Improved methane rejection and ethylene recovery

A process for the production of an ethylene product stream from a reactor effluent stream includes passing the reactor effluent stream and an ethylene recycle stream to a deethanizer zone to provide a light hydrocarbon feedstream and a C3+ stream. The light hydrocarbon stream goes to a demethanizer zone to provide a C2 bottom stream and an overhead stream, then splitting the C2 bottom stream into an ethane stream and an ethylene stream. The ethylene stream is divided into a first ethylene product stream and an ethylene co-feed stream, which is fed subsequently to the overhead stream to a pressure swing adsorption process producing an adsorber effluent stream during an adsorption step and a desorbed stream on desorption. The desorbed stream constitutes all or a portion of the ethylene recycle stream.