(585e) A Win-Win Strategy for Chemical Plant Shutdown: Integrating Economic and Environmental Objectives

Ground-level ozone is a pervasive air pollutant, which can be potentially aggravated by flaring emissions from olefin plant shutdown operations. Although, flaring is crucial to chemical plant safety, the excessive flaring, for instance the intensive flaring from plant shutdown operations, emits huge amounts of ozone pollution precursors (VOCs and NOx). This will cause tremendous industrial material loss and environmental damage; meanwhile result in tremendous economic loss and potential adverse impact on the regional air quality. Thus, the plant shutdown flare emissions should be minimized at any possibility. In this paper, plant-wide dynamic simulations for flare emissions with regional air-quality modeling are coupled together to quantify the air-quality impact and roughly evaluate the cost savings. It proposed a systematic methodology on both economy and air-quality conscious study for shutdown operations of an olefin plant. Through studies of original and optimal cases, it shows that the original plant shutdown operation procedure has a serious effect on the regional air quality and tremendous loss of raw material; however, the optimal shutdown operation procedure would significantly reduce such ozone impact together with the saving of tremendous raw material. This study can provide valuable and quantitative supports for decision makings involving multiple stakeholders, including environmental agencies, regional plants, and local communities.