Used oil re-refining
AssigneeExxon Research & Engineering Co.
InventorsLloyd E. Reid, Keith C. Yao, Douglas G. Ryan
Life of this patent
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Abstract
Used oils, especially used lubricating oils which are normally considered waste and are discarded or burned, are reclaimed for reuse by a re-refining procedure involving the steps of: (a) heat soaking the used oil; (b) distilling the heat soaked oil; (c) passing the distillate through a guard bed of activated material; (d) hydrotreating the guard bed treated distillate under standard hydrotreating conditions. If the used oil to be re-refined contains a quantity of water and/or fuel fraction which the practioner considers sufficiently large to be detrimental, the used oil may be subjected to a dewatering/defueling step prior to being heat soaked.
Claims11
A process for re-refining used oils so as to produce a basestock oil essentially equivalent in quality to basestock produced from virgin crude oil which process comprises the steps of:
- (A) heat soaking the used oil at from 250.degree. C.-340.degree. C. for a time sufficient to maximize halide, phosphorus and sludge precursors removal by conversion of these materials into materials which go with the residue during the distillation step;
- (B) passing the entire contents of the heat soaker directly to coke resistant distillation means;
- (C) distilling the contents from the heat soaker under conditions of residence time, temperature and pressure selected to produce a distillate whose end point is essentially that of the target stock product and a residue;
- (D) passing the distillate through a guard bed of activated material capable of removing residual phosphorus, halides and sludge from the distillate;
- (E) hydrotreating the guard bed treated distillate under standard hydrotreating conditions, thereby producing a re-refined base stock.
Dependencies are inferred from the claim text.