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Wu C.-F.,National Taiwan University | Wu T.-G.,National Taiwan University | Hashmonay R.A.,Atmosfir Optics Ltd. | Chang S.-Y.,National Taiwan University | And 5 more authors.
Atmospheric Environment | Year: 2014

Fugitive emission of air pollutants is conventionally estimated based on standard emission factors. The Vertical Radial Plume Mapping (VRPM) technique, as described in the US EPA OTM-10, is designed to measure emission flux by directly monitoring the concentration of the plume crossing a vertical plane downwind of the site of interest. This paper describes the evaluation results of implementing VRPM in a complex industrial setting (a petrochemical tank farm). The vertical plane was constructed from five retroreflectors and an open-path Fourier transform infrared spectrometer. The VRPM configuration was approximately 189.2m in width×30.7m in height. In the accompanying tracer gas experiment, the bias of the VRPM estimate was less than 2% and its 95% confidence interval contained the true release rate. Emission estimates of the target VOCs (benzene, m-xylene, o-xylene, p-xylene, and toluene) ranged from 0.86 to 2.18gs-1 during the 14-day field campaign, while estimates based on the standard emission factors were one order of magnitude lower, possibly leading to an underestimation of the impact of these fugitive emissions on air quality and human health. It was also demonstrated that a simplified 3-beam geometry (i.e., without one dimensional scanning lines) resulted in higher uncertainties in the emission estimates. © 2013 Elsevier Ltd.

Wu T.-G.,National Taiwan University | Chang S.-Y.,National Taiwan University | Wu C.-F.,National Taiwan University | Hashmonay R.,University of North Carolina at Chapel Hill | And 2 more authors.
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012

The benzene emission rates from a tank farm in a petrochemical plant were estimated in two different seasons using the Vertical Radial Pluming Mapping (VRPM) method, which involves collecting downwind concentration data by using the optical remote sensing (ORS) instrument. The benze flux ranged between 0.83 and 2.93 g/sec and 0.11 to 1.02 g/sec in the summer and winter, respectively. The SF6 flux was 0.51 7plusmn; 0.13 g/sec, ≈ 18% higher than the true release rate of 0.46 g/sec. This is an abstract of a paper presented at the 105th AWMA Annual Conference and Exhibition (San Antonio, TX 6/19-22/2012).

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