Demonstration of an ethane spectrometer for methane source identification.
Environ Sci Technol
; 48(14): 8028-34, 2014 Jul 15.
Article
in En
| MEDLINE
| ID: mdl-24945706
ABSTRACT
Methane is an important greenhouse gas and tropospheric ozone precursor. Simultaneous observation of ethane with methane can help identify specific methane source types. Aerodyne Ethane-Mini spectrometers, employing recently available mid-infrared distributed feedback tunable diode lasers (DFB-TDL), provide 1 s ethane measurements with sub-ppb precision. In this work, an Ethane-Mini spectrometer has been integrated into two mobile sampling platforms, a ground vehicle and a small airplane, and used to measure ethane/methane enhancement ratios downwind of methane sources. Methane emissions with precisely known sources are shown to have ethane/methane enhancement ratios that differ greatly depending on the source type. Large differences between biogenic and thermogenic sources are observed. Variation within thermogenic sources are detected and tabulated. Methane emitters are classified by their expected ethane content. Categories include the following biogenic (<0.2%), dry gas (1-6%), wet gas (>6%), pipeline grade natural gas (<15%), and processed natural gas liquids (>30%). Regional scale observations in the Dallas/Fort Worth area of Texas show two distinct ethane/methane enhancement ratios bridged by a transitional region. These results demonstrate the usefulness of continuous and fast ethane measurements in experimental studies of methane emissions, particularly in the oil and natural gas sector.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Spectrum Analysis
/
Air Pollutants
/
Ethane
/
Methane
Type of study:
Diagnostic_studies
Country/Region as subject:
America do norte
Language:
En
Journal:
Environ Sci Technol
Year:
2014
Document type:
Article