Gas oils (petroleum), hydrodesulfurized heavy vacuum; Heavy Fuel oil; [A complex combination of hydrocarbons obtained from a catalytic hydrodesulfurization process. It consists of hydrocarbons having carbon numbers predominantly in the range of C20 through C50 and boiling in the range of approximately 350 °C to 600 °C (662 °F to 1112 °C). This stream is likely to contain 5 wt. % or more of 4- to 6-membered condensed ring aromatic hydrocarbons.]