Process for producing diisopropyl benzenes

Claim 1

A PROCESS FOR THE CONTINUOUS PRODUCTION OF DIISOPROPYL BENZENE ISOMERS OF ORTHO-DIISOPROPYL BENZENE WHICH COMPRISES, IN COMBINATION: CHARGING PROPYLENE TO AN ALKYLATION ZONE TO CONTACT CUMENE THEREIN IN LIQUID PHASE IN THE PRESENCE OF CRACKING CATALYST AT CONDITIONS INCLUDING A TEMPERATURE IN THE RANGE BETWEEN 160* AND 300*C. AND A LIQUID HOURLY SPACE VELOCITY OF AT LEAST 4V./V./HR. TO PRODUCE A MIXTURE COMPRISING DIISOPROPYL BENZENES AND POLYISOPROPYL BENZENES; SUBJECTING SAID MIXTURE TO FRACTIONAL DISTILLATION TO RECOVER THEREFROM AS SEPARATE STREAMS AT LEAST: (1) A FRACTION COMPRISING ESSENTIALLY META- AND ORTHO-DIISOPROPYL BENZENE, (2) A FRACTION COMPRISING ESENTIALLY PARA-DIISOPROPYL BENZENE, (3) A FRACTION COMPRISING ESSENTIALLY POLYISOPROPYL BENZENES, AND CUMENE; PASSING AT LEAST SAID FRACTION (1) ND AT MOST BOTH SAID FRACTIONS (1) AND (2) TO AN ISOMERIZATION ZONE WHEREIN THEY ARE CONTACTED IN LIQUID PHASE WITH A CRACKING CATALYST AT CONDITIONS INCLUDING A TEMPERATURE IN THE RANGE BETWEEN 100* AND 300*C. AND A LIQUID HOURLY SPACE VELOCITY OF LESS THAN 5 V./V./HR. AND RECOVERING THEREFROM AN ISOMERIZATION PRODUCT CONTAINING NO MORE THAN 5% ORTHO-DIISOPROPYL BENZENE (BASED ON TOTAL DIISOPROPYL BENZENES); PASSING SAID POLYISOPROPYL BENZENE FRACTION (3) AND AT LEAST AN APPROXIMATELY EQUAL MOLAR AMOUNT OF AT LEAST ONE COMPOUND OF THE GROUP CONSISTING OF BENZENE AND CUMENE TO A TRANSALKYLATION ZONE WHEREIN THEY ARE CONTACTED IN LIQUID PHASE WITH A CRACKING CATALYST AT CONDITIONS INCLUDING A TEMPERATURE IN THE RANGE BETWEEN 160* AND 350*C. AND A LIQUID HOURLY SPACE VELOCITY OF LESS THAN 5 V./V./HR. AND RECOVERING THEREFROM A TRANSALKYLATION PRODUCT COMPRISING A SUBSTANTIAL PROPORTION OF DIISOPROPYL BENZENES CONTAINING NO MORE THAN 5% THEREOF AS ORTHO-DIISOPROPYL BENZENE; SUBJECTING SAID ISOMERIZATION PRODUCT AND SAID TRANSALKYLATION PRODUCT TO FRACTIONAL DISTILLATION AND RECOVERING THEREFORM AT LEAST ONE OF THE DIISOPROPYL BENZENE ISOMERS OF ORTHO-DIISOPROPYL BENZENE SUBSTANTIALLY FREE OF ORTHODIISOPROPYL BENZENE IN SUBSTANTIAL YIELD, AND FURTHER RECOVERING A CUMENE FRACTION FROM AT LEAST THE DISTILLATION OF SAID TRANSLAKULATION PRODUCT; AND ADDING CUMENE RECOVERED FROM ALL DISTILLATIONS, BENZENE RECOVERED FROM ALL DISTILLATIONS AND FRESH AROMATIC FEED TO AT LEAST ONE OF THE ZONES IN WHICH DIISOPROPYL BENZENE IS PRODUCED BY ADDITION OF ALKYL GROUPS TO AT LEAST ONE FEED COMPOUND SELECTED FROM THE GROUP CONSISTING OF BENZENE AND CUMENE.