ENV-13-62 Method of Sampling Limitations and Challenges Related to Refinery ICR Testing on Delayed Coking Unit Vents

Description:

The refinery ICR initiated a sampling and analysis undertaking that challenged the refineries, air testing groups and analytical laboratories. Many sources presented unique challenges in applying traditional EPA test methodologies. The request to gather standard pollutant and hazardous air pollutant (HAP) data from delayed coking unit (DCU) vent exhausts using traditional EPA combustion source test methods presented perhaps one of the most significant challenges. Most, if not all, DCU vent sources are comprised of moisture vapor on the order of >90% (and often up to 98-99%). In addition, these vents are typically hot and have high velocities during their short venting cycles. Despite pretesting discussions over the methods applicability, the refinery ICR went forward with the challenge of using traditional air testing methods to collect data from, essentially, a liquid stream. The challenge was met head on and through planning, pretesting, and imaginative modifications to the required test methods, DCU vent exhaust data was generated. Unfortunately, the generated data was shown to be limited in its application to the development of future MACT standards for DCU vent sources due to a number of factors, specifically, elevated limits of detection for a number of compound groups. This presentation is designed to show that through thoughtful consideration and imagination, solutions can be developed and applied to a seemingly “un-testable” source, but the use of air methods on super-saturated vent exhausts has brought into question the applicability of those methods based on the data results.