Production of alkyl aromatic hydrocarbons

Claim 1

PROCESS FOR THE CONVERSION OF HYDROCARBONS IN PART TO PARA-DIALKYL AROMATIC HYDROCARBONS WHICH COMPRISES IN COMBINATION THE STEPS OF CATALYTICALLY CRACKING ALKYLATE ONTAINED AS HEREINAFTER DEFINED, SEPARATING FROM THE PRODUCTS OF SAID CRACKING A FRACTION CONSISTING LARGELY OF CUMENE WITH MINOR AMOUNTS OF BENZENE, PASSING THE SAID FRACTION TO AN ALKYLATION ZONE WHEREIN IT IS ALKYLATED WITH PROPYLENE, SEPARATING FROM THE RESULTING ALKYLATE BY FRACTIONAL DISTILLATION A FRACTION CONSISTING LARGELY OF PARADIISOPROPYL BENZENE, PASSING TO THE SAID CATALYTIC CRACKING A FRACTION CONSISTING LARGELY OF OTTHO-AND META-DIISOPROPYL BENZENE AND CATALYTICALLY CRACKING THE SAME IN THE PRESENCE OF AT LEAST 50% BY VOLUME DILUENT GAS AT A TEMPERAPERATURE BETWEEN 300* C. AND 425* C. UNDER CONDITIONS WHEREBY VERY LITTLE CONVERSION TO BENZENE, ETHYLENE AND BUTYLENES IS OBTAINED, PASSING THE CRACKED PRODUCT TO SAID ALKYLATION ZONE AS AFORESAID, AND RETAINING THE CONCENTRATION OF ALKYL AROMATICS HAVING OTHER THAN C3 ALKYL GROUPS SUFFICIENTLY LOW IN THE ALKYLATION PRODUCT TO ALLOW SEPARATION OF SAID PARA-DIISOPROPYL BENZENE BY FRACTIONAL DISTILLATION BY WITHDRAWING IN ADDITION TO AND SEPARATE FROM SAID PARA-DIISOPROPYL BENZENE FRACTION A REGULATED PORTION OF THE ALKYLATE BOILING ABOVE SAID PARA-DISOPROPYL BENZENE FRACTION.