Kinetic studies of pyrolysis and combustion of Thar coal by thermogravimetry and chemometric data analysis

Sarwar, A.K.M. Golam; Khan, M. Nasiruddin; Azhar, Kaniz Fizza

doi:10.1007/s10973-011-1725-0

Cited by 39 publications

(22 citation statements)

References 21 publications

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“…Figure (a) shows the representative curves of mass loss (TG) and derivative mass loss (DTG) profiles as a function of temperature. Three distinct weight loss stages were identified in the temperature regions of 40–285, 286–612 and 613–950 °C, in agreement with the previous findings . During the entire conversion process, two maxima in the temperature ranges of 164–233 and 473–503 °C have been observed at the derivative plots.…”

Section: Resultssupporting

confidence: 90%

“…. E m is a measure of overall reactivity of coal and was calculated by

E_{m} = E_{1} + E_{2} + E_{3}

where E 1 , E 2 and E 3 are the reactivity measures of the individual regions and were calculated as E 1 = f 1 E a1 , E 2 = f 2 E a2 and E 3 = f 3 E a3 (here f 1 to f 3 are the weight fractions of the volatile matter released during devolatilization in each region).…”

Section: Resultsmentioning

confidence: 99%

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Activation energy distribution in pyrolysis of Thar coal, Pakistan

Khan

Sarwar

Shah

2015

Asia-Pacific J Chem Eng

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Thermochemical decomposition of 16 samples of low-rank Thar coal has been investigated using nonisothermal thermogravimetric data under an inert environment. Rapid weight loss of volatiles was found in the regions of 164-233 and 473-503°C. Kinetics of pyrolysis reaction showed that the volatiles released in three consecutive steps follow first-order reaction. The kinetic evaluation focuses on all the steps to estimate activation energy, pre-exponential factor and the contribution of each step to the overall reaction. The results showed that evaporation of moisture and low-temperature volatile compounds require 3.17-4.81 kJ mol À1 activation energy. The combustion of char required a higher amount of energy (10.86-36.11 kJ mol À1). The formation of secondary char required 10.34-24.00 kJ mol À1 energy. The results suggested that Thar coal has a substantial potential for gasification due to high volatile content and low activation energy.

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Section: Resultssupporting

confidence: 90%

“…. E m is a measure of overall reactivity of coal and was calculated by

E_{m} = E_{1} + E_{2} + E_{3}

Section: Resultsmentioning

confidence: 99%

Activation energy distribution in pyrolysis of Thar coal, Pakistan

Khan

Sarwar

Shah

2015

Asia-Pacific J Chem Eng

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“…The global reaction order of coal pyrolysis is determined to be higher than unity, and such a high value is a measure of complexity and multiplicity of the reaction mechanism . The apparent activation energy based on the optimized reaction order of coal pyrolysis is found in good agreement with the values from literature . On the other hand, the first stage of oil shale pyrolysis is predicted by two‐step model in Figure .…”

Section: Resultssupporting

confidence: 71%

Pyrolysis and char oxidation characteristics of oil shales and coal in a thermogravimetric analyzer

Park

Song

2017

Can J Chem Eng

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Non‐isothermal thermogravimetric analysis was carried out on two different oil shales and sub‐bituminous coal in order to evaluate effects of the fuel properties and compare the reaction characteristics. The samples and their chars after the devolatilization were heated up to 900 °C at a constant heating rate of 10 K/min under inert and oxidizing atmospheres, respectively. Experimental results exhibit distinct behaviour between the samples for both pyrolysis and char oxidation processes. Pyrolysis of oil shale occurs in two temperature regimes corresponding to its organic and mineral degradation, and mineral matter plays important roles in production of the residual char at the second pyrolysis stage and its reactivity to the subsequent char oxidation. Kinetic analysis was performed using the global one‐ and multi‐step models with nth order reaction mechanism. Organic devolatilization processes of coal and oil shale are analyzed by three‐ and two‐step models, respectively, however mineral degradation of oil shale and char oxidation are analyzed by a one‐step model. Finally, a reasonable fit to the experimental data can be achieved for all the samples and their chars at different atmospheres.

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“…TGA studies aiming to investigate the most important reactivity profile parameters for lignite (peak temperatures and apparent energy of activation) lack extensive research, especially for the newly explored resources. 8 In recent works, researchers have underpinned the importance of poor quality brown coal in the overall energy mix. 9,10 Pakistan has the world's largest lignite coal reserve comprising 175 billion tons spread over 9600 km 2 and having an electrical potential equivalent to 100 000 MW or 50 billion tonnes of oil equivalent.…”

Section: Introductionmentioning

confidence: 99%

Reactivity Analysis of Pakistani Thar Lignite Reserves in Oxidizing Thermogravimetric Analysis Atmospheres

et al. 2015

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and orders of reaction under the aforementioned reaction atmospheres were calculated using the Friedman method (a differential 15 isoconversional approach) and the Ghetti method. In this work, the primary dominating factor on the rate of mass loss from 16 devolatilization was the higher heating rate (40°C/min), and the second factor was the higher oxygen concentration of 30%. 17Overlapping of devolatilization and char oxidation zones was also observed at higher oxygen concentrations of 30%. Increased 18 reactivity of the Pakistani lignite was observed at a heating rate of 40°C/min and high oxygen concentrations of 30%.

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Kinetic studies of pyrolysis and combustion of Thar coal by thermogravimetry and chemometric data analysis

Cited by 39 publications

References 21 publications

Activation energy distribution in pyrolysis of Thar coal, Pakistan

Activation energy distribution in pyrolysis of Thar coal, Pakistan

Pyrolysis and char oxidation characteristics of oil shales and coal in a thermogravimetric analyzer

Reactivity Analysis of Pakistani Thar Lignite Reserves in Oxidizing Thermogravimetric Analysis Atmospheres

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