A chromatographic process of a type wherein a feedstock fluid containing a plurality of components is supplied into a circulative chromatographic separation system, the process comprising the steps of (i) supplying the feedstock fluid and withdrawing a fraction enriched in a component, (ii) supplying a desorbent fluid and withdrawing a fraction enriched in another component, and (iii) circulating the fluid through the bed without supplying or withdrawing any fluid thereby making a mixed zone comprising a plurality of components move, a cycle including steps (i), (ii) and (iii) being repeated while controlling the discharged pressure of a pump delivering the feedstock fluid, the desorbent fluid, and the circulating fluid constant.