AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Laboratory Characterization of Ultrafine Particle Number Size Distributions and Other Pollutants from Traditional and Improved Biomass Cookstoves
YUNGANG WANG, Daniel Wilson, Kathleen Lask, Ashok Gadgil, Lawrence Berkeley National Laboratory
Abstract Number: 113 Working Group: Combustion
Abstract Almost half of the world’s population still cooks on biomass cookstoves such as three stone fires (TSF) that exhibit poor efficiencies and primitive designs. Emissions from biomass cookstoves contribute to climate change and substantial morbidity and mortality. The smoke from biomass cooking fires has recently been found to be the largest environmental threat to human health and is associated with 4 million deaths each year. Ultrafine particles (UFP, D$_p < 100 nm) are widely reported in biomass combustion smoke, and dominate the total airborne particle number concentrations. Size-resolved and high time resolution (1 Hz) measurements of UFP emissions from biomass cookstoves have not been documented in the current literature. During the past decade, a number of improved cookstoves with higher energy efficiency (and some with lower emissions), have been designed and promoted across the world. However, relatively limited UFP emission data from these stoves were reported. These data were in the format of total number of particles per volume unit of air with low time resolution (every two minutes). Furthermore, only a few number of replicate tests were conducted, commonly three, for each stove being evaluated. In this study, the Berkeley Darfur Stove and the TSF have been tested and compared for their performance and emissions characteristics with 15 replicates under well-controlled laboratory conditions at the stove testing facility of Lawrence Berkeley National Laboratory. UFP particle number size distributions are measured at 1 Hz using a Fast Mobility Particle Sizer Spectrometer (FMPS, model 3091, TSI, Inc.), together with PM$_2.5, black carbon (BC) mass concentrations, and CO/CO$_2 gases. Results of stove performance (time to boil, fuel consumption and energy efficiency) and real-time emissions of UFP and other co-pollutants are presented. Source apportionment by Positive Matrix Factorization (PMF) is also carried out to interpret different stages of the combustion process.