Fundamental Issues in Control of Carbon Gasification Reactivity

ISBN-13: 9780792310808 / Angielski / Twarda / 1991 / 622 str.

LaHaye;Ehrburger; L. LaHaye

Opis

During the last decade there has been a renewed interest in under standing from a fundamental point of view the gasification of carbon. Basi cally there are two major issues in controlling the reactivity of carbon: i) reduction of the gasification rate of carbon materials in hostile environment ii) increase of the gasification rate in order to utilize carbonaceous compounds more effectively. Although these two objectives look somewhat contradictory, they are part of the general topics of understanding gasification reactivity of carbon. Refractory applications of carbon in furnace linings, seals and vanes, as well as the use of carbon-carbon or carbon-ceramic composites in struc tures able to withstand corrosion at high temperature require a better understanding of the fundamentals involved in carbon-oxidizing gas (02' CO, H 0) reactions. Furthermore a great interest of aluminium producers 2 2 is 10 extending the lifetime of carbon electrodes in alumina electrolysis which primarily depends on reducing their consumption rates by air or carbon dioxide. Proper control of gasification reactions is also of prime importance in manufacturing carbonaceous adsorbents like granular activated carbon clothes of high adsorption characteristics. The balance between increase of porosity and decrease in mechanical strength during activation is critical for developing new porous types of carbon materials in particular for carbon clothes and this can only be achieved by a careful control of the gasification reaction."

Spis treści

Chemical Kinetics of Carbon and Char Gasification.- 13C/12C Isotope Spectrometry in the Study of Carbon Reactivity.- Mass Transport and Carbon Reactivity at High Temperature.- Oxidation of Single Char Particles in an Electrodynamic Chamber.- The CO/CO2 Ratio in the Products of the Carbon-Oxygen Reaction.- Oxy-Reactivity of Coal at Low Temperature and High Pressure during Great Depth Underground Gasification Tests.- Forty Years Ago, “La Combustion du Carbone”.- Carbon Gasification: the Active Site Concept.- Active Sites and Carbon Gasification Kinetics: Theoretical Treatment and Experimental Results.- Active Sites in Relation to Gasification of Coal Chars.- Specific Reactivities of Pure Carbon of Diverse Origins.- Active Sites in Carbon Gasification with CO2 Transient Kinetic Experiments.- Reactive Surface Area: An Old But New Concept in Carbon Gasification.- Coke Microtexture: One Key for Coke Reactivity.- Thermally Induced Changes in Reactivity of Carbons.- Surface Complexes on Carbon During Oxidation and Gasification.- Applications of Energetic Distributions of Oxygen Surface Complexes to Carbon and Char Reactivity and Characterization.- The Nature of Isothermal Desorption of Carbon - Oxygen Surface Complexes Following Gasification.- Radical Sites as Active Sites in Carbon Addition and Oxidation Reactions at High Temperatures.- Catalytic Gasification of Carbon: Fundamentals and Mechanism.- An Approach to the Mechanism of the CO2-Carbon Gasification Reaction Catalyzed by Calcium.- The Determining Role of Mineral Matter on Gasification Reactivities of Brown Coal Chars.- Protection of Carbon Against Oxidation: Role of the Active Sites.- Inhibition of Carbon Gasification.- Passivation of Carbon Active Sites for Oxidation Protection.- Controlled Gasification of Carbon and Pore Structure Development.- Control of Anode Consumption During Aluminium Electrolysis.- Synthesis and Recommendations for Future Work.- List of Participants.