Abstract: For the purification of the norbornene obtained by the reaction of dicyclopentadiene or cyclopentadiene and ethylene, the crude reaction mixture containing light impurities having boiling temperatures lower than that of norbornene; medium-heavy impurities having the boiling temperatures between that of norbornene and that of ethylnorbornene; and heavy impurities containing ethylnorbornene and compounds boiling higher than ethylnorbornene, boiling temperatures greater than that ethylnorbornene, a first distillation of the crude reaction mixture is carried out in a tailing column (C1), removing a portion of the heavy impurities and a portion of the medium-heavy impurities; then a second distillation of the crude mixture, thus tailed, is carried out in a topping column (C2), removing the light impurities; and a third distillation of the mixture, thus topped, is subsequently carried out in a tailing column (C3), removing the remainder of the heavy and medium-heavy impurities.

Abstract: This process for the manufacture of norbornene from dicyclopentadiene (DCPD) and ethylene is characterized in that the DCPD is subjected to partial monomerization to CPD by preheating: at a temperature of 140° C. to 240° C.; and under a pressure of 20 to 300 bar abs., before reacting it with the ethylene; with an ethylene/DCPD molar ratio of 1 to 20; at a temperature of 200° C. to 320° C.; under a pressure of 20 to 300 bar abs.; and with a residence time of 1 to 10 minutes, under stable reaction conditions between the DCPD, the CPD and the ethylene.