PEP Review 82-1-2
Ethylene from Hydrocracked Vacuum Gas Oil Produced by the Unicracking/FPP
Published: August 1982
Unicracking/FPP (Feedstock Pretreatment Process) is a mild hydrocracking process jointly developed by C-E Lummus and Union Oil to upgrade vacuum gas oil (VGO) for use as an ethylene feedstock. The process differs from conventional hydrocracking processes in that the Unicracking/FPP operates at lower pressures and temperatures and at a once-through conversion of about 40 to 60%. Hydrocracked VGO produced by the Unicracking/FPP has steam cracking characteristics and yields resembling that of full range naphtha in ethylene production.
In comparing the ethylene values from several liquid feedstocks, it appears that hydrocracked VGO has an economic advantage over full range naphtha, but it is not as economical a feedstock as hydrodesulfurized VGO (light H2 absorption). Technically, however, hydrocracked VGO has many desirable properties as an ethylene feedstock which hydrodesulfurized VGO lacks.