Secrets of Wiped Film Distillation - Part 2

Secrets of Wiped Film Distillation - Part 2

Fractionation

Many times, wiped film distillation is dismissed as an option because it is not capable of separating the components cleanly. The desired product and another species have boiling points that are too close together to get the desired purity using a single theoretical plate.

Since molecular distillation and wiped film evaporators have just one theoretical plate, these are not even considered.

However, wiped film stills are built with fractional columns. The still is setup as with an external condenser, but a column is placed between the still and condenser. The system has reflux control and continuously collects distillate and residue. Many of these systems are capable of feeding mid-column or direct into the still body, depending on desired separation.

These systems can perform some very impressive separations, producing products that have the benefits of a pot still without the burning and long heat exposure. If you have a delicate mixture that needs fractionation, the hybrid wiped film still is a good option to consider.

Pictured is a hybrid still built by Pope Scientific. Picture is courtesy of Pope Scientific, Inc.