Nearly 75% of India's total power generation capacity is thermal, of which coal based power generation is nearly 90% and diesel, wind, gas and steam adding to about 10%. High ash content in the range of 30 to 50% in Indian coal is the major cause for large voluminous quantities of coal ash. India's dependence on coal as a major source of energy had been of prime importance in the past and shall continue in this millennium, and therefore fly ash management would remain an important area of national concern.
With ever increasing use of coal as source of energy particularly in thermal power stations increasing generation of fly ash as by product viz-a-viz its utilisation/disposal is being felt necessary and sometimes obligatory.
In the Indian context, with high ash content in coal from Indian coal mines and consequent generation of high quantity of fly ash the Government of India through Department of Science and Technology and Fly Ash Mission aims towards building confidence in gainful utilisation in various sectors like Cement products, Agriculture and as Fill material etc. Gainful disposal technology of fly ash through Technology Development Projects is need of the hour. Major production of fly ash is from coal based thermal power stations. Out of the present installed generating capacity of over 1,00,000 MW more than 70,000 MW is thermal comprising mainly coal-based generating plants. In the next 10 years, additional power generating capacity of 1,00,000 MW is envisaged. Even after giving more emphasis to develop hydro power to have appropriate hydro thermal mix, the bulk power generation will come from coal-based thermal power stations only. Currently 75-85 million tonne of fly ash is being produced annually and this is likely to cross the 100 million tonne mark in next few years. Presently, the coal ash is a well established resource material.
Due to increasing environmental concern and growing magnitude of the problem it has become imperative to manage fly ash. More importantly because fly ash has tremendous potential to be utilized. Keeping in view this versatility of fly ash, several Government and NGOs are involved in fly ash utilization and safe disposal efforts in the country.
Coal ash utilization represents an important and growing industry. Coal combustion products (CCPs) include fly ash, flue gas desulfurization materials, boiler slag and other materials that are finding increased application in the construction, road paving, and building trades. Today, this use represents a multi-billion dollar industry in the U.S., including markets for lightweight aggregate, high-strength pozzolans, wallboard, polymeric filler, cinder blocks, tile, and variety of other construction products. The re-use of these materials also contributes to improved environmental quality and sustainable development.