Emissions from South Asian brick production

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Climate Change Studies

Background:

• Brick kilns are a major source of air pollution in South Asia.
• Kiln design and fuel choice significantly impact emission profiles.
• Existing emission inventories may overestimate pollutant factors.

Purpose of the Study:

• To quantify aerosol and gaseous pollutant emissions from various South Asian brick kiln technologies.
• To compare emission factors across different kiln types and assess their climate warming impact.
• To provide more accurate emission data for global climate models.

Main Methods:

• Tested thirteen South Asian brick kilns representing six different technologies.
• Measured particulate matter (PM2.5), carbon monoxide (CO), and optical scattering/absorption in exhaust.
• Calculated emission factors for various pollutants, including elemental carbon (EC).

Main Results:

• Significant differences in emission factors (up to an order of magnitude) were observed between kiln types.
• Dominant traditional kilns exhibited the highest PM2.5 and light-absorbing carbon emissions.
• Improved Vertical Shaft, Tunnel, and zig-zag kilns demonstrated lower emission factors.
• Measured emission factors for PM2.5 and EC were substantially lower than those in current inventories.
• The ratio of EC to total carbon was higher than previously estimated for the dominant kiln type.

Conclusions:

• Brick kiln technology choice critically influences air pollutant emissions and climate impact.
• Upgraded kiln designs offer a pathway to reduce PM2.5 and carbon emissions.
• Revised emission factors are necessary for accurate climate modeling of the brick industry's contribution.