How is waste oil purified?

Waste oil is purified through a multi-step process that involves filtration, heating, and dehydration. Solid particles are removed through filters, while water and gases are extracted using vacuum dehydration. In some cases, centrifugation is used to separate water and sludge from the oil. Chemical treatments may also be applied to neutralize acids and other degradation products. The purified waste oil can be reused in non-critical applications or further processed for other uses.