A kinetic analysis of the pyrolysis of some australian coals by non-isothermal thermogravimetry

Ma, S.; Hill, J.O.; Heng, S.

doi:10.1007/bf01913852

Cited by 82 publications

(54 citation statements)

References 17 publications

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“…Three main temperature ranges of coal thermal decomposition are observed in these derivatograms: 1) 20-25150-170С (removal of adsorbed water), 2) 300-500С (a primary or quick pyrolysis stage) and 3) >500-600С (a secondary or slow pyrolysis stage). On the whole, the above described picture is characteristic for the processes of non-isothermal pyrolysis of solid fuels [10,11]. In the primary pyrolysis stage, CO 2 , CO, H 2 O, methane and its homologues, as well as light unsaturated hydrocarbons, are the prevailing components among the gaseous products released; these products are formed during the decomposition of aliphatic structures and elimination of lateral substitutes from carbon-based framework of coal organic matter [10,11].…”

Section: Resultsmentioning

confidence: 99%

“…On the whole, the above described picture is characteristic for the processes of non-isothermal pyrolysis of solid fuels [10,11]. In the primary pyrolysis stage, CO 2 , CO, H 2 O, methane and its homologues, as well as light unsaturated hydrocarbons, are the prevailing components among the gaseous products released; these products are formed during the decomposition of aliphatic structures and elimination of lateral substitutes from carbon-based framework of coal organic matter [10,11]. In the secondary (high temperature) pyrolysis stage, bond breaking and structural rearrangements of coal carbon-based matrix occur; in this process, the main gaseous products released are hydrogen and CO, as well as (in small quantities) CS 2 и HCN [11].…”

Section: Resultsmentioning

confidence: 99%

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Predicting the Possibility for Deep Hydroprocessing of Some Kuzbass Coals

Petrov

Tryasunov

2017

E3S Web Conf.

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Abstract. Using thermal analysis and photoacoustic IR spectroscopy techniques, the abilities to be hydrogenated for some low-metamorphosed Kuzbass coals have been estimated in the aim of studying the possibilities of their deep industrial processing to obtain liquid fuels and valuable chemical products. Two independent parameters for quick assessment of solid fuel suitability for hydrogenation processes under high pressure of hydrogen have been proposed: 1) the relative maximal rate of coal pyrolysis in the 300-500C temperature range, [(1/mo) • dm/dT] (calculated from thermal analysis data), and 2) the intensity of aliphatic IR absorption bands (the sum of their optical densities), normalized to the optical density of an IR absorption band associated with aromatic ring C=C-bonds [i.e., (D2920+D2860)/D1600] (obtained from photoacoustic FTIR spectra of coal materials). It has been shown that for a number of low-metamorphosed Kuzbass coals (Barzas sapromixite, Itatsky lignite and Karakansky longflame coal) the above mentioned parameters were in good consistency with generally accepted hydrogenation ability parameters of solid fossil fuelsatomic H/C ratios and volatile matter values.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Predicting the Possibility for Deep Hydroprocessing of Some Kuzbass Coals

Petrov

Tryasunov

2017

E3S Web Conf.

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“…Na análise de dados obtidos por meio dos ensaios isotérmicos, assumiu-se que a reação de pirólise tenha ocorrido segundo uma reação de primeira ordem ("single first order kinetics" -SFOR) (ÓRFÃO; FIGUEIREDO, 2001;BIAGINI et al, 2002). Já os dados obtidos a partir dos experimentos dinâmicos foram tratados segundo os métodos de Ozawa e Kissinger (BIGDA; MIANOWSKI, 2006;BIAGINI et al, 2002;MA;HILL;HENG, 1991), os quais assumem que, considerando uma conversão fixa, a temperatura na qual ocorre a principal reação de decomposição desloca-se em função das taxas de aquecimento aplicadas. Em ambos os casos (ensaios isotérmicos e dinâmicos), as constantes de velocidade foram consideradas como seguindo a lei de Arrhenius (ATKINS, 1998).…”

Section: Methodsunclassified

“…Os dados experimentais do deslocamento da temperatura na conversão fixa (Quadro 1) foram analisados de acordo com os métodos propostos por Kissinger e Ozawa (MA; HILL; HENG, 1991;BIAGINI et al, 2002).…”

Section: Cinética Da Pirólise Da Acácia-negra a Partir Dos Ensaios DIunclassified

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Análise termogravimétrica da pirólise da acácia-negra (Acacia mearnsii de Wild.) cultivada no Rio Grande do Sul, Brasil

et al. 2008

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RESUMO -Este trabalho reporta um estudo experimental que objetivou a investigação dos efeitos da temperatura, da taxa de aquecimento e do tempo na eficiência e nos parâmetros cinéticos da decomposição da madeira de acácia-negra (Acacia mearnsii De Wild.) plantada no Rio Grande do Sul. O processo da pirólise da acácia-negra foi investigado por análise termogravimétrica (TGA), e os parâmetros cinéticos foram obtidos a partir de ensaios dinâmicos e isotérmicos. Os ensaios dinâmicos foram conduzidos desde a temperatura ambiente até 900 C, sob taxas de aquecimento que variaram de 2 a 50 o C.min -1 . Os ensaios isotérmicos foram realizados entre 250 e 750 o C, ao aquecer a amostra até a temperatura desejada e mantendo-se nessa temperatura por 2 h. Os dados cinéticos obtidos dinamicamente foram tratados segundo os métodos de Ozawa e Kissinger. Já os parâmetros cinéticos conseguidos isotermicamente foram calculados ao considerar que a reação de pirólise segue uma cinética de primeira ordem em todo o intervalo de tempo e temperatura empregados. Os resultados denotaram a aplicabilidade dos métodos adotados, visto que os valores da energia de ativação do processo de pirólise, além de se aproximarem entre si, isto é, 170-180 kJ.mol -1 , segundo modelos dinâmicos, e 140 kJ.mol -1 , segundo o método isotérmico, aproximaram-se também dos valores reportados na literatura sobre a pirólise de compostos celulósicos (150-200 kJ.mol -1 ). Os resultados contribuem para a melhor compreensão dos processos de pirólise da biomassa, em especial da acácia-negra, o que pode levar ao melhoramento das atuais práticas de conversão da biomassa em carvão vegetal.Palavras-chave: Acácia-negra, pirólise, termogravimetria e energia de ativação. THERMOGRAVIMETRIC ANALYSIS OF THE PYROLYSIS OF Acacia mearnsii de Wild. HARVESTED IN RIO GRANDE DO SUL, BRAZIL

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Lifetime prediction of the epoxy system badgen = 0/1,2 DCH by thermogravimetric analysis

Núñez

Fraga

Núñez

et al. 2000

J. Appl. Polym. Sci.

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Lifetime of the system diglycidyl ether of bisphenol A (BADGE n = 0)/1,2‐diamine cyclohexane (DCH) was predicted by thermogravimetric analysis. Lifetime was considered when either 5% weight loss or 5% conversion was reached. Experimental results were treated using two different methods: The first method was independent of the degradation mechanism and the second was based on the thermodegradation kinetic mechanism. The activation energy of the reaction, determined using the Flynn–Wall–Ozawa method, was 148.51 kJ/mol. This value is in a good agreement with that of 144.01 kJ/mol obtained using Kissinger′s method. From the experimental results, it was found that the optimum temperature of service for this material is in the range of 100–140°C, at which the corresponding lifetime range is from 27 to 2633 years. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1239–1244, 2000

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A kinetic analysis of the pyrolysis of some australian coals by non-isothermal thermogravimetry

Cited by 82 publications

References 17 publications

Predicting the Possibility for Deep Hydroprocessing of Some Kuzbass Coals

Predicting the Possibility for Deep Hydroprocessing of Some Kuzbass Coals

Análise termogravimétrica da pirólise da acácia-negra (Acacia mearnsii de Wild.) cultivada no Rio Grande do Sul, Brasil

Lifetime prediction of the epoxy system badgen = 0/1,2 DCH by thermogravimetric analysis

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