(258b) Multi-Scale Dynamic Simulation and Optimization for Simultaneous Chemical Plant Emission Reduction and Regional Air Quality Improvement

Chemical industrial zones heavily populated by chemical plants often experience highly localized and transient air pollution events, with elevated concentrations of multiple air pollutants, and ozone concentrations that violate the National Ambient Air Quality Standards (NAAQS).  One identified major source related to these pollution events is air emissions of highly reactive volatile organic compounds (HRVOCs) from chemical industry flaring activities.  Flaring is crucial to the chemical plant safety. However, excessive flaring, especially the intensive flaring during chemical plant turnarounds, emits huge amount of volatile organic compounds (VOCs) and HRVOCs and also results in tremendous industrial material and energy loss.  Thus, the flare emission must be minimized by chemical plants. However, flare minimization at plant-wide scale is not enough to deal with regional air quality problems, because two problems are still insufficiently addressed or neglected today, which include i) what are the exact impacts of air emissions from chemical plant flaring? ii) are there any cost-effective ways available for chemical plants to help improve regional quality, instead of being simply enforced to reduce emissions continuously and aggressively.   

In this paper, we propose a systematic methodology on multi-scale dynamic simulation and optimization for simultaneous chemical plant emission reduction and regional air quality improvement.  It couples plant-wide dynamic simulation for flare minimization and emission quantification (i.e., hourly dynamic emissions from plant flaring activities), as well as regional scale air quality simulation for flare emission impact analysis. Based on such multi-scale dynamic simulations, optimization strategies for chemical plants operations will be proposed, which benefits regional air quality improvement, meanwhile provides cost-effective ways for chemical plant operations.