新疆维吾尔自治区石化企业典型工艺无组织VOCs排放特征及光化学反应活性

为探究新疆维吾尔自治区石化企业典型工艺〔LCZZ（蜡催装置工艺）、XHS（循环水工艺）、DFT（大芳烃工艺）、SX（三循工艺）、180万t（180万t加氢工艺）、200万t（200万t加氢工艺）〕无组织VOCs（挥发性有机物）的排放特征及光化学反应活性，采用气袋法进行样品采集，用GC-MS（气相色谱-质谱仪）定量分析其主要成分，并利用LOH法（·OH反应速率法）和MIR法（最大增量反应活性法）估算VOCs组分的臭氧生成潜势.结果表明:该石化企业中，各典型工艺无组织排放的ρ（TVOCs）（VOCs化合物质量浓度之和）较高，范围为87.2~185 μg/m3，其中LCZZ排放最高，180万t排放最低；各工艺检测到的VOCs成分构成整体上相似，均以烷烃和卤代烃为主，w（烷烃）和w（卤代烃）范围分别为41.7%~67.3%和24.3%~50.1%；不同工艺的无组织VOCs特征组分各有不同，但均为ρ（氟利昂113）最高，w（氟利昂113）范围为22.3%~45.8%.不同工艺无组织废气中臭氧生成贡献率较大的物种均为烯炔烃和烷烃；LCZZ、XHS、SX及180万t中的丙烯、DFT中的正丁烷和200万t中的2，3-二甲基丁烷是各工艺排放VOCs中臭氧生成贡献率最大的组分，同时也是对光化学污染贡献最为突出的污染物质.研究显示，该石化企业无组织VOCs的污染较为严重，具有明显的工艺差异性，VOCs组分较复杂，应采取分工艺、生产全过程控制的污染防治对策. 

Emission Characteristics and Photochemical Reaction Activity of VOCs in the Non-Organized Emission of Typical Processes of the Petrochemical Enterprise in Xinjiang Uygur Autonomous Region

To investigate the emission characteristics and photochemical reaction activity of volatile organic compounds (VOCs), the non-organized emission of six typical processes were tested in a representative petrochemical enterprise in the Xinjiang Uygur Autonomous Region, which were LCZZ (wax push device), XHS (circulating water), DFT (large aromatic hydrocarbons), SX (three loops), 1.8 million tons (1.8 million tons of hydrogenation) and 2 million tons (2 million tons of hydrogenation), respectively. VOCs samples were collected by air pocket method and their concentrations and chemical species were analyzed quantitatively by GC-MS (gas chromatography-mass spectrometry). In addition, LOH (·OH loss rate) and MIR (maximum increment reactivity) were applied to calculate OFP (ozone formation potential) of various VOCs species. The results showed that the mass concentrations of TVOCs were 87.2-185 μg/m3 in the non-organized emission of the six typical processes of the petrochemical enterprise, and the LCZZ process was the highest while 1.8 million tons process turned out to be the lowest. VOCs species in all processes were similar, and alkane and halogenated hydrocarbons were the main compounds, which accounted for 41.7%-67.3% and 24.3%-50.1% of TVOCs, respectively. The characteristic components were different from different processes, but Freon 113 was the most abundant fraction with the contribution of 22.3%-45.8% in all processes. The top two species for ozone formation were ene alkynes and alkane. The ene alkynes, especially propylene, in LCZZ, XHS, SX and 1.8 million tons, the alkane, especially n-butane, in the DFT and 2, 3-dimethylbutane in 2 million tons have the highest ozone formation potential in the petrochemical enterprise. In conclusion, the VOCs pollution was heavy from the non-organized emission of the petrochemical enterprise, and components varied with processes. Different countermeasures should be taken according to the pollution characteristics of different processes in the whole.