The process 1, further comprising separating and recycling {HEAD ~ CO2} contained in {TAIL ~ the resultant cracked gas} for thermal cracking 
contained in
The process 1 , further comprising separating and recycling { HEAD ~ CO2 } contained in { TAIL ~ the resultant cracked gas } for thermal cracking
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH