Adsorbent Regeneration in Light Olefin Recovery Process

A process for regenerating adsorbents in a methanol to olefin process, comprising:

• passing an oxygenate stream to a methanol to olefins reactor, thereby generating an intermediate olefins stream;
• compressing the intermediate olefins stream, creating a compressed olefins stream;
• separating the compressed olefins stream into a first stream comprising light olefins and oxygenates, and a second stream comprising C4 and heavier hydrocarbons;
• passing the first stream through an oxygenate adsorber and caustic scrubber, creating a light olefins stream with reduced oxygenate and CO2 content, and a recycle oxygenate stream;
• passing the light olefins stream with reduced CO2 content in a first adsorbent bed, creating a dry light olefins stream with reduced water and CO2 content;
• separating the dry light olefins with reduced CO2 content stream into a third stream comprising C3 and heavier hydrocarbons and a fourth stream comprising C2 and lighter gases;
• separating the fourth stream into a fifth stream comprising ethane and ethylene, and a sixth stream comprising methane and lighter gases;
• during regeneration of the first adsorbent bed, regenerating the adsorbent bed with a portion of the sixth stream, thereby creating a seventh stream;
• and
• passing the seventh stream to the methanol to olefins reactor as a purge gas.

A process for regenerating adsorbents in a methanol to olefin process, comprising:

• passing an oxygenate stream to a methanol to olefins reactor, thereby generating an intermediate olefins stream;
• compressing the intermediate olefins stream, creating a compressed olefins stream;
• separating the compressed olefins stream into a first stream comprising light olefins and oxygenates, and a second stream comprising C4 and heavier hydrocarbons;
• passing the first stream in a first adsorbent bed, creating a light olefins stream with reduced oxygenate and CO2 content, and a recycle oxygenate stream;
• separating the light olefins stream with reduced CO2 content into a third stream comprising C3 and heavier hydrocarbons and a fourth stream comprising C2 and lighter gases;
• separating the fourth stream into a fifth stream comprising ethane and ethylene, and a sixth stream comprising methane and lighter gases;
• passing the third stream to a depropanizing column, thereby creating an overhead stream comprising propane and propylene, and a bottoms stream comprising C4 and heavier hydrocarbons;
• passing the depropanizing overhead stream through a second adsorbent bed, thereby creating a purified C3 stream;
• mixing a portion of the bottoms stream with the sixth stream, and using the mixed stream to regenerate the second adsorbent bed, thereby creating a seventh stream;
• during regeneration of the first adsorbent bed, regenerating the adsorbent bed with a portion of the sixth stream, thereby creating an eighth stream;
• and
• passing the seventh and eighth streams to the methanol to olefins reactor as a purge gas.