Recovery of C4 olefins from a product stream comprising C4 olefins, dimethyl ether and C5+ hydrocarbons

A process for removing DME from an initial stream including C4 olefins, the process comprising the steps of:

• (a) separating a product effluent from a methanol-to-olefin reactor system into a light olefin stream comprising ethylene and propylene, and the initial stream, wherein the initial stream comprises C4 olefins, C5+ hydrocarbons, DME, and methanol;
• (b) contacting the initial stream with water in a methanol removal unit under conditions effective to separate the stream into a first overhead stream comprising the C4 olefins, the DME and the C5+ hydrocarbons, and a first bottoms stream comprising the methanol;
• (c) separating the first overhead stream into a second overhead stream comprising the C4 olefins and the DME, and a second bottoms stream comprising the C5+ hydrocarbons;
• and
• (d) contacting the second overhead stream with water in a DME removal unit under conditions effective to separate the second overhead stream into a third overhead stream comprising the C4 olefins and a third bottoms stream comprising the DME.

A process for removing DME from a product stream from a methanol-to-olefin reaction system, the process comprising the steps of:

• (a) separating a product effluent from the methanol-to-olefin reaction system into a light olefin stream comprising ethylene and propylene, and the product stream, wherein the product stream comprises DME, butenes, C5+ hydrocarbons and coboiling oxygenates;
• (b) removing the C5+ hydrocarbons and the coboiling oxygenates from the product stream to form a processed stream comprising the DME and the butenes;
• and
• (c) contacting the processed stream with water in a DME removal unit under conditions effected to separate the DME from the butenes.