Flaring efficiencies and NO x emission ratios measured for offshore oil and gas facilities in the North Sea

[摘要] Gas flaring is a substantial global source of carbonemissions to atmosphere and is targeted as a route to mitigating the oil andgas sector carbon footprint due to the waste of resources involved.However, quantifying carbon emissions from flaring is resource-intensive,and no studies have yet assessed flaring emissions for offshore regions. Inthis work, we present carbon dioxide ( CO 2 ), methane ( CH 4 ), ethane( C 2 H 6 ), and NO x (nitrogen oxide) data from 58 emission plumesidentified as gas flaring, measured during aircraft campaigns over the NorthSea (UK and Norway) in 2018 and 2019. Median combustion efficiency, theefficiency with which carbon in the flared gas is converted to CO 2 inthe emission plume, was 98.4 % when accounting for C 2 H 6 or98.7 % when only accounting for CH 4 . Higher combustion efficiencieswere measured in the Norwegian sector of the North Sea compared with the UKsector. Destruction removal efficiencies (DREs), the efficiency with whichan individual species is combusted, were 98.5 % for CH 4 and 97.9 %for C 2 H 6 . Median NO x emission ratios were measured to be0.003  ppm ppm −1  CO 2 and 0.26  ppm ppm −1  CH 4 , and the median C 2 H 6 :CH 4 ratio was measured to be 0.11  ppm ppm −1 . Thehighest NO x emission ratios were observed from floating productionstorage and offloading (FPSO) vessels, although this could potentially bedue to the presence of alternative NO x sources on board, such as dieselgenerators. The measurements in this work were used to estimate totalemissions from the North Sea from gas flaring of 1.4  Tg yr −1 CO 2 ,6.3  Gg yr −1 CH 4 , 1.7  Gg yr −1 C 2 H 6 and 3.9  Gg yr −1 NO x .

[学科分类] 医学（综合）