Unlike recycled oil, where only soluble impurities such as heavy metals and dirt are removed. The oil refining system includes extensive processing, filtration, distillation and dehydration to remove both soluble and insoluble contaminants.
When the workers are finishing used oil refining process, additives are removed through chemical processing, which creates an un-additized base oil that can then be distilled to remove any remaining water or additional impurities. A dehydrating process removes residual light fuel, ethylene glycol, and a vacuum distillation step removes the fraction of oil suitable for reuse as lubricating oil. This fraction of oil undergoes hydro treating that further removes remaining polymers and chemicals.
Because re-refined oil goes through the same oil refining and distillation process as the crude oil that later becomes virgin, it can be as high of quality if not higher than virgin. Re-refining waste oil is environmentally friendly and requires significantly less energy to produce than virgin. Re-refined motor oils can be refined again and again, keeping them in circulation versus becoming waste products.