Method for converting hydrocarbon feedstocks by means of thermal steam cracking

摘要

The invention relates to a process for converting hydrocarbon feeds by thermal steamcracking to at least one olefin-containing product stream comprising at least ethylene and propylene, with at least partial conversion of a first hydrocarbon feed in at least one first cracking furnace (1) and of a second hydrocarbon feed in at least one second cracking furnace (2). According to the invention, the second hydrocarbon feed comprises predominantly hydrocarbons having a carbon number of 5 or/and 4 and consists for the most part of one or more recycled fractions (P, T) which are obtained from the product stream, and the second hydrocarbon is converted in the second cracking furnace (2) with cracking conditions that lead to a ratio of propylene to ethylene of 0.7 to 1.6 kg/kg.

主权项

1. A process for converting hydrocarbon feeds by thermal steamcracking to an olefin-containing product stream comprising at least ethylene and propylene, with at least partial conversion of a first hydrocarbon feed in at least one first cracking furnace (1) and of a second hydrocarbon feed in at least one second cracking furnace (2), characterized in that the second hydrocarbon feed comprises predominantly hydrocarbons having a carbon number of 5 or/and 4 and consists for the most part of one or more recycled fractions (P, T) which are obtained from the product stream, the second hydrocarbon being converted in the second cracking furnace (2) with cracking conditions that lead to a ratio of propylene to ethylene of 0.85 to 1.6 kg/kg, the first hydrocarbon feed being supplied with at least one fraction (U) which has been separated from the product stream and is recycled, comprising predominantly hydrocarbons having a carbon number of at least 6, the first hydrocarbon feed being converted in the first cracking furnace (1) with cracking conditions that lead to a ratio of propylene to ethylene of 0.25 to 0.85 at the cracking furnace outlet, and the value for the ratio of propylene to ethylene for the second hydrocarbon feed being above the value for the ratio of propylene to ethylene for the first hydrocarbon feed.