dimers and trimers the main characteristics of the gasoline cut obtained at the bottom of the fractionation column 6 which is fed through line 7 to the gasoline pool and which amounts to 84 28 by weight of the initial charge are as follows ______________________________________density at 20 u00b0 c 0 739bromine number 111octane number ron clear 99 5astm distillationip 60 u00b0 c 5 104 u00b0 c 10 108 u00b0 c 20 109 u00b0 c 30 111 u00b0 c 40 113 u00b0 c 50 118 u00b0 c 60 125 u00b0 c 70 137 u00b0 c 80 156 u00b0 c 90 189 u00b0 c 95 193 u00b0 c fp 213 u00b0 c distillate 100 residue 0losses 0______________________________________ the specifications concerning the final points of the gasolines are recalled hereinafter here the charge to be treated is the same as in the preceding example the catalyst is the same the operating conditions in the two polymerization reactors 4 and 10 are also the same as in the preceding example the only difference is in the arrangement of the apparatus as a matter of fact in this example an additional distillation column 12 is used for independently distilling the effluents from reactors 4 and 10 the volume of recycled product is thus decreased this arrangement requires the use of two distillation columns which accordingly will generally be of a smaller size than the column of fig1 the effluent from the polymerization zone 4 is fed through line 5 to the fractionation column 6 a polymerizate is recovered from the bottom of the column through.