2018年夏季某石化工业区VOCs浓度特征及活性物种

为明确某石化工业区VOCs浓度特征及活性物种，利用法国Chromatotec公司生产的airmo VOC expert C₂-C₆和airmo VOC expert C₆-C₁₂分析仪联用系统在2018年夏季对该工业区VOCs进行连续监测.结果表明:①研究期间，石化工业区φ（TVOCs）（57种VOCs物种体积分数之和）为93.7×10-9±87.5×10-9，其中烯烃占比最高，达44.9%，当φ（TVOCs）日均值越高时烯烃占比越高.体积分数较高的物种主要为低碳烯烃、低碳烷烃、正己烷、甲苯和苯.②石化工业区φ（TVOCs）呈显著的夜高昼低变化特征，且各组分变化趋势相近，其中烯烃变幅高于其他组分.③各排放物质中对O₃生成贡献较大的主要是乙烯、丙烯、顺-2-丁烯、甲苯等物质，而对二次有机气溶胶生成贡献较大的主要是甲苯、异丙苯、间/对二甲苯等物质.④通过PMF解析发现，石化工业区内催化裂化及裂解、催化重整及废水废液处理、油储设施溢散的贡献率分别为51.7%、34.8%、13.5%.⑤降低石化工业区VOCs活性可以明显降低O₃超标率，若同时降低VOCs活性与φ（NO_x）可更有效地降低O₃超标率.研究显示，石化工业区VOCs排放强度较大，应对催化裂化及裂解等重点排放单元，以及乙烯、丙烯和甲苯等活性物质的排放进行控制，降低VOCs整体活性，并协同控制区域内NO_x排放，从而减少O₃污染. 

Characteristics of VOCs Concentrations and Active Species in a Petrochemical Industrial Area in the Summer of 2018

The VOCs concentration and active species produced in a petrochemical industrial area in the summer of 2018 were characterized by continuously monitoring outputs using a combined system of airmo VOC expert C₂-C₆ and airmo VOC expert C₆-C₁₂ analyzers. The analytical results indicate that: (1) In the petrochemical industrial area, volume fractions φ(TVOCs) of 57 VOCs were 93.7×10-9±87.5×10-9 during the study period. Olefin recorded the highest proportion of VOCs (44.9%). The higher the average day φ(TVOCs), the higher the proportion of olefin. Species with high volume fractions were mainly consisted of low alkanes, n-hexane, toluene and benzene. (2) φ(TVOCs) in the petrochemical industry area had a significant change trend of being high at night and low during the day. The variation trend of each component was similar, and the variation range of olefin was higher than that of other components. (3) Ethylene, propylene, cis-2-butene and toluene were the major contributors to the formation of O₃ in the petrochemical industrial area. The major contributions to the formation of secondary organic aerosols were toluene, isopropyl benzene and m/p-xylene. (4) PMF analysis indicted that the contribution of catalytic cracking was 51.7%, the contribution of catalytic reforming and waste-water treatment was 34.8%, and the contribution of oil storage facility spill was 13.5%. (5) A reduction of VOCs activity in the study area can significantly reduce O₃ pollution. If the activity of VOCs and the volume fraction of NO_x are simultaneously reduced, O₃ pollution can be more effectively reduced. Although results from this investigation indicate that the emission intensity of VOCs in a petrochemical industrial area is relatively high, VOCs activity can be reduced by controlling key units such as catalytic cracking and active substances (for example, ethylene, propylene and toluene). The combined effect of reducing VOCs activity and controlling NO_x emissions in the region at the same time will ultimately result in a reduction in O₃ pollution.