MODELLING THE FIELDS OF POLLUTANT DISPERSION IN THE ATMOSPHERE FROM FLARES

Abstract

The fields of pollutant dispersion in the air from three operating flare installations at the territory of the Mamontovskoye field in the Nefteyugansk District of the Khanty-Mansi Autonomous Territory were modelled on the basis of climatic data and technological parameters of flare installations. The amounts of pollutants entering the atmosphere from associated petroleum gas combustion were calculated: carbon monoxide (CO) - 83 %, nitrogen dioxide (NO2) - 0.7 %, soot - 10 %, methane - 6 %. The vegetation cover was mapped relying on the Sentinel-2 satellite image with the shooting date of June 14, 2021, displaying dispersion fields for СО, NO2 and soot. The distances from emission source (flare installation) to isolines with CO and soot concentrations equal to 1 MPCst (5 and 0.15 mg/m3) are 163 and 505 m, respectively (here MPCst is the maximum permissible concentration for short-term exposure level). Similarly, measured distance to the isoline with NO2 concentration 0.1 MPCst concentration (0.02 mg/m3) is 284 m. On average, CO concentration decreases by 1 mg/m3 at a distance of 86 m and becomes equal to 0.2 mg/m3 (0.04 MPCst) at a distance of about 572 m. The resulting model for CO dispersion does not contradict MERRA-2 satellite data, according to which the concentration of CO in the vicinity of the flare installation was 0.2 mg/m3. The gas chromatographic - mass spectrometric analysis of soil samples and plants collected to the north-east from the flare installation at a distance of 216, 486, 710, 1037 and 1380 m has shown that aliphatic hydrocarbons prevail in the composition of soil organic matter. Their content varies from 50 to 80 % of all identified compounds, with the predominance of high-molecular homologues (C27-C33). The maximum total amount of n-alkanes (75.3 μg/g) was detected in the soil sample taken at a distance of 710 m from the flare installation. In the organic matter of pine needles and blueberry leaves, C27 homologue dominates, and C25, C29, C31 characteristic of terrestrial vegetation are present. In addition, polyaromatic compounds were identified in the soil: anthracene/phenanthrene, fluoranthene and pyrene.