Heat and mass transfer within thermogravimetric analyser: From simulation to improved estimation of kinetic data for char gasification

Schulze, Sebastian; Nikrityuk, Petr A.; Abosteif, Ziad; Guhl, Stefan; Richter, Andreas; Meyer, Bernd

doi:10.1016/j.fuel.2016.09.048

Cited by 47 publications

(16 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The molecular diffusion coefficient is dependent on both the temperature and the pressure value, and it can be calculated from the Fuller-Schettler-Giddings equation shown as Eq. (8) [18]:…”

Section: The Transport Model Of O 2 In the Aptga Cruciblementioning

confidence: 99%

“…The term k D;O 2 , which is a mass transfer coefficient for the flat surface, may be defined by Eq. (11), [18]:…”

Section: The Transport Model Of O 2 In the Aptga Cruciblementioning

confidence: 99%

“…On the other hand, thermogravimetric analysis is a commonly used technique to investigate the kinetics of fast heterogeneous reactions such as the combustion of solid fuels, the oxidation of oxygen carriers [5,6,[11][12][13][14][15][16][17][18][19]. It is well known that kinetic parameters should be obtained under a chemical reaction-controlling regime [5,6,13,14,[17][18][19], which is important for the study of oxy-combustion kinetics.…”

Section: Introductionmentioning

confidence: 99%

“…It is well known that kinetic parameters should be obtained under a chemical reaction-controlling regime [5,6,13,14,[17][18][19], which is important for the study of oxy-combustion kinetics.…”

Section: Introductionmentioning

confidence: 99%

“…For particles raised in a gas stream, the O 2 transport rate coefficient is calculated from Froessling's equation [5,6,9,18,19,21,22]. For particles with a spherical geometry, this is expressed as follows:…”

mentioning

confidence: 99%

See 4 more Smart Citations

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Babiński

Ściążko

Ksepko

2017

J Therm Anal Calorim

View full text Add to dashboard Cite

A kinetic study of the oxy-combustion of chars obtained from two Polish steam coals was conducted. A comparative study was focused on the data analysis concerning oxy-combustion of coal chars collected from two thermobalances, which differed in construction, design of crucibles, sample size and gas flow direction. The influence of individual factors such as temperature, O 2 concentration, the dimensions of the crucibles and the dimensions of the char bed on the reaction rate was analysed. On the basis of these results, a global kinetic model was elaborated showing the influence of all factors, particularly mass transfer conditions, on reaction rates. The developed model can be extended to other mass transfer conditions or fluidised bed conditions and can be applied to other fast reactions to ensure they occur in the chemical reaction kinetics control regime during TG tests. It was concluded that the gas-solid fuel contact characteristics are crucial for the measured reaction rate and for the interpretation of kinetic data.

show abstract

Section: The Transport Model Of O 2 In the Aptga Cruciblementioning

confidence: 99%

“…The term k D;O 2 , which is a mass transfer coefficient for the flat surface, may be defined by Eq. (11), [18]:…”

Section: The Transport Model Of O 2 In the Aptga Cruciblementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Babiński

Ściążko

Ksepko

2017

J Therm Anal Calorim

View full text Add to dashboard Cite

show abstract

Optimizing kinetic evaluation through CFD‐based analysis of heat and mass transfer in a high‐pressure TGA

An,

Küster,

Guhl

et al. 2024

AIChE Journal

View full text Add to dashboard Cite

Accurate measurement of heterogeneous reaction kinetics in thermogravimetric analysis (TGA) requires accurate estimation of concentration and temperature in the sample. However, this information is difficult to estimate during the measurement, especially at high temperatures and pressures. Computational Fluid Dynamics (CFD) is used to perform a comprehensive analysis of the temperature and species distribution throughout a high‐temperature, high‐pressure test rig, including temperature and species transport within the probe sample. The temperature and gas concentration within the sample are accurately calculated by CFD, providing a much deeper insight into the local temperature and species distribution. The numerical results show a significant decrease in gas concentration and temperature in the core region of the packed bed, indicating that bed diffusion dominates the overall conversion for the char reaction studied in this article. The re‐evaluation based on the model considers the limitations of heat and mass transfer at each measurement point. This forms the basis for a novel, model‐driven approach that derives heterogeneous kinetics from TGA measurements with significantly improved accuracy and reliability.

show abstract

Study on CO ₂ gasification kinetics of biomass char based on pore structure analysis: Theoretical modelling of structural parameter ψ in random pore model

Song

Wang

et al. 2020

Int J Energy Res

View full text Add to dashboard Cite

Summary In this work, the structural function of char gasification is modelled theoretically. Considering that different components will have different pore characteristics after pyrolysis, char is divided into different micro‐structures according to its corresponding components, and then a structural equation is constructed to realize the theoretical calculation of the structural parameter. Through comparison, it is found that the proposed model has high accuracy and shows applicability for different demineralized biomass samples. An analysis of the influence of sample characteristics on the structural parameter shows that, with an increase in char particle size and initial porosity, the structural parameter shows a decreasing trend, while, with an increase in fuel ratio, the structural parameter first increases and then decreases. The model can directly predict char gasification through the characteristic parameters of the sample, including proximate analysis, ultimate analysis, initial porosity of the sample and char particle size, thus replacing previous predictions of char gasification by testing the characteristic parameters of the char pores.

show abstract

Heat and mass transfer within thermogravimetric analyser: From simulation to improved estimation of kinetic data for char gasification

Cited by 47 publications

References 35 publications

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Optimizing kinetic evaluation through CFD‐based analysis of heat and mass transfer in a high‐pressure TGA

Study on CO ₂ gasification kinetics of biomass char based on pore structure analysis: Theoretical modelling of structural parameter ψ in random pore model

Contact Info

Product

Resources

About

Heat and mass transfer within thermogravimetric analyser: From simulation to improved estimation of kinetic data for char gasification

Cited by 47 publications

References 35 publications

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Limitation of thermogravimetry for oxy-combustion analysis of coal chars

Optimizing kinetic evaluation through CFD‐based analysis of heat and mass transfer in a high‐pressure TGA

Study on CO 2 gasification kinetics of biomass char based on pore structure analysis: Theoretical modelling of structural parameter ψ in random pore model

Contact Info

Product

Resources

About

Study on CO ₂ gasification kinetics of biomass char based on pore structure analysis: Theoretical modelling of structural parameter ψ in random pore model