Revised Framework for SO₂ Emission Norms in Thermal Power Plants
The Union Environment Ministry has defended its decision to introduce a revised framework for thermal power plants regarding sulphur dioxide (SO₂) emission norms. This move, as per the ministry, is based on sectoral emission trends, evidence, and sustainability imperatives.
Key Aspects of the Revised Framework
- The new compliance framework exempts many coal- and lignite-based plants from retrofitting with flue gas desulphurization devices.
- Research indicates no significant difference in ambient SO2 concentrations between cities with or without the technology.
- SO2, a harmful gas emitted during coal combustion, contributes to secondary pollutants.
Health and Environmental Impact
- The ministry claims current SO2 exposure levels do not present a major public health concern under existing ambient conditions.
- Sulfate aerosols from SO2 form a small fraction of PM 2.5.
Compliance Categories
- Category A: Plants near Delhi-NCR or cities with over a million population must comply by 2027.
- Category B: Plants near critically polluted areas will have case-by-case evaluations.
- Category C: Plants outside these areas are exempted from SO2 norms but must meet stack height criteria.
Financial Implications
- Retrofitting with FGD technology nationwide requires an estimated capital expenditure of Rs 2.54 lakh crore.
- The ministry stresses careful scrutiny of these high-cost investments against their limited environmental benefits.
Conclusion
The revised policy is presented as a pragmatic, scientifically justified, and cost-effective approach, reflecting declining SO₂ levels and the limited role of SO₂ in PM2.5 health impacts, while considering resource demands.
