Characteristics of volatile organic compounds emissions from indoor burning of biomass pellets
This study conducted a series of field-based emission tests on volatile organic compounds(VOCs)from residential burning of biomass pellets in rural northern China.Characteristics of VOCs for two different pellets were compared and discussed.The results of GC-MS analysis showed that the emission factor of total VOCs(TVOCs)ranged from 48.5 to 684.5mg/kg,with the aromatic hydrocarbons accounting for 37.0%~85.8%of the total,followed by the halogenated hydrocarbons at 14.2%~63.0%.Benzene and toluene were two predominant species,followed by methylene chloride and styrene.The real-time emission dynamic,by using the PID sensor instrument,showed similar releasing trends in the TVOCs and CO.Fuel type and stove use circumstances had obviously different VOCs emission performance.53.0%~71.2%of the total VOCs were emitted during the ignition phase and flaming phase,while the VOCs levels were much lower during the smoldering phase.TVOCs formation was statistically not correlated with the combustion efficiency change during the burning period(P>0.05).The emission factors being calculated from the PID instrument and the GC-MS technology correlated with each other;however,there were significant differences in the values from these two methods.Components quantitatively detected by the GC-MS technology only accounted for 4%of the total VOCs mass from the PID instrument analysis.Clarifying emission characteristics and impacts of VOCs from biomass pellet combustion would improve the inventory of VOCs with lower uncertainties.