Patent ID: 7727383

Claim:
The process of producing a light petroleum oil that contains ultra-low levels of nitrogen containing compounds that comprises the steps of: (a) providing a light petroleum oil feedstock containing up to 2 ppm nitrogen-containing compounds wherein the light petroleum oil feedstock is produced by liquid-liquid extraction or extractive distillation using a nitrogen-containing extractive solvent that includes N-formyl-morpholine, N-methyl-2-pyrrolidone, and mixtures thereof and the light petroleum oil feedstock comprises extracted aromatics that have boiling points of less than about 140° C. and wherein essentially all of the nitrogen-containing compounds in the petroleum oil feedstock that have boiling points in this boiling range are soluble in water; (b) contacting the light petroleum oil feedstock with an aqueous extractive solvent at extraction conditions in a liquid-liquid extractor that is a multi-stage vessel that continuously contacts the light petroleum oil feedstock with the aqueous extractive solvent; (c) separating the product of step (b) into (i) a raffinate product stream comprising separated light petroleum oil and (ii) an aqueous extract phase; and (d) removing water from the raffinate product stream to yield dehydrated nitrogen-free aromatics that contain 100 ppb or less of nitrogen.