VGO—See Vacuum gas oil

VGO Isomax [Vacuum gas oil] A hydrodesulfurization process adapted for treating vacuum gas oil, a petroleum fraction. Developed by Chevron Research Company in the early 1970s. In 1972, five plants were in operation and six were under construction. See also RDS Isomax and VRDS Isomax. 

The FCC process is the most important refinery process mainly for the production of gasoline from heavy petroleum fractions, such as atmospheric and vacuum gas oil (VGO). In the FCC unit, the long hydrocarbons are cracked in the 480—540°C temperature range over zeolite catalysts to smaller n- and i-parafiins, n- and i-olefins, and aromatics. Conventional FCC feedstocks are relatively aromatic, with a high sulfur and nitrogen content, in contrast to FT waxes that are highly paraffinic with extra-low aromatics content (<1 wt%) and viitually zero sulfur (<5 ppm) (see Table 18.4). The development therefore of new catalyst formulations, as well as optimization of the overall process parameters, are both very critical to optimize the yield and quality of FCC products from FT waxes. 

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