Particulate and Aromatic Hydrocarbon Emissions from a Small-Scale Biomass Gasifier–Generator System

Abstract

Distributed gasification of biomass has potential as a renewable energy alternative, but the emissions from gasifier–generator systems raise potential environmental and human health concerns. Producer gas from gasifiers contains high concentrations of aromatic compounds, tars, and particulate matter. In gasifier–generator systems, producer gas is used to feed an internal combustion engine connected to a generator. Little is known about the extent to which spark-ignited engine combustion eliminates these harmful components. This study measured emissions at three locations of a 10 kW electric, fixed-bed, downdraft gasifier–generator system to determine the effectiveness of the packed-bed filter and the spark-ignited engine to reduce pollutant concentrations in the producer gas. Emissions were compared to regulated levels. Particulate matter concentrations were approximately 75 mg/Nm3 in the pre-filtered producer gas and were reduced by about 99% by the packed-bed filter to about 1 mg/Nm3. Particulate matter...