A recent study commissioned by the Office of the Principal Scientific Adviser (PSA) and carried out by the National Institute of Advanced Studies (NIAS), Bengaluru, has suggested that the Union Environment Ministry re-consider its order mandating coal-based power plants to install Flue Gas Desulphurisation (FGD) units in order to bring down sulphur emissions.
The study argues that the directive, issued in 2015 and later amended in 2022, may not be the most cost-effective or scientifically justified approach to tackling air pollution. Instead, it suggests that alternative measures, such as dispersing Sulphur emissions through taller stacks and adopting cleaner coal technologies, could achieve comparable environmental benefits at a lower cost.
Key Findings of the Study
1. Doubtful Cost-Benefit Ratio – The research points out that the estimated ₹90,000 crore cost of FGD installation at India’s coal-based power plants may not provide corresponding improvements in air quality. According to the researchers, Sulphur dioxide (SO₂) only accounts for 2-11% of particulate matter (PM2.5) pollution in all regions, and other sources such as vehicular exhaust and burning biomass account for more.
2. Alternative Solutions Proposed – Instead of FGDs, the study recommends:
- Taller Stacks – Increasing stack heights to disperse emissions more widely, reducing localised pollution.
- Coal Washing – Using washed coal with lower sulphur content before combustion.
- Focus on Regional Pollution Hotspots – Implementing stricter SO₂ controls only in critically polluted areas like Delhi-NCR, rather than a nationwide mandate.
3. Global Precedents – The report refers to US and European examples, where FGDs were fitted solely in polluted areas, but dispersion methods were used in other areas.
Industry and Environmental Responses
The electric power industry has been arguing for years that FGD installations are costly and technically demanding, resulting in compliance delays. Industry organizations have greeted the study by saying that a more flexible system could help decrease costs without sacrificing air quality objectives.
But environmentalists have raised concerns. “Rolling back FGD mandates would retard India’s advancement in reducing toxic emissions,” Centre for Research on Energy and Clean Air (CREA)’s Sunil Dahiya said. “Sulphur dioxide is a significant health risk, and India is already behind the curve in emission control.”
Government’s Stance
The Environment Ministry officially remains to be seen responding to the recommendations made by the study. Sources suggest that the results will be studied by the Central Pollution Control Board (CPCB) and other stakeholders prior to any revision of policy.
The 2015 emission standards asked all thermal plants to install FGDs by 2022, but deadlines were pushed back several times because of logistical and fiscal challenges. If the ministry accepts the study recommendations, it would be an important change in India’s coal pollution control policy.
The NIAS study offers a fact-based case for reconsidering India’s FGD mandate, weighing economic viability against environmental objectives. While controversies rage on, the government is confronted with a key choice—whether to impose expensive Sulphur scrubbers or implement alternative strategies to effectively address air pollution.