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Increasing the flaring emission factor

Oilfield Technology,

The GPA has filed comments with the US EPA recommending that the agency withdraw its proposed changes to section 13.5 of AP-42, ‘Compilation of Air Pollutant Emission Factors’. GPA member companies own facilities using the AP-42 emission factors and would be subject to increased regulatory burdens under the agency’s proposed substantial increase in the emission factor for nitrogen oxides emitted from industrial flares.

Mark Sutton, GPA President and CEO said, “finalising the proposed emission factors will cause uncertainty to both regulators and the regulated community alike; there are no benefits. In addition, the midstream sector of the natural gas industry across the US will be substantially harmed if performance testing or other methods must be used as alternatives to the current publicised emission factor for industrial flares.”

The GPA has shown concern regarding the sample size used to develop the new emission factors, which was based on only five new data points, with one value from a facility ‘orders of magnitude higher than the average of the other four.’ The GPA also said that emission factors apply to different facility types within oil and gas operations, as well as other industry sectors, and that the EPA has based its proposed factors on flare data from one type of flare, from only one type of facility, and in one industry sector, petroleum refineries, plus a test facility.

Sutton continued, “refineries are large sources of air emissions and typically fall into major source categories. The majority of midstream facilities with flares are minor sources and use flares as control devices and stay below major source thresholds. Increasing the NOx emission factor by a factor of 42 as proposed could result in hundreds of midstream facilities becoming inappropriately categorised as major sources. The increase in permit applications alone could result in a significant regulatory burden on both the regulatory authorities and the regulated community.”

The association has recommended that EPA withdraw all proposed changes to AP-42 Section 13.5, keep the existing factors and instead determine new industrial flare emission factors using data from multiple industry segments. In addition, GPA asked the agency to consider determining separate factors for different flare types, feed composition and industrial applications prior to making any changes to the emission factors.

Edited from press release by Claira Lloyd

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