The present invention provides for a process for purifying atmospheric air prior to {HEAD ~ its separation} by {TAIL ~ cryogenic distillation} 
by
The present invention provides for a process for purifying atmospheric air prior to { HEAD ~ its separation } by { TAIL ~ cryogenic distillation }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL