Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement
The Eagle Ford Shale in southern Texas is home to a booming unconventional oil and gas industry, the climate and air quality impacts of which remain poorly quantified due to uncertain emission estimates. We used the atmospheric enhancement of alkanes from Texas Commission on Environmental Qualit...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2017-09-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/17/11163/2017/acp-17-11163-2017.pdf |
| _version_ | 1811255654083461120 |
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| author | G. Roest G. Schade |
| author_facet | G. Roest G. Schade |
| author_sort | G. Roest |
| collection | DOAJ |
| description | The Eagle Ford Shale in southern Texas is home to a booming unconventional
oil and gas industry, the climate and air quality impacts of which remain
poorly quantified due to uncertain emission estimates. We used the
atmospheric enhancement of alkanes from Texas Commission on Environmental
Quality volatile organic compound monitors across the shale, in combination
with back trajectory and dispersion modeling, to quantify C<sub>2</sub>–C<sub>4</sub> alkane
emissions for a region in southern Texas, including the core of the Eagle
Ford, for a set of 68 days from July 2013 to December 2015. Emissions were
partitioned into raw natural gas and liquid storage tank sources using gas
and headspace composition data, respectively, and observed enhancement
ratios. We also estimate methane emissions based on typical ethane-to-methane
ratios in gaseous emissions. The median emission rate from raw natural gas
sources in the shale, calculated as a percentage of the total produced
natural gas in the upwind region, was 0.7 % with an interquartile range
(IQR) of 0.5–1.3 %, below the US Environmental Protection Agency's (EPA)
current estimates. However, storage tanks contributed 17 % of methane
emissions, 55 % of ethane, 82 % percent of propane, 90 % of
<i>n</i>-butane, and 83 % of isobutane emissions. The inclusion of
liquid storage tank emissions results in a median emission rate of 1.0 %
(IQR of 0.7–1.6 %) relative to produced natural gas, overlapping the
current EPA estimate of roughly 1.6 %. We conclude that emissions from
liquid storage tanks are likely a major source for the observed non-methane
hydrocarbon enhancements in the Northern Hemisphere. |
| first_indexed | 2024-04-12T17:27:15Z |
| format | Article |
| id | doaj.art-42664fa5298f4123b5ed30b1b9efc466 |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-12T17:27:15Z |
| publishDate | 2017-09-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-42664fa5298f4123b5ed30b1b9efc4662022-12-22T03:23:15ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242017-09-0117111631117610.5194/acp-17-11163-2017Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancementG. Roest0G. Schade1Department of Atmospheric Sciences, Texas A&M University, 3150 TAMU, College Station, Texas 77843-3150, USADepartment of Atmospheric Sciences, Texas A&M University, 3150 TAMU, College Station, Texas 77843-3150, USAThe Eagle Ford Shale in southern Texas is home to a booming unconventional oil and gas industry, the climate and air quality impacts of which remain poorly quantified due to uncertain emission estimates. We used the atmospheric enhancement of alkanes from Texas Commission on Environmental Quality volatile organic compound monitors across the shale, in combination with back trajectory and dispersion modeling, to quantify C<sub>2</sub>–C<sub>4</sub> alkane emissions for a region in southern Texas, including the core of the Eagle Ford, for a set of 68 days from July 2013 to December 2015. Emissions were partitioned into raw natural gas and liquid storage tank sources using gas and headspace composition data, respectively, and observed enhancement ratios. We also estimate methane emissions based on typical ethane-to-methane ratios in gaseous emissions. The median emission rate from raw natural gas sources in the shale, calculated as a percentage of the total produced natural gas in the upwind region, was 0.7 % with an interquartile range (IQR) of 0.5–1.3 %, below the US Environmental Protection Agency's (EPA) current estimates. However, storage tanks contributed 17 % of methane emissions, 55 % of ethane, 82 % percent of propane, 90 % of <i>n</i>-butane, and 83 % of isobutane emissions. The inclusion of liquid storage tank emissions results in a median emission rate of 1.0 % (IQR of 0.7–1.6 %) relative to produced natural gas, overlapping the current EPA estimate of roughly 1.6 %. We conclude that emissions from liquid storage tanks are likely a major source for the observed non-methane hydrocarbon enhancements in the Northern Hemisphere.https://www.atmos-chem-phys.net/17/11163/2017/acp-17-11163-2017.pdf |
| spellingShingle | G. Roest G. Schade Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement Atmospheric Chemistry and Physics |
| title | Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement |
| title_full | Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement |
| title_fullStr | Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement |
| title_full_unstemmed | Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement |
| title_short | Quantifying alkane emissions in the Eagle Ford Shale using boundary layer enhancement |
| title_sort | quantifying alkane emissions in the eagle ford shale using boundary layer enhancement |
| url | https://www.atmos-chem-phys.net/17/11163/2017/acp-17-11163-2017.pdf |
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