Pyrolysis Kinetics of Low-Rank Coals Using Three Model-Free Methods

The kinetics during the pyrolysis process depend on both chemical structure and inherent mineral matters in coal, but normally, only one of these components is investigated in literature. In the present work, four low-rank coals were pyrolyzed in a thermogravimetric analyzer at a heating rate of 10 K/min in a constant nitrogen stream at a temperature up to 900 °C to study the pyrolysis behavior and kinetics. Two of the samples were raw coal (R-YL) and clean coal (C-YL) obtained through the washing process. The results showed that the coal-washing process mainly affected the inorganic part (mineral matters) and structure in coal, which did not largely change the chemical properties. The pyrolysis behavior in primary stage (before 550 °C) was mainly affected by the chemical properties of coal, while the pyrolysis behavior in higher temperature also depended on inherent mineral matters. The kinetics of four coals were obtained using the Coats–Redfern (CR) method with five theoretical models. The difference of E value was almost negligible for R-YL and C-YL, also showing that the coal-washing process did not largely change the chemical properties. The higher frequency factor A for clean coal C-YL showed a more porous structure due to the coal-washing process. The apparent activation energy E in the third stage was affected by the thermodynamic property of inherent minerals.

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Hybrid Genetic Algorithm and Model-Free Coupled Direct Search Methods for Pyrolysis Kinetics of ZSM-5 Catalyzed Decomposition of Waste Low-Density Polyethylene

Industrial & Engineering Chemistry Research ◽

10.1021/ie0615483 ◽

2007 ◽

Vol 46 (17) ◽

pp. 5485-5492 ◽

Cited By ~ 10

Author(s):

Biswanath Saha ◽

Aloke K. Ghoshal

Keyword(s):

Genetic Algorithm ◽

Hybrid Genetic Algorithm ◽

Direct Search ◽

Low Density Polyethylene ◽

Low Density ◽

Pyrolysis Kinetics ◽

Search Methods ◽

Direct Search Methods ◽

Model Free ◽

Kinetics Of

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Comparative pyrolysis kinetics of various biomasses based on model-free and DAEM approaches improved with numerical optimization procedure

PLoS ONE ◽

10.1371/journal.pone.0206657 ◽

2018 ◽

Vol 13 (10) ◽

pp. e0206657 ◽

Cited By ~ 9

Author(s):

Miloš Radojević ◽

Bojan Janković ◽

Vladimir Jovanović ◽

Dragoslava Stojiljković ◽

Nebojša Manić

Keyword(s):

Numerical Optimization ◽

Optimization Procedure ◽

Pyrolysis Kinetics ◽

Model Free ◽

Kinetics Of

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Pyrolysis characteristics and kinetics of low rank coals by TG-FTIR method

Fuel Processing Technology ◽

10.1016/j.fuproc.2016.10.008 ◽

2017 ◽

Vol 156 ◽

pp. 454-460 ◽

Cited By ~ 105

Author(s):

Huijuan Song ◽

Guangrui Liu ◽

Jinzhi Zhang ◽

Jinhu Wu

Keyword(s):

Low Rank ◽

Pyrolysis Characteristics ◽

Kinetics Of ◽

Low Rank Coals

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Pyrolysis characteristics and kinetics of low rank coals by distributed activation energy model

Energy Conversion and Management ◽

10.1016/j.enconman.2016.08.082 ◽

2016 ◽

Vol 126 ◽

pp. 1037-1046 ◽

Cited By ~ 47

Author(s):

Huijuan Song ◽

Guangrui Liu ◽

Jinhu Wu

Keyword(s):

Activation Energy ◽

Energy Model ◽

Low Rank ◽

Distributed Activation Energy Model ◽

Pyrolysis Characteristics ◽

Kinetics Of ◽

Low Rank Coals

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Investigation of Pyrolysis Kinetics of Humic Acids from Low Rank Anatolian Coal by Thermal Analysis

Energy Sources Part A Recovery Utilization and Environmental Effects ◽

10.1080/00908310500287475 ◽

2007 ◽

Vol 29 (10) ◽

pp. 931-938 ◽

Cited By ~ 6

Author(s):

Y. Tonbul ◽

S. Erdogan

Keyword(s):

Thermal Analysis ◽

Humic Acids ◽

Low Rank ◽

Pyrolysis Kinetics ◽

Kinetics Of

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Kinetic Analysis of Low-Rank Coal Pyrolysis by Model-Free and Model-Fitting Methods

Journal of Chemistry ◽

10.1155/2019/9075862 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Qiuli Zhang ◽

Min Luo ◽

Long Yan ◽

Aiwu Yang ◽

Xiangrong Hui

Keyword(s):

Model Fitting ◽

Decomposition Reaction ◽

Low Rank ◽

Coal Pyrolysis ◽

Pyrolysis Kinetics ◽

Heating Rates ◽

Pyrolysis Characteristics ◽

Model Free ◽

Thermal Analyzer ◽

Thermogravimetric Data

Coal SJC, coal WJG, coal ZJM, and coal HCG were selected to investigate the pyrolysis kinetics of northern Shaanxi coals. TG and DSC experiments of four coals were carried out with a synchronous thermal analyzer at heating rates 5, 10, 15, and 20 C/min, respectively. The pyrolysis characteristics were described by thermogravimetric data, and the kinetic parameters were calculated by Flynn–Wall–Ozawa (FWO), Kissinger, general integration, and MacCallum–Tanner methods. The results show that coal SJC, coal ZJM, and coal HCG all conform to the reaction series equation, the thermal decomposition reaction rate is controlled by chemical reaction, and coal WJG conforms to Avrami–Erofeev equation. The activation energies of the four coals are 177.53 kJ/mol, 200.34 kJ/mol, 158.59 kJ/mol, and 240.47 kJ/mol, respectively.

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