Fugitive volatile organic compound (VOC) emissions from equipment leaks in the petroleum refining industry threaten ambient air quality and human health. The impact of a long-term leak detection and repair (LDAR) on mitigating these emissions has not been adequately elucidated. Herein, we explored the VOC emission characteristics and mitigation from a petroleum refinery in a long-term LDAR implementation, established emission factors at production unit-level and enterprise-level, and assessed the VOC mitigation, ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAP) from equipment leaks of petroleum refining in Guangdong, China. The results indicated that the long-term implementation of LDAR at the enterprise-level petroleum refining facility resulted in an approximately 40.5% reduction in overall VOC emissions. Kerosene hydrotreating unit (KHU), catalytic reforming unit (CRU), delayed coking unit (DCU), aromatics recovery complex (ARC), and hydrocracking unit (HCU) were the top five units for emission reduction, while valves and connectors were the top two sealing points. The implementation of LDAR across all petroleum refineries in Guangdong Province achieved annual VOC emission reductions ranging from 129.0 to 160.5 tons between 2018 and 2022, with corresponding reductions in OFP and SOAP of approximately 68.2%. Alkenes/alkynes were the primary contributors to OFP, whereas aromatics dominated SOAP. Three recommendations were proposed for the optimization of future LDAR implementation policies: to emphasize the quality control and assurance of LDAR detection data; to establish a refined LDAR work plan that integrates production units and sealing points; and to conduct LDAR work on a regular and continuous basis.
Sun et al. (Sun,) studied this question.