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