Characterisation of Benue Trough Coals for Efficient Utilisation

Abstract

Nigeria is Africa’s largest economy, and coal is the country’s most abundant fossil fuel. Its utilisation in Nigeria faces significant challenges due to limited data on its characterisation and properties. The research looks at the physicochemical, mineralogical, functional groups, and thermogravimetric properties of three Nigerian coals—Gombe coal, Kogi coal, and Lafia-Obi coal—using X-ray Diffraction (XRD) to examine their morphological structures, FTIR spectroscopy to identify the functional groups and cross-linked molecules, and Thermogravimetric Analysis (TGA) to monitor the changes in sample weight with time and temperature. The mineralogical analysis showed that graphite, quartz, and goethite are present in all three of the coals examined. Orthoclase is found in both the Gombe and Kogi coals, while microcline is only present in the Lafia-Obi coal. Moreover, anatase is also found in Gombe coal. Interestingly, since it has a high sulphur content (0.83%), low aromatics, a high oxygen content (5%), and minerals such as anatase (0.96%) and orthoclase (10%), this coal is not suitable for coke production. On the other hand, the Kogi coal was found to contain a high amount of fixed carbon (52.40%), have low sulphur (0.23%), and possess prominent graphite, which means it can be used for coking when blended. Furthermore, it was noted that Lafia-Obi coal is the most appropriate for coking, as it has a high fixed carbon content (56.40%), low moisture (2.96%), a high aromatic content, and contains the minerals graphite, quartz, and microcline. Hence, this study presents important insights into the characteristics of coals widely available in Nigeria and could help support industrial applications and more efficient use.