| 摘要 |
Hydrocarbon oils, particularly petroleum oils, more particularly lube, transformer, white oil and other specialty oils can be extracted to remove aromatic hydrocarbon components therefrom using a combination polar extraction solvent, such as n-methyl pyrrolidone phenol or furfural, preferably NMP in combination with aliphatic-aromatics, polar naphthenes or morpholine, preferably alkylbenzene, mixed extraction solvent. The combination of polar extraction solvent and aliphatic-aromatic, polar naphthene or morpholine extraction solvent mixture contains and from 1 to up to but not including 10 LV% aliphatic-aromatic, polar naphthene or morpholine and mixtures thereof, preferably from 2.5 to less than 10% aliphatic-aromatic, polar naphthene or morpholine and from 0 to 10 LV% water, the amount of polar extraction solvent being suitably adjusted to reflect the presence of the water. Extraction using the combination solvent is conducted at a temperature above the haze point of the oil being extracted but at a tower bottoms temperature at least 30.degree.C, and preferably 40.degree.C, or more below the critical solution temperature of the feed-solvent mixture. |
