Study on the deferrization and desalting for crude oils

Three high-iron crude oils were studied for iron distributions, deferrization, and desalting in the desalting process. Observations showed that ∼48%−75% of the iron in crude oil exists as organacid salts, and ∼6%−40% exists as an iron complex. Four deferric agents were synthesized for the testing. Deferric agents TE-3 and TE-4 of the polyamine carboxylate types had a better deferrization effect than TE-1 and TE-2 of the organophosphate types. In regard to the polyamine carboxylate type, TE-4 that was synthesized with polyamine yielded a better result than TE-3 that was synthesized with monoamine. The deferric agent TE-4 can remove most of the iron from crude oil, which decalcifying agents cannot do, and also can effectively remove calcium, sodium, and magnesium, as well as some of the nickel and vanadium. The addition of deferric agents did not affect the salt content of the oils in the desalting process. The dosage of deferric agent TE-4 had an optimal value, at which inorganic and organacid iron in high...