Volatile organic compounds emission characteristics and factors from stage-dependent combustion in typical biomass stoves in northern China: Field measurements and environmental implications.

Abstract

Residential biomass burning (RBB) has significant impact on the ambient air quality in rural China. To explore the detailed emission characteristics and impact of various stove types and their combustion stages of RBB, which unresolved issue in existing studies, this study investigated the volatile organic compounds (VOCs) emissions of different combustion stages from four typical RBB stoves in Northern China, including kang stove (KS), brick stove (BS), metal stove (MS) and pellet stove (PS). The KS has the highest VOCs emission factors (EFs) (1.51 g/kg), which was related to the inadequate combustion caused by poor air circulation in the stove structure, and the moisture content and lower lignin content in the fuel. The smoldering stage exhibited the highest VOCs EFs, especially for BS (3.19 g/kg) and KS (1.57 g/kg), which were due to the lower air flow velocity for BS and KS. In addition, the direct contact of ash and fuel could increase the secondary decomposition of particulate pollutants, which also contribute mainly to higher EFs. Oxygenated volatile organic compounds (OVOCs) contributed most than other species during the smoldering stage. The calculation results of RBB emissions in different regions of China indicated that Northeast China have the highest emission proportion, which may be attributed to the high demand for RBB. The KS exhibited the highest ozone formation potential and health risk, especially during the smoldering stage. This study comprehensively measured the EFs of different stoves at different combustion stages and fuels, filling the gap in existing research and providing data support for related research work in the future.