Process and equipment design improvements, particularly with regard to crude unit and delayed coker distillation column performance, can reduce metals content. Optimization of components, including vacuum column stripping section and coker main fractionator wash zones, should be considered.
Managing vanadium in FCC feed streams originating from atmospheric crude, vacuum crude, and the delayed coker is becoming more important as refiners increase the amount of high vanadium crudes imported from Canada, Mexico, and Venezuela. Vanadium reduces hydrotreater run-length and lowers FCC conversion due to its impact on catalyst activity. Total vanadium in FCC feed streams can be as high as 5 to 10 ppmw --- depending on crude oil, vacuum column cutpoint, unit process design, and distillation unit operation and equipment design. Experience shows that total gas oil metals can be reduced by 20 to 50% or heavy vacuum gas oil (HVGO) product yield can be increased for a given metals target by optimizing primary distillation system performance.
A 22.0°API Bachequero Field (BCF) blend will be used to illustrate the potential metals reduction based on optimized primary distillation design and operation...