Predicting lignite devolatilization with the multiple parallel and two-competing reaction models

Sprouse, Kenneth M.; Schuman, M. D.

doi:10.1016/0010-2180(81)90026-2

Cited by 16 publications

(9 citation statements)

References 7 publications

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“…However, the utility of this model too, may be restricted by the need to determine the parameters DOC), k, Eo, and 0' for the specific coal dust of interest. Sprouse and Schuman (1981) have compared the lignite data of Figure 3.8 (1000-2100 K) with predictions from Eqns. (3.7) and (3.8) as shown in Figure 3.…”

Section: Chaptermentioning

confidence: 99%

Coal Combustion and Gasification

1985

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This limited facsimile edition has been issued for the purpose of keeping this title available to the scientific community. © 1985 Springer Science+Business Media New York Originally published by Plcnum Press, New York in 1985 Softcover reprint of the hardcover Ist edition 1985 AII rights reservedNo part of this book may bc reproduced, storcd in a retrieval system, or transmittcd in any form or by any means, electronic, mechanical, photocopying, microfilming.recording, or othcrwise, without written permission irom the Publisher · .. II, that r",weth light, and cont",,,,th In C",/, re",vtlh mort bght: and that bght grou,tlh brighter and brighter .. Doctrine and Covenants 50:24 DEDICATIONRecognizing its several limitations, we unpretentiously dedicate this book to our Creator, Who, through holy writ, has inspired us to seek light and understanding where darkness exists, and Who, through these same records, has taught us to place our professional pursuits in perspective with greater obligations of service to family and to society. PREFACE ix 4. Chapters 9, 10, and 14 provide the fundamental equations and background for turbulent combustion systems. 5. Chapters 11-13 and 15 document in some detail the approach and theory for the interactions between chemistry and turbulence in reacting systems encompassing gaseous flames, particle-laden systems, and pollutant formation in these systems.This work has formed the basis for model development at our Combustion Laboratory. These fundamentals were treated generally in the first book. The treatment in this new book for governing equations and for radiation is not greatly changed. However, significant new material is added for chemically reacting, turbulent, heterogeneous systems and for formation of nitrogen oxide pollutants. Included in several of these chapters are comparisons of measurements with predictions from a comprehensive model developed at the Combustion Laboratory. These comparisons demonstrate the state of development of the comprehensive code which, in the view of the authors, is suitable for some practical application to pulverized-coal systems. While this method has been developed principally for pulverized-coal combustion and gasification, this and similar methods have far more general applicability. The code is directly applicable to nonreactive gaseous and particle-laden flows and to reactive gaseous systems. Progress is being made for application to coal slurries and only minor work would be required for use with liquid fuel flames.The authors recognize the several uncertainties in constructing and applying models of this nature. Coal is a very complex heterogeneous substance whose structure and behavior are highly variable and are not well known. Pyrolysis and oxidation of coal are dependent upon coal type, size, size distribution, temperature history, etc., thus making generalization difficult. In addition, the complexities of turbulent recirculating flows, turbulent reacting flows, and turbulent two-phase flows are not fully resolved. Only recently ...

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Section: Chaptermentioning

confidence: 99%

Coal Combustion and Gasification

1985

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“…(19). However, choosing realistic ranges for the preexponential factor still results in Eovw being close to Ei,st, as shown in Tables 2 and 3 (0.6% error).…”

Section: Accuracy Of the Ofw Methods When Applied To Multiple Reactionsmentioning

confidence: 66%

“…Equation (19) shows that the difference between the observed activation energy, EoFw, and the mean activation energy, Einst , depends on the spread of activation energies, as given by at. In practice this spread will be limited by the nature of the reactions occurring.…”

Section: Accuracy Of the Ofw Methods When Applied To Multiple Reactionsmentioning

confidence: 99%

Meaningful activation energies for complex systems

Dowdy¹

1987

Journal of Thermal Analysis

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It is known that the application of an inappropriate kinetic method to the thermal analysis of complex systems can lead to misleading results. To avoid this problem, the new parameter 'instantaneous mean activation energy' is introduced and the Ozawa-Flynn-Wall method is assessed as a means of obtaining it. It is concluded that good results can generally be obtained by this method, provided that the various reactions occurring in the complex system are of the same type. The pyrolysis of coal is considered as a possible application of the method.

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“…Figure 2 is a typical result with Illinois #6 coal showing the gasifier's space residence time to be less than 0.5 second for 100 wt% carbon conversion at a nominal 82% cold gas efficiency (CGE -higher heating value, HHV, basis). This figure was developed from a detailed computer model by Sprouse (1980) and Sprouse and Schuman (1981). As a comparison, commercial gasifiers operating without multi-element rapid-mix injectors (such as Royal Dutch Shell's and General Electric's Texaco gasifiers that rely on large internal recirculation zones for temperature suppression) require space residence times on the order of 3 seconds.…”

Section: Executive Summarymentioning

confidence: 99%