An important missing source of atmospheric carbonyl sulfide: Domestic coal combustion

Abstract

Carbonyl sulfide (COS), carbon monoxide (CO), and sulfur dioxide (SO2) emissions generated from prevailing domestic coal stoves fueled with raw bituminous coal were studied under alternation cycles of flaming and smoldering combustion. The measurements in the laboratory and the farmer's house indicated that COS and CO emissions mainly occurred under the condition of flame extinguishment after coal loading, whereas SO2 emissions were mainly generated through combustion with flame. The COS emission factors for the domestic stoves in the laboratory and the farmer's house were recorded as 0.57 ± 0.10 g COS kg−1 and 1.43 ± 0.32 g COS kg−1, being approximately a factor of 50 and 125 greater than that generated from coal power plants, respectively. Based on the COS emission factors measured in this study, COS emission from only domestic coal combustion in China would be at least 30.5 ± 5.6 Gg S yr−1 which was 1 magnitude greater than the current COS estimation from the total coal combustion in China.

Biomass Burning Unlikely to Account for Missing Source of Carbonyl Sulfide

“…Observed atmospheric surface mixing ratios from global and hemispheric averages of NOAA air monitoring sites (Montzka et al, ), as well as annually averaged tropospheric mixing ratios from Jungfraujoch (Lejeune et al, ), show a moderate decline in the 1990s followed by similarly moderate growth in the 2000s (both approximately 1% year −1 ), with relatively little interannual variation. These time trends have been attributed to trends in the anthropogenic inventory, driven by a decline in residential coal in the early 1990s and the decline and growth of the rayon industry from 1990 onward (Campbell et al, ; Du et al, ; Zumkehr et al, , ).…”

Open burning of rice, corn and wheat straws: primary emissions, photochemical aging, and secondary organic aerosol formation

“…The emission factors of the speciated NMHCs, PM, NO x , CO and SO 2 from combustion of raw bituminous coal, which is currently prevalent for cooking and heating in rural areas, have been reported to be 0.56-5.40, 25.49 ± 2.30, 0.97 ± 0.03, 208 ± 5 and 2.43-5.36 g kg −1 , respectively (Du et al, 2016;Liu et al, 2017). Annually burned crop residues and domestic coals were estimated to be 160 Tg (Q.…”

“…Our measured emission factors of SO 2 were lower than those reported by Cao et al (2008) and Kim Oanh et al (2015) for rice straw, but higher than those reported by Cao et al (2008) for corn and wheat straw. Due to low sulfur contents in crop straws, the SO 2 emission factors for open burning of crop residues were much lower than those for domestic coal combustion, which were determined to be 2.43-5.36 g kg −1 for raw bituminous coal (Du et al, 2016). Table S1, in which a comprehensive dataset of emission factors measured in this work is included.…”

Direct oceanic emissions unlikely to account for the missing source of atmospheric carbonyl sulfide

“…There are indications of other parts of the OCS budget being underestimated, such as domestic coal combustion (Du et al, 2016). Emissions of biomass burning and direct and indirect anthropogenic emissions have been considered in previous estimates (e.g., 315.5 Gg S yr −1 in Berry et al, 2013, 224 Gg S yr −1 in Kuai et al, 2015, and 219 Gg S yr −1 in Glatthor et al, 2015), but a recent anthropogenic emission estimate by Lee and Brimblecombe (2016) increases this number to 598 Gg S yr −1 , which would already bring sources and sinks closer to agreement.…”