A treatment train, not one machine
Basel guidance distinguishes reprocessing and reclamation from regeneration. Settling, heating, filtration, dehydration and centrifugation mainly address water, light fractions or insoluble material. Regeneration goes further by producing base oils through a controlled sequence of physical and chemical treatments.
A re-refinery can be mapped as feed acceptance, dehydration and light-end separation, recovery of lube-range fractions, and finishing. Each stage needs input, product and residue controls. Final base-oil yield alone does not describe environmental or product performance.
- Define the accepted feed envelope before choosing technology.
- Specify every intermediate and final cut.
- Track wastewater, off-gas, solids and heavy residues.
What the principal process families target
Vacuum distillation separates lube-range fractions from lighter material and less volatile bottoms by boiling behaviour. Clay, solvent or hydrogen finishing then targets material that remains within the recovered cuts.
Acid and clay routes can address polar and resinous compounds but generate acid tar and spent clay. Hydrotreating can reduce sulphur-, nitrogen- and oxygen-containing compounds and saturate reactive molecules, subject to catalyst, severity and feed preparation. Thin-film evaporation and solvent extraction provide other separation options, but no process label establishes universal removal efficiency.
- Treat removal as a process target, not guaranteed elimination.
- Do not infer API group from the route.
- Do not describe historical acid and clay routes as current best available technique without current evidence.
Judge the complete output and residue map
EU BAT conclusions require incoming waste-oil monitoring for chlorinated compounds such as chlorinated solvents or PCBs. They also recognise residues from vacuum distillation, solvent extraction and thin-film evaporation, making feed acceptance and residual management part of technology qualification.
A comparison should document accepted feed, product cuts, recovery yield, air and water emissions, energy and hydrogen demand, process chemicals, solid and liquid residues and the destination of every output. Product conformity then requires base-stock testing rather than inference from process description.
- Use historical Basel guidance for taxonomy, not proof of current BAT.
- Include abnormal and rejected material in the balance.
- Evaluate the legal and environmental route for every residue.
Read the underlying documents.
- Technical guidelines on used-oil re-refiningBasel Convention ↗
- Waste Treatment BREFEuropean Commission Joint Research Centre ↗
- Waste Treatment BAT conclusions, Decision 2018/1147European Union ↗
Source links and status were reviewed on 31 July 2026. Standards and regulations may be revised after publication.