EFFECT OF DILUTION RATIO ON MEASUREMENT OF PM<sub>2.5</sub> DURING DILUTION SAMPLING PROCESS OF COKING COAL CHARGING FLUE

CAO Ruining; LI Zhen; YAN Yulong; PENG Lin; HAN Donghang; NIU Yueyuan; DUAN Xiaolin; XU Yinjie

doi:10.13205/j.hjgc.202308016

Volume 41 Issue 8

Aug. 2023

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CAO Ruining, LI Zhen, YAN Yulong, PENG Lin, HAN Donghang, NIU Yueyuan, DUAN Xiaolin, XU Yinjie. EFFECT OF DILUTION RATIO ON MEASUREMENT OF PM_2.5 DURING DILUTION SAMPLING PROCESS OF COKING COAL CHARGING FLUE[J]. ENVIRONMENTAL ENGINEERING , 2023, 41(8): 127-136. doi: 10.13205/j.hjgc.202308016

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EFFECT OF DILUTION RATIO ON MEASUREMENT OF PM_2.5 DURING DILUTION SAMPLING PROCESS OF COKING COAL CHARGING FLUE

doi: 10.13205/j.hjgc.202308016

1. MOE Key Laboratory of Resources and Environmental System Optimization, School of Environmental Science and Engineering, North China Electric Power University, Beijing 102206, China;
2. Engineering Research Center of Clean and Low-carbon Technology for Intelligent Transportation, Ministry of Education, School of Environment, Beijing Jiaotong University, Beijing 100091, China;
3. Changzhi Academy of Eco-Environmental Science(Changzhi Eco-Environmental Technology Service Center), Changzhi 046000, China

Received Date: 2023-01-12
Available Online: 2023-11-15

Abstract

Abstract

To investigate the effects of different dilution ratios on the particle size distribution and carbonaceous fraction of PM_2.5 in the dilution sampling process of coking coal charging flue, the experiment of the coal coking process was carried out with a tube furnace. With low, medium, and high dilution ratios, PM_2.5 size distribution, PM_2.5 mass concentration, the ratio of organic carbon to elemental carbon (OC/EC) and polycyclic aromatic hydrocarbons (PAHs) concentration were determined under different dilution conditions. The result showed that the dilution ratio had a significant effect on ultrafine particles. As the dilution ratio increased, the particle number concentration showed an increasing trend, and the PM_2.5 number concentration at the high dilution ratio increased by about 3.7 and 1.3 times, compared with the medium and low dilution ratios after particle filtration, respectively. In contrast, the concentration of PM_2.5 with the high dilution ratio before particle filtration increased by 1.1 times approximately, compared to those at both the medium and low dilution ratios. As the dilution ratios increased, the corrected PM_2.5 mass concentration and OC/EC ratio showed a decreasing trend. No significant changes in the corrected PM_2.5 mass concentration and OC/EC ratio were observed when the dilution ratio increased from low level to medium level. At the high dilution level, the corrected PM_2.5 mass concentration and OC/EC ratio decreased by about 64.8% and 45.1%, respectively, compared to those at low dilution ratios. The ring number distribution of PAHs was relatively stable at different dilution ratios. The normalized proportion of 4- and 5-ring aromatic hydrocarbons in PM_2.5 was more than 29.1%. The dilution ratio increase promoted the gas-particle conversion of the organic matter, and the homogeneous condensation of gaseous organic matter on the small particle size range was enhanced. So that many ultrafine particles were generated and the total particle number concentration of PM_2.5 drastically increased. A further increase in the dilution ratio could reduce the concentration of gaseous organic matter in the mixed gas system. Therefore, the heterogeneous condensation onto the larger size particles was impaired, and the corrected PM_2.5 mass concentration was reduced. With medium dilution ratios (41 to 52), the gas-particle conversion of gaseous organic matter was more adequate than those at low dilution ratios, and both the disruption of the gas-particle phase equilibrium and over-condensation of organic matter due to the high dilution ratios were avoided. So it was recommended to determine the PM_2.5 emission from the coking coal charging process with a medium dilution ratio range.
- coking industry,
- fine particulate matter,
- dilution sampling,
- size distribution,
- organic carbon,
- polycyclic aromatic hydrocarbons

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References(63)

References

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