Residues (petroleum), catalytic reformer fractionator; Heavy fuel oil (A complex combination of hydrocarbons produced as the residual fraction from distillation of the product from a catalytic reforming process. It consists of predominantly aromatic hydrocarbons having carbon numbers predominantly in the range of C 10 through C 25 and boiling in the range of approximately 160 to 400 °C. This stream is likely to contain 5 wt % or more of four- or six-membered condensed ring aromatic hydrocarbons.)