Recycling Techniques#
The design of preparative chromatography poses major challenges in balancing the interdependence of product purity and yield, as well as the efficiency of the column and its pressure drop. To improve difficult separations, it may be necessary to increase the column’s separation efficiency by using a longer column or reducing the particle size of the stationary phase. However, using a longer column or a particles can result in an excessively high pressure drop. To overcome this issue, several recycling techniques exist to effectively improve the separation. By connecting the column’s outlet to its inlet, the separation can pass through the column multiple times, without the need for a longer column or smaller particles, and hence, with a manageable pressure drop.
In the following different recycling concepts are introduced.