**2. Stress corrosion cracking in fuel ethanol environments**

A corrosion failure such as stress corrosion cracking is an insidious form of corrosion which has far more adverse effects. Usually there is no prior warning before failure due to SCC. A 2004 survey of causes for failure in refining and petrochemical plants in Japan shows that a majority of the failures were due to corrosion, with the highest percentage due to SCC [11, 12]. The chart in **Figure 1** shows percentages of failures by type of material of construction [11]. Stress-corrosion failures can affect public health as in pollution due to escaping product from corroded

*Structural Integrity of Materials in Fuel Ethanol Environments DOI: http://dx.doi.org/10.5772/intechopen.86383*

**Figure 1.**

*Component failure frequencies [12].*

equipment or due to the corrosion product itself. Sudden failure could result into fire, explosion, release of toxic products and construction collapse [1, 12, 13].

Commencing just about 2002, a number of ethanol storage tanks at blending terminals which have been used for a period of <2 years suffered leaks owing to SCC [14, 15]. Afterwards, more than 35 incidences of SCC failures in tanks, associated piping, and fittings have been discovered by an industry survey [14]. All failures so far have been in blending terminals, occurring in several regions in the United States. No SCC case has been reported by ethanol producers, transportation trucks, service stations and rail cars. Brazil has manufactured and distributed ethanol for quite a few years and has not likewise reported any SCC. Because of these failures, there was concern about the ability of pipelines to safely transport ethanol to and from blending terminals.
