Computational fluid dynamics simulation of Lafia-Obi bituminous coal in a fluidized-bed chamber for air- and oxy-fuel combustion technologies

Coal still remains the most plentiful and dominant fossil fuel. Coal is an inhomogeneous organic fuel formed mainly from decomposed plant matter consisting of aromatic and hydroaromatic structures joined by short aliphatic chains whereby aromaticity increases with coalification rank. The use of coal, particularly for electricity generation, is expected to continue for the foreseeable future. In this research study, computational fluid dynamics (CFD) is applied to simulate air-coal and oxy-coal flow, combustion, and emission characteristics in a fluidized-bed combustion chamber. This work investigates Lafia-Obi coal, which is found in the Middle Benue Trough (MBT) of Nigeria. As far as the authors are aware, this research presentation represents the first CFD-based assessment and analysis for any Nigerian coal. Realistic primary objectives of fluidized-bed combustion research in Nigeria would be the following: (1) establishing an understanding of the physics and emission characteristics of various fuels (coal, waste, etc.) in the country with a view to future scale-up; and (2) developing and establishing measures to curb pollutant emissions in such future power plants for electricity generation. The pertinent combustion parameters of this research were validated with existing experimental data; good agreement was achieved. This work furthers the understanding of the Lafia-Obi coal combustion mechanism and its potential utilization as fuel for future coal-power plants for electricity generation in Nigeria.