Fly Ash Management and Utilisation Mission

In News

• The National Green Tribunal (NGT) directed the constitution of a ‘Fly Ash Management and Utilisation Mission’ in its recent order. 

Image Courtesy: ToI 

About

• The order by the NGT takes note of the ‘unscientific handling and storage’ of the fly ash by coal thermal power stations.
  • For example, the draining of industrial effluents and fly ash in the Rihand Reservoir.

• Goal: 
  • The Mission’s primary goal will be to ‘coordinate and monitor issues relating to the handling and disposal of fly ash and associated issues.’
• Immediate reason: 
  • Where remedial action and relief were sought from it against violations by coal thermal power plants.
• Headed by:
  • The Mission is to be jointly headed by the secretaries of the Union Ministry of Environment, Forest & Climate Change (MoEF&CC), Union Ministry of Coal and Power and the chief secretaries of Uttar Pradesh and Madhya Pradesh.
• Nodal agency: 
  • The secretary of MoEF&CC will be the nodal agency for coordination and compliance. 
• Other focus areas of the mission:
  • The Mission may also monitor scientific management and utilisation of fly ash by power projects outside Singrauli and Sonbhadra, in coordination with chief secretaries of concerned states.
• Earlier cases dealt with:
  • The mandate for scientific management and utilisation of fly ash.
  • The draining of industrial effluents and fly ash in the Rihand Reservoir.
  • The breach in the fly ash pond of the Sasan Ultra Mega Power Plant resulted in the deaths of six persons including an eight-year-old boy washed away in fly ash slurry.
  • The serious gaps in storing fly ash in ponds and dykes and associated failure to prevent unintentional and undesirable emissions from it.  

Fly Ash

• About: 
  • Fly ash is an unwanted unburnt residue of coal combustion in a coal thermal power plant. 
  • During combustion, mineral impurities in the coal (clay, feldspar, quartz, and shale) fuse in suspension and float out of the combustion chamber with the exhaust gases. As the fused material rises, it cools and solidifies into spherical glassy particles called fly ash. 
  • It is emitted along with flue gases during the burning of coal in a furnace and collected using electrostatic precipitators.
• Collection and transportation: 
  • The fly ash collected with the help of precipitators is converted into a wet slurry to minimise fugitive dust emissions. 
  • It is then transported to the scientifically designed ash ponds through slurry pipelines.
• Data: 
  • Gross under-utilisation of this by-product over the years has led to the accumulation of 1,670 million tonnes of fly ash according to the Summary of Ash Generation and Utilisation during 2020-2021 by the Joint Committee earlier constituted by the NGT.     
• Type of coal and ash: 
  • The low-grade coal used in thermal power generation carries 30-45% ash content. The high-grade imported coal has a low ash content of 10-15%. 
  • Since most of the coal used in thermal plants is low-grade, it generates a large quantity of ash which requires a large area as a landfill or ponds for disposal.
• Composition:
  • Fly ash includes substantial amounts of silicon dioxide (SiO2), aluminium oxide (Al2O3), ferric oxide (Fe2O3) and calcium oxide (CaO).
• Usage:
  • It is an excellent material for making construction materials such as bricks, mosaic tiles and hollow blocks. 
  • Bricks made of fly ash can help conserve soil to a great extent.
  • There are several eco-friendly ways to utilise fly ash so that it does not pollute air and water.
  • It includes the use of fly ash in the manufacturing of cement, ready-mix concrete; constructing roads, dams and embankments, and filling of low-lying areas and mines.

Issues 

• Fly ash contains toxic and heavy metals. 
• The ponds where fly ash is usually dumped are poorly managed. Fly ash becomes dry as temperature increases and gets airborne. 
  • Thus, it becomes one of the major sources of air and water pollution. 
• Air in areas around coal-fired power plants in polluted with fly ash.
• Apart from causing various diseases, it also leads to a reduction in the recharging of groundwater. 

Initiatives Taken

• Optimum utilization of fly ash: 
  • To facilitate 100% ash utilization by all coal-based thermal power plants, a web portal for monitoring of fly ash generation and utilization data of Thermal Power Plants and a mobile-based application titled “ASHTRACK” has been launched by the Government. 
• Ash-park: 
  • To create an awareness programme for utilisation of fly ash and its products conducted at various platforms.. 
• Roles played NTPC:
  • National Thermal Power Corporation (NTPC) has developed an infrastructure to transport fly ash from power plants in bulk to cement plants, at a cheaper cost.
  • NTPC intends to transform the fly ash it produces into a revenue-generating by-product.
  • It has developed geopolymer and nano aggregates from residual fly ash for use in the construction of roads and houses as a manifestation of this.
• Latest Fly Ash Notification 2021:
  • It mandates all coal and lignite-based TPPs to utilise 100 per cent fly ash in an environment-friendly manner for making construction sector products
  • It has made provision for the ‘enforcement, monitoring, audit and reporting of the progress of fly ash utilisation and implementation of the clauses of the notification by coal thermal power plants and user agencies.
• Goods and Services Tax (GST) rates on fly ash and its products have been reduced to 5%.

Way Forward 

• Promoting R&D for increasing the efficiency of power plants will also help in reducing ash generation.
• Proper management of fly ash is important for the environment and also for power plants as it occupies a  lot of land space.
• The order by the NGT takes note of the ‘unscientific handling and storage’ of the fly ash by coal thermal power stations. The Fly Ash Management and Utilisation Mission is expected to streamline the fly ash management process.

Source: DTE