Recently, the Union Minister for Power and New & Renewable Energy informed about the installation of Flue Gas Desulphurisation (FGD) equipment in thermal power plants.

Background

• Thermal power plants are required to install Flue Gas De-sulphurisation (FGD) equipment to adhere to emission regulations, as per the guidelines set by the Ministry of Environment.
• The aim of this process is to guarantee adherence to emission norms established by the Ministry of Environment, Forest and Climate Change (MoEF& CC) and follow the directives provided by the Central Pollution Control Board (CPCB).

About FGD

• It is a technology to removes sulphur dioxide (SO2) from the flue gas (exhaust gas) stream of fossil-fuel power plants and other industrial processes that emit SO2.
• In this process a sorbent is used which is usually lime or limestone, to react with SO2 in the flue gas and convert it into harmless products.
• The sorbent could be injected as a dry powder, sprayed as a wet slurry or circulated as a seawater solution and resultant products can be collected as solid residues, dissolved in water or discharged into the sea.
• Wet scrubbing, Wet sulphuric acid process, Dry sorbent injection and Spray-dry scrubbing are four major different types of FGD.

Benefits of FGD

• Reduced SO2 emissions: FGD can remove up to 95% or more of SO2 from flue gas, significantly improving air quality.
• Reduced acid rain: SO2 is a major contributor to acid rain, which damages forests, lakes, and buildings. FGD helps mitigate this problem.
• Improved public health: SO2 exposure can cause respiratory problems, especially for people with asthma. FGD reduces these health risks.
• By product utilization: Wet FGD produces gypsum, which can be used in various applications like wallboard manufacturing or cement production.

 Sulphur Dioxide (SO₂)

• Fossil fuels such as coal and oil often contain high amounts of sulphur, and when these fuels are burned, around 95% or more of the sulphur is converted to sulphur dioxide (SO2), which is emitted as flue gas.
• Sulphur dioxide in itself is a major air pollutant which impacts all life.
• It is also a precursor of acid rain, which has significant adverse impacts on forests, freshwaters, and soils, in turn killing insect and aquatic life forms, causing paint to peel, corrosion of steel structures such as bridges, and weathering of stone buildings and statues.

Central Pollution Control Board (CPCB)

• Established under the Water (Prevention and Control of Pollution) Act, 1974
• Also entrusted powers and responsibilities under Air (Prevention and Control of Pollution) Act, 1981
• Founded: 22 September 1974
• Headquarters: New Delhi