Fuel Characterization of Newly Discovered Nigerian Coals

Abstract

This study seeks to characterize and highlight the fuel properties, rank, and classification of coals from Ihioma (IHM) and Ogboligbo (OGB) in Imo and Kogi states of Nigeria, respectively. The fuel properties were examined based on ultimate, proximate, and bomb calorific analyses. The results indicated that IHM coal contains comparatively higher C and H but lower O, N, and S content than OGB. In addition, the nitrogen (N) and sulphur (S) content for both coal samples were above 0.7 wt.% and 1.5 wt.%, respectively, which indicates high potential for pollutant emissions. Furthermore, the coal proximate properties were below 5 wt.% for Moisture; Volatiles (70 wt.%); Fixed Carbon (45 wt.%) and Ash (2.5 wt.%) on average. IHM coal has an HHV of 19.40 MJ/kg whereas OGB is 15.55 MJ/kg. This is due to the low carbon (C), hydrogen (H) and high oxygen (O) content in OGB whereas IHM contains higher VM and HHV. Furthermore, OGB presents better handling, storage, and transport potential. Furthermore, OGB has a higher fuel ratio and value index due to lower moisture, ash content, and volatiles. Based on the ASTM D388 standard, the coals were classified as Lignite (Brown) Low-Rank Coals (LRCs) with potential for energy recovery.

Physicochemical, Mineralogy, and Thermo-Kinetic Characterisation of Newly Discovered Nigerian Coals under Pyrolysis and Combustion Conditions

“…In this study, the moisture content of below 10% observed for all the coal samples are within the acceptable limits for electric power generation or conversion into value-added products (Chukwu et al 2016;Akinyemi et al 2020a). In contrast, the volatile matter (VM) is an important factor for determining not only the coal rank but also its suitability for potential energy recovery from thermal processes such as combustion and pyrolysis (carbonisation) (Speight 2012;Nyakuma 2016). The findings also showed that AKZ contains the highest fixed carbon (FC) content, which is typically inversely proportional to the VM content.…”

Air-Steam Gasification of Nigerian Lignite Coals for Hydrogen and Syngas Production

“…Table 1. Proximate, Ultimate and Sulphanal analysis of BMK and IHM (Nyakuma et al 2017) 3. Results and Discussion…”

Physicochemical, Mineralogy, and Thermo-Kinetic Characterisation of Newly Discovered Nigerian Coals under Pyrolysis and Combustion Conditions

“…The findings also showed that AKZ contains the highest fixed carbon (FC) content, which is typically inversely proportional to the VM content. The FC of coal is a measure of the estimated coke yield after devolatilization from carbonisation or slow pyrolysis (Nyakuma 2016).…”