IIT research recommends use of desulphurisation technology at thermal power plants in Delhi-NCR

The Ministry of Environment, Forest and Climate Change (MoEFCC) has received multiple extensions since the requirement for FGD installation was first notified in 2015. The latest extension has pushed the deadline to the end of 2029, making it mandatory for every thermal power plant to install FGD.

A petition was filed in the Supreme Court last year during a period of severe air quality issues in Delhi. The Supreme Court has asked the MoEFCC to explain why the extended deadline for FGD installation cannot be moved up to 2027. The MoEFCC is required to submit its response by April 29.

The IIT Bombay study reveals that transboundary sources account for approximately 85% of PM2.5 pollution. This suggests that most cities, even if they were to completely eliminate local anthropogenic sources, would still be unable to meet national clean air targets, as the majority of pollutants come from outside their boundaries.

The study also identified biomass burning (32%), energy generation (16%), and industrial activities (15%) as the main contributors to transboundary PM2.5 emissions.

IIT Delhi’s research mapped the factors influencing pollution patterns both across and within states. The study found that transboundary pollution is the largest contributor to PM2.5 levels, accounting for between 13% and 94%, followed by domestic emissions (2%–41%), industry (1–25%), transport (1–12%), and power generation (1–12%).

“While stringent penalties have been imposed on farmers for seasonal agriculture residue burning, the year-round industrial and power sector emissions continue largely unchecked due to regulatory leniency and delays in enforcement,” said Manoj Kumar N, researcher at the Centre for Research on Energy and Clean Air, examined the current status of FGD implementation, sulphur dioxide (SO₂) emissions, and insights from two new scientific studies published in 2025 by IIT Delhi and IIT Bombay.