1. Jonathan Peters Miguel Bagajewicz

2.  Conventional Distillation  Pre-flash Fractionation  Previous Work  Mission Statement  Optimization  Results: Light Crude  Results: Heavy Crude

3. Inject steam in the bottom Feed is desalted and heated 5 products

4.  ASTM standard - specifies product purity  Defined as a percentage of the product that boils at a specific temperature  Naphtha – 95% D86 182 o C

7. Minimum gap refers to the lowest temperature difference required to obtain the desired separation Gaps greater than the minimum are acceptable Boiling Point Temp.

11. draw steam product return 4 trays No reboiler or condenser Inject steam to control separation Draw from column Return to tray above draw

12. Add side columns

13. Add pumparounds to reduce heat utility

14. Simulation PFD for conv. optimization

15. 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

16. Heat Demand-Supply Diagram Shift heat from PA1 to PA2

17. Heat Demand-Supply Diagram Shift heat from PA2 to PA3

18. Heat Demand-Supply Diagram Some heat demand still remains

19. Heat Exchanger Network Crude Unit PFD with HEN

20. Pinch Calculator Replace HEN with a “black box”

21. Pinch Calculator Add a preflash drum

22. 34 Trays Total Tray 15 Heated to 163 o C Tray 1 Send vapor to Tray 15

23. Pre-flash reduces vapor-liquid holdup

25. Residue/feed ratio decreases with an increasing K value

26.  Concluded that pre-flash was only more energy efficient if gas oil yield was reduced  Steam cannot replace all carrier effect of light components

27.  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

28. Set pre-flash temperature

29. Vapors are sent to column

30. Set pumparound duty

31. Red - simulation did not converge, readjust

32. Blue – simulation converged

33.  Light Crude  Heavy Crude

34.  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

35. For the light crude, the new design increases gas oil yield from pre-flash design, but not from conventional

36. New design reduces min. heat utility

37. New design steam usage is about the same as conv.

38. New design increases gas oil yield over the conventional case

39. New design reduces min. heat utility

40. New design steam usage is about the same as conv.

41. Light Crude Heavy Crude New design increases profit from conv. for heavy crude

42.  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

43. 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).

44. Stephanie English Jesse Sandlin Ernest West Chris Wilson Su Zhu Dan Dobesh