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Report: Suitability of Leak Detection Technology for Use In Ethanol-Blended Fuel Service
Citation:
McKernan, J., J. Enriquez, A. Dindal, AND S. Bessler. Report: Suitability of Leak Detection Technology for Use In Ethanol-Blended Fuel Service. U.S. Environmental Protection Agency, Washington, DC, 2016.
Impact/Purpose:
The ETV Program’s AMS Center conducts third-party performance testing of commercially available technologies that monitor, sample, detect, and characterize contaminants or naturally occurring species across all matrices. The purpose of ETV is to provide objective and quality-assured performance data on environmental technologies so that users, developers, regulators, and consultants can make informed decisions about purchasing and applying these technologies. Stakeholder committees of buyers and users of such technologies recommend technology categories, and technologies within those categories, as priorities for testing. This paper discusses the relationship between fuel properties and operating principles against the performance standards established in the federal LD requirements.
Description:
As the use of biofuels has increased in the last decade, there has been a level of concern over the effect that ethanol blends have on the material compatibility and operability of existing infrastructure. The focus of this research is to determine whether leak detection (LD) technologies are functioning properly in ethanol fuel blends. Fuels with different concentrations of ethanol have different intrinsic properties. As new fuels with varying blends of ethanol emerge, the resulting variations in fuel properties might affect the functionality of LD technologies. Technology to detect leaks has been required since late 1989 when UST operators were required to implement procedures to prevent and detect leaks in existing and new USTs under Title 40 of the Code of Federal Regulations Part 280 (40 CFR 280) Technical Standards and Corrective Action Requirements for Owners and Operators of Underground Storage Tanks (Subpart D). When first employed, test procedures used to determine LD technology performance were commonly performed on USTs containing diesel fuel, in which the technologies tested generally behave in a similar manner as they do in gasoline. LD technologies tested with one of these procedures were then “listed” by the National Work Group on Leak Detection Evaluations (NWGLDE) as having been evaluated by a third party in accordance with an approved leak detection protocol. Currently, the increasing desire to use motor fuels containing ethanol, such as E15 and Flex Fuel (also referred to as E85), has led EPA, NWGLDE, and others to question the appropriateness of use of these LD technologies with fuels that have different properties than the fuel on which they were originally tested and for which the test methods were designed. Fuel property research was conducted in order to better understand how ethanol blended into fuels in different concentrations can affect the properties of those blends. The objective of examining fuel properties was to identify when various blends are significantly different with respect to a fuel property. The fuel blends included E0, E10, E15, E30, E50, E85 and an isobutanol blend at 16 percent (I16). Subsequently, various LD technology categories were described with respect to operating principle and how the change in fuel property may affect the operability of the technologies in that category. For the purpose of this technology review, ethanol blends are categorized as low-ethanol (i.e., E10, and E15) and high-ethanol blends (51 to 83 percent ethanol) and categorized as: technology is expected to be suitable for indicated use, technology has limitations with the indicated use, technology is expected to not be suitable for indicated use. As all technologies are different, have different algorithms, and are influenced by human inputs and installation, these conclusions may not be appropriate for every technology in a category. This paper discusses the relationship between fuel properties and operating principles against the performance standards established in the federal LD requirements. The potential negative impacts are highlighted in the following sections for consideration. In some cases, the technology may need to be modified to recognize these changes at the regulatory level with adjustments of threshold values and monitoring data processing.