Moisture Content Effects on Energy and Emissions Released During Combustion of Pyrophytic Vegetation

Abstract

A series of small-scale laboratory fires were conducted to study the influence of species type and moisture content (MC) on the burning of vegetative fuels common in wildland fires. The experimental results seek to understand the effects these have on the release of gaseous emissions, namely carbon dioxide and carbon monoxide, as well as particulate matter (PM2.5), and fire radiative energy (FRE). Current wildland fire emissions estimates rely on remote sensing techniques coupled with empirically-based linear relationships to relate FRE to biomass consumed, regardless of fuel type and moisture content. Emission factors (EF) are then applied to the estimated fuel consumption to estimate total emissions of specific combustion byproducts. In this study, we revisit these assumptions under the influence of moisture content for species containing volatile oils (pyrophytic species). Experimental results show that while the relationship between FRE and biomass consumed remains linear for dead, dry fuels, pyrophytic species examined in this study failed to follow existing relationships when their moisture content was increased.