Preparing olefins comprises converting educt mixture, separating mixture into e.g. olefin and gasoline hydrocarbons, mixing hydrocarbons with inert medium, converting mixture into product mixture, separating hydrocarbons feeding streams

摘要

Preparing 2-4C olefins comprises: converting the educt mixture into a reaction mixture comprising olefins and gasoline hydrocarbons; separating the reaction mixture into a 2-4C olefin-rich mixture, a mixture rich in C 5+ gasoline hydrocarbons and an aqueous phase; mixing the gasoline hydrocarbons with an inert medium; converting the obtained mixture into a product mixture containing 2-4C olefins; recirculating the product mixture; separating the C 5+ gasoline hydrocarbons into product streams; feeding the product streams containing the C 7+ hydrocarbons and the 5-6C hydrocarbons. Preparation of 2-4C olefins, preferably propylene, from an educt mixture containing water vapor, methanol vapor and/or dimethyl ether vapor, comprises: converting the educt mixture into a low-molecular reaction mixture comprising olefins and gasoline hydrocarbons in at least one first reactor (1) on a granular, shape-selective zeolite catalyst; separating the reaction mixture in a first separator (3) into a 2-4C olefin-rich mixture, a mixture rich in C 5+ gasoline hydrocarbons and an aqueous phase; mixing the gasoline hydrocarbons with an inert medium; converting the obtained mixture into a product mixture containing 2-4C olefins in at least one second reactor (2) on a granular zeolite catalyst; recirculating the product mixture to the first separator; separating the C 5+ gasoline hydrocarbons into a product stream containing 5-6C hydrocarbons and a product stream containing C 7+ hydrocarbons in a second separator (4); feeding the product stream containing the C 7+ hydrocarbons to the second reactor; and feeding the product stream containing the 5-6C hydrocarbons to the first reactor together with the educt mixture. An independent claim is also included for a system for the production of 2-4C olefins, comprising first reactor and second reactor, which contains granular, form-selective zeolite catalyst respectively, first separator for isolation of the reaction mixture obtained in the first reactor, a second separator for the isolation of a mixture rich at C 5+ benzine hydrocarbons, before the supply into the second reactor, from a product stream containing a 5-6C hydrocarbons and C 7+ hydrocarbons, and a back-feed pipe that leads from the second reactor to the first separator.