Adsorptive separation of multi-component fluid mixtures

An adsorptive separation process and system are used for separation of multi-component fluid mixtures. The separation process and system may include establishing, in a fluid flow within the system, a concentration distribution of the fluid mixture components based upon the components' relative affinities to the adsorbent. The concentration distribution could be establishing using a simulated moving bed system, wherein it is possible to maintain separately-identifiable portions of the fluid flow, respectively rich in strongly-adsorbing, intermediately-adsorbing, and weakly-adsorbing compounds of the fluid mixture. An intermediate raffinate of high purity in the intermediately-adsorbing compound is directly withdrawn from the portion of the fluid flow rich in intermediately-adsorbing compound(s), providing a single-stage adsorptive separation of a compound having intermediate affinity to the adsorbent. The portion of the fluid flow rich in intermediately-adsorbing compound(s) may be established directly upstream from the point of fluid mixture feed injection into the fluid flow.