Abstract: The present invention refers to a method for the regeneration of used petroleum oils which comprises the following steps: (a) demetallization of the used mineral oil by means of chemical treatment of said oil with an aqueous solution of a chemical reagent containing anions which form low solubility salts with the metals of the oil, followed by the separation of the demetallized oil; (b) distillation of the demetallized oil obtained in step (a) at atmospheric pressure and in the presence of alkaline hydroxides; and (c) distillation of the bottom liquid obtained in the atmospheric distillation in step (b) under vacuum and in the presence of alkaline hydroxides to obtain lubricant bases.

Abstract: The present invention refers to a method for the regeneration of used petroleum oils which comprises the following steps: (a) demetallization of the used mineral oil by means of chemical treatment of said oil with an aqueous solution of a chemical reagent containing anions which form low solubility salts with the metals of the oil, followed by the separation of the demetallized oil; (b) distillation of the demetallized oil obtained in step (a) at atmospheric pressure and in the presence of alkaline hydroxides; and (c) distillation of the bottom liquid obtained in the atmospheric distillation in step (b) under vacuum and in the presence of alkaline hydroxides to obtain lubricant bases.

Abstract: A process to re-refine used petroleum oils by extraction with aliphatic solvents, wherein after eliminating the extract solvent, the process consists of the following treatments, (a) flash, continuous vaporization, at atmospheric pressure or near atmospheric pressure, to separate the light fractions, in the presence of small amounts of a basic compound or a reducing agent or a combination of both and (b) continuous distillation, in a fractionating column, of the bottom liquid obtained in stage (a), under vacuum and moderate temperatures, in the presence of a basic compound or a reducing compound or a combination of both, with recirculation from the bottom of the column to its feed; separating, as lateral extractions, the vacuum gas-oil or spindle oil and the lubricant bases and, as bottom product, a fuel-oil or asphaltic component.