Process for recovery of high purity hydrocarbons

Claim 1

A PROCESS FOR RECOVERING DURENE FROM AN AROMATIC FEED STOCK BOILING WITHIN THE RANGE FROM ABOUT 360* TO ABOUT 400*F. AND CONTAINING FROM ABOUT 5 TO 40 PERCENT DURENE, SAID PROCESS COMPRISING THE STEPS OF DISSOLVING SAID FEED STOCK IN ABOUT 0.5 TO ABOUT 1.5 VOLUMES PER VOLUME OF FEED STOCK OF LIQUEFIED NORMALLY GASEOUS REFRIGERANT COMPRISING A SOLVENT FOR SAID FEED STOCK, CHILLIING THE RESULTANT SOLUTION BY AUTOREFRIGERATION IN A CRYSTALIZATION ZONE TO A TEMPERATURE OF MAXIMIZED CRYSTAL FORMATION WITHIN THE RANGE OF ABOUT -50* TO ABOUT -100*. TO FORM A SLURRY OF CRYSTALS OF SAID DURENE IN A LIQUID MEDIUM CONSISTING OF A LIQUEFIED REFRIGERANT AND MOTHER LIQUOR, NEXT CONTINUOUSLY CYCLING A TURBULENTLY FLOWING STREAM OF SAID SLURRY FROM SAID CRYSTALIZATION ZONE TO AN ISOTHERMAL FILTRATION ZONE TO TURBULENTLY ISOTHERMALLY SEPARATE SAID STREAM INTO A FILTRATE FRACTION AND A CONCENTRATED SLURRY FRACTION, CONTINUOUSLY DISCARDING SIAD FILTRATE FRACTION, CONTINUOUSLY RETURNING SAID CONCENTRATED SLURRY FRACTION TO SAID CRYSTALLIZATION ZONE, CONTINUING SAID CYCLING OPERATION FOR A PERIOD OF TIME SUFFICIENT TO REMOVE AT LEAST ABOUT 90 VOLUME PERCENT TO SAID MOTHER LIQUOR FROM SAID SLURRY WHILE PROVIDING AN AMOUNT OF SAID LIQUIEFIED REFRIGERANT SUFFICIENT TO PROVIDE A SLURRY IN SAID CRYSTALLIZATION ZONE CONTAINING NOT MORE THAN ABOUT 70 WEIGHT PRECENT OF CRYSTALS AND THEN SEPARATING SAID CRYSTALLIZED DURENE FROM SAID SLURRY WHEREBY SAID DURENE IS RECOVERED AS A PRODUCT HAVING A PURITY OF AT LEAST ABOUT 95 WEIGHT PERCENT.