scholarly journals INCREASING EFFICIENCY OF THE PYROLYSIS PROCESS BY INFLUENCING THE INITIATION OF THERMAL DECOMPOSITION OF HYDROCARBONS

Author(s):  
ELENA MAGARIL ◽  
ROMEN MAGARIL
2012 ◽  
Vol 730-732 ◽  
pp. 611-616 ◽  
Author(s):  
Alexandra Castro ◽  
Cândida Vilarinho ◽  
Delfim Soares ◽  
Fernando Castro

The presence of organic compounds on wastes, especially plastics, is considered an important source of energy. However, most of these plastics contain polyvinyl chloride (PVC), causing recycling problems when it is considered a thermal valorization process for its treatment [1], preventing the use of those residues on these processes, which main goal is the energy recovery [2,3]. A possible solution is to remove the chlorine from PVC containing waste through a pyrolysis process before being subjected to a thermal treatment, for energetic valorization. In this work, it was developed a kinetic model for the thermal decomposition of PVC, in view of its de-chlorination. DTA/TGA testing were performed at different temperatures (between the range of decomposition temperatures of the PVC molecule) indicated a first order reaction and an activation energy of 133800 J/mol, value very close to the one obtained in others works reported [4]. A factorial plan was carried out with different temperatures, performed in lab scale, in which best results were obtained at the temperature of 340 °C, proving the kinetic model obtained.


2011 ◽  
Vol 255-260 ◽  
pp. 2150-2154
Author(s):  
Hui Jiang ◽  
Hai Yan Chen

Pyrolysis analysis of waste computer mainboard was carried out at heating rate of 10 °C /min, 20°C/min and 25 °C/min in nitrogen atmosphere. The thermogravimetric analysis result shows that the weight loses change in three steps: the curve of TG is smooth from room temperature to 300°C in the first step, which possess about 1 percent of the total weight. The weight loses abruptly increase from 300 °C to 450 °C in the second step, and the curve of TG recoveries to be smooth at the temperature of 450 °C, that is the third step. There is an evident exothermic peak and an evident endothermic peak during the pyrolysis process, the exothermic peak is due to the thermal decomposition of waste computer mainboard, the endothermic peak is related to the melting of copper. At the same time the pyrolysis process make the surface morphology and elevation morphology change. The experimental study provided valuable basis for the industrial recovery of waste computer mainboard.


2015 ◽  
Vol 7 (1) ◽  
pp. 5-22 ◽  
Author(s):  
Alok Dhaundiyal ◽  
Jitendra Gangwar

Abstract A kinetic study of the pyrolysis process of pine needles was examined using a thermogravimetric analyser. The weight loss was measured in nitrogen atmosphere at a purge flow rate of 100 ml/min. The samples were heated over a range of temperature of 19°C–600°C with a heating rate of 10°C/min. The results obtained from the thermal decomposition process indicate that there are three main stages: dehydration, active and passive pyrolysis. The kinetic parameters for the different samples, such as activation energy and pre-exponential factor, are obtained by the shrinking core model (reaction-controlled regime), the model-free, and the first-order model. Experimental results showed that the shrinking model is in good agreement and can be successfully used to understand degradation mechanism of loose biomass. The result obtained from the reaction-controlled regime represented actual values of kinetic parameters which are the same for the whole pyrolysis process; whereas the model-free method presented apparent values of kinetic parameters, as they are dependent on the unknown function ϕ(C), on the sum of the parameters of the physical processes, and on the chemical reactions that happen simultaneously during pyrolysis. Experimental results showed that values of kinetic constant from the first-order model and the SCM are in good agreement and can be successfully used to understand the behaviour of loose biomass (pine needles) in the presence of inert atmosphere. Using TGA results, the simulating pyrolysis can be done, with the help of computer software, to achieve a comprehensive detail of the devolatilization process of different types of biomasses.


2020 ◽  
Vol 71 (1) ◽  
pp. 13-18
Author(s):  
Paweł Kazimierski ◽  
Sara Vieira ◽  
Dariusz Kardaś

The goal of this experiment is to assess the mass and volume loss of medium size pine wood particles undergoing pyrolysis. Wood samples of different sizes and shapes were pyrolysed at 500 ºC with different residence times. A thermogravimetric analysis was carried out for comparison purposes. Finally, the pyrolysed samples were analysed using radiographic methods. A connection between the different analyses was found. For larger particles, the heating rate is lower, and a time gap between hemicellulose and cellulose thermal decomposition was noticed. Research shows that an important part of the analysis of the process is the rate of biomass heating and sample size. As the sample size increases, the pyrolysis time increases; however, the increase is not linear. The publication also shows the great possibilities of radiographic methods in analysing the pyrolysis process.


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