This specific carbonate concentration improves the settling characteristics of the catalyst and reduces {HEAD ~ catalyst carryover} into {TAIL ~ the crude hexamethylene diamine} during decantation 
into
This specific carbonate concentration improves the settling characteristics of the catalyst and reduces { HEAD ~ catalyst carryover } into { TAIL ~ the crude hexamethylene diamine } during decantation
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 TAIL TAIL OTH OTH