Internal Corrosion Control for Downstream Products

Internal Corrosion Consideration

1) Water: either carried in by refined products or as an individual sources.
2) Oxygen: often ingression through refining process

Internal Corrosion Mitigation

Dehydration
Glycol dehydration (MEG, TEG dehydration) is often designed for natural gas dehydration. Activated alumina and molecular seive processes are often utilised for liquid refined products. However, dehydration is not compatible to the product with certain additives e.g. alcohols, surface active detergents etc.

Oil soluble inhibitors
Oil soluble inhibitors are often used in refined products. They are usually large molecule oil soluble compounds. Some special considerations for refined products include:
1) Non emulsify property,
2) Compatible to other additives, e.g. antiknock agents, metal deactivators, antioxidants etc.,
3) non water soluble if used for aviation fuel,
4) No degradation of fuel other performance.

Oil soluble inhibitors deployment consideration
1)  New pipeline: starting from high concentration, and stablise to designed dosing level in a few days.
2) Old pipeline starting inhibition program: starting from lower concentration and cleaning pigging program  and resume to designed level after scale and settlement are removed.