Coal-Fired Power Plants: Catalysts of India's Secondary PM2.5 Pollution

A CREA analysis reveals that 42% of India's PM2.5 pollution originates from secondary particulate matter, mainly ammonium sulfate formed from sulfur dioxide (SO2). The study emphasizes the need for stricter SO2 controls, especially in coal-fired plants, for effective air quality management.

A new analysis from the Centre for Research on Energy and Clean Air (CREA) has found that 42% of PM2.5 pollution in India comes from secondary sources like ammonium sulfate, formed from sulfur dioxide emissions primarily linked to coal-fired power plants. India remains the world's largest sulfur dioxide emitter, with power plants contributing to at least 60% of national emissions.

The current regulatory framework has significantly weakened efforts to control sulfur dioxide at the source by exempting around 78% of coal-fired power plants from installing essential flue gas desulphurization systems. The study by CREA urges for mandatory FGD systems across all plants to mitigate secondary ammonium sulfate formation, crucial for reducing PM2.5 pollution under the National Clean Air Programme (NCAP).

Seasonal analysis shows ammonium sulfate is a persistent component of PM2.5 year-round, peaking in winter and post-monsoon, and contributing up to 42% of the PM2.5 mass. As NCAP revises strategies, experts stress that addressing secondary particulate matter is vital for sustainable improvements in India's air quality.

(With inputs from agencies.)