Emission Source Characterization during an Ethylene Plant Shutdown

Abstract

To conduct a well‐planned plant shutdown, so as to reduce flare emissions for the sake of plant profitability and local environmental sustainability, one of the primary tasks is to perform comprehensive and precise accountings for flare emissions. Since the literature is still lacking systematic and quantitative studies, plant‐wide dynamic simulations are employed to simulate an ethylene plant shutdown and characterize its flare emission sources through which dynamic emission profiles of various emission species changing with respect to time are obtained. Plant shutdown emission inventories are enriched with details for point emission sources, and possible technical supports are provided to both industry and environmental agencies on evaluating and developing cost‐effective flare minimization strategies in the future.

Air-Quality Considered Study for Multiple Olefin Plant Startups

“…However, excessive flaring, especially the flaring during olefin plant startups, emits huge amounts of emissions: carbon dioxide (CO 2 ), carbon monoxide (CO), nitrogen oxides (NO x ), volatile organic compounds (VOC), highly reactive VOC (HRVOC, defined in Texas air quality regulation as ethylene, propylene, isomers of butene, and 1,3-butadiene), and partially oxygenated hydrocarbons (e.g., formaldehyde). These emissions may cause highly localized and transient air pollution events and negative societal impacts. − For instance, HRVOCs have been identified to play a significant role in ground-level ozone formation in the HGB area (Houston–Galveston–Brazoria). According to Texas Administrative Code (TAC) title 30, chapter 115, subchapter H, industrial flaring emissions have been identified as the largest source for HRVOC emissions…”

Generic Approach of Using Dynamic Simulation for Industrial Emission Reduction under Abnormal Operations: Scenario Study of an Ethylene Plant Start-up

“…Besides, Lyondell Chemicals purportedly executed several FM procedures at its olefin sites. , Turnaround operations are usually modified by coupling some new FM plans; hence, detailed FM operation strategies are better to be virtually examined in advance to ensure operational safety and feasibility. In the past decade, dynamic simulations are largely employed to investigate the unit performance − or serve as a platform to refine or optimize FM operation strategies during ethylene plant turnaround operations. − …”