为了解生物质掺烧下烟气中挥发性有机物（VOCs）的排放特性，在58 MW循环流化床（CFB）机组开展烟气中挥发性有机物排放特征研究。结果表明，掺烧的生物质可显著降低VOCs以及NOx和SO2的排放。混合燃料燃烧特性的改变导致VOCs减排，VOCs减排效果最明显出现在生物质掺烧比从20％提升至30％时。生物质含有更少的S和N元素，是降低NOx和SO2排放的原因。生物质掺烧比为40％时VOCs等污染物排放最低。综合电厂实际运行情况，30％为最优掺烧比；分析表明，VOCs组分数量与燃料中生物质比例有很强的正相关性。生物质掺烧条件下VOCs的排放具有与燃煤锅炉和生物质锅炉不同的特征。在2种不同掺烧比下，VOCs排放占比最大的均为苯系物，分别达44.38％（20％）和33.75％（40％）。在20％掺烧比下其次是烷烃类（33.62％）、酯类（9.96％）等。在40％掺烧比下依次为酯类（22.75％）、烷烃类（16.16％）等。苯系物的排放以苯、甲苯等为主，烷烃的排放以正己烷为主，酯类则以乙酸乙酯为主；臭氧生成潜势（OFP）采用最大增量反应活性法进行分析，在20％和40％掺烧比下臭氧生成潜势贡献均主要来自于苯系物，贡献分别为69.88％和70.24％，烷烃的贡献也可占25.76％和17.75％。

 In order to understand the emission characteristics of volatile organic compounds (VOCs) in the flue gas under biomass co-combustion, the research on the emission characteristics of volatile organic compounds in the flue gas was carried out on a 58 MW circulating fluidized bed (CFB) unit. The results show that the emissions of VOCs and NOx and SO2 can be significantly reduced due to the co-firing of biomass. The change of the combustion characteristics of the mixed fuel leads to the emission reduction of VOCs. The emission reduction of VOCs is most obvious when the biomass mixing ratio increases from 20% to 30%. The reason for the reduction of NOx and SO2 emissions is that biomass contains less S and N elements. The emission of pollutants such as VOCs is the lowest when the biomass blending ratio is 40%. Based on the actual operation of the power plant, the optimal mixing ratio is 30%.The analysis show that the amount of VOCs components has a strong positive correlation with the proportion of biomass in the fuel. The emission of VOCs under the condition of biomass blending has different characteristics from coal-fired boilers and biomass boilers.Under the two different mixing ratios, the largest proportion of VOCs emissions is benzene series, reaching 44.38% (20%) and 33.75% (40%), respectively. At 20% blending ratio, it is followed by alkanes (33.62%), esters (9.96%) and so on. At 40% blending ratio, esters (22.75%), alkanes (16.16%) and so on are followed. The emission of benzene series is dominated by benzene and toluene, the emission of alkanes is dominated by n-hexane, and the emission of esters is dominated by ethyl acetate. The ozone formation potential (OFP) was analyzed by the maximum incremental reactivity method. The contribution of ozone generation potential at 20% and 40% mixing ratios was mainly from benzene series, which contributed 69.88% and 70.24%, respectively, and The contribution of alkanes could also account for 25.76% and 17.75%.

0 引言

1 试验与方法

   1.1 设备与原料

   1.2 样品采集与分析

2 结果与讨论

   2.1 污染物排放与生物质掺烧比的影响

   2.2 生物质比例与VOCs组分数量相关性分析

   2.3 生物质掺烧VOCs源成分谱

   2.4 特征比例分析

   2.5 臭氧生成潜势分析

3 结论