| abstract |
A process for reclaiming used hydrocarbon oils through prepurification by means of coagulation, adsorption, filtration, distillation, and after-treatment, wherein said oils are prepurified and then dehalogenated, fractionally distilled and hydrogenated. It is preferred that for the prepurification, said coagulation and said adsorption are carried out by means of a hydroxide or hydroxide mixture, preferably aluminum and/or ferric hydroxide, in a proportion of 0.5 - 5.0% by weight, preferably 1-2% by weight, of hydroxide relative to said used oil at a reaction temperature of from 20 DEG - 200 DEG C, preferably from 50 to 150 DEG C, said hydroxide or hydroxides being produced directly in said used oil in the presence of water or being introduced into said used oil in the form of an aqueous slurry. It is also preferred that the dehalogenation and accompanying desulfurization are carried out through treatment of said oil with an alkali metal, especially Na or K, an alkaline earth metal, especially Mg or Ca, an alkali, alkaline earth or aliminum alcoholate, an alkali hydride or amide, an organic base, especially pyridine or piperidine, or with metallic aluminum or anhydrous aluminum chloride, in a proportion of the respective treatment agent of from 1 to 2000 moles per metric ton of said oil in the absence of air and humidity at a reaction temperature of from 15 DEG - 300 DEG C. |