Nigerian coal power stations : their future in the light of global warming

Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.Nigeria is presently being faced with a growing electricity demand problem following its population growth rate. The total installed capacity is far less than the current demand for electricity supply. As a way of bridging out this supply gap, the federal government is mobilizing all of its potential energy options. Coal is widely used for power generation in many countries. But today, the continued usage of coal for power generation is being challenged by the disturbing global warming phenomenon. This is due to the quantity of uncontrolled carbon dioxide emission from traditional coal-fired power plants. The aim of this dissertation is to critically analyse the future of the Nigerian coal power stations following the need to do carbon dioxide emission control necessary for ensuring a sustainable environment. Achieving this aim entails the appraisal of environmental regulation standards and cost structures of carbon dioxide (C02) emission reduction options for the coal power stations. Controlling carbon dioxide emission from existing coal power stations requires retrofit system that captures and effectively sequestrates the captured CO2. The cost and performance effect of the CO2 retrofit system on the existing power plant can be simulated with standard computer software models. In this study the lECM-cs computer modelling tool for power plants was used in determining the cost and performance impacts of applying an Amine-based C02 capture system to the Oji river power station in Nigeria. With the lECM-cs model, it was established that reducing C02 emission imposes an additional cost on the power plant which increases the unit cost of electricity generated. This additional cost index requires economic justification for its acceptance. This is due to the need to demonstrate its viability judging from the cost of electricity generated from other sources in the Nigerian economy. For the Oji river case, the station is old and requires extensive renovation. This causes a cost escalation over and above the cost associated with the CO2 sequestration system. As such, Oji coal power station does not have an economic future if C02 emission sequestration becomes obligatory. The future of coal power stations in Nigeria can be considered from two scenarios: one where the current national environmental standard is retained and another where it is revised. The revision classifies CO2 as a pollutant which makes its emission reduction imperative for coal power plants. Under the current standard, building modern large capacity pulverized coal-fired power plants with improved steam cycles should be encouraged. But with the review of the national standard, the focus should be on building new large capacity coal power stations with integrated CO2 emission control. This will ensure an environmentally friendly future for coal power stations in Nigeria.Master