FERC Filings
EPSA's Comments on Natural Gas Council’s White Papers
Background
The NGC+ technical groups’ white papers, “White Paper on Liquid Hydrocarbon Drop Out in Natural Gas Infrastructure” (HDP White Paper) and “White Paper on Natural Gas Interchangeability and Non-Combustion End Use” (Interchangeability White Paper), filed on February 28, 2005, addressed interchangeability issues related to high heating value LNG imports and hydrocarbon liquid drop out issues specific to domestic natural gas supplies. The HDP White Paper examined current principles and measures used to control hydrocarbon liquid drop out by all constituents along the natural gas delivery stream. The paper concluded that using cricondentherm hydrocarbon dewpoint as a control parameter offers the greatest operational flexibility for all stakeholders and recommended that additional research be conducted to, among other things, develop a cost-effective, hydrocarbon-specific, direct reading dew point analyzer.
The Interchangeability White Paper addressed the development of acceptable ranges of natural gas characteristics that can be consumed by end users while maintaining safety, reliability, and environmental performance. The report concluded that the Wobbe index generally provides the most efficient and robust single measure of natural gas interchangeability and recommended that further research be done to fill data gaps regarding regional characteristics and specific limitations and tolerances of end use equipment. The white paper suggests interim guidelines for new gas supplies that allow for a range of plus or minus 4 percent Wobbe number variation from local historical average gas subject to a maximum Wobbe number limit of 1,400 and a maximum hating value of 1,100 Btus per cubic foot. Additional constituent limits included a maximum limit of butanes above 1.5 mole percent and a maximum limit of total inert elements of 4 mole percent.
The NGC+ presented the white papers to the Commission on March 2, 2005, and the Commission convened a technical conference on May 17, 2005, to hear industry views on the NGC+ papers. On May 16, 2005, NGSA filed a petition for rulemaking on gas quality and interchangeability which included proposed draft regulations. At the technical conference, the Commission requested comment on the best procedural vehicle for addressing gas quality and interchangeability issues. Specifically, the Commission seeks comments on the NGSA petition and its viability as a NOPR or policy statement.