Numerical investigation of the heterogeneous combustion processes of solid fuels

Alganash, B.; Paul, Manosh C.; Watson, Ian

doi:10.1016/j.fuel.2014.10.060

Cited by 29 publications

(19 citation statements)

References 34 publications

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“…The effects of the kinetic parameter values of R2 and R3 as a function of temperature can potentially cause a different reaction rate for char [39]. As mentioned previously, the initial Simulation 1 used the set of kinetic values based on the study of Blaid et al [38]. Both of R2 and R3 in this case have the lowest reaction rates compared to the other results, and it is thus understood that these rates are slow compared to the other reactions and hence, the char remained unaffected.…”

Section: Investigation Of the Kinetic Parameters Of R2 And R3mentioning

confidence: 99%

Investigation of coal particle gasification processes with application leading to underground coal gasification

Sutardi¹,

Paul²,

Karimi³

2019

Fuel

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A coal particle model is developed to investigate the thermochemical processes of gasification for underground coal applications. The chemical reactions are defined with an Eddy Break up (EBU) model for controlling the reaction mechanisms and the study is particularly focused on identification of the important kinetic parameters, which control the consumption rate of coal mass. As an initial validation, the coal particle oxidation based on the experimental results is used for comparison. The gasification reactions are subsequently applied for the thermochemical process investigation, and the results show that the best agreement of coal oxidation is achieved by the pre-exponent factor (A) of 0.002 and 85500, for the reactions, R2 (C + O2 = CO2) and R3 (C + 0.5O2 = CO), respectively. The kinetic parameters for the gasification process of coal particle leading to the syngas production are also optimised. The results show that the production of H2 and CO is controlled significantly by the level of oxygen concentration in the char reactions. However, their chemical rates are strongly dependent upon the reaction zones. For example, CO is produced in both oxidation and reduction reaction zones, while H2 production is dominated in the reduction zone. Spatio-temporal distributions of the gas species along with the coal particle temperature provide additional information for further development of UCG modelling. Ultimately, the model gives a good guideline with the associated thermochemical processes that can help developing advanced coal gasification technology and lead to improved syngas quality.

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Section: Investigation Of the Kinetic Parameters Of R2 And R3mentioning

confidence: 99%

Investigation of coal particle gasification processes with application leading to underground coal gasification

Sutardi¹,

Paul²,

Karimi³

2019

Fuel

Self Cite

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“…However, the relative error of the H 2 /CO ratio curve is close to 30%. Considering that there are many options of reaction kinetic parameters for simulation in literatures, ,,− such an error is possibly caused by the inappropriate setting of kinetic parameters such as the pre-exponential factor ( A ) of some reactions in Table , as also mentioned in Section .…”

Section: Resultsmentioning

confidence: 99%

“…The overall reaction mechanism was applied with the Eulerian–Eulerian method. The reaction rates ( k ) of all reactions were calculated according to Arrhenius law − with the parameters listed in Table . …”

Section: Mathematical Modelsmentioning

confidence: 99%

Numerical Study of Load Characteristics of a CFB Coal Gasifier by Using the Generalized Drag Model

Huo

Liu

et al. 2020

Energy Fuels

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The load characteristics of a large circulating fluidized bed (CFB) coal gasifier were simulated by using the Eulerian− Eulerian method with the generalized drag model, QC-EMMS. The simulations predicted the gas−solid two-phase flows and coal gasification in a 60 m high CFB gasifier for 50, 80, and 100% loads. The results show that the simulated pressure drop, temperatures, and syngas compositions at the 50% load agree well with the field test data. The solid mass circulation rate and the H 2 /CO ratio then increase linearly with the increasing load. The average temperature in the riser decreases slightly by 4% with the increasing load. The yield of effective syngas per ton coal stabilizes at 465 Nm 3 /t for loads over 80%. The study verifies that the QC-EMMS drag model can be used to accurately simulate the complicated gas−solid reaction processes in a large industrial CFB.

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“…[1][2][3][4][10][11][12][13] The effects of coal type and operating conditions (temperature, pressure, and gasify agencies) on gasification reactivity have been extensively investigated, and the particle size has also been found to significantly influence the ignition and thermal history of coal particle, and consequently the flame distribution and gasification characteristics. [14] Experimental studies using thermogravimetric analyzers have shown that the heating and devolatilization processes with fine particles commenced early and rapidly because of the increased specific surface area with decreased particle size. This then leads to improved ignition characteristics and reactivity of coal char, and in turn high burning rate and short burnout time.…”

Section: Introductionmentioning

confidence: 99%

Effect of coal particle size on gasification performance of two‐stage entrained‐flow coal gasifier

Fan

Yinhe

et al. 2021

Can J Chem Eng

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To clarify the effect of coal particle sizes on gasification performance of an advanced two-stage entrained-flow coal gasifier for IGCC (integrated gasification combined cycle) application, a comprehensive three-dimensional numerical model is established by incorporating the shrinking core model combined with the Langmuir-Hinshelwood kinetic rate expression, which considers the inhibitory effect of CO on char-CO 2 reaction. The flow, temperature, and species distributions were obtained, and the results are consistent with the operating data. Results show that the helical flow and eight recirculation zones in the gasifier improve carbon conversion efficiency through extending the residence time of coal particles. Slow devolatilization of large particles caused by slow heating retards volatiles combustion, and thus char combustion and gasification. As a result, less char gasification and higher gas temperature appear in the injection region of the first stage. Higher inertia of larger particles produces higher slip velocity, which enhances heat transfer and mass diffusion to char particles and increases char consumption rate in diffusionlimited regions. The regions of high inner wall temperature spread from locations around burners to the whole inner wall of the injection and bottom regions in the first stage with increase of coal particle sizes.

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Numerical investigation of the heterogeneous combustion processes of solid fuels

Cited by 29 publications

References 34 publications

Investigation of coal particle gasification processes with application leading to underground coal gasification

Investigation of coal particle gasification processes with application leading to underground coal gasification

Numerical Study of Load Characteristics of a CFB Coal Gasifier by Using the Generalized Drag Model

Effect of coal particle size on gasification performance of two‐stage entrained‐flow coal gasifier

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