工业区VOCs排放通量遥测方法研究

Emissions of volatile organic compounds(VOCs) and other toxic and harmful gases from multi-point source, plane source and unorganized emissions source of industrial production process are a significant source of atmospheric pollutants，monitoring of the flux of each emission source is not only a key link of grasping space and time distribution and diffusion model of the atmospheric pollution, but also an important means of monitoring、evaluating and recognizing each emission source. At present in China, it’s lack of convenient and fast monitoring means, especially there is no continuous automatic monitoring method to acquire the flux information of VOCs..According to the condition, this project plans to take advantage of the technology of fourier transform infrared spectroscopy (FTIR), then on this basis carries out the research of the technology of solar occultation flux based on FTIR (SOF-FTIR). Making use of a device of sun-tracker, system plans to use infrared radiation of direct sunlight as receiving light source, makes rapid scanning of the chemical factory under a mobile platform, gets every sampling site’s column concentration of the plume profile through spectral analysis, then gets profile’s surface density, at last calculates the flux of pollution source combined with the atmospheric transmission model and wind field data, obtains the emission flux’s information of VocS and other hazardous gases of industrial district, which provided a effective automatic means of VOCs’ control and management, and also a powerful data support for the environmental decision-making.

工业生产过程中多点源、面源和无组织源排放的VOCs及其它有毒有害气体是大气污染物的重要来源，监测各个排放源的通量信息是掌握多组分大气污染成分时空分布及扩散模型的关键环节，也是对各个排放源进行监测、评估以及污染识别的重要手段。目前国内对于多点源、无组织排放源VOCs的排放通量，一直缺乏便捷和快速的自动监测手段。针对这种现状，本项目拟利用FTIR的技术优点，开展基于FTIR光学监测方法的车载掩日法通量遥测方法研究。该研究拟利用太阳跟踪装置将太阳红外辐射作为系统接收光源，在移动平台上对工业区域上空污染气体进行实时快速扫描，通过光谱分析获得烟羽剖面各采样点污染成分的柱浓度并积分得到剖面的面密度，结合大气传输模型以及风场数据计算出污染源的排放通量，获得工业区VOCs及其它有毒有害气体的排放通量信息，为工业区VOCs的控制和治理提供有效的自动监测手段，进而为政府相关决策提供切实的科学依据和数据支撑。

化工园区生产过程中多点源、面源和无组织源排放的VOCs及其它有毒有害气体是大气污染物的重要来源，关于其排放总量、排放特征的研究一直缺乏便捷和快速的自动监测手段。本项目针对VOCs监测的迫切需求，利用傅立叶变换红外光谱法（FTIR）的技术优点并在此基础上开展了基于FTIR光学监测方法的车载掩日法通量遥测技术（SOF-FTIR）的研究，利用车载移动平台走航监测并结合太阳光谱采集技术，集成了大气红外透过率地基车载走航遥测系统，开展了光谱筛选算法的研究并开发了相应的自动筛选软件。在光谱质量得到保证的基础上，进行了基于非线性最小二乘法的柱浓度以及排放通量反演算法的研究，并给出了系统的误差分析。通过在实验室搭建了系统性能指标测试平台量对系统各项性能指标进行了测试，同时设计了外场高架试验来对系统的排放通量反演结果进行验证。经过测试，系统关键指标如下：光谱分辨率1cm-1；光谱测量范围2～15μm；垂直柱浓度检测限1～15ppm·m；测量精度优于5%；通量检测限0.01～0.09kg/h。利用研制的SOF-FTIR走航遥测系统开展了外场监测试验，对试验结果进行了分析并给出试验结论。通过外场监测试验，系统的稳定性和易操作性得到了检验，监测结果的准确性和可靠性也得到验证，反应出SOF-FTIR系统在化工园区VOCs排放通量实时、在线监测以及污染源应急监测等场合良好的应用前景。