PROCESS AND PLANT FOR PRODUCING OLEFINS

A process (100) is proposed for obtaining olefins, comprising a steam cracking process (1) in which a first gas mixture (b) is generated and an oxygenate-to-olefin process (2) in which a second gas mixture (s) is generated, the first gas mixture (b) and the second gas mixture (s) each comprising at least hydrocarbons having one to four carbon atoms. Proposed is the formation from the first gas mixture (b) of a first fraction (h), comprising at least the predominant part of the hydrocarbons previously present in the first gas mixture (b) that have four carbon atoms; the formation from the second gas mixture (s) of a second fraction (y), comprising at least the predominant part of the hydrocarbons previously present in the second gas mixture (s) that have four carbon atoms; and the subjection, to a predominant extent, of the hydrocarbons present in the second fraction (y) and previously present in the second gas mixture (s) to cracking conditions, in the steam cracking process (1), under which there is less than 92% conversion of n-butane present. A corresponding plant is likewise a subject of the present invention.