红外掩日遥感监测炼油厂非甲烷烷烃排放通量

采用红外掩日通量遥感监测(SOF)技术分别在2014年5月~2015年12月和2021年10月监测了我国7座大型炼油厂(其中6座原油年加工量均超过1000万t)非甲烷烷烃排放通量(kg/h)及分布.每座炼油厂监测3~8d,测量18~73次,总计获得328个排放通量测量数据,根据国内炼油厂VOCs排放烟羽中非甲烷烷烃质量分数估算了VOCs排放量,结合监测期间实际原油加工量计算了非甲烷烷烃和VOCs排放系数.结果显示:7座炼油厂2014~2015年的非甲烷烷烃排放系数测定值为0.016%~0.11%,平均为0.081%;VOCs排放系数估算为0.020%~0.14%,平均为0.10%.无组织排放约占炼油厂非甲烷烷烃排放总量的70%以上,其中轻油贮罐排放占比过半.国内7座炼油厂2014~2015年非甲烷烷烃排放系数的最好水平与美国南加州6座炼油厂同期SOF监测的最好水平相当,但非甲烷烷烃排放系数的平均水平约为其平均水平的3.9倍,国内炼油厂的VOCs排放控制水平更加参差不齐.国内1座千万吨级炼油厂2021年监测的非甲烷烷烃排放通量和排放系数分别较2015年削减72.4%和74.2%.SOF可为石化VOCs无组织排放监测、量化和排放清单修订提供最佳实用技术,本研究结果提供了国内石化行业VOCs综合整治初期典型炼油厂非甲烷烷烃和VOCs的基线排放实测数据,以及1座千万t级炼油厂6a后治理攻坚效果.

Measurement of emission fluxes of total non-methane alkanes from refineries using solar occultation flux remote sensing technique

The emission fluxes (kg/h) and distributions of total non-methane alkanes from seven major refineries (in which six refineries were processing crude oil more than ten million tons per year) in China were quantified during May 2014 and December 2015 and in October 2021 using the Solar Occultation Flux (SOF) method. At each refinery site, 18~73measurement transects were performed during three to eight individual measurement days. In total, 328measurements of total non-methane alkane emission flux were performed for the seven refineries. Total VOC emissions were estimated from the measured total non-methane alkane emissions based on the average mass fraction of non-methane alkanes in total volatile organic compounds (VOC) measured in VOC emission plumes of several refineries in China. Total non-methane alkanes and VOC emission factors were calculated by scaling measured emissions of total non-methane alkanes and estimated emissions of VOCs with crude oil processing rates during the measurement period. The monitoring results indicate that the measured total non-methane alkanes emission factors ranged from 0.016% to 0.11% for the seven studied refineries and were 0.081% on average. The estimated VOC emission factors for the seven studied refineries ranged from 0.020% to 0.14%, with an average value of 0.10% during 2014 and 2015. Fugitive emissions accounted for more than 70% of total non-methane alkane emissions from refineries, and light oil tanks contributed more than 50% of fugitive non-methane alkane emissions. The results were compared to SOF measurements at six refineries in the South Coast Air Quality Management District (SCAQMD) in 2015, and the lowest level of total non-methane alkane emission factors in the seven refineries in China measured during 2014 and 2015 was the same as that for all six refineries in SCAQMD. However, the average level of total non-methane alkane emission factors of the seven refineries in China was 3.9times higher than that of the six refineries in SCAQMD, and there was a higher variability in total non-methane alkane emission factors among the seven refineries in China. The emission flux and emission factor of non-methane alkanes monitored in a major Chinese refinery in 2021 showed a reduction by 72.4% and 74.2% respectively compared with 2015. SOF could be developed as the best available technique for monitoring and quantifying fugitive and diffuse VOC emissions from petroleum and petrochemical industrial sites, and for revising VOC emission inventories. This study has provided a baseline of measured emissions of total non-methane alkanes and VOCs from typical refineries in the initial stage of VOC emissions control actions implemented in China in 2015, and VOCs control effectiveness of a major refinery after 6 years.