AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Controlled Studies on Aerosol Formation During Biomass Combustion in a Flat Flame Reactor
JIAXI FANG, Anna Leavey, Pratim Biswas, Washington University in St Louis
Abstract Number: 384 Working Group: Combustion
Abstract Billions of people worldwide rely on biomass to cook their food each day. Biomass is also receiving renewed interest as a potential carbon-neutral energy alternative. The use of biomass as a fuel has the advantages of being renewable and sustainable; however burning it typically results in higher PM emissions often due to use of poorly designed combustion systems. In rural areas, the resulting poor air quality has been shown to significantly contribute to the global burden of respiratory and other diseases. Despite this enormous reliance on biomass, and its severe health consequences, there is a surprising paucity of fundamental studies examining particle formation during the initial stages of biomass combustion. This is an important omission given that particles are primarily formed at this stage of the combustion process.
A flat flame reactor was designed to study the early stages of combustion. Studying the well controlled rapid pyrolysis of biomass, factors contributing to particulate emissions were examined. Four different types of biomass, including juliflora ,cotton stalk, poplar, and applewood were pyrolysed in a methane-air flat flame. Particulate matter formed was characterized through measuring the CO emissions and surface, mass, and particle number size distributions. The moisture content of biomass feed stock was varied from 0%- 25% moisture content while the particle feed sizes were maintained below 100um to maintain a thermally thin regime. Thermo-gravimetric Analysis (TGA) was also conducted on the biomass to obtain mass fraction data(% volatiles, moisture content) along with kinetic data. Experiments have shown that factors contributing to reduced the efficiency of devolitilization promote higher emissions as such factors will be discussed in this presentation. Results from this study can be used to optimize biomass combustion for use as fuel in household settings to minimize negative impacts due to poor air quality. Implications on atmospheric aerosols will also be elucidated.