Study on volatile organic compound source profiles and dynamic emission inventories in an integrated refinery-petrochemical complex

Volatile organic compound (VOCs) emissions from integrated refinery-petrochemical complex (IRPC) were difficult to quantify due to complex production processes and significant fugitive emissions. Previous studies had largely focused on upstream refinery units, with limited research on comprehensive emission factors (EFs) and inventories for the entire IRPC. We analyzed multiple emission sources within IRPC, including equipment leaks (EL), stationary combustion (SC), cooling towers (CT), storage tanks (ST), wastewater collection and treatment systems (WT), process vents (PV), flares (F), and loading operations (LO). The EFs of IRPC was 0.21 kg VOCs/t of crude processed. Additionally, to mitigate the temporal lag associated with traditional emission inventories, we developed dynamic accounting methods for VOCs emissions in IRPC. These methods integrate monitoring data and time-varying meteorological parameters (e.g., temperature, air pressure, wind speed) to estimate emissions from SC and ST. An integrated analytical system combining gas chromatography-mass spectrometry (GC-MS) and flame ionization detection (FID) was used to characterize and quantify 115 VOCs species. Composite source profiles were sampling from 35 sites collected across 18 units using a weighted average method. This detailed breakdown provided a more comprehensive view of IRPC emissions compared to studies focusing solely on upstream units. In the IRPC, key pollutants identified include propane, ethane, acetone, ethanol, propylene, and dichloromethane. Alkenes and alkynes had the highest ozone formation potential (OFP) contribution, while aromatics had the greatest secondary organic aerosol formation potential (SOAP) contribution. The study's detailed source profiles and dynamic emission inventory aid petrochemical pollution control and regional air quality improvements.