The Removal of Naphthenic Acids from Beijiang Crude Oil With a Sodium Hydroxide Solution of Ethanol

A new method is introduced in this article to separate naphthenic acids from Beijiang highly acidic crude oil with a sodium hydroxide solution of ethanol. The sodium hydroxide solution of ethanol was used as the acid removal reagent by mixing with the crude oil and then allowing the two phases to separate, with the naphthenic acids being extracted from the crude oil. Data indicated that the optimal content of sodium hydroxide in crude oil was 3,000 mu g/g and the optimal extraction time was 5 min with the reagent/oil ratio being 0.4:1 (wt/wt). The suitable reaction temperature could be room temperature. The total acid number of the crude oil was lowered from 3.92 to 0.31 mg KOH/g and the acid removal could reach up to 92.1%.