AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Light Absorbing Organic Carbon Aerosol Emissions from Cookstoves in India
APOORVA PANDEY, Sameer Patel, Pratim Biswas, Shamsh Pervez, Judith Chow, John Watson, Rajan Chakrabarty, Washington University in St Louis
Abstract Number: 565 Working Group: Carbonaceous Aerosols in the Atmosphere
Abstract Combustion of solid biomass in traditional cookstoves in south Asia is the largest source of carbonaceous aerosols emissions in the region. Currently, there is a high level of uncertainty in the estimated aerosol direct forcing over this region from the underlying uncertainties and discrepancies in inputs to climate models. As a step towards resolving these discrepancies, our objectives were to (1) develop particulate emission factors for in-field operation of traditional biomass cookstoves, and (2) estimate wavelength dependent Mass Absorption Cross-sections (MAC) of the emitted aerosols and their light absorbing organic carbon (LAOC) components.
A field study was conducted in Raipur, Chhattisgarh (a central Indian state) in December 2015. Common types of biomass fuel—fuel-wood, agricultural residue and cow dung — from different regions of India were used in a traditional mud stove to prepare typical meals in a household kitchen. Emissions were sampled with an eight-armed probe and analyzed using a portable mobility particle sizer, a TSI SidePak and a TESTO gas analyzer. Particle samples were collected on Teflon and quartz fiber filters during the ignition, steady flaming and smoldering phases of the combustion cycle. The Teflon filters were used for gravimetric analysis and UV-vis spectrophotometry on the filter deposits and their extracts in water and acetone. Thermo-optical (IMPROVE-TOR) analysis on the quartz filters yielded the elemental and organic carbon fractions. Emission factors (PM2.5, EC, OC and CO) were calculated using the carbon balance method. Filter transmission spectra were used to calculate the total aerosol MAC, which was apportioned to Black Carbon and LAOC using the two-component model. The total contribution of LAOC to aerosol light absorption was estimated by integrating its absorption coefficient with solar irradiance in the 300-900 nm wavelength range.