Without these extractive distillation agents, {HEAD ~ no improvement} above {TAIL ~ the azeotrope composition} will occur in a rectification column 
above
Without these extractive distillation agents , { HEAD ~ no improvement } above { TAIL ~ the azeotrope composition } will occur in a rectification column
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH