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Title: Final Report - Classification of Methane Emissions from Industrial Meters, Vintage vs Modern Plastic Pipe, and Plastic-lined Steel and Cast-Iron Pipe

Abstract

The project focus was to improve the characterization of methane (CH4) emissions currently detailed in the U.S. Environmental Protection Agency (EPA) Greenhouse Gas Inventory (GHGI) for categories of assets within the Natural Gas (NG) distribution system to isolate what is driving inflation or deflation behind current, nationwide, aggregated Emission Factors (EFs). These specific categories included industrial/commercial NG customer meters, modern and vintage plastic pipe, along with plastic-lined steel and cast-iron pipe. CH4 emission rate data was gathered during 25 sampling campaigns at industrial/commercial meter sites, vintage and modern plastic pipe sites, as well as plastic-lined steel and cast-iron sites located within NG distribution networks. For industrial/commercial meters, 13 three-to-five day field sampling campaigns were performed within six U.S. geographical regions. Sampling sites were selected by pseudo-randomly choosing a starting location for a sampling day then optimizing driving routes to visit the maximum number of meters possible. A total of 24,670 components were examined across six regions, for six types of industrial/commercial meter sets (Rotary, Turbine, Diaphragm, Orifice, Ultrasonic, and Regulating Equipment), across ten different companies, and at a mix of various types of industrial and commercial facilities within the sector. A total of 458 individual components leaks were quantified nationwide.more » Ten, three-to-five day field sampling campaigns were conducted in five of the six geographical regions across the U.S. to study potential differences between CH4 emissions from buried modern and vintage plastic pipe. Field sampling was conducted using a Hi Flow sampler and surface enclosure, with vintage plastic pipe defined and categorized as being installed prior to 1986, and modern plastic pipe as installed after 1986. We screened 339 potential underground leak sites with emission rates quantified from 186 of the sites. Of these 186 quantified leaks, GTI was able to verify that 103 leaks were located on either modern or vintage plastic pipe with 45 leaks measured on modern plastic pipe and 58 measured on vintage pipe. GTI completed walking surveys of 18 segments of cured-in-place plastic lined steel and cast-iron totaling 3,057.4 m. The randomly selected sites covered roughly 10% of the 33.6 km of the reconditioned cast iron reported by PHMSA in 2016, signified by Re-conditioned Cast Iron (RCI) found in the pipeline database. During the surveys, one leak was found. Upon digging, the utility was able to verify that the “leak” consisted of two smaller leaks - one on the nearby low pressure unlined main and one on an unlined service. Although this verified the validity of the GTI leak survey method, no leaks were found on any of the cured-in-place plastic lined steel or cast-iron segments surveyed. GTI determined that the use of plastic-liners by industry may be limited due to liners being difficult to install in urban areas, as well as the pipe still being classified as a “leak-prone” – even after installation of the liner. Key Findings and Recommendations 1. Industrial/commercial meter sets are likely emitting more CH4 than currently presented in the GHGI. This is due to significant emission rate differences between industrial and commercial meters, across regions, and among meter set types. 2. To further increase the accuracy, separate EFs delineated first by facility type then by region are ultimately recommended to increase the accuracy of the GHGI. 3. An alternative suggestion to meter set emission population or leaker-only emission factors would be the Canadian method of disaggregating meter set leaks into component emission calculations. This has the added benefit of reducing uncertainty in EF calculations compared to using nationwide, aggregated meter set EFs. This would require close collaboration between EPA and industry to obtain current and historical records of component counts. 4. Addressing “heavy-tailed” emitters (top 10% of leaks) that produce data outliers and cause significant impacts on meter set emission rates and thus EFs is recommended and requires additional study. As such, repairing the top 10% of emitting meter sets would result in a 72.5% reduction in emissions. 5. Data collected for vintage and plastic pipe suggested that differences in leak rates between modern and vintage plastic pipes is insignificant. However, the limited sample size created uncertainty around this finding. Additional study is needed to definitively conclude whether heavy-tailed emissions are more prevalent in vintage plastic pipe. 6. Plastic-lined pipe typically exists in short, discrete sections within the pipeline network ranging from tens of meters to thousands of meters. Therefore, tracking of total length is significantly challenging. 7. Emission rate quantification using surface enclosures may be an unreliable method to determine emission rates of buried plastic pipes if attempting to attribute emissions to a specific pipe material. Excavation and verification of pipe material is needed to alleviate uncertainty caused by such factors as incorrect or incomplete pipeline records, urban areas with multiple types of pipe located in a small footprint and leaks potentially migrating from one subsurface area to another. 8. No leaks were observed on any of the cured-in-place plastic lined steel or cast-iron segments surveyed. This may be the result of limited plastic-liner use by industry may be limited due to installation difficulties in urban areas, as well as the pipe maintaining a “leak-prone” classification - even after installation of the liner.« less

Authors:
ORCiD logo [1];  [1];  [1]
  1. Gas Technology Institute
Publication Date:
Research Org.:
Gas Technology Institute
Sponsoring Org.:
USDOE Office of Fossil Energy (FE)
OSTI Identifier:
1556081
Report Number(s):
DOE-GTI-FE29061
DOE Contract Number:  
FE0029061
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
03 NATURAL GAS

Citation Formats

Moore, Christopher, Stuver, Susan, and Wiley, Kristine. Final Report - Classification of Methane Emissions from Industrial Meters, Vintage vs Modern Plastic Pipe, and Plastic-lined Steel and Cast-Iron Pipe. United States: N. p., 2019. Web. doi:10.2172/1556081.
Moore, Christopher, Stuver, Susan, & Wiley, Kristine. Final Report - Classification of Methane Emissions from Industrial Meters, Vintage vs Modern Plastic Pipe, and Plastic-lined Steel and Cast-Iron Pipe. United States. doi:10.2172/1556081.
Moore, Christopher, Stuver, Susan, and Wiley, Kristine. Mon . "Final Report - Classification of Methane Emissions from Industrial Meters, Vintage vs Modern Plastic Pipe, and Plastic-lined Steel and Cast-Iron Pipe". United States. doi:10.2172/1556081. https://www.osti.gov/servlets/purl/1556081.
@article{osti_1556081,
title = {Final Report - Classification of Methane Emissions from Industrial Meters, Vintage vs Modern Plastic Pipe, and Plastic-lined Steel and Cast-Iron Pipe},
author = {Moore, Christopher and Stuver, Susan and Wiley, Kristine},
abstractNote = {The project focus was to improve the characterization of methane (CH4) emissions currently detailed in the U.S. Environmental Protection Agency (EPA) Greenhouse Gas Inventory (GHGI) for categories of assets within the Natural Gas (NG) distribution system to isolate what is driving inflation or deflation behind current, nationwide, aggregated Emission Factors (EFs). These specific categories included industrial/commercial NG customer meters, modern and vintage plastic pipe, along with plastic-lined steel and cast-iron pipe. CH4 emission rate data was gathered during 25 sampling campaigns at industrial/commercial meter sites, vintage and modern plastic pipe sites, as well as plastic-lined steel and cast-iron sites located within NG distribution networks. For industrial/commercial meters, 13 three-to-five day field sampling campaigns were performed within six U.S. geographical regions. Sampling sites were selected by pseudo-randomly choosing a starting location for a sampling day then optimizing driving routes to visit the maximum number of meters possible. A total of 24,670 components were examined across six regions, for six types of industrial/commercial meter sets (Rotary, Turbine, Diaphragm, Orifice, Ultrasonic, and Regulating Equipment), across ten different companies, and at a mix of various types of industrial and commercial facilities within the sector. A total of 458 individual components leaks were quantified nationwide. Ten, three-to-five day field sampling campaigns were conducted in five of the six geographical regions across the U.S. to study potential differences between CH4 emissions from buried modern and vintage plastic pipe. Field sampling was conducted using a Hi Flow sampler and surface enclosure, with vintage plastic pipe defined and categorized as being installed prior to 1986, and modern plastic pipe as installed after 1986. We screened 339 potential underground leak sites with emission rates quantified from 186 of the sites. Of these 186 quantified leaks, GTI was able to verify that 103 leaks were located on either modern or vintage plastic pipe with 45 leaks measured on modern plastic pipe and 58 measured on vintage pipe. GTI completed walking surveys of 18 segments of cured-in-place plastic lined steel and cast-iron totaling 3,057.4 m. The randomly selected sites covered roughly 10% of the 33.6 km of the reconditioned cast iron reported by PHMSA in 2016, signified by Re-conditioned Cast Iron (RCI) found in the pipeline database. During the surveys, one leak was found. Upon digging, the utility was able to verify that the “leak” consisted of two smaller leaks - one on the nearby low pressure unlined main and one on an unlined service. Although this verified the validity of the GTI leak survey method, no leaks were found on any of the cured-in-place plastic lined steel or cast-iron segments surveyed. GTI determined that the use of plastic-liners by industry may be limited due to liners being difficult to install in urban areas, as well as the pipe still being classified as a “leak-prone” – even after installation of the liner. Key Findings and Recommendations 1. Industrial/commercial meter sets are likely emitting more CH4 than currently presented in the GHGI. This is due to significant emission rate differences between industrial and commercial meters, across regions, and among meter set types. 2. To further increase the accuracy, separate EFs delineated first by facility type then by region are ultimately recommended to increase the accuracy of the GHGI. 3. An alternative suggestion to meter set emission population or leaker-only emission factors would be the Canadian method of disaggregating meter set leaks into component emission calculations. This has the added benefit of reducing uncertainty in EF calculations compared to using nationwide, aggregated meter set EFs. This would require close collaboration between EPA and industry to obtain current and historical records of component counts. 4. Addressing “heavy-tailed” emitters (top 10% of leaks) that produce data outliers and cause significant impacts on meter set emission rates and thus EFs is recommended and requires additional study. As such, repairing the top 10% of emitting meter sets would result in a 72.5% reduction in emissions. 5. Data collected for vintage and plastic pipe suggested that differences in leak rates between modern and vintage plastic pipes is insignificant. However, the limited sample size created uncertainty around this finding. Additional study is needed to definitively conclude whether heavy-tailed emissions are more prevalent in vintage plastic pipe. 6. Plastic-lined pipe typically exists in short, discrete sections within the pipeline network ranging from tens of meters to thousands of meters. Therefore, tracking of total length is significantly challenging. 7. Emission rate quantification using surface enclosures may be an unreliable method to determine emission rates of buried plastic pipes if attempting to attribute emissions to a specific pipe material. Excavation and verification of pipe material is needed to alleviate uncertainty caused by such factors as incorrect or incomplete pipeline records, urban areas with multiple types of pipe located in a small footprint and leaks potentially migrating from one subsurface area to another. 8. No leaks were observed on any of the cured-in-place plastic lined steel or cast-iron segments surveyed. This may be the result of limited plastic-liner use by industry may be limited due to installation difficulties in urban areas, as well as the pipe maintaining a “leak-prone” classification - even after installation of the liner.},
doi = {10.2172/1556081},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2019},
month = {8}
}