AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
On-line and Batch Lab Measurements of Primary and Photochemically Aged Biomass Cook-stove Emissions
STEPHEN REECE, Aditya Sinha, Roshan Wathore, Andrew Grieshop, North Carolina State University
Abstract Number: 514 Working Group: Aerosol Chemistry
Abstract Combustion in rudimentary and improved cook-stoves used by billions in developing countries emits black carbon (BC), primary organic aerosols (POA) and precursors for secondary organic aerosol (SOA). Recent studies suggest that SOA formed during photo-oxidation of primary emissions from biomass burning may make important contribution to its atmospheric impacts. However, the extent to which stove type and operating conditions affect the amount, compositions and characteristics of SOA formed from the aging of cookstoves emissions is still largely undetermined. Here we present results from experiments with a field portable oxidation flow reactor (F-OFR) designed to assess aging of cook-stove emissions in both laboratory and field settings. Lab testing will compare the quantity and properties of fresh and aged emissions from an open fire and alternative stove designs operated on the standard water boiling test (WBT) and alternate protocols.
Diluted cook-stove emissions were exposed to a range of OH and O$_3 concentrations in the OFR. Primary emissions were aged both on-line, to study the influence of combustion variability, and sampled from a fixed emission population in a smog chamber to examine different aging conditions. Data from real-time particle- and gas-phase instruments and integrated filter samples were collected up and down stream of the OFR. Preliminary experiments aging diluted biomass emissions from distinct phases of stove operation (smoldering and flaming) showed peak enhancement for both phases occurring between 3 and 6 equivalent days of aging with slightly greater enhancement during the flaming phase. OA emission factors, determined using the carbon balance, were also distinct to burn conditions for fresh and aged emissions. OA/BC ratios were orders of magnitude greater during smoldering than the flaming phase and both phases increased with aging. These results highlight importance of stoves operating conditions and aging on composition and characteristics of SOA with important climate forcing implications.