PR-186-12204-R02 Guidelines on the Effects of Ethanol on Pump Stations and Terminal Facilities

Ethanol has been used for the last several years as an environmentally friendly alternative to methyl tertbutyl ether (MTBE), which is an oxygenate additive to gasoline, to increase octane levels, and to facilitate the combustion process. However, the need to find alternatives to imported oil and gas has spurred the increased use of ethanol as an alternative fuel source. Further, ethanol is being promoted as a potential trade-off for CO2 emissions from the burning of fossil fuels since CO2 is consumed by the plants used as the ethanol source. Legislation mandates a significant increase in ethanol usage as fuel over the next twenty years. The widespread use of ethanol will require efficient and reliable transportation from diverse ethanol producers to distribution terminals. Pipelines are, by far, the most cost-effective means of transporting large quantities of liquid hydrocarbons over long distances. For transporting ethanol, both existing pipeline infrastructure and new pipeline construction are being contemplated.

In companion PRCI projects, the stress corrosion cracking (SCC) of pipeline steels and the performance of select elastomer seals/gaskets have been studied in fuel grade ethanol (FGE). The SCC study not only included piping grade steel, but also a cast steel that could be used in pumps. Many of the issues related to corrosion of pipeline steels have been resolved in these projects. However, to address completely the effect of ethanol and gasoline-ethanol blends in pipeline systems, investigation of the effects of ethanol on other components, such as pumps, valves, screens, springs, and metering devices was required. These components have different materials (e.g., non-ferrous alloys), different types of loading, and different exposure conditions.

This report serves as a guidance document for identifying and selecting appropriate materials of construction that are exposed to ethanol and ethanol blends pumped and stored at pump stations and terminal facilities. The guidelines provided in this document are a culmination of knowledge gained from industry surveys, literature reviews, long-term testing programs, and past performance.