Flue Gas Desulphurization Units: Systems Designed to Remove Sulfur Dioxide from Power Plant Emissions
Slow Implementation of Flue-Gas Desulphurisation (FGD) Systems in Indian Coal-fired Power Plants
India's push towards reducing sulphur emissions from coal-fired power plants has faced several challenges, as highlighted by the slow commissioning of FGD systems. As of August 2024, only 39 units have been commissioned out of the total installed coal capacity of approximately 214 GW, which equals 46% of the total generation mix.
Economic and Technical Challenges
The high capital cost of installing FGD systems, around Rs 0.6-0.8 crore per MW, and the operational costs, including increased auxiliary power consumption, have posed significant barriers. Auxiliary power consumption related to FGD could increase carbon emissions, with some studies projecting an additional 69 million tonnes of CO₂ emissions from 2025-2030.
Regulatory Shifts
The initial mandate for FGD installation was issued in 2015 by the Ministry of Environment, Forest and Climate Change (MoEFCC). However, due to compliance difficulties, the deadlines have been extended multiple times, with the latest being 2024/25/26 for Category A/B/C plants. A government order in July 2025 exempted about 78-79% of coal-fired power plants from mandatory FGD installation, subjecting only plants near major cities and pollution hotspots to strict deadlines.
Plant Location and Pollution Categorization
Plants within 10 km of highly polluted urban centers ("Category A") remain under strict FGD deadlines, but "Category B" and "Category C" plants farther away receive exemptions or are subject to looser norms. This spatial differentiation considers local air quality impacts and attempts to balance environmental and economic concerns.
Coal Quality
Indian plants have relatively low sulphur content (below 0.5%), which some studies argue reduces the environmental and economic justification for universal FGD mandates. SO₂ levels in many regions are reportedly below the National Ambient Air Quality Standards (NAAQS).
Environmental and Public Health Concerns
SO₂ is a precursor to PM2.5 fine particulate pollution, linked to respiratory and cardiovascular diseases. Environmental groups warn that relaxing FGD installation risks worsening air quality and public health.
Industry Market Uncertainty
The changing regulatory landscape has created market and industry uncertainty. The initial mandate stimulated large-scale investment and contracts for FGDs, but the latest policy relaxations have put many projects’ future in doubt.
In conclusion, the main factors affecting the implementation of FGD systems are the capital and operational costs of FGD systems and associated CO₂ emission concerns, evolving government regulations and exemptions based on plant location, coal quality (low sulphur content reducing urgency), logistical and technical difficulties in installation, environmental and public health considerations, and market and industry uncertainty from policy shifts. These factors interact to slow broad FGD implementation in Indian coal-fired thermal power plants despite the policy intent to reduce sulphur emissions.
The European Union's Large Combustion Plant Directive (LCPD) includes emission ceilings and an opt-out for limited operating hours, leading to the retirement of older plants and a decrease in SO₂ emissions by 85% from 1990 to 2020. Despite coal growth, SO₂ emissions have fallen by 87%. The average capital cost for an FGD system is approximately ₹1.2 crore per MW, with a nationwide roll-out on 219 GW costing over ₹2.5 lakh crore. Various initiatives, such as funding for a NTPC-IIT-BHU collaborative pilot on SNOX technology for multi-pollutant scrubbers, ring-fencing 20% of NCAP grants for staff augmentation and forensic audits of FGD performance, and the establishment of a statutory Indo-Gangetic Airshed Council to harmonise State action plans, are being undertaken to address these challenges.
- The slow implementation of Flue-Gas Desulphurisation (FGD) systems in Indian coal-fired power plants is a result of economic and technical challenges, regulatory shifts, plant location and pollution categorization, coal quality, environmental and public health concerns, and industry market uncertainty.
- High capital cost and operational costs, including increased auxiliary power consumption, pose significant barriers to the installation of FGD systems.
- A government order in July 2025 exempted about 78-79% of coal-fired power plants from mandatory FGD installation.
- Plants near major cities and pollution hotspots are subject to strict FGD deadlines, while "Category B" and "Category C" plants receive exemptions or are subject to looser norms.
- Indian plants have relatively low sulphur content, which some studies argue reduces the environmental and economic justification for universal FGD mandates.
- SO₂ is a precursor to PM2.5 fine particulate pollution, linked to respiratory and cardiovascular diseases.
- The changing regulatory landscape has created market and industry uncertainty, putting many FGD projects’ future in doubt.
- The European Union's Large Combustion Plant Directive includes emission ceilings and an opt-out for limited operating hours, leading to the retirement of older plants.
- Various initiatives, such as funding for a NTPC-IIT-BHU collaborative pilot on SNOX technology, are being undertaken to address the challenges in implementing FGD systems.
- The European Union's efforts to reduce SO₂ emissions by 85% from 1990 to 2020 are remarkable, despite coal growth.
- The average capital cost for an FGD system is approximately ₹1.2 crore per MW, with a nationwide roll-out on 219 GW costing over ₹2.5 lakh crore.
- The establishment of a statutory Indo-Gangetic Airshed Council to harmonise State action plans is aimed at addressing these challenges and promoting health and wellness, environmental-science, education-and-self-development, personal-growth, career-development, policy-and-legislation, and job-search, as well as general-news and skills-training in the industry.
