The Ministry of Power in India recently made a significant announcement. It informed the Lok Sabha that to meet Sulphur dioxide (SO2) emission norms, Thermal Power Plants are implementing the use of Flue Gas Desulphurisation (FGD) equipment. This comes after the Ministry’s decision in September 2022 to extend the deadline for Coal-Fired power plants installation of FGD by a span of two years, aiming to reduce harmful sulphur emissions.
Categorisation of Power Plants for Installing FGD
The Ministry has divided power plants into different categories for installing FGD based on their location and timelines for compliance:
1. Category A power plants are those located within a 10 km radius of the National Capital Region (NCR) or cities with a population of over a million (as per the 2011 India census). These power plants have until 31st December 2024 to comply.
2. Category B power plants, found within a 10 km radius of Critically Polluted Areas or Non-attainment cities (as defined by CPCB), have until 31st December 2025.
3. Lastly, Category C power plants – which are not included in the other two categories, have until 31st December 2026 to install FGD.
What is Flue Gas Desulfurization (FGD)?
FGD refers to the process through which sulfur compounds are removed from the exhaust emissions of fossil-fueled power stations. Absorbents are added, which can eliminate up to 95% of the sulphur dioxide from flue gas – the material emitted when fossil fuels such as coal, oil, natural gas, or wood are burned for heat or power.
The Need for FGD in India
Indian cities bear the burden of some of the world’s most polluted air. Emissions of SO2 in India are nearly double that of the next highest country, Russia. Thermal utilities, producing 75% of the country’s power, contribute to around 80% of industrial emissions of sulphur and nitrous oxides. These emissions result in harmful lung diseases, acid rain and smog. The delay in implementing norms and installing FGD is causing significant health and economic damage to society. High levels of SO2 pollution in India could be curbed soon since FGD systems have successfully reduced emission levels in countries like China, which was responsible for the highest level of SO2 Pollution in 2005.
Sulfur Dioxide Pollution: Source and Impact
The burning of fossil fuels by power plants and other industrial facilities is the most substantial source of SO2 in the atmosphere. Other smaller sources include industrial processes such as extracting metal from ore, natural sources such as volcanoes, and vehicles like locomotives and ships.
Short-term exposure to SO2 can severely impact the human respiratory system, making breathing difficult. Individuals with asthma, particularly children, are sensitive to the effects of SO2. The World Health Organisation estimates that it causes 4.2 million deaths globally each year.
Additionally, SO2 emissions that lead to high concentrations of SO2 in the air can also lead to the formation of other sulfur oxides (SOx). These can react with other compounds in the atmosphere to form small particles, contributing to Particulate Matter (PM) pollution.
