Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A
Researchers have utilized Other Test Method (OTM) 33A to quantify methane emissions from natural gas infrastructure. Historically, errors have been reported based on a population of measurements compared to known controlled releases of methane. These errors have been reported as 2<i>σ</i>...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Environments |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-3298/9/4/47 |
| _version_ | 1797434755094937600 |
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| author | Robert Heltzel Derek Johnson Mohammed Zaki Aron Gebreslase Omar I. Abdul-Aziz |
| author_facet | Robert Heltzel Derek Johnson Mohammed Zaki Aron Gebreslase Omar I. Abdul-Aziz |
| author_sort | Robert Heltzel |
| collection | DOAJ |
| description | Researchers have utilized Other Test Method (OTM) 33A to quantify methane emissions from natural gas infrastructure. Historically, errors have been reported based on a population of measurements compared to known controlled releases of methane. These errors have been reported as 2<i>σ</i> errors of ±70%. However, little research has been performed on the minimum attainable uncertainty of any one measurement. We present two methods of uncertainty estimation. The first was the measurement uncertainty of the state-of-the-art equipment, which was determined to be ±3.8% of the estimate. This was determined from bootstrapped measurements compared to controlled releases. The second approach of uncertainty estimation was a modified Hollinger and Richardson (H&R) method which was developed for quantifying the uncertainty of eddy covariance measurements. Using a modified version of this method applied to OTM 33A measurements, it was determined that uncertainty of any given measurement was ±17%. Combining measurement uncertainty with that of stochasticity produced a total minimum uncertainty of 17.4%. Due to the current nature of stationary single-sensor measurements and the stochasticity of atmospheric data, such uncertainties will always be present. This is critical in understanding the transport of methane emissions and indirect measurements obtained from the natural gas industry. |
| first_indexed | 2024-03-09T10:37:35Z |
| format | Article |
| id | doaj.art-43924e5ee55c473cb1327c2cece00c64 |
| institution | Directory Open Access Journal |
| issn | 2076-3298 |
| language | English |
| last_indexed | 2024-03-09T10:37:35Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Environments |
| spelling | doaj.art-43924e5ee55c473cb1327c2cece00c642023-12-01T20:51:38ZengMDPI AGEnvironments2076-32982022-04-01944710.3390/environments9040047Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33ARobert Heltzel0Derek Johnson1Mohammed Zaki2Aron Gebreslase3Omar I. Abdul-Aziz4Department of Mechanical and Aerospace Engineering, Statler College of Engineering, West Virginia University, Morgantown, WV 26505, USADepartment of Mechanical and Aerospace Engineering, Statler College of Engineering, West Virginia University, Morgantown, WV 26505, USAWadsworth Department of Civil and Environmental Engineering, Statler College of Engineering, West Virginia University, Morgantown, WV 26505, USAWadsworth Department of Civil and Environmental Engineering, Statler College of Engineering, West Virginia University, Morgantown, WV 26505, USAWadsworth Department of Civil and Environmental Engineering, Statler College of Engineering, West Virginia University, Morgantown, WV 26505, USAResearchers have utilized Other Test Method (OTM) 33A to quantify methane emissions from natural gas infrastructure. Historically, errors have been reported based on a population of measurements compared to known controlled releases of methane. These errors have been reported as 2<i>σ</i> errors of ±70%. However, little research has been performed on the minimum attainable uncertainty of any one measurement. We present two methods of uncertainty estimation. The first was the measurement uncertainty of the state-of-the-art equipment, which was determined to be ±3.8% of the estimate. This was determined from bootstrapped measurements compared to controlled releases. The second approach of uncertainty estimation was a modified Hollinger and Richardson (H&R) method which was developed for quantifying the uncertainty of eddy covariance measurements. Using a modified version of this method applied to OTM 33A measurements, it was determined that uncertainty of any given measurement was ±17%. Combining measurement uncertainty with that of stochasticity produced a total minimum uncertainty of 17.4%. Due to the current nature of stationary single-sensor measurements and the stochasticity of atmospheric data, such uncertainties will always be present. This is critical in understanding the transport of methane emissions and indirect measurements obtained from the natural gas industry.https://www.mdpi.com/2076-3298/9/4/47OTM 33Ameasurement errormethane emissionscontrolled releases |
| spellingShingle | Robert Heltzel Derek Johnson Mohammed Zaki Aron Gebreslase Omar I. Abdul-Aziz Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A Environments OTM 33A measurement error methane emissions controlled releases |
| title | Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A |
| title_full | Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A |
| title_fullStr | Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A |
| title_full_unstemmed | Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A |
| title_short | Understanding the Accuracy Limitations of Quantifying Methane Emissions Using Other Test Method 33A |
| title_sort | understanding the accuracy limitations of quantifying methane emissions using other test method 33a |
| topic | OTM 33A measurement error methane emissions controlled releases |
| url | https://www.mdpi.com/2076-3298/9/4/47 |
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