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Matthew R Johnson - One of the best experts on this subject based on the ideXlab platform.
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Computationally efficient quantification of unknown Fugitive Emissions sources
Atmospheric Environment: X, 2019Co-Authors: Carol A Brereton, Lucy J Campbell, Matthew R JohnsonAbstract:Abstract Fugitive Emissions or unintentional losses of gas (e.g. leaks) are a significant source of greenhouse gases within the oil and gas sector. Previous work has demonstrated the potential of a scalar transport adjoint method for using sparse sensor data to locate and quantify multiple simultaneous unknown Fugitive Emission sources within a bluff-body dominated facility environment. This paper builds directly on that work and demonstrates the significant computational time reductions that can be achieved by modifying this approach to use a database of pre-computed retro-tracers (PRT). The computational cost, as well as estimated source Emission rates and locations, were compared for both an open field release and multiple releases in a bluff-body dominated domain when using the PRT method versus the concurrent gas transport computations from previous work. For the open-field release, given the same wind input there were no significant differences in results of the two approaches. For the bluff-body dominated multiple source case (a domain representative of an actual gas plant), using simplified wind fields for the PRT database generation allowed major sources to be successfully located. The Emission rates were computed within −75% to −32% of their actual value. When the wind direction coverage was increased to 110° from ∼60°, the Emission rate computations improved to within approximately −30% to −25%. The total computational cost for both methods was of a similar order of magnitude when including the initial database generation for the PRT method, but non-reusable computational time was reduced by a factor of 200–600 times making the PRT method feasible on a standard desktop computer once the database is generated. This is a noteworthy achievement as it raises the possibility of continuous or near-continuous characterization of unknown Fugitive Emissions sources within a complex facility which could allow sources to be identified as they arise.
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Fugitive Emission source characterization using a gradient based optimization scheme and scalar transport adjoint
Atmospheric Environment, 2018Co-Authors: Carol A Brereton, Ian M Joynes, Lucy J Campbell, Matthew R JohnsonAbstract:Abstract Fugitive Emissions are important sources of greenhouse gases and lost product in the energy sector that can be difficult to detect, but are often easily mitigated once they are known, located, and quantified. In this paper, a scalar transport adjoint-based optimization method is presented to locate and quantify unknown Emission sources from downstream measurements. This Emission characterization approach correctly predicted locations to within 5 m and magnitudes to within 13% of experimental release data from Project Prairie Grass. The method was further demonstrated on simulated simultaneous releases in a complex 3-D geometry based on an Alberta gas plant. Reconstructions were performed using both the complex 3-D transient wind field used to generate the simulated release data and using a sequential series of steady-state RANS wind simulations (SSWS) representing 30 s intervals of physical time. Both the detailed transient and the simplified wind field series could be used to correctly locate major sources and predict their Emission rates within 10%, while predicting total Emission rates from all sources within 24%. This SSWS case would be much easier to implement in a real-world application, and gives rise to the possibility of developing pre-computed databases of both wind and scalar transport adjoints to reduce computational time.
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Identifying sources of Fugitive Emissions in industrial facilities using trajectory statistical methods
Atmospheric Environment, 2012Co-Authors: Carol A Brereton, Matthew R JohnsonAbstract:Abstract Fugitive pollutant sources from the oil and gas industry are typically quite difficult to find within industrial plants and refineries, yet they are a significant contributor of global greenhouse gas Emissions. A novel approach for locating Fugitive Emission sources using computationally efficient trajectory statistical methods (TSM) has been investigated in detailed proof-of-concept simulations. Four TSMs were examined in a variety of source Emissions scenarios developed using transient CFD simulations on the simplified geometry of an actual gas plant: potential source contribution function (PSCF), concentration weighted trajectory (CWT), residence time weighted concentration (RTWC), and quantitative transport bias analysis (QTBA). Quantitative comparisons were made using a correlation measure based on search area from the source(s). PSCF, CWT and RTWC could all distinguish areas near major sources from the surroundings. QTBA successfully located sources in only some cases, even when provided with a large data set. RTWC, given sufficient domain trajectory coverage, distinguished source areas best, but otherwise could produce false source predictions. Using RTWC in conjunction with CWT could overcome this issue as well as reduce sensitivity to noise in the data. The results demonstrate that TSMs are a promising approach for identifying Fugitive Emissions sources within complex facility geometries.
Zhaojie Cui - One of the best experts on this subject based on the ideXlab platform.
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Process-based volatile organic compound Emission inventory establishment method for the petroleum refining industry
Journal of Cleaner Production, 2020Co-Authors: Yeye Liu, Feng Han, Wei Liu, Xiaowei Cui, Xiaoyu Luan, Zhaojie CuiAbstract:Abstract The petroleum refining industry is an important contributor to industrial volatile organic compounds (VOCs) Emission. As a foundational work for VOCs control, previous VOCs inventories usually treated the petroleum refining industry as an integrated part resulting the unknown of VOCs Emission characteristic among different units. Refined management has becoming an inevitability with the increasing strictness of environment standards. This study aims to develop a holistic method for VOCs Emission inventory of the petroleum refining industry toward specificity, accuracy and economization, in which a source categorization was proposed from unit angle, and a systematic estimation method was developed from the material flow point of view. This method provides a more specific and accurate quantification method, especially for Fugitive Emission sources which is a pivotal but difficult problem in VOCs inventory establishment. Through application to a typical medium-scale refinery located in northern China, a unit-specific VOCs Emission inventory with 48 Emission sources and respective local VOCs Emission factors (EFs) was established. Estimation results and economic cost of the developed method were compared with those of other methods. In this study, the integrated EF was 0.77 kg-VOCs/t-crude oil refined, which was in the same order with most previous studies. Inventory results implied that increasing hydrotreating unit, reducing chemical device and solvent-used unit (e.g., polypropylene production, furfural refining unit), upgrading catalytic reforming unit were beneficial to control VOCs Emissions in this study. Using floating-roof tanks rather than fixed-roof tanks is an effective way to reduce VOCs Emissions from storage tanks, which decrease 72%–86% of diesel storage Emissions. Economic cost analysis showed that the advantage of this method lied in lower labor cost, and no subsequent monitoring cost. Suggestions proposed from this study provide feasible measures for local policy makers to control VOCs Emission and determine abatement strategies of the petroleum chemical industry. Meanwhile, this study greatly helps enterprises promote the fine management of VOCs-containing materials from the overall processes to identify VOCs control emphasis.
Carol A Brereton - One of the best experts on this subject based on the ideXlab platform.
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Computationally efficient quantification of unknown Fugitive Emissions sources
Atmospheric Environment: X, 2019Co-Authors: Carol A Brereton, Lucy J Campbell, Matthew R JohnsonAbstract:Abstract Fugitive Emissions or unintentional losses of gas (e.g. leaks) are a significant source of greenhouse gases within the oil and gas sector. Previous work has demonstrated the potential of a scalar transport adjoint method for using sparse sensor data to locate and quantify multiple simultaneous unknown Fugitive Emission sources within a bluff-body dominated facility environment. This paper builds directly on that work and demonstrates the significant computational time reductions that can be achieved by modifying this approach to use a database of pre-computed retro-tracers (PRT). The computational cost, as well as estimated source Emission rates and locations, were compared for both an open field release and multiple releases in a bluff-body dominated domain when using the PRT method versus the concurrent gas transport computations from previous work. For the open-field release, given the same wind input there were no significant differences in results of the two approaches. For the bluff-body dominated multiple source case (a domain representative of an actual gas plant), using simplified wind fields for the PRT database generation allowed major sources to be successfully located. The Emission rates were computed within −75% to −32% of their actual value. When the wind direction coverage was increased to 110° from ∼60°, the Emission rate computations improved to within approximately −30% to −25%. The total computational cost for both methods was of a similar order of magnitude when including the initial database generation for the PRT method, but non-reusable computational time was reduced by a factor of 200–600 times making the PRT method feasible on a standard desktop computer once the database is generated. This is a noteworthy achievement as it raises the possibility of continuous or near-continuous characterization of unknown Fugitive Emissions sources within a complex facility which could allow sources to be identified as they arise.
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Fugitive Emission source characterization using a gradient based optimization scheme and scalar transport adjoint
Atmospheric Environment, 2018Co-Authors: Carol A Brereton, Ian M Joynes, Lucy J Campbell, Matthew R JohnsonAbstract:Abstract Fugitive Emissions are important sources of greenhouse gases and lost product in the energy sector that can be difficult to detect, but are often easily mitigated once they are known, located, and quantified. In this paper, a scalar transport adjoint-based optimization method is presented to locate and quantify unknown Emission sources from downstream measurements. This Emission characterization approach correctly predicted locations to within 5 m and magnitudes to within 13% of experimental release data from Project Prairie Grass. The method was further demonstrated on simulated simultaneous releases in a complex 3-D geometry based on an Alberta gas plant. Reconstructions were performed using both the complex 3-D transient wind field used to generate the simulated release data and using a sequential series of steady-state RANS wind simulations (SSWS) representing 30 s intervals of physical time. Both the detailed transient and the simplified wind field series could be used to correctly locate major sources and predict their Emission rates within 10%, while predicting total Emission rates from all sources within 24%. This SSWS case would be much easier to implement in a real-world application, and gives rise to the possibility of developing pre-computed databases of both wind and scalar transport adjoints to reduce computational time.
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Identifying sources of Fugitive Emissions in industrial facilities using trajectory statistical methods
Atmospheric Environment, 2012Co-Authors: Carol A Brereton, Matthew R JohnsonAbstract:Abstract Fugitive pollutant sources from the oil and gas industry are typically quite difficult to find within industrial plants and refineries, yet they are a significant contributor of global greenhouse gas Emissions. A novel approach for locating Fugitive Emission sources using computationally efficient trajectory statistical methods (TSM) has been investigated in detailed proof-of-concept simulations. Four TSMs were examined in a variety of source Emissions scenarios developed using transient CFD simulations on the simplified geometry of an actual gas plant: potential source contribution function (PSCF), concentration weighted trajectory (CWT), residence time weighted concentration (RTWC), and quantitative transport bias analysis (QTBA). Quantitative comparisons were made using a correlation measure based on search area from the source(s). PSCF, CWT and RTWC could all distinguish areas near major sources from the surroundings. QTBA successfully located sources in only some cases, even when provided with a large data set. RTWC, given sufficient domain trajectory coverage, distinguished source areas best, but otherwise could produce false source predictions. Using RTWC in conjunction with CWT could overcome this issue as well as reduce sensitivity to noise in the data. The results demonstrate that TSMs are a promising approach for identifying Fugitive Emissions sources within complex facility geometries.
Robert Kagann - One of the best experts on this subject based on the ideXlab platform.
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measurement of Fugitive volatile organic compound Emissions from a petrochemical tank farm using open path fourier transform infrared spectrometry
Atmospheric Environment, 2014Co-Authors: Changfu Wu, Ram A. Hashmonay, Tzonggang Wu, Shihying Chang, Yusyuan Wu, Chunping Chao, M Chase, Robert KagannAbstract:Abstract 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 189.2 m in width × 30.7 m 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 2.18 g s−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.
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radial plume mapping a us epa test method for area and Fugitive source Emission monitoring using optical remote sensing
2008Co-Authors: Ram A. Hashmonay, Ravi Varma, Mark Modrak, Robert Kagann, Robin Segall, Patrick D SullivanAbstract:This paper describes the recently developed United States Environmental Protection Agency (US EPA) test method that provides the user with unique methodolo- gies for characterizing gaseous Emissions from non-point pollutant sources. The radial plume mapping (RPM) methodology uses an open-path, path-integrated optical remote sensing (PI-ORS) system in multiple beam configurations to directly identify Emission "hot spots" and measure Emission fluxes. The RPM methodology has been well devel- oped, evaluated, demonstrated, and peer reviewed. Scanning the PI-ORS system in a horizontal plane (horizontal RPM) can be used to locate hot spots of Fugitive Emission at ground level, while scanning in a vertical plane downwind of the area source (vertical RPM), coupled with wind measurement, can be used to measure Emission fluxes. Also, scanning along a line-of-sight such as an industrial fenceline (one-dimensional RPM) can be used to profile pollutant concentrations downwind from a Fugitive source. In this paper, the EPA test method is discussed, with particular reference to the RPM methodology, its applicability, limitations, and validation.
Johan Mellqvist - One of the best experts on this subject based on the ideXlab platform.
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Measurements of Fugitive Emissions using the solar occultation flux method
2015Co-Authors: Johan Mellqvist, Jerker SamuelssonAbstract:The Solar Occultation Flux Method (SOF) is a relatively new optical remote sensing technique for quantifying Fugitive VOC Emissions from industrial sources. In Europe, the SOF technique is Best Available Technology for measurements of Fugitive Emission of VOC from refineries and it is presently being standardized within CEN together with several other optical methods. The method is used to screen all larger Swedish refineries and petrochemical. The measurements provide the total Emission coming from the whole refinery (the bubble), divided into sub parts, e.g., process areas, crude oil storage, product storage tanks, water treatment facilities, flares, and loading operations. The estimated uncertainty for the Emissions is 30 % for the bubble, and higher for the individual parts. The measurements often show higher Emissions than reported by 3-10 times.
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measurements of Fugitive Emission using the solar occultation flux sof method
Air Quality Measurement Methods and Technology Conference 2013; Sacramento CA; United States; 19 November 2013 through 21 November 2013, 2014Co-Authors: Marianne Ericsson, Johan Mellqvist, Jerker SamuelssonAbstract:The SOF method is an emerging remote sensing technique based on measuring infrared intensity of solar spectra from a mobile platform (car, boat). From the infrared solar spectra, utilizing known absorption features and with a good knowledge of wind profile, the total mass of ethylene, propylene, alkanes and several other species along the path of the solar light can be retrieved. The method is today used to screen and quantify VOC Emissions from industrial conglomerates down to sub-areas in individual plants. The SOF method is usually combined with mobile DOAS by which it is possible to measure also SO 2, NO2 and formaldehyde. The SOF method has been applied in several larger campaigns in both Europe and the US and in more than 70 individual plant surveys over the last 10 years. In the various campaign studies it has been found that the measured Emissions obtained with SOF are 5-10 times higher than the reported Emission obtained by standard calculation methods. For instance in studies in Houston, TexAQS 2006 and campaigns 2009 and 2011, it was shown that the industrial releases of alkenes for the Houston Galveston area, on average, were 10 times higher than what was reported. For alkanes the discrepancy factor was about 8.
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quantifying Fugitive Emission of vocs using the solar occultation flux technique sof
2004Co-Authors: Johan MellqvistAbstract:Detection limits down to 0.5 mg·m 2 can be achieved which corresponds to measuring a point source of 0.5 kg·h -1 at a distance of 50 m with a precision better than 3%. Trace gas experiments show that an accuracy of 3-5% may be obtained under favorable conditions with Emissions from a single point at an open field. This applies under the condition that 10-20 measurements are averaged. Individual measurements are usually within 20% but may deviate as much as 50% from the correct value. Under more complicated conditions, with Emissions occurring from a complex structure with an unknown plume lift larger systematic errors will occur, primarily due to uncertainties in assessing the plume lift and the associated wind field. In cases where most of the Emission plume is above the first 20-30 m, which we believe apply for most process area measurements and measurements conducted at distances > 500 m downwind, the uncertainty in the estimated wind is estimated to be 15-30%. Consequently the same accuracy will be obtained in the Emission estimates. The accuracy is similar to what is reported for the DIAL technique, where accuracies around 20% are reported. The SOF measurements have not been compared directly with the DIAL technique, but measurements conducted at several swedish industrial facilities (Preem, Scanraff and oilharbor) show Emission values which correspond quite well (within 20-30%) with previous DIAL measurements. The SOF technique is today used at most of the swedish refineries to estimate their annual Emissions, instead of using DIAL which has been in the past for almost 10 years. In comparison to the DIAL technique the SOF method is more cost effective since both considerably cheaper hardware and less manpower is required. This is particularly true for locations with good sun and wind statistics, in contrast to south Sweden, on which measurements on a plant can be conducted within a few days, thanks to the mobility of the method and on-line evaluation capability.
