scholarly journals Emission factors and light absorption properties of brown carbon from household coal combustion in China

Author(s):  
Jianzhong Sun ◽  
Guorui Zhi ◽  
Regina Hitzenberger ◽  
Yingjun Chen ◽  
Chongguo Tian ◽  
...  

Abstract. Brown carbon (BrC) draws increasing attention due to its effects on climate and other fields. In China, household coal burned for heating/cooking purposes releases huge amounts of carbonaceous particles every year; however, BrC emissions have rarely been estimated in a persuasive manner due to the unavailable emission characteristics. Here 7 coals jointly covering geological maturity from low to high were burned in 4 typical stoves at both chunk and briquette styles. The optical integrating sphere (IS) method was applied to measure the emission factors (EFs) of BrC and BC via an iterative process using the different spectral dependence of light absorption for BrC and BC. It is found that (i) the average EFs of BrC for anthracite coal chunks and briquettes are (1.08 ± 0.80) g kg−1 and (1.52 ± 0.16) g kg−1, respectively, and those for bituminous coal chunks and briquettes are (8.59 ± 2.70) g kg−1 and (4.01 ± 2.19) g kg−1, respectively, reflecting a more significant decline of BrC EFs for bituminous coals than for anthracites due to briquetting, (ii) the BrC EF peaks at the middle of coal's geological maturity, displaying a bell shaped curve between EF and volatile matter (Vdaf), (iii) the calculated BrC emissions from China's residential coal burning amounted to 592 Gg (1 Gg = 109 g) in 2013, which is nearly half of China's total BC emissions, (iv) absorption Ångström exponent (AAEs) of all coal briquettes are higher than those of coal chunks, indicating that the measure of coal briquetting increases the BrC / BC emission ratio and thus offsets some of the climate cooling effect of briquetting, and (v) in the scenario of current household coal burning in China, solar light absorption by BrC (350–850 nm in this study) accounts for more than a quarter (0.265) of the total absorption. This implies the significance of BrC to climate modeling.

2017 ◽  
Vol 17 (7) ◽  
pp. 4769-4780 ◽  
Author(s):  
Jianzhong Sun ◽  
Guorui Zhi ◽  
Regina Hitzenberger ◽  
Yingjun Chen ◽  
Chongguo Tian ◽  
...  

Abstract. Brown carbon (BrC) draws increasing attention due to its effects on climate and other environmental factors. In China, household coal burned for heating and cooking purposes releases huge amounts of carbonaceous particles every year; however, BrC emissions have rarely been estimated in a persuasive manner due to the unavailable emission characteristics. Here, seven coals jointly covering geological maturity from low to high were burned in four typical stoves as both chunk and briquette styles. The optical integrating sphere (IS) method was applied to measure the emission factors (EFs) of BrC and black carbon (BC) via an iterative process using the different spectral dependence of light absorption for BrC and BC and using humic acid sodium salt (HASS) and carbon black (CarB) as reference materials. The following results have been found: (i) the average EFs of BrC for anthracite coal chunks and briquettes are 1.08 ± 0.80 and 1.52 ± 0.16 g kg−1, respectively, and those for bituminous coal chunks and briquettes are 8.59 ± 2.70 and 4.01 ± 2.19 g kg−1, respectively, reflecting a more significant decline in BrC EFs for bituminous coals than for anthracites due to briquetting. (ii) The BrC EF peaks at the middle of coal's geological maturity, displaying a bell-shaped curve between EF and volatile matter (Vdaf). (iii) The calculated BrC emissions from China's residential coal burning amounted to 592 Gg (1 Gg  =  109 g) in 2013, which is nearly half of China's total BC emissions. (iv) The absorption Ångström exponents (AAEs) of all coal briquettes are higher than those of coal chunks, indicating that the measure of coal briquetting increases the BrC ∕ BC emission ratio and thus offsets some of the climate cooling effect of briquetting. (v) In the scenario of current household coal burning in China, solar light absorption by BrC (350–850 nm in this study) accounts for more than a quarter (0.265) of the total absorption. This implies the significance of BrC to climate modeling.


2018 ◽  
Author(s):  
Xin Wang ◽  
Hailun Wei ◽  
Jun Liu ◽  
Baiqing Xu ◽  
Mo Wang

Abstract. Amounts of insoluble light-absorbing particles (ILAPs) deposited on the surface of snow and ice can significantly reduce the snow albedo and accelerate the snow melting process. In this study, ~ 67 snow/ice samples were collected in 7 high mountain glaciers over the Tibetan Plateau (TP) regions from May 2013 to October 2015. The mixing ratio of black carbon (BC), organic carbon (OC), and mineral dust (MD) was measured using an integrating sphere/integrating sandwich spectrophotometer (ISSW) system associated with the chemical analysis by assuming the light absorption of mineral dust due to iron oxide. The results indicate that mass mixing ratios of BC, ISOC, and MD show a large variation of 10–3100 ng g-1, 10–17000 ng g-1, 10–3500 ng g-1, with a mean value of 218 ± 397 ng g-1, 1357 ± 2417 ng g-1, 241 ± 452 ng g-1 on TP glaciers during the entire snow field campaign, respectively. The chemical elements and the selected carbonaceous particles were also analyzed of the attributions of the particulate light absorption based on a positive matrix factorization (PMF) receptor model. On average, the industrial pollution (33.1 %), biomass/biofuel burning (29.4 %), and soil dust (37.5 %) were the major sources of the ILAPs in TP glaciers. Although the soil dust assumed to be the highest contributor to the mass loading of ILAPs, we noted that the averaged light absorption of BC (50.7 %) and ISOC (33.2 %) was largely responsible for the measured light absorption in the high mountain glaciers at the wavelengths of 450–600 nm.


2021 ◽  
Vol 21 (4) ◽  
pp. 2329-2341 ◽  
Author(s):  
Jianzhong Sun ◽  
Yuzhe Zhang ◽  
Guorui Zhi ◽  
Regina Hitzenberger ◽  
Wenjing Jin ◽  
...  

Abstract. Recent studies have highlighted the importance of brown carbon (BrC) in various fields, particularly relating to climate change. The incomplete combustion of biomass in open and contained burning conditions is believed to be a significant contributor to primary BrC emissions. So far, few studies have reported the emission factors of BrC from biomass burning, and few studies have specifically addressed which form of light-absorbing carbon, such as black carbon (BC) or BrC, plays a leading role in the total solar light absorption by biomass burning. In this study, the optical integrating sphere (IS) approach was used, with carbon black and humic acid sodium salt as reference materials for BC and BrC, respectively, to distinguish BrC from BC on filter samples. A total of 11 widely used biomass types in China were burned in a typical stove to simulate the real household combustion process. (i) Large differences existed in the emission factors of BrC (EFBrC) among the tested biomass fuels, with a geometric mean EFBrC of 0.71 g kg−1 (0.24–2.09). Both the plant type (herbaceous or ligneous) and burning style (raw or briquetted biomass) might influence the value of EFBrC. The observed reduction in the emissions of light-absorbing carbon (LAC) confirmed an additional benefit of biomass briquetting in climate change mitigation. (ii) The calculated annual BrC emissions from China's household biomass burning amounted to 712 Gg, higher than the contribution from China's household coal combustion (592 Gg). (iii) The average absorption Ångström exponent (AAE) was (2.46±0.53), much higher than that of coal-chunk combustion smoke (AAE=1.30±0.32). (iv) For biomass smoke, the contribution of absorption by BrC to the total absorption by BC+BrC across the strongest solar spectral range of 350–850 nm (FBrC) was 50.8 %. This is nearly twice that for BrC in smoke from household coal combustion (26.5 %). (v) Based on this study, a novel algorithm was developed for estimating the FBrC for perhaps any combustion source (FBrC=0.5519ln⁡AAE+0.0067, R2=0.999); the FBrC value for all global biomass burning (open+contained) (FBrC-entire) was 64.5 % (58.5 %–69.9 %). This corroborates the dominant role of BrC in total biomass burning absorption. Therefore, the inclusion of BrC is not optional but indispensable when considering the climate energy budget, particularly for biomass burning emissions (contained and open).


2011 ◽  
Vol 361-363 ◽  
pp. 882-886
Author(s):  
Ming Yan Gu ◽  
Xu Hui Liu ◽  
Biao Ma ◽  
Jia Xin Li

In this study, the combustion behaviors of three kinds of coal and their mixtures under the pure oxygen and air atmosphere were studied by using a thermo-gravimetric analyzer. The combustion characteristics such as ignition and burnout behavior were investigated in the temperature from 20°C to 800°C. The influence of mixing Shenhua coal with Huaibei bituminous and Sanming anthracite coal on combustion characteristics was conduced. The results obtained show that pure oxygen content accelerated the coal burning process greatly; the coal volatile matter started to release at a lower temperature and the coal burning process was finished earlier compared with the burning process under the air atmosphere. The addition of Shenhua coal improved the combustion characteristics of both Huaibei bituminous coal and Sanming anthracite in a different way. For the Huaibei bituminous coal, both the ignition and burnout temperature decreased linearly with the increasing ratio of Shenhua coal; while for the Sanming anthracite, the addition of Shenhua coal greatly lowered the mixture ignition temperature, and the burnout temperature was nearly the same. The activation energy of the mixture coal with Shenhua and Huaibei coal reduced with the ratio of Shenhua coal. For the Shenhua and Sanming coal mixture, the activation energy changed differently at the two burning stages.


2019 ◽  
Vol 13 (1) ◽  
pp. 309-324 ◽  
Author(s):  
Xin Wang ◽  
Hailun Wei ◽  
Jun Liu ◽  
Baiqing Xu ◽  
Mo Wang ◽  
...  

Abstract. The deposition of insoluble light-absorbing particles (ILAPs) on snow and ice surfaces can significantly reduce albedo, thereby accelerating the melting process. In this study, 67 ice samples were collected from seven glaciers located on the Tibetan Plateau (TP) between May 2013 and October 2015. The mixing ratios of black carbon (BC), organic carbon (OC), and mineral dust (MD) were measured with an integrating sphere/integrating sandwich spectrophotometer (ISSW) system, which assumes that the light absorption of MD is due to iron oxide (Fe). Our results indicate that the mass-mixing ratios of BC, OC, and Fe exhibit considerable variability (BC: 10–3100 ng g−1; OC: 10–17 000 ng g−1; Fe: 10–3500 ng g−1) with respective mean values of 220±400 ng g−1, 1360±2420 ng g−1, and 240±450 ng g−1 over the course of the field campaign. We observed that for wavelengths of 450–600 nm, the measured light absorption can be largely attributed to the average light absorption of BC (50.7 %) and OC (33.2 %). Chemical elements and selected carbonaceous particles were also analyzed for source attributions of particulate light absorption based on a positive matrix factorization (PMF) receptor model. Our findings indicate that on average, industrial pollution (33.1 %), biomass or biofuel burning (29.4 %), and MD (37.5 %) constitute the principal sources of ILAPs deposited on TP glaciers.


2020 ◽  
Author(s):  
Jianzhong Sun ◽  
Guorui Zhi ◽  
Regina Hitzenberger ◽  
Yingjun Chen ◽  
Chongguo Tian

Abstract. Recent studies have highlighted the importance of brown carbon (BrC) in various fields, particularly relating to climate change. The incomplete combustion of biomass in open and contained burning conditions is believed to be a significant contributor to primary BrC emissions. So far, few studies have reported the emission factors of BrC from biomass burning, and few studies have specifically addressed which form of light absorbing carbon, such as black carbon (BC) or BrC, plays a leading role in the total solar light absorption of biomass burning. In this study, the optical integrating sphere (IS) approach was used, with carbon black and humic acid sodium salt as reference materials for BC and BrC, respectively, to distinguish BrC from BC on the filter samples. Eleven widely used biomass types in China were burned in a typical stove to simulate the real household combustion process. (i) Large differences existed in the emission factors of BrC (EFBrC) among the tested biomass fuels, with a geomean EFBrC of 0.71 g/kg (0.24, 2.18). Both the plant type (herbaceous or ligneous) and burning style (raw or briquetted biomass) might influence the value of EFBrC. (ii) The calculated annual BrC emissions from China's household biomass burning amounted to 712 Gg, higher than the contribution from China's household coal combustion (592 Gg). (iii) The average absorption Ångström exponent (AAE) was (2.46 ± 0.53), much higher than that of coal-chunks combustion smoke (AAE = 1.30 ± 0.32). (iv) For biomass smoke, the contribution of absorption by BrC to the total absorption by BC + BrC across the strongest solar spectral range of 350–850 nm (FBrC) was 50.8 %. This was nearly twice that for BrC in smoke from household coal combustion (26.5 %). (v) Based on this study, a novel algorithm was developed for estimating the FBrC for any combustion sources (FBrC = 0.5519 lnAAE + 0.0067, R2 = 0.999); the FBrC value for global entire biomass burning (open + contained) (FBrC-entire) was 64.5 % (58.5–69.9 %). This corroborates the dominant role of BrC in total biomass burning absorption. Therefore, BrC is not optional but indispensable when considering the climate energy budget, particularly for biomass burning emissions (contained and open).


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