Improving environmental performance

This area of the India project comprises two parts:

Emission control:

Evaluation of the status of installation of control technologies for particulate matter ( PM), sulphur dioxide (SO2) and nitrogen oxides (NOx) and how coal-fired power plants can maximise the potential for co-benefit mercury reduction.

Ash management:

Evaluation of the status of ash management and use in India. This section of work will determine options to reduce ash waste in ponds whilst enhancing ash use in both construction materials and high-value end products.

Emission control:

The coal-fired power sector is one of India’s most polluting industrial sectors – coal-fired power plants contributed 60% of the total particulate matter, 45% of the total SO2, 30% of the total NOX, and more than 80% of the total mercury emissions from all industrial sectors in the country in 2020. In response to ongoing environmental concerns, the Indian government set new emission limits for PM, SO2, NOx and mercury from coal plants in December 2015.

However, implementation of this legislation has been hindered by delays and derogations which hinge on the argument that compliance is either too technically challenging for Indian coals or too expensive. However, in terms of health effects and GDP within India, compliance with the new emission limits is significantly more cost-effective than non-compliance. It is therefore vital that all stakeholders work together to facilitate compliance most cost-effectively.

Despite the introduction in 2015 of legislation requiring reductions in SO2 and NOx emissions, the uptake of control technologies in India has been slow. The graph below shows the status of the installation of flue gas desulphurisation (FGD) for SO2 emission reduction across India according to this new ICSC study (Sloss and others, 2023 – in draft).

As discussed in the desk report, the reasons for delay are numerous, relating to cost, equipment availability, age of the plant, and space and water restrictions. The desk report on this work will be available in the first half of 2023 from this page.

Ash management:

The Indian government has a goal for 100% ash use throughout India by 2024. Whilst some States are achieving this and more through the additional recovery of older ash pond stockpiles, others have regional issues to address. For many plants, the challenge is finding industrial partners to take and use the fly ash at, or above, the rate of production (the latter being required to remediate stockpiles). The ash use directives have evolved to require coal plants to deliver ash to end-users free of charge within a radius of 300 km. But some regions do not have sufficient users or markets (mainly construction) within 300 km, or any economic delivery distance, from the plants. There may be mutual benefits from coordinating longer-range transport of bulk ash via rail networks and also for establishing construction and building material franchises at or near power plants in these cases.

There is also potential for selling ash for high-value end uses. For example, cenospheres (hollow, light weight fly ash ’bubbles’) can be highly valuable as fillers in paints and plastics. The extraction of rare earth elements (REE) from ash in India could have dual benefits, including the production of high-value materials both for export and for use in the growing national technology manufacturing base. It will be necessary to evaluate market prospects in conjunction with feasibility studies on Indian ash (see also the ICSC reports by Ian Reid and others relating to ash, available from our ICSC library [link to library search page].

To achieve the goal of 100% utilisation of power station by-products India will need to focus more on the challenge of legacy ash piles, which can pose a significant risk to human health in some regions. Many of these ashes may be unsaleable. It will also be prudent for utilities to plan to establish markets for the gypsum that will arise from the FGD processes required across much of the coal power fleet. There is potential for India to use all this additional material profitably if the market is prepared.

The map below shows the fly ash utilisation rate, %, as established in the new ICSC report.

Some states are finding it hard to achieve 100% ash utilisation whereas others are achieving over 200% ash utilisation, made possible by adding the use of legacy and stockpiled ash to the ash produced daily.

This report has been published and can be downloaded here. Based on the report findings, training materials has been designed and regional training in India is underway – Four regional workshops are in progress:

  • 29 & 29 May, 2023, Raipur
  • 5 & 6 June, 2023, Delhi
  • 27 & 28 July, 2023, Nagpur
  • 3 & 4 August, 2023, Chennai

More information and registration here