Emissions of Wood Pelletization and Solid Bioenergy Use in the United States

Abstract

Despite a significant increase in United States biomass energy sector activity especially in wood pellet production for overseas exports, their criteria pollutant emissions are not well quantified in current regulatory emissions inventories. We present an updated U.S. emissions inventory, with emphasis on wood-based biomass pretreatment and energy generation. Since a significant number of wood pellet production facilities are not included in current inventories, we find that this sector’s emissions could be potentially underestimated by a factor of two. Emissions from biomass-based facilities are on an average up to 2.8 times higher than their non-biomass counterpart per unit energy. Upto 2.3 million people live within 2km of a biomass facility, and who could be subject to adverse health impacts from their emissions. Overall, bioenergy sector contributes to about 3 – 17% of total emissions from all energy, i.e., electric and non-electric generating facilities in the U.S. In comparison to residential wood combustion, bioenergy sector emissions are lower in VOC, CO, NH3, and directly emitted PM2.5, but higher in NOX and SO2. We also review some drivers of bioenergy expansion, various feedstocks and technologies deployed with an emphasis on wood-based bioenergy and discuss their implications for future air quality and health impacts.

Keywords: biomass, Bioenergy, Renewable Energy, emissions inventory, wood pellets