Aliphatic olefins and cyclic process for manufacture thereof

Claim 1

A CYCLIC PROCESS WHICH COMPRISES CONVERTING PROPYLENE TO A MIXTURE OF POLYMERIC OLEFINS BOILING ABOVE ABOUT 325*F. AND BELOW ABOAUT 520* F. BY CONTACTING PROPYLENE WITH AN ACID POLYMERIZATION CATALYST IN A POLYMERIZATION ZONE, SEPARATING FROM THE REACTION MIXTURE A LOWER BOILING BUT NORMALLY LIQUID OLEFIN POLYMER FRACTION, RECYCLING SAID LOWER BOILING LIQUID POLYMER FRACTION TO THE POLYMERIZATION ZONE, RECOVERING FROM THE REACTION PRODUCTS A HIGHER BOILING MIXTURE OF POLYMERIC OLEFINS BOILING ABOVE 325*F., AND INHIBITING DECLINE IN CONVERSION RATE TO SAID HIGHER BOILING POLYMERIC OLEFIN MIXTURE BY REJECTING FROM THE POLYMERIZATION CYCLE A FRACTION COMPRISING SATURATED HYDROCARBONS FORMED IN SAID POLYMERIZATION ZONE.