Solid Biofuels in Residential Heating Appliances and Related Air Pollution in Northern Italy

The study extends recent knowledge in solid biofuels and residential heating applications as they play a crucial role in air pollution at the regional level in northern Italy. Comparative evaluation with popular firewood and market-based pellets showed similar heating values (17-18 MJ/kg) and relatively low mass fractions of ash contents (1%). Low chlorine and sulfur contents, the adequate mass fraction of nitrogen were indicated in correlation with potential gaseous pollutants. Comprehensive analysis on spatial distribution at provincial and municipal scales in relation to settlement size and geographical altitude details were used as an insight inventory approach. Residential solid biofuel combustion appliances contribute 43% of the total emission of solid particles, approximately five times more than industrial combustion units, while it contributes about 6% of the total energy consumption in the region. The importance of solid fuel substitution by specific fuel standards, low emission technology innovation, proper installation, and improved maintenance were discussed in a novel approach to direct emission control. Emission standards, strategic measures, legislative interventions, and future perspectives were emphasized as complementary instruments providing a significant step to enable effective pollution reduction in the residential heating sector.