Technology Unit

Bottom fraction from the C₆/C₇ separator column (C₇⁺) is fed to the deoctanizer.
Top fraction of deoctanizer is benzene-depleted pyrolysis gasoline (C₇-C₈) having Benzene content less than 1.5%.
It is a naphtha range product with a high aromatic content used for gasoline blending or feedstock for BTX extraction unit.
Bottom from the deoctanizer is a C₉⁺ rich mix of heavy hydrocarbons from C₉ to C₁₅.

Source: Y.A. Sastry & Uday Krishna Dy, DUAL FEED CRACKER UNIT & ASSOCIATED UNIT, ONGC Petro additions Limited (OPaL), Uploaded on 28^th Jan 2018 on SCRIBD.