Tetrapropylene quality improvement

Claim 1

IN A PROCESS OF ALKYLATING BENZENE BY THE REACTION OF A C9-C24 OLEFIN WITH BENZENE IN THE PRESENCE OF ALUMINUM CHLORIDE CATALYST WHEREIN SAID OLEFIN IS A POLYMERIZATION PRODUCT PREPARED BY INTRODUCING A PROPYLENE FEEDSTOCK COMPRISING AT LEAST 85 WT. PERCENT PROPANE AND PROPYLENE IN A MOLAR RATIO OF BETWEEN 0.5-4:1 INTO A REACTOR CONTAINING A SOLID PHOSPHORIC ACID POLYMERIZATION CATALYST MAINTAINED AT A TEMPERATURE IN THE RANGE OF 200* TO 600*F. AND A PRESSURE OF 500 TO 800 P.S.I.G. AND RECOVERING SAID OLEFIN THEREFROM, THE IMPROVEMENT WHICH COMPRISES INTRODUCING INTO SAID REACTOR DURING SAID POLYMERIZATION 0.3 TO 0.7 MOLE OF HYDROGEN GAS PER MOLE OF SAID PROPYLENE, RECOVERING SAID OLEFIN FROM SAID REEACTOR AND EMPLOYING SAID OLEFIN TO PREPARE ALKYL BENZENE IN THE PRESENCE OF ALUMINUM CHLORIDE CATLAYST, THE OLEFIN RECOVERED FROM THE IMPROVED PROCESS HAVING A LOWER HDI THAN THE OLEFIN RECOVERED FROM THE UNIMPROVED PROCESS.