Emission factors and light absorption properties of brown carbon
from household coal combustion in China
Jianzhong Sun1,2,5, Guorui Zhi2, Regina Hitzenberger4, Yingjun Chen1,3, Chongguo Tian1, Yayun Zhang2,6, Yanli Feng7, Miaomiao Cheng2, Yuzhe Zhang2,6, Feng Chen7, Yiqin Qiu7, Zhiming Jiang7, Jun Li8, Gan Zhang8, and Yangzhi Mo81Key Laboratory of Coastal Environmental Processes and Ecological Remediation, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China 2State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China 3State Key Laboratory of Pollution Control and Resources Reuse, Key Laboratory of Cities' Mitigation and Adaptation to Climate Change, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China 4University of Vienna, Faculty of Physics, Boltzmanngasse 5, 1090 Vienna, Austria 5University of Chinese Academy of Sciences, Beijing, 100049, China 6College of Chemical Engineering, China University of Petroleum, Beijing 102249, China 7Institute of Environmental Pollution and Health, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China 8State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
Received: 13 Dec 2016 – Accepted for review: 12 Jan 2017 – Discussion started: 13 Jan 2017
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.
Sun, J., Zhi, G., Hitzenberger, R., Chen, Y., Tian, C., Zhang, Y., Feng, Y., Cheng, M., Zhang, Y., Chen, F., Qiu, Y., Jiang, Z., Li, J., Zhang, G., and Mo, Y.: Emission factors and light absorption properties of brown carbon
from household coal combustion in China, Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-1090, in review, 2017.