Pretreatment is important because a reduction in the feed stream sulfur content translates to lower sulfur levels achieved in FCC gasoline product which helps to meet the increasingly stringent global clean fuels specifications. For example, a 1,200 ppm sulfur concentration in the FCC feed is converted to approximately 60 ppm sulfur content in FCC product gasoline. Thoughtfully designed FCC pretreat hydrotreaters may remove the need for further downstream hydrotreating to reduce fuel sulfur content.
Pretreating the FCC feed also helps to minimize octane losses associated with saturating olefins and aromatics which are undesirable results of hydrotreating the FCC product streams. The lower sulfur content of the FCC feed also translates to lower SOx emissions from the FCC regenerator further assisting the refiner in being an environmental steward.