Representation of coal and coal derivatives in process modelling

• Published in: Journal of the Southern African Institute of Mining and Metallurgy Vol. 115; no. 5; pp. 339 - 348
• Main Authors: Theron, J A, le Roux, E
• Format: Journal Article
• Language: English
• Published: 01-05-2015
• Subjects: Carbon; Coal; Combustion; Derivatives; Guidelines; Liquids; Metallurgy; Representations
• ISSN: 2225-6253
• DOI: 10.17159/2411-9717/2015/v115n5a1

This paper provides guidelines on performing mass and energy balance modeling involving coal and coal derivatives. Usually, the inputs to a pyrometallurgical process would be specified in terms of elements and compounds. Reliable thermochemical data is more widely available for species involving uniquely defined, relatively smaller molecules. However, in the case of coal, the molecules are extremely large and not uniquely defined. Consequently, modeling processes involving coal and its derivatives involve several potential pitfalls. These are outlined in the present paper. It is recommended that an "enthalpy correction value" be incorporated in energy balances involving combustion, devolatilization, or conversion of coal and coal derivatives, e.g. coke, char, or tar. That would imply that proximate analysis, elemental analysis, as well as the gross CV would be required for all solid or liquid coal-derived substances being modeled. No other correction due to carbon being present in a form other than graphite should be used, as that would imply double-counting some effects.