An efficient head-tail co-conversion process for high quality gasoline via rational catalytic cracking

To meet the requirement of gasoline new standard, a concept process for head-tail co-conversion of the longer chain n-alkanes (C10-C12) and olefins (C5^[dbnd]-C7^[dbnd]) with similar C-C bonding energy in FCC gasoline was developed to reduce olefin content and T₅₀ of gasoline simultaneously. Here 1-hexene and n-decane were chosen as head-tail model compounds of these olefin and n-alkane components in FCC gasoline. By analyzing the product distribution of co-feeding and single-feeding of n-decane and 1-hexene at different reaction temperatures, higher yield of gasoline with lower T₅₀ and higher content of i-paraffin could be obtained through co-feeding process at 325 °C. Besides, the olefin content of gasoline could be successfully decreased. Based on chemical kinetic analysis, it could be found that by co-conversion of n-decane and 1-hexene, the cracking path of 1-hexene was restrained and the formation of i-paraffin was enhanced due to the hydrogen transfer of n-decane with carbocation converted from 1-hexene.