Brick kilns and air pollution
Context: A new study on Bangladesh's zigzag brick kilns shows that simple heat-loss reduction measures can significantly cut emissions and energy use, offering scalable solutions for South Asia's informal sector pollution.
Important Pointers:
Brick Kilns and Air Pollution: Brick kilns contribute 8–14% of total air pollution in South Asia, emitting high levels of PM2.5 and black carbon, impacting public health.
Air Pollution in Bangladesh: As per IQAir 2024, Bangladesh had the second-worst air quality, with PM2.5 levels over 15 times the WHO limit; brick kilns are major contributors.
Zig-Zag Kiln Technology: Forces hot air to move in a zigzag path, enhancing combustion and heat transfer, reducing emissions and fuel consumption, and improving brick quality.
Key Government Intervention: The mandatory shift to Zig-Zag kiln technology is recommended to improve energy efficiency and lower emissions.
Recent Study Findings (Science, 2024): A trial on 276 kilns in Bangladesh showed a 23% reduction in energy use, a 20% drop in CO₂ and PM2.5 emissions, and lower fuel costs per brick.
Low-Cost Efficiency Interventions: Included continuous fuel feeding, improved brick stacking, ash layer on top, sealed kiln gates, and use of biomass fuel.
Adoption Success: 65% of kilns adopted suggested practices; researchers found no rebound effect, making savings more impactful.
Public Health Impact: Full adoption across 6,352 kilns in Bangladesh could cut 2.4 million tonnes of CO₂ in one firing season (~2% of annual emissions).
Relevance to India: Similar interventions can be scaled across South Asia, including India, where informal kilns remain major polluters.