I think used oil is being marketed under this premise.
Yes. One example is Valvoline NextGen. When you take that used oil in to Pep Boys or Autozone to dispose of it, this is what happens to most of it. It is re-refined, and resold. From what I understand, re-refining used motor oil down to it's pure base stock isn't that difficult. The quality of the recycled product may not be quite as high as new virgin synthetic oil, but it is quite good.
Oh, and those auto parts stores SELL the oil you bring to them for disposal. It is worth money...ask Valvoline!