Adsorption-desorption process

Claim 1

IN A PROCESS FOR THE SEPARATION OF CHEMICALLY UNLIKE COMPONENTS IN A LIQUID HYDROCARBON MIXTURE BY THE SELECTIVE ADSORPTION OF ONE OF SAID COMPONENTS ON A SOLID ADSORBENT, WHEREIN THE LIQUID COMPRISING THE COMPONENTS TO BE SEPARATED IS INTRODUCED INTO CONTACT WITH A DOWNWARDLY MOVING CONTIGUOUS PARTICULATE COLUMN OF SAID SOLID ADSORBENT, A LIQUID DESORBENT LESS READILY ADSORBED THAN THE EXTRACT PRODUCT OF SAID PROCESS IS CONTACTED WITH SAID SOLID ADSORBENT CONTAINING COMPONENTS ADSORBED FROM SAID HYDROCARBON MIXTURE TO DESORB SAID COMPONENTS THEREFROM, A RESULTING RAFFINATE IS PASSED UPWARDLY THROUGH THE ZONE OF ADSORPTION FROM AN INTERMEDIATE POINT THEREIN, SOLID ADSORBENT WETTED WITH DESORBENT LIQUID IS WITHDRAWN FROM A LOWERMOST PORTION OF SAID ADSORPTION ZONE AND RETURNED TO AN UPPERMOST PORTION THEREOF, AND IN SAID UPPERMOST PORTION RAFFINATE IS CONTACTED WITH SAID WETTED ADSORBENT AND DISPLACES DESORBENT LIQUID THEREFROM TO FORM A MIXTURE OF RAFFINATE AND LIQUID DESORBENT, THE IMPROVEMENT COMPRISING WITHDRAWING A LIQUID STREAM FROM SAID RAFFINATE-DESORBENT LIQUID MIXTURE DISPOSED IN SAID UPPERMOST ZONE, MAINTAINING RAFFINATE FREE FROM LIQUID DESORBENT IN A ZONE SUBJACENT SAID UPPERMOST ZONE, WITHDRAWING DESORBENT-FREE RAFFINATE FROM SAID SUBJACENT ZONE AND REGULATING THE FLOW OF RAFFINATE WITHDRAWN FROM SAID SUBJACENT ZONE AT A RATE SUCH THAT THERE IS SUBSTANTIALLY NO DOWNWARD FLOW OF DESORBENT LIQUID DISPLACED IN SAID UPPERMOST ZONE INTO SAID SUBJACENT ZONE.