Adequate power supply is an unavoidable prerequisite to any nation’s development. Local electric utilities around the world, take advantage of different power sources most accessible to them such as coal mines; dammed rivers, and new supplies of natural gas or nuclear plants to generate electricity.
The current state of electricity in Nigeria has played a major role in the hindrance of the nation’s economic growth and development. However, research has shown that there are vast energy resources in the country such as “Coal”. Coal is an important energy resources across the world, especially for electricity generation. With a global proven reserves of nearly 1 trillion tonnes. Coal is evenly spread across Nigerian states with an estimated reserve of 2.7 billion tonnes.
Research also shows that Coal is use by the power sector as a source of power generation in many countries around the world. The fossil fuel accounts for one-third of total energy consumption, second only to oil. Many of the world’s top coal producers are also the biggest users of coal for electricity, with China, U.S, and India (Essien and Igweonu, 2015).
Nigeria with estimated coal reserve of 2.734 billion tonnes spread across 22 locations continues to solely depend on oil and hydro sources for its power needs in the midst of continuous widening of the gap between Nigeria’s electricity demand and supply. However, this uses of coal as a source of power comes at a cost of environmental sustainability.
Nigerian coal is currently in high demand in the international market on account of its low Sulphur and moderate ash content. However, the nation’s supply is low, leading to the loss of $1 billion annually, this information was revealed by The Nigerian Bureau of Statistics (NBS). According to the current Minister of power Babatunde Fashola , Nigeria had no functional coal power plant, adding that the ministry had started issuing electricity generation licenses to firms that would generate power from renewable sources. This means there’s a need for coal, but the nation is not producing enough to meet the demand/need, in the case of electricity the nation could be burning coal as an alternative or complimentary source of power (electricity).
Burning coal for electricity: How it works
Almost all coal plants operating today use “pulverized coal” (PC) technology, which involves grinding the coal, burning it to make steam, and running the steam through a turbine to generate electricity. A newer technology known as integrated gasification combined cycle (IGCC) converts coal into a gas, runs the gas through a combustion turbine to generate electricity, and uses the excess heat from that process to generate additional electricity via a steam turbine (hence the term “combined cycle”).
Illustrative: Source (US Environmental Protection Agency, 2016)
Coal burning: what are the effects?
Coal is an important mineral that could be used to increase a nation’s electricity capacity, there is still the question of “At what cost?” . The most popular effect is the global warming emissions, through the release toxic chemicals that pollute our air and water. Which has an adverse, and costly effects on public health. These impacts include global warming, air quality deterioration, oil spills, and acid rain. Countries around as small amounts of radioactivity are released to the atmosphere from time to time from the coal-fired plants.
The commonwealth summit
These issues were addressed in the recent commonwealth summit in Paris, France. Where 53 leaders the growing appetite for coal-fired electricity generation, and their concern on the impact of coal on climate change and its global effects such as the ISIS and other rebel groups. At the summit world leaders were advised to stop/reduce the burning of coal, as a measure to reduce the impact on human health and global warming.
The 4 major impact of coal-fired plants
1. Global Warming
According to scientists, the gases emitted when fossil fuels are burned, one of the most significant is carbon dioxide, a gas that traps heat in the earth’s atmosphere. Over the last 150 years, burning fossil fuels has resulted in more than a 25 percent increase in the amount of carbon dioxide in our atmosphere. Climate scientists also predict that if carbon dioxide levels continue to increase, the planet will become warmer in the next century. Projected temperature increases will most likely result in a variety of impacts. In coastal areas, sea-level rise due to the warming of the oceans and the melting of glaciers may lead to the inundation of wetlands, river deltas, and even populated areas. Altered weather patterns may result in more extreme weather events. And inland agricultural zones could suffer an increase in the frequency of droughts.
2. Air Quality Deterioration
Clean air is essential to life and good health. Several important pollutants are produced by fossil fuel combustion: carbon monoxide, nitrogen oxides, sulfur oxides, and hydrocarbons. Carbon monoxide is a gas formed as a by-product during the incomplete combustion of all fossil fuels. Exposure to carbon monoxide can cause headaches and place additional stress on people with heart disease. Cars and trucks are the primary source of carbon monoxide emissions. They can irritate the lungs, cause bronchitis and pneumonia, and decrease resistance to respiratory infections. The fossil fuel use also produces particulates, including dust, soot, smoke, and other suspended matter, which are respiratory irritants. In addition, particulates may contribute to acid rain formation.
3. Water and Land Pollution
Coal mining also contributes to water pollution. Coal contains pyrite, a sulfur compound; as water washes through mines, this compound forms a dilute acid, which is then washed into nearby rivers and streams. Coal mining, especially strip mining, affects the area that is being mined. After the mining is completed, the land will remain barren unless special precautions are taken to ensure that proper topsoil is used when the area is replanted. Materials other than coal are also brought to the surface in the coal mining process, and these are left as solid wastes. As the coal itself is washed, more waste material is left. As the coal is burned, the remaining ash is left as a waste product.
4. Thermal Pollution
During the electricity-generation process, burning fossil fuels produce heat energy, some of which is used to generate electricity. The process is inefficient, much of the heat is released to the atmosphere or to water that is used as a coolant. Heated air is not a problem, but heated water, once returned to rivers or lakes, can upset the aquatic ecosystem.
Coal burning: Managing the effects
Burning coal, such as for power generation, gives rise to a variety of wastes which must be controlled or at least accounted for. So-called ‘clean coal’ technologies are a variety of evolving responses to late 20th century environmental concerns, including that of global warming due to carbon dioxide releases to the atmosphere. However, many of the elements have in fact been applied for many years, and they will be only briefly mentioned here:
- Coal cleaning by ‘washing’ has been standard practice in developed countries for some time. It reduces emissions of ash and sulfur dioxide when the coal is burned.
- Electrostatic precipitators and fabric filters can remove 99% of the fly ash from the flue gases – these technologies are in widespread use.
- Flue gas desulfurization reduces the output of sulfur dioxide to the atmosphere by up to 97%, the task depending on the level of sulfur in the coal and the extent of the reduction. It is widely used where needed in developed countries.
- Low-NOx burners allow coal-fired plants to reduce nitrogen oxide emissions by up to 40%. Coupled with re-burning techniques NOx can be reduced 70% and selective catalytic reduction can clean up 90% of NOx emissions.
- Increased efficiency of plant – up to 46% thermal efficiency now (and 50% expected in future) means that newer plants create less emissions per kWh than older ones. See Table 1.
- Advanced technologies such as Integrated Gasification Combined Cycle (IGCC) and pressurized fluidized Bed Combustion (PFBC) enable higher thermal efficiencies still – up to 50% in the future.
- Ultra-clean coal (UCC) from new processing technologies which reduce ash below 0.25% and sulfur to very low levels mean that pulverized coal might be used as fuel for very large marine engines, in place of heavy fuel oil. There are at least two UCC technologies under development. Wastes from UCC are likely to be a problem.
- Gasification, including underground coal gasification (UCG) in situ, uses steam and oxygen to turn the coal into carbon monoxide and hydrogen.
- Sequestration refers to disposal of liquid carbon dioxide, once captured, into deep geological strata.
Some of these impose operating costs and energy efficiency loss without concomitant benefit to the operator, though external costs will almost certainly be increasingly factored in through carbon taxes or similar which will change the economics of burning coal.
Coal based electricity generation: What are the prospects?
Clean coal based generation has been a major source of power in so many countries with coal deposits like Nigeria. The economic growth of countries like the USA, China, South Africa, Australia, India, to mention just a few has correlation with their level of generation which is boosted by clean coal based generation. The exploration of this opportunity that coal presents, the nation could device a system of power generation that leverage on the strengths of the six geo-political zones through their resources, such as coal, wind, solar, water and gas, among others, to improve power supply. A more comprehensive approach to resolving problems in the power sector is what Nigeria needs at this moment. There is the need to look at the energy strengths of each of the geo-political zones for growth.
For instance, states such as Benue, Kogi, Plateau, and others within the Middle Belt zone rely on hydro power, and should be allowed to use hydro power sufficiently. The Eastern part of Nigeria should rely on coal because of the abundant coal deposit in the area, to solve the energy needs of that zone. The Southern part of the country especially the South-south should rely on gas, which means that turbines would operate optimally in that area, once there is gas infrastructure. A lot of the demands for gas are in the South-western part of the country, especially Lagos and Ogun axis. They have thermal plants and some of these plants are operating sub-optimally due to lack of gas. The power plants should be linked to gas pipelines to power the turbines. There are huge but unexplored opportunities in the country
Professional bodies have advised that Coal use will be significant in the future. The IEA (International Energy Agency) believes that greater efforts are needed by government and industry to embrace less polluting and more efficient technologies to ensure that coal becomes a much cleaner source of energy in the decades to come. Nigeria has all the needed advantages to integrate coal based generation in its energy mix. Due to the global campaign against the emission of greenhouse gas (GHG) to the environment where coal combustion is a major contributor, clean coal generation technology options are recommended as Nigeria kick start this integration.
The China deal
The president of the federal republic of Nigeria, Muhammed Buhari recently signed a deal with china that has the prospect to open doors of opportunity to the nation. China being one of the top 5 coal users might be interested in investing in the sector.
Conclusion
Nigeria continues to search for means to reinforce its economic, social development and compete economically with the developed countries of the world. The integration of clean coal power generation in the Nigeria electricity mix could contribute a great deal to attainment of this objective. It is crucial to note that if the nation decides to use coal as an alternative or compliment for electricity, all the issues and managing options must be consider. If countries like China, USA that are developed countries, and even our continental neighbors South Africa could exploit coal for electricity and it’s been working for them so far, Nigeria can do the same.
2016-5-9-1462789820