Thin Film Evaporation

In used oil re-refining, two separation routes give a designer two different tools: vacuum distillation for the bulk split, and thin film for the difficult, high-boiling or thermally sensitive fraction. Thin film evaporation is not strictly a rival to vacuum distillation; in many plants the two step in together, with the film recovering the heavy end that a conventional column cannot reach cleanly.

The Roles Each Plays

Vacuum distillation separates large flows by boiling point under reduced pressure, a workable means for the primary cut and a practical basis for large-scale design. Thin film evaporation instead spreads the feed as a thin film across a heated surface, delivering quick heat transfer with a short thermal exposure, which makes it suited to the viscous, high-boiling fraction a full column handles poorly.

Recovering the Heavy Material

Heavy and degraded oils carry high-boiling hydrocarbon that still has commercial value. Recovering that value without forcing it through extra heat is where the film route earns its keep, holding the short exposure and the close control a column can struggle to give when the fraction is sticky and heat-sensitive. The goal is not maximum evaporation but efficient separation of the useful oil from the unwanted.

The Hybrid Configuration

In practice the two step together. A common scheme runs pre-treatment, then vacuum distillation, then thin film evaporation, then a finish, with the final layout set by feed analysis, the target base and the project economics. Choosing purely on the lowest price or a listed vacuum number therefore misses how the two stages combine in the finished separation.

Matching the Route to the Feed

Klean Industries begins with the feed’s character, its consistency, water burden, viscosity and additive load, and then settles which separation performance the product demands, rather than defaulting to the more specialised unit. That gives a configuration that meets the required product at an acceptable total project value, for a small line or a fully integrated plant.

Learn More:

• Feasibility Studies for Waste-to-Value Projects
• Turn-Key EPC Delivery
• Plant Design & Engineering
• Facility Efficiency Upgrades
• Resource Recovery Projects

Recover the Heavy End Without Paying In Heat

The cleanest base oil is the one that never touched more heat than the job required.

Klean Industries maps the film and vacuum stages to recover the valuable heavy cut with minimal thermal exposure.

Considering a thin film evaporation project?

Contact Klean Industries about thin film evaporation » GO.