Modelling and Simulation for Regional Ozone Impact by Flaring Destruction and Removal Efficiency of Oil & Gas Industries

Abstract

Abstract Flaring is a necessary measure for plant safety in oil & gas industries. However, the industrial flaring generates large amounts of VOC and NOx, which could transiently aggravate regional ozone concentrations that could affect on human health and the environment. Currently, the national standard value of 98% or 99% for destruction and removal efficiency (DRE) is regulated and presumed for industrial flaring operations. However, the DRE value could be lower than the national standard under various atmospheric and operating conditions, such as the high cross-wind speed and flare jet velocity. Thus, it is important to know the quantity and sensitivity of the regional ozone impact due to lower DREs in oil & gas industries. In this paper, a systematic study on industrial ozone pollution impacts due to the lower flaring DREs caused by cross-wind speed and flare jet velocity has been performed. First, the DRE formulas considering crosswind speed and jet velocity were derived based on available references. Second, the emission inventory assisted by the DRE formulas was updated in a certified episode of air-quality model from Texas Commission on Environmental Quality (TCEQ), where compressive information of meteorology (e.g., solar radiation intensity, wind speed, temperature, pressure and humidity), geography (e.g., population densities and land use) and emission inventory (e.g., point source emissions, area emissions, on-road emissions and biological emissions) were modeled. After that, comprehensive air quality model with extensions (CAMx) based air-quality modelling was conducted to simulate the regional ozone formation and transformation, as well as to study the ozone increments due to effects on DRE changes. This study could provide valuable and quantitative support for all relevant stakeholders, including environmental agencies, regional plants, and local communities.