Characterization of Non-methane Hydrocarbons Emitted from Various Cookstoves Used in China

Abstract

Emission contributions from cookstoves to indoor, regional, and global air pollution largely depend on stove and fuel types. This paper presents a database on emission factors of speciated non-methane hydrocarbons (NMHCs) for 16 fuel/stove combinations burning 2 types of crop residue, wood, 4 types of coal, kerosene, and 3 types of gaseous fuels. The emission factors are presented both on a fuel mass basis (compound mass per fuel mass) and on a cooking task basis (compound mass per unit energy delivered to the pot). These fuel/stove combinations cover a large spectrum of the cookstoves used in both urban and rural households in China. Up to 54 hydrocarbons were identified, some of which are reactive precursors of photochemical smog. Based on published maximum incremental reactivity (MIR) values for NMHCs, we estimated stove-specific and fuel-specific ozone forming potentials (OFPs). The results indicate that raw coal powder, wood, and crop residues have higher OFP values than the other types of fuels tested. Strikingly, burning the coal briquette and honeycomb coal briquette produced OFP values more than 2 orders of magnitude lower than burning unprocessed (raw) coal, even in the same vented metal stove, for every 1 MJ delivered to the pot.

Ambient air benzene at background sites in China's most developed coastal regions: Exposure levels, source implications and health risks

“…5b, although fairly good correlations (r N 0.7, p b 0.001) between toluene and benzene were observed at SY NECP , YC NCP and DH PRD sites, the T/B slopes were quite different. They were 0.20 and 0.40 respectively at SY NECP and YC NCP sites within that of 0.23-0.68 for biomass/biofuel burning (Andreae and Merlet, 2001;Liu et al, 2008;Li et al, 2009;Wang et al, 2009;Akagi et al, 2011) or 0.13-0.71 for coal combustion (Tsai et al, 2003;Liu et al, 2008), implying input from biomass/biofuel burning and coal combustion at the two sites. Contrastingly, the T/B slope of 1.66 at DH PRD site was close to that of~1.6 for vehicle emissions (Perry and Gee, 1995;Gelencser et al, 1997;Wang et al, 2002;Barletta et al, 2005;Tang et al, 2007;Liu et al, 2008;Gentner et al, 2013), indicating the contribution of traffic-related sources.…”

“…In 2012, 14.6% of the 0.182 billion tons of coal consumed in the Liaoning Province, and 11.4% of the 0.402 billion tons coal consumed in the Shandong Province were used for heating supply (NBSC, 2013b). This increase in coal consumption for domestic heating supply has been assumed to be the major reason for elevated benzene levels in winter, as coal combustion is an important source of benzene (Tsai et al, 2003;Moreira dos Santos et al, 2004;Liu et al, 2008). In fact, a recent study in Beijing revealed that coal combustion contributed significantly more to ambient VOCs in the winter (19%) than in the summer (4%) .…”

“…One possible reason is that the reported benzene emission factor of 25.8-1050 mg/kg for rural residential coal combustion (Tsai et al, 2003) is extremely high when compared to that of 0.59 mg/kg for controlled power plant's and industrial coal combustion (Garcia et al, 1992;USEPA, 1995). Additionally, biofuel could account for about two thirds of the total energy used for cooking and heating in China's rural areas (Yan et al, 2006;Wei et al, 2008;Tang et al, 2009), so more benzene emissions from biofuel-stoves in rural areas in the winter could also result in the higher ambient benzene levels (Tsai et al, 2003;Wang et al, 2009). A cleaner energy supply for heating, therefore, should be an effective way to lower the exposure to benzene, particularly in rural areas in winter time.…”

Source Profiles of Volatile Organic Compounds from Biomass Burning in Yangtze River Delta, China

“…As reported by Wang et al (2009), C6-C7 aromatics, propylene, C2-C3 o-VOC were the major VOC species from typical biomass burning in northern China. Of the hydrocarbons, C2-C3 hydrocarbons and C6-C7 aromatics were abundant both in Liu et al (2008) and Tsai et al (2003) study. Nevertheless, significant variations of the specific proportions of VOC species were identified between this study and previous studies.…”

“…One reason was the variability of emissions from different burning tests, largely associated with the variations in fire tending behavior (Tsai et al, 2003). The burning cycle usually began with the ignition which was characterized by incomplete combustion, followed by a stable and complete combustion, and ended with combustion of the remaining charcoal.…”