Separation process control method

Claim 1

IN A PROCESS FOR RECOVERING DESIRED CONSTITUENTS FROM A FLUID MIXTURE COMPRISING CONTACTING SAID MIXTURE WITH A SOLVENT SELECTIVE FOR SAID CONSTITUENTS IN A DISSOLUTION ZONE, WITHDRAWING RESIDUE FLUID FROM SAID DISSOLUTION ZONE, PASSING ENRICHED SOLVENT FORM SAID DISSOLUTION ZONE TO A DISTILLATION ZONE, PASSING STEAM CONSTITUENTS FROM SAID DISTILLATION ZONE TO A RECTIFYING ZONE; WITHDRAWING WATER FROM AN INTERMEDIATE REGION FO SAID RECITFYING ZONE, REMOVING HEAT FROM SAID WATER AND RECYCLING THE COOLED WATER TO THE UPPER REGION FO SAID RECTIFYING ZONE; WITHDRAWING SAID CONSTITUENTS FROM SAID RECTIFYING ZONE, WITHDRAWING WATER FROM SAID RECTIFYING ZONE, AND WITHDRAWING SOLVENT FROM SAID RECTIFYING ZONE, THE IMPROVEMENT IN CONTROL WHICH COMPRISES DETERMINING THE CONCENTRATION OF SAID CONSTITUENTS IN SAID RESIDUE FLUID, MANIPULATING THE FLOW OF STEAM TO SAID DISTILLATION ZONE IN RESPONSE TO SAID DETERMINED CONCENTRATION, DETERMINING THE HEAT INPUT TO SAID DISTILLATION ZONE, AND MANIPULATING THE RATE OF HEAT REMOVAL FROM SAID RECTIFYING ZONE IN RESPONSE TO SAID DETERMINED HEAT INPUT TO MAININT THE RATIO OF HEAT INPUT TO THE HEAT REMOVED SUBSTANTIALLY CONSTANT.