Fundamentals Of The Physical Chemistry Of Pulverized Coal Combustion

The study of coal for the production of energy is certainly not a new area of research. Many research works were carried out to improve the efficiency of industrial and domestic facilities. In the sixties, however, because of the availability and low cost of petroleum, coal consumption decreased and the research effort in this area was minimum. Meanwhile, the situation has totally changed. Considering the reserves of oil and the instability ofregions where they are located, it is becoming absolutely necessary to develop other sources of energy.The major alternative to oil appears to be coal, at least for the near future. Indeed, the reserves known today represent several centuries of energy consumption.!t is therefore becoming urgent to develop efficient and non polluting technologies to produce energy from coal. The main possibilities are : · liquefaction · gasification · directed combustion. Research and development efforts on liquefaction have been considerably reduced because of high cost of technologies involved and poor prospects for the next two decades. Research works on gasification are progressing; it is a promising approach. However, direct combustion either in pulverized coal furnaces or in fluidized beds is the more promising way of expanding rapidly the utilization of coal. These techniques are already used in some facilities but many environmental problems remain, slowing down their development.

This work is a broad, integrated treatment of the fundamentals of coal combustion and gasification. Most of the authors are recognized professionals in the field and all are conducting research work in the Advanced Combustion Engineering Research Center. The focus of the book is on clean and efficient use of coal. Practical chapters on coal processes, including coal technology projects and on acid rain formation control, lay a foundation for the fundamental treatment. The book is comprehensive in its treatment with over 1000 world-wide references, most of which are from the past five years.

viii and approaches could be adapted to other coal conversion and combustion problems, we have not considered combustion or gasification in fluidized or fixed beds or in situ processes. In addition, we have not considered other fossil-fuel combustion problems associated with oil shale, tar sands, etc., even though many aspects of pulverized-coal combustion would relate to these problems. For the case of pulverized-coal models, we have attempted to provide a detailed description of the model foundations. Parts I and II of this book emphasize general principles for describing reacting, turbulent or laminar, multiphase systems. General conservation equations are developed and summarized. The basis for computing thermochemical equilibrium in complex, heterogeneous mixtures is presented, together with techniques for rapid computation and reference to required input data. Rate processes are then discussed, including pertinent aspects of turbulence, chemical kinetics, radiative heat transfer, and gas-particle convective-diffusive interactions. Much of Part II deals with parameters and coefficients for describing these complex rate processes. This part of the book provides recommended values of coefficients and parameters for treating complex reacting flows. Parts I and II may well be suitable for use in an advanced course in reacting flows, and have been written partly with that in mind. Part III deals with more specific aspects of pulverized-coal characteristics and rate processes. Following a general description of coal structure and constitution, coal pyrolysis and char oxidation processes are considered.

Harness State-of-the-Art Computational Modeling Tools Computational Modeling of Pulverized Coal Fired Boilers successfully establishes the use of computational modeling as an effective means to simulate and enhance boiler performance. This text factors in how computational flow models can provide a framework for developing a greater understanding of the underlying processes in PC boilers. It also provides a detailed account of the methodology of computational modeling of pulverized coal boilers, as well as an apt approach to modeling complex processes occurring in PC boilers in a manageable way. Connects Modeling with Real-Life Applications Restricted to the combustion side of the boiler (the authors assume some prior background of reaction engineering and numerical techniques), the book describes the individual aspects of combustion and heat recovery sections of PC boilers that can be used to further improve the design methodologies, optimize boiler performance, and solve practical boiler-related problems. The book provides guidelines on implementing the material in commercial CFD solvers, summarizes key points, and presents relevant case studies. It can also be used to model larger boilers based on conventional, super-critical, or ultra-super critical technologies as well as based on oxy-fuel technologies. Consisting of six chapters, this functional text: Provides a general introduction Explains the overall approach and methodology Explores kinetics of coal pyrolysis (devolatilization) and combustion and methods of its evaluation Presents computational flow modeling approach to simulate pulverized coal fired boiler Covers modeling aspects from formulation of model equations to simulation methodology Determines typical results obtained with computational flow models Discusses the phenomenological models or reactor network models Includes practical applications of computational modeling Computational Modeling of Pulverized Coal Fired Boilers explores the potential of computational models for better engineering of pulverized coal boilers, providing an ideal resource for practicing engineers working in utility industries. It also benefits boiler design companies, industrial consultants, R & D laboratories, and engineering scientists/research students.

Combustion technology has traditionally been dominated by air/fuel combustion. However, two developments have increased the significance of oxygen-enhanced combustion-new technologies that produce oxygen less expensively and the increased importance of environmental regulations. Advantages of oxygen-enhanced combustion include less pollutant emissi

The seventy-five refereed papers in this volume represent the second in a series of biannual benchmarks for technologies that maximize energy conversion while minimizing undesirable emissions. Covering the entire range of industrial and transport combustion as well as strategies for energy R&D, these state-of-the-art contributions will be indispensable to mechanical and chemical engineers in academia and industry, and technical personnel in military, energy, and environmental agencies of government.

Careful organization and empirical correlations help clarify the prodigious technical information presented in this useful reference. Key Features * Written for practicing engineers, this comprehensive book supplies an overall framework of the combustion process; It connects information on specific reactions and reaction sequences with current applications and hardware; Each major group of combustion solids is evaluated; Among the many topics covered are: * Various biomass forms * The coalification process * Grate, kiln, and suspension firing * Fluidized bed combustion * Gasification of solids * The manufacturing process