A recent article in Hydrocarbon Processing prompted my thinking about ethanol with regard to refinery and pipeline/storage issues that have been raised in the past.
Where will the extra facilities needed to blend in transport all of this additional ethanol in our gasoline come from? I postulate that it will come from us, the refiners. But this does not come without risk. There is a reason we have had a blend wall for all these years at 10% ethanol and gasoline. Not to mention the fact that most of the blending was done at the gasoline terminal. At the refinery. we will need to build additional or modify the existing facilities at all levels of the supply chain to achieve these goals.
A quick review of the literature reveals a number of concerns with blending gasoline and ethanol in our facilities. Those include but are not limited to:
- Stress Corrosion Cracking (SCC) of the pipes and vessels
- Water based contamination of the ethanol
- Corrosion products concentrating in the aqueous phase
- Solubility breakdown of the gasoline/ethanol blend
In a recent Inspectioneering article about the SCC concern, they highlight the results of API technical report 939–D. extra inspection, wet florescent magnetic particle testing, and mitigation, post weld heat treating (PWHT), are just some techniques that our industry must consider when dealing with the streams.
Some additional resources are shown in an excellent Survey of existing research literature done by Oak Ridge National Laboratory.
- US breaks 10% ‘blend wall’ for ethanol in gasoline
- Stress Corrosion Cracking of Carbon Steel in Fuel Grade Ethanol
- Ethanol, Biofuels, and Pipeline Transportation
- Ethanol and stress corrosion in petroleum storage tanks and pipelines
- ORNL – Ethanol pipeline corrosion literature study
- Pipeline considerations for ethanol