Coal conversion submodels for design applications at elevated pressures. Part I. devolatilization and char oxidation

Niksa, Stephen; Liu, Guisu; Hurt, Robert H.

doi:10.1016/s0360-1285(03)00033-9

Cited by 207 publications

(164 citation statements)

References 64 publications

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“…The kinetic model (18) for the Boudouard-Bell reaction under isothermal conditions was proposed and is based on the combination of three kinetic constants: k 1 -the relatively rapid gasification reaction called the Boudouard reaction, k -1 -the disproportionation reaction called the Bell and k 3 -the CO desorption process. From a mathematical point of view, Eq.…”

Section: Discussionmentioning

confidence: 99%

“…(18) and (28) indicates on the necessity of consideration of the reverse reaction in the calculations, known as the Bell reaction [22], although the kinetic constant of this reaction should tend toward 0 with increasing temperature (k -1 ? 0).…”

Section: Coke Qualitymentioning

confidence: 99%

“…(8) can be expanded by connecting the Boudouard-Bell (B-B) reactions with the partial oxidation process that occurs in the presence of oxygen (POX-bis) [16][17][18][19] or by introducing secondorder terms including the partial pressure of CO 2 [16,20].…”

Section: Introduction Ergun Considerations and Their Consequencesmentioning

confidence: 99%

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The reactivity of cokes in Boudouard–Bell reactions in the context of an Ergun model

Mianowski

Radko

Siudyga

2015

J Therm Anal Calorim

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In previous studies, a kinetic equation based on the Ergun mechanism and concept presented in 1956 was applied to Boudouard-Bell reactions for granular coke (1-3 mm) in the temperature range T = 1173-1423 K. In contrast to several other works on this subject, the proposed equation was based on only three kinetic constants: k 1 , the rate constant for the Boudouard reaction; k -1 , the rate constant for the Bell reaction; and k 3 , which is related to the oxy-carbon decomposition and CO desorption process. The dependence of these constants on temperature allows certain values characteristic of the aforementioned processes to be calculated, including activation energy of gasification reaction, enthalpy of disproportionation reaction of gasification and activation energy of desorption process. When k -1 [ 0, i.e., the Bell reaction and inhibitory effects occur, the kinetic constant k 3 can be determined using a portion of the experimental [CO] versus time data normalized to the maximum contribution of CO in the outlet gases.

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Section: Discussionmentioning

confidence: 99%

Section: Coke Qualitymentioning

confidence: 99%

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The reactivity of cokes in Boudouard–Bell reactions in the context of an Ergun model

Mianowski

Radko

Siudyga

2015

J Therm Anal Calorim

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“…A comprehensive coal oxidation model needs precise prediction of coal swelling ratio. A correlation of coal swelling ratio with pyrolysis pressure, and carbon content of the parent coal was developed by Benfell [15], which predicts change of the coal swelling ratio with increased pressure from medium heating rate coal pyrolysis(~ 10 4 K/s), but overestimates swelling ratio for high heating rate pyrolysis (~10 5 K/s). Since practical pulverized coal combustion occurs at high temperature (2000K) and heating rate (10 6 K/s), such correlations should include the effects of heating rate.…”

Section: Swelling Ratiomentioning

confidence: 99%

Fundamental Investigation of Fuel Transformations in Pulverized Coal Combustion and Gasification Technologies

Hurt¹,

Calo²,

Fletcher³

et al. 2004

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“…Carbon content as mass fraction (%Y C ) is a common coal type number that has been used by many authors, such as Niksa, et al [1], Mill [2], and Genetti [3]. The light gas and tar yields are the common indicators for expressing how the pyrolysis behaves.…”

Section: Introductionmentioning

confidence: 99%

New Correlations for Coal and Biomass Pyrolysis Performances with Coal-Biomass Type Number and Temperature

Bindar

2013

j.eng.technol.sci.

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Abstract. The pyrolysis of coal and biomass is generally reported as the mass yield of released chemicals at various temperatures, pressures, heating rates and coal or biomass type. In this work, a new coal-biomass type number, N CT , is introduced. This number is constructed from the mass fractions of carbon, hydrogen, and oxygen in the ultimate analysis. This number is unique for each coal or biomass type. For 179 different species of coal and biomass from the literature, the volatile matter mass yield can be expressed by the second order polynomial function ln(N CT ). This unique correlation allows the effects of the temperature and heating rate on the volatile yield Y VY for coal and biomass to be empirically correlated as well. The correlation for the mass fraction of each chemical component in the released volatile matter correlation is obtained from the Y VY correlation. The weight factor for some of the components is constant for the variation of N CT , but not for others. The resulted volatile matter and yield correlations are limited to atmospheric pressure, very small particles (less than 0.212 mm) and interpreted for wire-mesh pyrolysis reactor conditions and a nitrogen gas environment.

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Coal conversion submodels for design applications at elevated pressures. Part I. devolatilization and char oxidation

Cited by 207 publications

References 64 publications

The reactivity of cokes in Boudouard–Bell reactions in the context of an Ergun model

The reactivity of cokes in Boudouard–Bell reactions in the context of an Ergun model

Fundamental Investigation of Fuel Transformations in Pulverized Coal Combustion and Gasification Technologies

New Correlations for Coal and Biomass Pyrolysis Performances with Coal-Biomass Type Number and Temperature

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