As {HEAD ~ the hydrocarbon feedstock} for {TAIL ~ the thermal cracking}, basically C2+ alkanes, especially ethane, propane and butane, can be used advantageously 
As { HEAD ~ the hydrocarbon feedstock } for { TAIL ~ the thermal cracking } , basically C2 + alkanes , especially ethane , propane and butane , can be used advantageously
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH