Heat Demand-Supply Diagram Heat supply and demand are represented by areas. Supply can only cover demand on the left. Uncovered demand is satisfied by utilities (red area). Shift heat from condenser to PA1 to reduce Utility
Heat Demand-Supply Diagram Shift heat from PA1 to PA2
Heat Demand-Supply Diagram Shift heat from PA2 to PA3
Heat Demand-Supply Diagram Some heat demand still remains
Residue/feed ratio decreases with an increasing K value
Concluded that pre-flash was only more energy efficient if gas oil yield was reduced Steam cannot replace all carrier effect of light components
Previous work studied pre-flash fractionation with the addition of one flash drum This work studies the effect of pre-flash fractionation with the addition of multiple flash drums in both light and heavy crude systems Systematic optimization of pre-flash fractionation
In the process of investigating this, a new design was proposed Technical details of this new design cannot be made public at this time We will only disclose the impact of the new design in terms of new flow rates of products and the economics
For the light crude, the new design increases gas oil yield from pre-flash design, but not from conventional
New design steam usage is about the same as conv.
Light Crude Heavy Crude New design increases profit from conv. for heavy crude
Multiple pre-flashing does not reduce the minimum heat utility ◦ Gas Oil flow rate is reduced and Residue is increased The new design shows noticeable energy improvement and gas oil recovery from conventional distillation for heavy crudes Further studies are warranted
1. Bagajewicz M. and S. Ji. Rigorous Targeting Procedure for the Design of Crude Fractionation Units with Pre-Flashing or Pre-Fractionation. Industrial and Engineering Chemistry Research, 41, 12, pp. 3003-3011 (2002). 2. Bagajewicz M. and S. Ji. Rigorous Procedure for the Design of Conventional Atmospheric Crude Fractionation Units Part I: Targeting. Industrial and Engineering Chemistry Research. Vol. 40, No 2, pp. 617-626 (2001).
Stephanie English Jesse Sandlin Ernest West Chris Wilson Su Zhu Dan Dobesh