Coal-based power generation continues to be the mainstay of electricity generation in the country, constituting over 75 per cent of the total power generated in 2015-16. However, coal-based generation results in a large quantity of fly ash emissions, especially with the use of domestic coal, which has 30-45 per cent ash content. To prevent the deleterious impact of fly ash on the ecosystem, its appropriate utilisation is of critical importance. Merely disposing of the ash requires a large area of land/water and results in large-scale environmental damage.
The government has been prescribing standards for the proper utilisation of fly ash for a long time. The Fly Ash Utilisation Programme (FAUP), launched in 1994, aimed at promoting the utilisation of ash as well as research in this area. Meanwhile, the Ministry of Environment, Forest and Climate Change (MoEFCC) issued the first notification on fly ash utilisation in September 1999 (which was subsequently amended in 2003, 2009, 2015 and 2016), stipulating targets for fly ash utilisation. According to the 2009 amendment, all coal/lignite power station/expansion units in operation before November 2009 were mandated to achieve 100 per cent fly ash utilisation within five years of the date of notification, and those commissioned after November 2009, to achieve 100 per cent fly ash utilisation within four years from the date of their commissioning. However, the current level of fly ash utilisation in the country remains far below the prescribed targets.
Recently, the MoEFCC, through a notification dated January 25, 2016, has stipulated guidelines to enhance the profitable utilisation of fly ash. It has prescribed that the cost of transportation of fly ash would be borne entirely by the TPP up to 100 km and equally shared between the user and the TPP for more than 100 km and up to 300 km. It has further been made mandatory to use fly ash-based products in government schemes, such as the Pradhan Mantri Gram Sadak Yojana and the Swachh Bharat Abhiyan.
Trends in fly ash utilisation
Between 2005-06 and 2014-15, fly ash generation grew at a compound annual growth rate (CAGR) of 7.14 per cent to reach 184 mt. On a year-on-year basis, it grew 6.52 per cent from 173 mt in 2013-14 to 184.28 mt in 2014-15. Further, in the first six months of financial year 2015-16 (April to September 2015), ash generation stood at 84 mt, recording a decline of 8.69 per cent over the 92 mt in the corresponding period of the previous year.
On the fly ash utilisation front, between 2005-06 and 2014-15, there was a modest improvement, from 45.69 per cent to 55.69 per cent. In absolute terms, fly ash utilisation in 2014-15 stood at 103 mt against 100 mt in the previous year. Further, in the first six months of financial year 2015-16 (April to September 2015), fly ash utilisation stood at 56.04 per cent against 53.01 per cent in the corresponding period of the previous year. Meanwhile, during the 10-year period, the highest level of fly ash utilisation was recorded in 2009-10 at 62.6 per cent.
With regard to fly ash utilisation in the first half of 2015-16, the Central Electricity Authority (CEA) analysed the performance of 132 TPPs (aggregating 130,429 MW of installed capacity and consuming 251.69 mt of coal with 33.23 per cent ash content), 15 TPPs aggregating 19,039 MW recorded 100 per cent (and above) fly ash utilisation, 21 TPPs aggregating 14,298 MW recorded 90-100 per cent utilisation, and 47 TPPs aggregating 62,382 MW of capacity recorded fly ash utilisation of less than 50 per cent, among others.
State-wise, in the first half of 2015-16, four states – Chhattisgarh, Maharashtra, Uttar Pradesh and West Bengal – generated over 9 mt of fly ash each, with Uttar Pradesh recording the highest fly ash generation at 12 mt. Meanwhile, Delhi recorded over 100 per cent fly ash utilisation, and Gujarat, Haryana, Jharkhand, Punjab, Rajasthan, Tamil Nadu and West Bengal achieved fly ash utilisation of over 75 per cent.
In terms of the end-use of fly ash, in the first half of 2015-16, the maximum utilisation of fly ash, of 42 per cent of the total utilisation was recorded in the cement sector, followed by 13 per cent in making bricks and tiles, 11 per cent in reclaiming low-lying areas and 11 per cent in mine filling, among others.
CEA’s recommendation for ash utilisation
In a recent report, the CEA has made the following recommendations for improving the levels of ash utilisation in the country:
- Efforts to renovate and modernise TPPs need to take into account the technological advancements required to ensure the development of dry fly ash collection, storage and disposal facilities so that fly ash in its dry form can be made available to users.
- Greater sensitisation through policy intervention, planning strategies, fiscal incentives, etc. is required in states and districts where TPPs are located for the proper utilisation of fly ash and fly ash-based building products. Measures should be taken to promote their use in the construction of buildings, highways, roads, flyovers and other infrastructure projects.
- There is a need for strict enforcement of the MoEFCC’s notifications dated January 25, 2016 and November 3, 2009 mandating the use of fly ash-based building products in construction works within a radius of 100 km of any TPP. This can be enforced by the government agencies responsible for the approval of building plans in the government and private sectors.
- Greater awareness is required among the National Highways Authority of India, the Central Public Works Department, state public works departments and other agencies involved in the construction of highways, roads, flyovers, etc., about the stipulations of the MoEFCC. This has to be ensured from the project formulation stage and included in the tender documents by having a prior tie-up with the concerned TPP.
- The use of fly ash in backfilling/stowing of opencast and underground mines within a radius of 50 km of any TPP should be ensured from the initial stage of the preparation of a mine development plan.
- There is significant potential for large-scale utilisation of fly ash in the construction of embankments for laying railway lines. However, research must be carried out to address safety concerns regarding its use in constructing railway embankments with passenger traffic.
- There are certain reservations regarding the use of fly ash in the development of agricultural land and wasteland due to the presence of heavy metals and radioactive elements. However, research indicates that there are no adverse effects in using fly ash on agricultural land, and better awareness can allay such fears.
- A number of projects like the FAUP by the Department of Science and Technology have been undertaken for technology development, as well as for demonstration, dissemination of information and creating awareness about the safe management and increased commercial applications of fly ash.
- Efforts have to be made by individual TPPs to explore and promote all possible modes of fly ash utilisation at their respective stations. TPPs must ensure the use of fly ash and fly ash-based building products for the development of infrastructure like buildings, roads and flyovers, reclamation of low-lying areas and raising of ash dykes.
To conclude, there is an urgent need for concerted efforts by all the stakeholders (TPP developers, end-use industries, etc.) for undertaking the utilisation of fly ash. Further, promoting profitable utilisation of ash would encourage developers to undertake fly ash management. Besides, strict enforcement of the prescribed norms is critical for accelerated and better utilisation of fly ash.