What is it
Coal blending may be defined as the process of mixing two or more different types of coals to obtain a product with desired properties. The ever increasing dependency of the power sector on coal, in recent times, and the decreased availability of coal resulted in the blending of coal. Reduction of cost of generation is another reason for adopting coal blending. It has been found that blending of high grade imported coals with low grade high ash coal matches well to the requirements and makes the heat generating properties of coal better for commercial purposes.
The Benefits
Blending of coal is popularly utilized at power plants as it improves the performance of coal to meet the explicit terms and also reduces the coal costs a great deal. It has been seen that whenever coal is burnt, a large amount of ash is produced along with various toxic oxides and sulphides. Coal blending, also known as beneficiation, reduces the effect of the harmful materials in ash production in large scale. The beneficiation process also improves the quality of the coal and certain reactive materials are added to the resultant coal which increases the overall enthalpy of the coal. Using blended coal in power stations reduces the production, maintenance, and even the investment costs, thus reducing the overall cost of the power so produced.
The lowdown
When coal is used to produce power it has to undergo the process of burning. However, along with the useful power, many harmful products like arsenic and toxic gases like sulphur dioxide and nitrogen oxide are also produced. The dangerous carbon dioxide, which is one of the main reasons for pollution and global warming, is produced in tons in the power stations. Besides the severe effects of coal gases on environment, one should not forget that it is a non renewable source of energy. This fossil fuel is becoming less and less with time and so should be used in a proper way.
Green Alternatives:
1. Geothermal power generation
Geothermal energy refers to the energy generated from the earth by its heat. This energy is clean, sustainable, and renewable as this energy has a source that is found a few miles beneath the earth’s surface. This form of energy has been harnessed in the form of hot springs, and for cooking, for centuries, but now it is being used to generate electricity.
For the construction of geothermal power plants, capital costs are much higher than for coal based power plants. But geothermal power plants can be operated and maintained at reasonable costs. The power so generated is environmental friendly as it produces no pollution. The disadvantages, however, are its high initial cost and the place required to lay the piping system can be quite large and is thus not suitable for small developments.
2. Solar thermal power generation
Solar energy refers to the energy that we get from sun’s heat. This thermal energy is used by humans to generate electricity. The sun’s radiant heat on the earth’s surface is collected by parabolic shaped trough systems or the solar power plant may incorporate the use of lenses and mirrors to concentrate the sun’s energy and generate electricity out of it. All these systems generate a tremendous amount of electricity harnessing sun’s heat. This power generation is more than wind power and nuclear power plants. This free and renewable source of energy is also environmental friendly. Though it has a great potential, its still costlier than the coal based power.
The bottom line
Though blended coal reduces a little amount of greenhouse gases, but this is still not enough and is not a perfect solution for the problem of pollution as beneficiated coal incorporates good quality and bad quality coal. This coal again fills the environment with green house gases whenever burnt to generate power but instead of reducing the carbon emission and the motto of going green is somehow not a reality.
