ETHYLENE RECOVERY FROM OFF-GAS

摘要

A method for the recovery of ethylene from an off-gas is provided. This method includes providing an ethylene containing feed gas stream, introducing the ethylene containing gas stream into a first cryogenic separation device, thereby producing a first condensed stream and a first ethylene poor stream, and introducing the ethylene poor stream into a first feed compressor, thereby producing a pressurized first ethylene poor stream. This is repeated three times, resulting in a pressurized third ethylene poor stream, which is introduced into a pressure swing adsorber, thereby producing a high purity hydrogen stream and a PSA tail gas stream. The PSA tail gas stream is into a PSA tail gas compressor, thereby producing a pressurized PSA tail gas stream, which is then combined with an ethylene containing gas stream to produce the ethylene containing feed gas stream. The first condensed stream, the second condensed stream and the third condensed stream are combined to produce a combined condensed stream, which is introduced into an ethylene separation column thereby producing an ethylene rich stream and a methane rich stream. The methane rich stream is introduced into a methane compressor thereby producing a methane fuel stream.