Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, 220005, Nigeria; School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT, UK.
School of Geography, Earth and Environmental Sciences, University of Birmingham, B15 2TT, UK.
Environ Pollut. 2019 Mar;246:284-293. doi: 10.1016/j.envpol.2018.12.021. Epub 2018 Dec 11.
An understanding of the dispersion and level of emissions source of atmospheric pollutants; whether point, area or volume sources, is required to inform policies on air pollution and day-to-day predictions of pollution level. Very few studies have carried out simulations of the dispersion pattern and ground-level concentration of pollutants emitted from real-world gas flares. The limited availability of official data on gas flares from the oil and gas industries makes accurate dispersion calculations difficult. Using ADMS 5 and AERMOD, this study assessed the sensitivity of dispersion and ground-level concentration of pollutants from gas flares in the Niger Delta to prevailing meteorological condition; fuel composition; and flare size. Although, during the non-WAM (West African Monsoon) months (November and March), the simulated ground-level concentrations of pollutants from a single flare are lower, the dispersion of pollutants is towards both the inland and coastal communities. In the WAM months, the ground-level concentrations are higher and are dispersed predominantly over the inland communities. Less buoyant plumes from smaller flares (lower volume flow rates) and/or flaring of fuel with lower heat content results in higher ground-level concentrations in areas closer to the flare. Considering the huge number of flares scattered around the region, a mitigation of the acute local pollution level would be to combine short stacks flaring at lower volume flow rates to enhance the volume flow rate of a single exhaust, and hence, the buoyancy of the plume exiting the stack.
需要了解大气污染物的分散和排放源水平，无论是点状、面状还是体积状源，以便为空气污染政策和日常污染水平预测提供信息。很少有研究对来自实际天然气火炬的污染物的扩散模式和地面浓度进行模拟。由于石油和天然气行业对天然气火炬的官方数据有限，因此难以进行准确的扩散计算。本研究使用 ADMS 5 和 AERMOD，评估了尼日尔三角洲天然气火炬排放的污染物在盛行气象条件、燃料成分和火炬大小下的扩散和地面浓度的敏感性。虽然在非 WAM（西非季风）月份（11 月和 3 月），单个火炬产生的污染物的模拟地面浓度较低，但污染物的扩散方向是内陆和沿海社区。在 WAM 月份，地面浓度较高，主要分布在内陆社区。较小火炬（较低体积流量）和/或低热含量燃料的浮力较小的羽流会导致靠近火炬的区域的地面浓度更高。考虑到该地区周围散布着大量的火炬，如果要减轻当地的急性污染水平，可以将低体积流量的短烟囱一起燃烧，以提高单个排气的体积流量，从而提高烟囱出口羽流的浮力。
