(20b) Emissions Testing of Sonic Velocity Flares Validates High Destruction Efficiency

Emissions Testing of Sonic Velocity Flares Validates High Destruction Efficiency

Scot Smith, Director Flare Products, Zeeco

In a 2012 report by the EPA’s Flare Review Panel, regulations for flares that tended to operate outside their stable flame envelope were expanded to include limits on velocity as a function of net heating value.

EPA regulations do not currently allow sonic velocity flares to be permitted and operated without first performing an alternate means of emissions limitation test to validate destruction efficiencies.  Existing regulations affect the application of multi-point staged flares since these flares operate at sonic exit velocities that exceed the maximum exit velocity requirements cited in 40 CFR 60.18 and 40 CFR 63.11(b) and applicable state regulations.

Over the years, Zeeco has conducted numerous destruction efficiency tests on its multi-point sonic flares. All of these tests demonstrated high destruction efficiency at velocities exceeding the EPA’s limits.  The purpose of these tests, performed at Zeeco’s industrial-scale combustion test facility near Tulsa, Oklahoma, was to validate sonic tips for more applications using an expanded range of gases and conditions. Extractive sampling was used to measure the emissions from the exhaust plume at staging and de-staging pressures.  The extracted gas concentrations were used to calculate the destruction efficiency of the multi-point sonic flare tips at each test point. Even with sonic gas exit velocities, the Zeeco-designed sonic flare tips maintained high destruction efficiency.

Despite pressure from both end users and regulators, Zeeco’s flare burner tests and results have been maintained internally.  This paper will present those results to the industry for the first time.