Abstract: A process for separating at least one component of a mixture in a set of closed-loop chromatographic columns is described, whereby the loop comprises at least one feedstock injection point, a raffinate draw-off point, an eluant injection point, and an extract draw-off point, in which a determination is made between an injection point and a draw-off point or vice-versa a chromatographic zone, and at the end of a given period of time, all of the injection and draw-off points are shifted by one column or column section in a given direction that is defined relative to that of the flow of a main fluid that circulates through the loop. During the period, the shifting of different injection and draw-off points of a column or column section is done at different times in such a way that the lengths of the zones that are defined by said different points are variable. The process is useful for the seperation particularly of stereoisumers for pharmaceuticals.