Is naphthenic acids corrosive?
Naphthenic acids become corrosive around 220°C (430°F) and reach their highest activity at 350°C (662°F). Over 400°C (750°F) no evidence of NAP corrosion was reported due to naphthenic acid decomposition at high temperature 2,3,4.
What is naphthenic acid corrosion?
Naphthenic acid corrosion (NAC) is a non-aqueous corrosion process caused by naphthenic acids. Naphthenic acid corrosion is a problem for refineries processing crudes containing high levels of naphthenic acid. It most typically affects crude and vacuum units.
How do you make naphthenic acid?
Naphthenic acids are generally obtained by caustic extraction of petroleum distillates boiling between 200 and 370 °C. A continuous process has been developed for removing naphthenic acids from refinery streams by caustic washing. Caustic extraction also removes other acidic components of the petroleum fraction.
What is naphthenic acid used for?
The major uses of naphthenic acids are as oil-soluble metal soaps for driers and other catalysts, wood preservatives, tire cord adhesion promoters, and in amine derivatives for corrosion inhibitors.
Where is naphthenic acid found?
Athabasca oil sands
Naphthenic acids are the major contaminant in water produced from the extraction of oil from Athabasca oil sands (AOS). Naphthenic acids have both acute and chronic toxicity to fish and other organisms.
Can calcium naphthenate?
A calcium soap of naphthenic acids in crude oil. Naphthenates are formed through interaction of naphthenic acids in crude oil with metal ions such as calcium and sodium. Naphthenates can also be deposited as solids in pipelines and can cause flow-assurance problems.
What contains naphthenic and palmitic acids?
Aluminium salts of naphthenic acid and palmitic acid were combined during World War II to produce napalm. The word “napalm” is derived from the words naphthenic acid and palmitic acid.
What causes calcium naphthenate?
A calcium soap of naphthenic acids in crude oil. Naphthenates are formed through interaction of naphthenic acids in crude oil with metal ions such as calcium and sodium.
What is Naphthenate used for?
Copper naphthenate is an active ingredient used predominantly in industrial and commercial wood preservation for non-pressure (dip/brush/spray) and pressure treatments (vacuum/full cell) to protect against fungal rot, decay, termites and wood-boring insects in unfinished wood and various fabricated wood products.
What foods are high in palmitic acid?
Palmitic acid, C16:0, saturated
- Milk and milk products; such as butter, cream, ice cream, sour cream, yoghurt, cheese and more.
- Red meat and products made from red meat.
- Palm oil and products that contains palm oil, such as pastry, crackers, fried potatoes, potato chips and more.
- Coconut and coconut oil.
Does copper preserve wood?
Copper naphthenate is most widely used in wood preservation and for protecting other cellulosic materials such as textiles and cordage from damage by decay fungi and insects.
Where does the corrosion of naphthenic acid occur?
Naphthenic acid corrosion occurs primarily in high-velocity areas of crude distillation units in the 220-400 °C (430-750 °F) temperature range. No corrosion damage is usually found at temperatures greater than 400 °C (750 °F), probably due to the decomposition of naphthenic acids or protection from the coke formed at the metal surface.
How is naphthenic acid used in the petroleum industry?
It is often used in the synthesis of metals and promotes corrosion in high-velocity areas and vessels for petroleum applications. Naphthenic acid is industrially sourced by extraction from kerosene and diesel petroleum fractions.
How to reduce the acidity of naphthenic acid?
When possible, the operating conditions have to be adjusted to limit the temperature and fluid flow rate. Mixing naphthenic crudes with noncorrosive feedstocks at the distillation inlet to reduce the average TAN by about 0.2−0.5 mg KOH/g is also a commonly-used method.
How does acidity affect the severity of corrosion?
Generally, the severity of corrosion increases with increasing acidity of the feedstock (remembering that several acidic species make up the total acidity of the feedstock).