No abstract

Industrial biomass boilers (IBBs) are widely promoted in China as a type of clean energy. However, they emit large amount of volatile organic compounds (VOCs) and the emission characteristics and the underlying factors are largely unknown due to the sampling di culties. In this study, three wood pelletfueled and two wood residue-fueled IBBs were selected to investigate the characteristics of VOCs emissions and to discover their underlying impacting factors. The emission factor of VOCs varied from 21.6 ± 2.8 mg/kg to 286.2 ± 10.8 mg/kg for the IBBs. Oxygenated VOCs (OVOCs) were the largest group, contributing to 30.3%-73.6% of the VOCs emissions. Signi cant differences were revealed in the VOCs source pro les between wood pellet-fueled and wood residue-fueled IBBs. Operating load, excess air, furnace temperature and fuel type were identi ed as the primary factors in uencing VOCs emissions. The excess air coe cient should be limited below 3.5, roughly corresponding to the operating load of 62% and furnace temperature of 630 °C, to effectively reduce VOCs emissions. VOCs emissions also showed great differences in different combustion phases, with the ignition phase having much greater VOCs emissions than the stable combustion and the ember phases. The ozone formation potential (OFP) ranged from 4.3 mg/m 3 to 31.2 mg/m 3 for the IBBs, and the wood residue-fueled IBBs yielded higher OFP than the wood pellet-fueled ones. This study underscored the importance of OVOCs in IBB emissions, and reducing OVOCs emissions should be prioritized in formulating control measures to mitigate their impacts on the atmospheric environment and human health. combustion in China. Atmos Res 248.

No abstract

Industrial biomass boilers (IBBs) are widely promoted in China as a type of clean energy. However, they emit large amount of volatile organic compounds (VOCs) and the emission characteristics and the underlying factors are largely unknown due to the sampling difficulties. In this study, three wood pellet-fueled and two wood residue-fueled IBBs were selected to investigate the characteristics of VOCs emissions and to discover their underlying impacting factors. The emission factor of VOCs varied from 21.6 ± 2.8 mg/kg to 286.2 ± 10.8 mg/kg for the IBBs. Oxygenated VOCs (OVOCs) were the largest group, contributing to 30.3%-73.6% of the VOCs emissions. Significant differences were revealed in the VOCs source profiles between wood pellet-fueled and wood residue-fueled IBBs. Operating load, excess air, furnace temperature and fuel type were identified as the primary factors influencing VOCs emissions. The excess air coefficient should be limited below 3.5, roughly corresponding to the operating load of 62% and furnace temperature of 630 °C, to effectively reduce VOCs emissions. VOCs emissions also showed great differences in different combustion phases, with the ignition phase having much greater VOCs emissions than the stable combustion and the ember phases. The ozone formation potential (OFP) ranged from 4.3 mg/m3 to 31.2 mg/m3 for the IBBs, and the wood residue-fueled IBBs yielded higher OFP than the wood pellet-fueled ones. This study underscored the importance of OVOCs in IBB emissions, and reducing OVOCs emissions should be prioritized in formulating control measures to mitigate their impacts on the atmospheric environment and human health.