加油站埋地油罐呼吸排放因子法的本地化应用

Localization application of breathing emission factor method for underground oil tank in gas station

加油站汽油挥发是挥发性有机物(VOCs)的重要来源之一。加油站VOCs排放包括卸油排放、加油排放、呼吸排放、加油枪滴油和胶管渗透排放等5个环节。针对加油站各环节排放因子已开展了诸多统计研究,但并未考虑加油站工艺及设备配置、日均加油规模等因素对排放因子的影响。参考美国CARB认证规程,采用自主研发的加油站呼吸排放测试系统,以北京某年销汽油量约9000 t且未安装油气处理装置的加油站为测试站点,开展埋地油罐呼吸排放因子的本地化研究。通过对呼吸排放量的连续监测,采用实验检测与数据统计相结合的方法,研究呼吸排放因子与加油量的相关性。结果表明:加油站的埋地油罐呼吸排放因子与日均加油量显著相关;对于标准化加油站,日均加油量小于15920 L时,呼吸排放因子为0;随着日均加油量的升高,呼吸排放因子逐步升高,且符合多项式方程;超过28800 L后,呼吸排放因子变化趋于稳定在约30 mg·L^(-1)。综合考虑后处理装置安装成本和产生的环境效益,年汽油销售规模超过4500 t的加油站应安装后处理装置,以降低呼吸排放的油气量。本研究结果可为不同规模加油站的VOCs排放分级管理提供参考。

Gasoline volatilization from gasoline filling station is one of the important sources of volatile organic compounds(VOCs).VOCs emissions from gas filling stations include five links:oil unloading emissions,refueling emissions,breathing emissions,fuel gun oil dripping and hose permeation emissions.Many statistical studies on the emission factors of gasoline filling station have been carried out.However,the influence of gas station technology,equipment configuration,daily refueling scale and other factors on emission factors has not been considered.In this paper,an independent designed breathing emission monitoring system based on the CARB certified procedure was installed in a gasoline filling station(9000 t·a^(−1))in Beijing without vapor recovery device,then the study of local breathing emission factor of underground storage tank was carried out.After continuously collecting date,the relationship between breathing emission factors and refueling volume was investigated by the combined methods of experimental testing and data statistics.The results showed that the correlation between breathing emissions factor of underground storage tank and daily refueling volume was significant.For the standardized gasoline filling stations,when average daily refueling volume was less than 15920 L,the breathing emission factor was 0.With the increase of daily refueling amount,the breathing emission factor increased gradually,and it was in accordance with polynomial equation.When the average daily refueling volume was more than 28800 L,the breathing emission factor tended to stable at about 30 mg·L^(−1).Taking into account the installation cost and environmental benefits of reprocessing devices,gas stations with annual gasoline sales of more than 4500 t should install reprocessing devices to reduce the amount of oil and gas emitted by breathing.The results can provide reference for the hierarchical management of gasoline filling station with different sale volume.