Method for recovering paraxylene

Claim 1

IN A PROCESS FOR RECOVERING A SELECTED CYCLIC HYDROCARBON COMPOUND FROM A FEED STOCK CONSISTING ESSENTIALLY OF A MIXTURE OF CYCLIC HYDROCARBON COMPOUNDS BY CHILLING SAID MIXTURE TO SELECTIVELY CRYSTALLIZE SAID SELECTED COMPOUND TO FORM A SLURRY OF LESS THAN 30 WEIGHT PERCENT OF CRYSTALS OF SAID SELECTED COMPOUND IN A MOTHER LIQUOR CONSISTING OF UNCRYSTALLIZED HYDROCARBON COMPOUNDS INITIALLY PRESENT IN SAID FEED STOCK, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF ESTABLISHING A BODY OF SLURRY OF CRYSTALS OF SAID SELECTED COMPOUND IN SAID MOTHER LIQUOR AT ABOUT THE LOWERMOST TEMPERATURE OF SELECTIVE CRYSTALLIZATION FOR SAID SELECTED COMPOUND, WITHDRAWING A STREAM OF SAID SLURRY FROM SAID BODY WHILE MAINTAINING SAID BODY AT ABOUT SAID LOWERMOST TEMPERATURE OF SELECTIVE CRYSTALLIZATION AND TURBULENTLY ISOTHERMALLY FILTERING SAID STREAM TO SEPARATE A PORTION OF SAID MOTHER LIQUOR FROM SAID STREAM, DISCARDING SAID PORTION OF SAID MOTHER LIQUOR AND RETURNING THE REMAINING PORTION OF SAID STREAM TO SAID BODY IN AN AMOUNT SUFFICIENT TO INCREASE THE CRYSTALS CONTENT OF SAID BODY TO ABOUT 30 TO 60 WEIGHT PERCENT AND, AFTER AN AVERAGE RESIDENCE TIME OF ABOUT 0.5 TO 4 HOURS, RECOVERING CRYSTALLIZED SELECTED HYDROCARBON FROM SAID THUS CONCENTRATED BODY OF SLURRY.