Revista de Engenharia Química e Tecnologia de Processos
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Abstrato

Elucidation of the Influence of Coal Properties on Coal-Char Reactivity: A Look at Southern Hemisphere Coals

Andrew Odeha, Samuel Ogbeideb and Charity Okieimenc

Pyrolysis is the first step in most coal conversion processes such as combustion, gasification and liquefaction. Coal char combustion is influenced by a wide variety of parameters (burnout time, heat release, mineral matter content etc.) which are factored into the reactivity of the char. On heat treatment, the coal particles undergo thermochemical decomposition with liberation of tars and volatiles and the formation of a resultant char. The reactivity of the char is dependent on both the physical and chemical changes that accompanying heat treatment of the coal particles. The char reactivity exhibited the same trend of decrease with increasing pyrolysis temperature for the four temperature program used in this evaluation. The derived aromaticity, total reflectance, surface area and porosity were found to increase with increasing pyrolysis temperature. The activation energy of the various chars were also determined with an mean activation energy of 184 for lignite, 154 for sub-bituminous, 94 for low volatile bituminous, 146 for high volatile bituminous, 113 for semi-anthracite and 152 KJ/mol for the anthracite coal respectively.