Physical and Chemical Characterization of Particulate and Gas Phase Emissions From Biomass Burning.

摘要

Biomass burning is a dynamic combustion process during which large concentrations of particles and trace gases are released into the atmosphere. Trace gases emitted by fires include significant amounts of carbon monoxide, nitrogen oxides, volatile organic compounds, and long-lived greenhouse gases such as carbon dioxide and methane. This work surveys 18 different vegetation types of southeast (SE) and southwest (SW) U.S. commonly present in prescribed burns. The work provides key factors for prediction of Particulate Matter (PM) and gas phase emissions, and serves as a basis for atmospheric models used for land management. It was found that EC/TC ratio is the best surrogate for prediction of hydrocarbon emissions, performing better than the commonly used Modified Combustion Efficiency (MCE). The emissions factors were observed to decrease exponentially with elemental carbon to total carbon ratio (EC/TC ratio) used as an indirect measure of fire intensity. No regional/vegetation type dependency was observed for hydrocarbon emissions; the emissions tend to change with MCE and fire intensity. PM emission factors were found to correlate with EC/TC ratio or MCE. Metals, anion, and cation emissions were affected most directly by fuel composition.