Mass Absorption Efficiency of Black Carbon from Residential Solid Fuel Combustion and Its Association with Carbonaceous Fractions

Abstract

Black carbon (BC) emissions, derived primarily from incomplete fuel combustion, significantly affect the global and regional climate. Mass absorption efficiency (MAE) is one important parameter in evaluating the climate impacts of BC. Here, values and variabilities in the MAE of BC (MAEBC) from real-world residential emissions were investigated from a field campaign covering 163 burning events for different fuel–stove combinations. MAEBC (average: 12 ± 5 m2/g) was normally distributed and varied greatly by 2 orders of magnitude. Statistically significant differences in MAEBC were found for various fuels, while no significant differences were observed among different stoves. The fuel difference explained 72 ± 7% of the MAEBC variation. MAEBC did not correlate with the modified combustion efficiency but positively correlated with the ratio of organic carbon (OC) to elemental carbon (EC) and negatively correlated with char-EC. The OC/EC ratio was not always lower in coal emissions in comparison to biomass burning emissions. Coal- and biomass-burning emissions had different profiles of carbon fractions. Char-EC, OC, OC/EC, and char-EC/soot-EC can explain 68.7% of the MAEBC variation, providing the potential for predicting MAEBC from the carbon fractions, since they are more commonly measured and available.

Review of Brown Carbon Aerosols in China: Pollution Level, Optical Properties, and Emissions

“…No significant difference is found between the results for crop residue and wood (J. Sun et al., 2016; L. Zhang, Luo, et al., 2021). But a laboratory study by J.…”

“…For example, the study by Fan et al (2016) reported higher MAE WSOC for the combustion of crop than wood while trend is opposite in the study of Fan et al (2018), although both studies collected samples in a laboratory chamber simulating open burning in the field. Although studies have tested various types of stoves for the burning of biomass, for example, the traditional three-stone fire and a forced-draft fan type cookstove in M. Xie et al (2018), and metal stoves, built-in-place stoves and Kang in L. Zhang, Luo, et al (2021), no specific conclusion has been drawn regarding the influence of stove type on the MAE of BrC from biomass burning emission. Meanwhile, studies have shown that BrC MAE from residential biomass burning in stoves are greater than open biomass burning, implying higher temperature and more flaming combustion in stoves (M. Xie et al, 2018).…”

“…Due to the limited number of studies with inconsistent variation trends, we adopt the EF BrC of 1.6 ± 0.88 gC kg −1 and MAE BrC of 5.1 ± 1.5 m 2 gC −1 averaged for five different biomass fuels reported by L. Zhang, Luo, et al. (2021). The results by Cai et al.…”

“…Total consumed biomass in China is 648 Tg yr −1 in 2020, among which 71% is from residential combustion, followed by agricultural open burning (23%) and open wildfire (6%). Due to the limited number of studies with inconsistent variation trends, we adopt the EF BrC of 1.6 ± 0.88 gC kg −1 and MAE BrC of 5.1 ± 1.5 m 2 gC −1 averaged for five different biomass fuels reported by L Zhang, Luo, et al (2021)…”

“…C Yan et al (2021Yan et al ( , 2017Yan et al ( , 2015,Yang et al (2009),Zhai et al (2019),. L Zhang, Luo, et al (2021),. L., Q Zhang, Ning, et al (2017),.…”