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

Authors: Odeh AO, Ogbeide SE, Okieimen CO

DOI Info: N/A

ABSTRACT

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. Six coals of different ranks were subjected to conventional, advanced characterization and combustion reactivity experiments. The char reactivity exhibited the same trend of decrease with increasing pyrolysis temperature for the different coals evaluated at four combustion temperatures. The derived aromaticity, total reflectance, surface area and porosity were found to increase with increasing pyrolysis temperature. The activation energy of the various chars was also determined and a mean value of 184 kJ/mol for lignite, 154 kJ/mol for sub-bituminous, 94 kJ/mol for low volatile bituminous, 146 kJ/mol for high volatile bituminous, 113 kJ/mol for semi-anthracite and 152 kJ/mol for the anthracite coal respectively were obtained.

Download Full Text