ENV-10-34 Results from Emissions Measurement Projects Conducted on Delayed Coking Unit Atmospheric Depressurization Vents

Description:

The potential air emissions associated with delayed coking unit atmospheric depressurization vents have been the subject of increased scrutiny by US EPA, several state regulatory agencies, and other stakeholders over the last several years. A series of experimental measurement efforts performed by California’s South Coast Air Quality Management District (SCAQMD) and URS Corporation (URS), as well as optical remote sensing projects conducted at refineries in the US and Canada, have reported widely varying mass emission rates of volatile organic compounds from delayed coking units. Some of the data collected by SCAQMD and URS Corporation have been used by US EPA to develop a draft of the first available emissions factors for depressurization vents. Interest in additional emissions data for depressurization vents has spread, and the operating permits of several refineries have already been impacted from claims that emissions from delayed coking units have not been properly accounted for. Emissions data from several source tests of depressurization vents are discussed.