Comparison of Remote Sensing and Extractive Sampling Measurements of Flare Combustion Efficiency

• Published in: Industrial & engineering chemistry research Vol. 51; no. 39; pp. 12621 - 12629
• Main Authors: Wormhoudt, Joda, Herndon, Scott C, Franklin, Jon, Wood, Ezra C, Knighton, Berk, Evans, Scott, Laush, Curtis, Sloss, Mark, Spellicy, Robert
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03.10.2012
• Subjects: Applied sciences; Chemical engineering; Combustion; Combustion efficiency; Error analysis; Exact sciences and technology; Flares; Fluctuation; Fuels; Remote sensing; Sampling; Combustion; Sampling; Remote sensing; Samplings
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie202783m

The 2010 Comprehensive Flare Study provided the opportunity for the first blind validation of a remote sensing technique for flare combustion efficiency (CE) against extractive analysis techniques. The overall test results show that both remote sensing and extractive sampling accurately determined the flare performance curve. Both remote and extractive sampling techniques are challenged by the fluctuating and inhomogeneous nature of the flare exhaust plume. Accurate measurement of CE values near 100% is of interest to flare manufacturers, users, and regulators, while measurement of low CE flares is of interest in the development of other applications of combustion monitoring, and the 2010 tests provided information on both. In practice, accurate values of CE can be determined through the measurement of a small number of gaseous species, including fuel components and products of combustion. Nominal error bars generated from the fluctuations in these component measurements were adequate to account for most of the differences between the remote and extractive sampling CE measurements. The additional analysis reported here focused on individual species measurements and on cases where CE values measured by the two techniques differed by more than the nominal error estimates. In all cases, the key difference was the measurement of the main component of the fuel (in these tests, propene or propane). We discuss the challenges involved in these measurements.