The purity of the gas product stream or {HEAD ~ sales gas product} is achieved by controlling {TAIL ~ a reflux stream} returned to a purification zone 
The purity of the gas product stream or { HEAD ~ sales gas product } is achieved by controlling { TAIL ~ a reflux stream } returned to a purification zone
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH