Coal is the world’s largest source for electricity production and is indispensable for other industrial developments, such as steel and cement production. The diversity and abundance of coal reserves in the world mean that this mineral can meet the strategic challenge of having energy in the future, and thus, it is estimated that coal’s share will be 40% by 2100, when oil as an energy source would virtually disappear. Therefore, clean coal technology has to address the dual challenge of producing energy in an economical and environmentally friendly way.
In the 80′s, some governments initiated collaborative programs with private industry to encourage the development of Clean Coal technologies, so that it could improve both energy efficiency and environmental tolerance in the extraction, preparation and uses of coal – and thereby achieve a reduction of pollutant emissions such as sulphur and nitrogen oxide and increased the amount of energy harnessed. In general, the Clean Coal technology is cleaner and more efficient and less expensive than conventional processes, and is based on altering the basic structure of coal in some phases of the combustion process.
Moreover, modern methods of exploration and extraction minimize the environmental impact and improve the utilization efficiency of the mine. Measures to reduce noise and dust, and contamination of groundwater or methane gas, which can be a potential risk, are generalized and improved to the point that sometimes the gas is used as an energy source. When preparing the coal has been reduced to ash content and impurities such as mud or sulphur, while improving the quality of waste water.
Among the various technologies under development that are used at present, include coal gasification. This system consists of putting coal in contact with steam and oxygen, so thermo chemical reactions occur that generate a combustible gas composed primarily of carbon monoxide and hydrogen, which when burned can be used for gas turbines. Some hybrid combined cycle Clean Coal technologies using the best features of the gasification and combustion technologies, achieving efficiencies greater than 50%.
The so-called “Central Fluidized Bed Combustion” improves performance in the combustion of coal and reduces environmental impact. In these plants burn coal in a bed of inert particles, such as limestone, through which circulates air improves combustion. In the long term, carbon capture and storage of CO2 have enormous environmental and economic potential, to allow coal to be at the core of an economy based on hydrogen.
In short, if the coal will be a basic energy source for future sustainable development, it is necessary to build new plants that work with this type of clean coal technology, in order to reduce emissions of greenhouse gases and help to achieve the targets. The provision of such technologies by European coal industry companies could bring benefits for both the environment and the same companies that are currently before an uncertain future. In this regard, there several European programs that encourage research and development of technologies that pursue those objectives.