Emission factors from residential combustion appliances burning Portuguese biomass fuels

摘要

Smoke from residential wood burning has been identified as a major contributor to air pollution,motivating detailed emission measurements under controlled conditions. A series of experiments wereperformed to compare the emission levels from two types of wood-stoves to those of fireplaces. Eighttypes of biomass were burned in the laboratory: wood from seven species of trees grown in thePortuguese forest (Pinus pinaster, Eucalyptus globulus, Quercus suber, Acacia longifolia, Quercusfaginea, Olea europaea and Quercus ilex rotundifolia) and briquettes produced from forest biomasswaste. Average emission factors were in the ranges 27.5–99.2 g CO kg 1, 552–1660 g CO2 kg 1, 0.66–1.34 g NO kg 1, and 0.82–4.94 g hydrocarbons kg 1 of biomass burned (dry basis). Average particleemission factors varied between 1.12 and 20.06 g kg 1 biomass burned (dry basis), with higher burnrates producing significantly less particle mass per kg wood burned than the low burn rates. Particlemass emission factors from wood-stoves were lower than those from the fireplace. The average emissionfactors for organic and elemental carbon were in the intervals 0.24–10.1 and 0.18–0.68 g kg 1 biomassburned (dry basis), respectively. The elemental carbon content of particles emitted from the energyefficient‘‘chimney type’’ logwood stove was substantially higher than in the conventional cast ironstove and fireplace, whereas the opposite was observed for the organic carbon fraction. Pinus pinaster,the only softwood species among all, was the biofuel with the lowest emissions of particles, CO, NO andhydrocarbons.