A PROCESS FOR THE SEPARATION/RECOVERY OF GASES

摘要

A process for the separation/recovery of gases is descrribed where the desired component to be separated from the gaseous mixture is present in low/very low mo lar amount and/or low/moderate pressure, the process comprising contacting the gaseo us mixture with a separation membrane unit containing high permeability/medium selectivity membranes which separate the feed stream into a permeate stream, enriched in the desired component and at a lower pressure and a retentate stream lean in the desired component and at a higher pressure. The retentate stream is made to convey its pressure to the permeate stream which then is directed to an adsorpti on PSA unit for further purification of the permeate stream so that the effluent st ream from the PSA unit which contains the purified component has a purity of up to 99.90%. The process is useful for separating hydrogen from refinery off gases such as FCC ga ses and can also be applied to other gases such as helium and any other valuable gas es present in gaseous streams in low to very low molar contents and low to moderate pressures.