The objective of the work was to study the corrosion of API 5LX 46 and API 5LX 65 alloys,
used for pipelines, in anhydrous ethanol, hydrated ethanol and fuel E25 through laboratory
immersion tests, NACE TM-0172 tests and dynamic tests (corrosion loops). Based on the
results of this study, it was concluded that it is advisable that the internal surface of
hydrated ethanol storage tanks be painted in order to avoid the corrosion of the internal
walls which, despite being incipient, determines color changes which is unacceptable in the
market. Furthermore, in pipelines used only for ethanol transportation, the painting of the
internal walls of the tubes is not necessary because both the anhydrous ethanol and the
hydrated ethanol are not aggressive to the steel, as long as the relative movement of the
liquid is guaranteed. Finally, in pipelines used for ethanol and for petroleum derivatives
transportation, it is advisable that the internal surfaces of these pipes be painted in order to
avoid the contamination of the ethanol (anhydrous or hydrated) which makes the ethanol
aggressive to the steel and changes its color (unacceptable in the market).
Keywords: biofuel, biofuel corrosivity, ethanol, E25, pipeline, storage tank.