The Process: How Oil Is Rerefined

Step 1: Vacuum Distillation

1. Used oil arrives.
2. Rejection of inappropriate feedstocks.
3. Chemical pretreatment.
4. Dehydration (water as steam is cooled and discharged to municipal sewage treatment).
5. Vacuum distillation. Asphalt flux is stripped off the bottom and sold for roofing materials. Gasoil is recovered as refinery fuel.
6. Lube oil distillates result.

Step 2: Hydrofinishing

7. Hydrotreating reactor
8. Hydrotreating reactor
9. Hydrotreating reactor
10. Fractionation results in 100-neutral base oil and 300-neutral base oil.
11. Transport to blender to make into finished lubricants.