Emission of trace compounds from catalytic reforming units

Catalytic reforming units (CRUs) are a potential emissions source of a number of compounds listed as Hazardous Air Pollutants (HAPs) in the 1990 Clean Air Act Amendments. Some of these compounds are released in depressurization and purge of the unit at initiation and conclusion of the regeneration process. Some form in the catalyst regeneration process and are then emitted. In this work, we developed improved average and median emission factors for these HAPs, based on 54 new field test data points, covering 14 compounds. For some of these compounds (HCl and particulates), there are large differences between the average and the median emission factors due to significant scatter in the raw data. Comparisons are made to previously published emission factors from data collected by the U.S. Environmental Protection Agency (EPA). The new data points and the EPA collection have been combined and analyzed to provide guidance on HAP emissions based on the type of CRU. These new average emission factors should provide for more representative estimates for both permitting and emissions reporting when actual monitoring data are not available. It was also found that the emission per unit feed rate to the CRU does not differ significantly with the mode of regeneration utilized.