[Characteristics of volatile organic compounds (VOCs) emitted from biofuel combustion in China].

Biofuel combustion is an important source of VOCs in China. Measurements were conducted to determine the characteristics of VOCs emitted from combustion of 5 typical biofuels. A carbon mass balance method was used to determine VOCs emission factors. The emission factors of the total VOCs from agricultural residues and wood combustion are (4.37 +/- 2.23) g x kg(-1) and (2.12 +/- 0.77) g x kg(-1), respectively. The emission factors of the agricultural residues are higher than those of the wood. Aromatics and aldehydes dominate the VOC emissions, both accounting for over 25% of the total VOC emissions. Distribution of VOC components from agricultural residues and wood combustion are similar, except for halogenated hydrocarbons and nitriles. On the basis of measured emission factors and the published maximum incremental reactivity values for VOCs, the ozone forming potential (OFPs) of speciated VOCs is estimated. The results indicate that the average OFPs of the total VOCs from agricultural residues and wood combustion are (16.9 +/- 8.2) g x kg(-1) and (10.8 +/- 4.9) g x kg(-1), respectively. The components with the highest OFPs values are: aldehydes, aromatics and alkenes/alkynes. Aldehydes accounts for over 50% of the total OFPs.