Investigating Sasol Coal Characteristics for Power Plant Boiler Firing using Thermal Gravimetric and CHNS Analytical Techniques

Abstract–: The operational efficiency of a coal-fired boiler is strongly dependent on the type of coal fuel used for firing the boiler. The coal quality is based on its characteristics i.e., organic, inorganic chemical composition, and heating value. This study investigates the operational effectiveness of the coal-fired boiler used for steam generation operated by Sasol synfuel limited in Secunda Mpumalanga province in the Republic of South Africa based on the coal used as the primary feedstock for firing the boiler. The coal samples were collected for laboratory analysis to determine their characteristics i.e., proximate, ultimate analysis, and heating values. And evaluate how the coal characteristics affect the boiler’s operational efficiency. These coal samples were analysed using the CHNS technique to determine their percentage elemental composition (Carbon, Hydrogen, Nitrogen, Sulphur, and Oxygen) and thermal gravimetric analysis (TGA) to determine the sample’s inorganic constituents (moisture content, volatile matter, mineral matter, fixed carbon content, ash content). The international organisation of standardisation (ISO) method was used to calculate the coal sample’s proximate analysis. In applying the analysed results on the boiler performance, a structured designed questionnaire was used to collect data on the temperature and output steam pressure changes during the boiler operation at Sasol synfuel operations in Secunda, Mpumalanga. The data was collected for 30 days. The results from the analysed laboratory coal samples and the statistical data in this study indicated that the coal used for firing the boiler(s) is composed of suitable characteristics and the boiler performance can be increased by routine regular maintenance and replacement of the ageing heat transfer tubes.