Patent ID: 8754280

Claim:
A method for start-up of an Oxygenate-to-Olefins process in which C4+ olefins are recycled, which process comprises the steps: a) providing an oxygenate-comprising feedstock to an Oxygenate-to-Olefins reaction zone and contacting the feedstock with a zeolite-comprising catalyst at a temperature in the range of from 450 to 700° C., to obtain an reaction product containing olefins; b) separating the reaction product obtained in step a) into at least a product fraction containing ethylene and/or propylene and a product fraction containing C4+ olefins; c) recycling at least part of the C4+ olefins in the product fraction containing C4+ olefins to the Oxygenate-to-Olefins reaction zone in step (a), characterised in that upon start-up the oxygenate-comprising feedstock initially comprises a first amount of externally supplied tert-alkyl ether and subsequently the amount of externally supplied tert-alkyl ether in the oxygenate-comprising feedstock is reduced as C4+ olefins become available from step (c) and are recycled.