PROCESS AND PLANT FOR PRODUCING OLEFINS

A method (100) for producing olefins is proposed, wherein a first gas mixture (b) is produced by means of a steam cracking process (1) and a second gas mixture (s) is produced by means of an oxygenate-to-olefin process (2), the first gas mixture (b) and the second gas mixture (s) each containing at least hydrocarbons with one to four carbon atoms. It is proposed that from the first gas mixture (b) a first fraction (h) is formed which contains at least the great majority of the hydrocarbons with four carbon atoms previously contained in the first gas mixture (b), from the second gas mixture (s) a second fraction (y) is formed which contains at least the great majority of the hydrocarbons with four carbon atoms previously contained in the second gas mixture (s), and that the hydrocarbons contained in the second fraction (y) and previously in the second gas mixture (s) are predominantly subjected in the steam cracking process (1) to cracking conditions under which any n-butane present is reacted by less than 92%. The invention further relates to an apparatus for this purpose.