Patent ID: 9630891
Date: 2017-04-25
CPC Classifications: C07C,C10G

Claim:
1. A process for converting feeds composed of hydrocarbons by thermal steamcracking to at least one olefin-containing product stream comprising at least ethylene and propylene, with at least partial conversion of the feeds in at least one first cracking furnace ( 1 ) and in at least one second cracking furnace ( 2 ), wherein a fresh feed (B) is fractionated into at least one first and one second fresh feed fraction (B 1 , B 2 ) of different composition and the first fresh feed fraction (B 1 ) is conducted at least partly into the first cracking furnace ( 1 ) and the second fresh feed fraction (B 2 ) at least partly into the second cracking furnace ( 2 ), characterized in that the second fresh feed fraction (B 2 ) comprises predominantly hydrocarbons having a maximum carbon number of 5, in that the first fresh feed fraction (B 1 ) comprises predominantly hydrocarbons having a carbon number of at least 6, in that cracking conditions that lead to a ratio of propylene to ethylene of 0.7 to 1.6 kg/kg at the cracking furnace exit exist in the second cracking furnace ( 2 ), and in that cracking conditions that lead to a ratio of propylene to ethylene of 0.25 to 0.85 kg/kg at the cracking furnace exit exist in the first cracking furnace ( 1 ), the values attained for the ratio of propylene to ethylene in the second cracking furnace ( 2 ) being above those in the first cracking furnace ( 1 ).