AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Effects of Fuel Moisture Content on Pollutant Emissions from a Rocket-Elbow Cookstove
LIZETTE VAN ZYL, Nicholas Good, Kelsey Bilsback, Kristen Fedak, John Volckens, Colorado State University
Abstract Number: 768 Working Group: Combustion
Abstract Rudimentary cookstoves are a major but poorly quantified source of air pollution. Fuel moisture content is expected to be an important determinant of cookstove emissions, however it has been investigated in few studies and for a limited number of climate- and health-relevant pollutants.
We measured emissions from fuels with 5%, 15%, and 25% fuel moisture contents. The tests were conducted in a controlled laboratory environment on a rocket-elbow cookstove with chopped and milled Douglas fir wood from the same tree. Gas-phase emissions measurements included carbon dioxide, carbon monoxide, and volatile organic compounds. Particle-phase emissions included PM2.5, elemental carbon, organic carbon, and ultrafine particles.
At 5% fuel moisture content, PM2.5 emissions (grams per kilogram of fuel burned) were reduced by 63% (p<0.001) compared to 25% fuel moisture content. The PM2.5 composition changed significantly between 5% and 25% fuel moisture content, with the elemental carbon to organic carbon ratio decreasing from 1.2 at 5% to 0.1 at 25% (p<0.001). Carbon monoxide emissions (grams per kilogram of fuel burned) were reduced by 49% (p=0.001) at 5% compared to 25% fuel moisture content. Carbon dioxide emissions did not change significantly (p=0.6) between fuel with 5% and 25% fuel moisture content. The hand cut and milled fuels showed no significant differences (p>0.05) in pollutant specific emissions on a dry fuel-mass basis, suggesting no comparative benefit of either preparation method.
These results suggest that using fuel with 5% moisture content instead of 25% substantially reduces emissions of some health-relevant pollutants. Our results indicate that drying fuel below the EPA recommended 20% moisture content could be of further benefit. Analysis of emission factors for volatile organic compounds, carbonyls, and ultrafine particles is currently underway.