the model of three-dimensional diffusion (the Ginstling-Brounshtein equation). On the basis of the models, the calculation results for the pseudo activation energy indicated that the thermal stability of the asphalt binder in the pyrolysis process was obviously improved by the addition of MH. We conclude that the flame retardancy of asphalt binders can be enhanced by the use of MH, and MH may be a potential flame retardant for asphalt binders used in tunnel asphalt pavement.

show abstract

“…The same experiment was repeated at least twice to ensure the repeatability and the accuracy of the experimental data. Some previous investigations − on copyrolysis for thermogravimetric studies showed the lack of interactions, which have low heating rates. Under very low heating rate conditions, the temperature ranges for pyrolysis of two components differ considerably, indicating that the two processes are well separated and, therefore, obvious synergies cannot be found.…”

Section: Methodsmentioning

confidence: 98%

Study on the Characteristics of the Oil Shale and Shale Char Mixture Pyrolysis

Yan¹,

Jiang²,

Han³

2009

Energy Fuels

View full text Add to dashboard Cite

The pyrolysis experiments of the mixture fuels of Huadian oil shale and its shale char prepared at a retorting temperature of 520 °C were conducted using a Q5000IR thermogravimetric analyzer, and the characteristics of the copyrolysis at different mixing ratios were obtained. The release of organic matter tended to decrease while the decomposition of inorganic constituents tended to increase slightly with increasing shale char fraction. The interaction during the copyrolysis was investigated by comparing the experimental result with the theoretical one and only some little interaction was observed. The reactivity between 250 and 600 °C followed a decreasing trend with the increase of shale char fraction due to the lower volatile content and carbon condensation structures in shale char, and for each sample, the reactivity increased first and then decreased as the temperature increased because of the rearrangement of internal structure of sample particles. According to the kinetic analysis, increasing the shale char fraction in the mixtures would result in a decreasing apparent activation energy at temperatures ranging from 250 to 600 °C since the pyrolysis of shale char in this temperature range did not undergo the process of the decomposition of bitumen which existed in the pyrolysis of oil shale and needed much energy.

show abstract

Pyrolysis kinetics of polypropylene

Cited by 31 publications

References 31 publications

Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis

Thermogravimetric characteristics and kinetics of scrap tyre and Juglans regia shell co-pyrolysis

Pyrolysis properties and kinetic model of an asphalt binder containing a flame retardant

Study on the Characteristics of the Oil Shale and Shale Char Mixture Pyrolysis

Contact Info

Product

Resources

About