The carbon dioxide recycle stream is combined with {HEAD ~ the feed} to {TAIL ~ the carbon dioxide PSA unit} 
The carbon dioxide recycle stream is combined with { HEAD ~ the feed } to { TAIL ~ the carbon dioxide PSA unit }
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL