Emission Factors and Optical Properties of Pollutants Emitted from the Laboratory-Simulated African Biomass Burning

Abstract:

Emissions from open biomass burning and residential cookstoves are the major sources of particulate and gaseous air pollutants. Indoor and outdoor air pollutants are responsible for multiple health impacts leading to 4-6 million premature deaths globally, with more than 90% of the population residing in low- and middle-income countries. The largest global sources of black carbon are open burning of forest and savannas and is believed to be one of the key components of air pollutants and climate warming. Emissions from Africa are the major sources of global carbon emissions however they are poorly quantified due to limited studies. In this study, we present the data from laboratory measurement of biomass burning emissions from six different African fuels. The particulate matter (PM) emission factor shows dependency on modified combustion efficiency (MCE) with a range from 0.8 to 25 g/kg for pure flaming and pure smoldering emissions. Although, CO and CO₂ emission factor shows MCE dependency, the emission factor of NO shows fuel type dependency with some fuels showing consistently higher emissions factor regardless of burn conditions. We also explore the particulate number emission factor and found that it also shows dependency with MCE like PM mass. Furthermore, we explored the size and mass-specific aerosol optical properties namely mass absorption cross-section and single scattering albedo and found that burning conditions impact the absorptive properties of aerosol regardless of fuel types. We found that absorption angstrom exponent (AAE) and mass absorption cross-section (MAC) of size-selected aerosol shows an inverse relationship with higher AAE for lower MAC.

We acknowledge the support from the national Science Foundation grant number NSF-#1831013