炼焦过程VOCs排放特征及臭氧生成潜势

    Emission Characterization and Ozone Formation Potential of VOCs During the Coking Process

    • 摘要: 分别对顶装焦炉Ⅰ和侧装捣固焦炉Ⅱ的焦炉炉顶无组织烟气、装煤和出焦烟气、干熄焦烟气进行了挥发性有机物(VOCs)的样品采集和测试分析,研究了炼焦过程各环节的VOCs排放特征,并分别用最大增量反应活性法(MIR)和OH自由基的反应速率法(LOH)分析了VOCs各组分的臭氧生成潜势及反应活性.研究发现,炼焦过程中焦炉炉顶无组织烟气的VOCs质量浓度较高,达到几百μg/m3.顶装焦炉与捣固焦炉的焦炉炉顶无组织烟气VOCs的化学成份谱相似性高,乙烷、乙烯、苯为主要物种,它们的体积分数分别达到22.7%±2.1%和24.2%±0.6%、44.3%±1.9%和54.1%±2.0%、14.3%±3.8%和7.3%±0.5%.顶装焦炉与捣固焦炉装煤和出焦烟气以癸烷、乙烯、乙炔为主,它们的体积分数分别为6.5%±2.4%和20.3%±7.5%、29.4%±3.3%和39.8%±4.2%、31.6%±3.8%和15.0%±3.8%.干熄焦烟气中癸烷体积分数最大为53.8%±6.3%.炼焦过程中焦炉炉顶无组织烟气、装煤和出焦烟气中的烯烃类物质(乙烯和丙烯)、干熄焦烟气中的烷烃类物质(癸烷),是焦化行业排放VOCs中臭氧生成潜势最大的物种,同时也是对光化学污染贡献最为突出的污染物质.

       

      Abstract: The concentration and chemical speciation of volatile organic compounds(VOCs) was quantitatively analyzed from three kinds of smoke,which were the fugitive emissions gas,the dust removing station smoke,and the coke quenching smoke,respectively.And two types of coke oven were test,which were top charging coke oven and tamping coke oven.In addition,Maximum Increment Reactivity(MIR) and OH loss rate(LOH) was used to quantify the ozone formation potential(OFP) and reaction activity of various VOCs species.According to the measurement results,the concentration of VOCs in the fugitive emissions reaches to hundreds ppb,and the VOCs species in the fugitive gas are similar between top charging coke oven and tamping coke oven.Ethane,ethylene,benzene are the major VOC species,and their volume fraction percentages are 22.7% ± 2.1% and 24.2% ± 0.6% 、44.3% ± 1.9% and 54.1% ± 2.0% 、14.3% ± 3.8% and 7.3% ± 0.5%,respectively.Decane,ethylene,acetylene are the major VOC species in the dust removing station smoke.Their volume fraction percentages in the top charging coke oven and tamping coke oven are 6.5% ± 2.4% and 20.3% ± 7.5%,29.4% ± 3.3% and 39.8% ± 4.2%,31.6% ± 3.8% and 15.0% ± 3.8%,respectively.In thecoke quenching smoke,decane is the major VOC species,and its volume fraction percentage is 53.8% ± 6.3%.The alkenes especially ethylene and propene in the fugitive emissions gas and the dust removing station smoke,the alkanes especially decane in the coke quenching smoke have the highest ozone formation potential in the coking process.

       

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