| Tianjin as an important industrial city in the northern region, one of the most rapidly developing petrochemical industries in China, the air has been discharged a large amount of VOCs pollutants, and photochemical air pollution characterized by high ozone level was frequently observerd in Tianjin City, which exert negative influences upon normal life of the residents. As VOCs is mainly from industrial emissions,research on the emission characterise of VOCs pollution sources are crucial for the formation mechanism of compound pollution in the atmosphere. this study carry out research on petrochemical emission source VOCs in Tianjin, estimating the VOCs emissions of the industry, launching research on VOCs emissions characteristics of different processing units in the enterprise.On the basis of tracing the relationship between VOCs species and the raw materials, process and treatment technology, to identify the main VOCs emission components, sources and contributions. In order to provide basic information to improve the quality of the surrounding air environment in the future and air quality model data providing the basic information for the environmental protection department to develop a scientific VOCs pollution control policy.Through to the field investigation for Dagang Petrochemical Industries in Tianjin, estimating the VOCs emissions inventory from petrochemicalindustries sources in 2014, petroleum refining emission sources is the main emission sources. Priority selected 2 typical petrochemical enterprises as the research object of this paper, including gas fractionation process, the process of gasoline and diesel tanks, sewage tank process in A enterprise, wastewater stripping process, delayed cokingprocess, coking gasoline tank tank process, sewage treatment plant process in B enterprise. Sourcesamples were collected by 2-liter stainless steel canisters with fugitive emission and chimmey discharge with organized emission. The samples were tested and analyzed by using the pre concentration-GC-MS, and 76 VOCs species were detected following EPA TO-14and TO-15 methods, dividing into six groups, alkanes, olefins, aromatics, oxygenated VOCs, halohydrocarbons and sulfide.According to the VOCs sample collection result, the different processing units VOCs emission source components spectrum in two enterprises were obtained, to identify the emission characteristics of VOCs species, the main conclusions of the study are as follows:(1) Similar source profile patterns were found for the enterprise, withacetone, 2-butene, and butane as the important components oftheir respective processes in A, with dichloromethane as the most abundant species, and hexane and pentane as the second contributor in the B profiles.(2) Sourcecharacteristicsexhibited differences among different emissions of enterprises. Benzene and toluene were the major species of wastewater treatment plant, while 2-methyl butyland isobutenewere important compounds of wastewater stripping processes.(3) Oxygenated VOCs were one of most significant VOC groups for source profilesof petrochemical industries in Tianjin, but not reported in other regions, which is the characteristic pollutant of A enterprise.(4) The emission characteristics of VOCs are closely related to the origin of raw materials and reaction mechanism. In addition, the addition of organic solvents such as oil tanks and chemical production equipment will affect the emission of VOCs chemical species in the target unit. |
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