CBE 417 “Unit Operations”

1. CBE 417 “Unit Operations” Lecture: 5 12 Sep 2012

2. Overview • Brief thermodynamics review • Binary flash with energy balance • Multicomponent flash Separation Factor (eqn 1-4; Seader et.al.) Relative Volatility (eqn 2-21; Seader et.al.)

3. Other Equilibrium Diagrams: P = 1.013 bar T = various oC Benzene - Toluene Y vs X diagram T vs X or Temp vs Composition

4. Other Equilibrium Diagrams:

5. Y vs X Diagram (LLE)

6. Effect of Pressure:

7. Effect of Pressure: • Seader & Henley (2006)

8. Other Equilibrium Diagrams:

9. CBE 417 “Chemical Engineering Equilibrium Separations” Lecture: 6 14 Sep 2012

10. Overview • Brief thermodynamics review • Binary Flash with material balance and energy balance • Sequential solution • Simultaneous solution • Multicomponent Flash

11. Binary Flash Overall mole balance mole balance on a mole balance on b equilibrium eqn for a mole balance on a

12. Binary Flash Flash separation: Specify: Find: a = n-pentane b = n-hexane

13. Binary Flash Overall mole balance mole balance on a mole balance on b equilibrium eqn for a mole balance on a

14. Binary Flash Flash separation: Specify: Find: a = n-pentane b = n-hexane

15. Binary Flash Graphical Solution: mole balance on a solve for ya “Operating Line”

16. Binary Flash Graphical: Equilibrium curve y = x Solution! What if f is unknown, but T is known? Za Limits: f = 0 f = 1

17. Binary Flash Energy Balance EB on CV:

18. Other Equilibrium Diagrams:

19. Alternative Thermodynamics Older (hand methods): Raoult’s law Relative Volatility (VLE): Aside (couple with MB)

20. Separation Factor or Relative Volatility

21. Effect of Pressure: • Seader & Henley (2006)

22. Constant Relative Volatility?

23. Alternative Thermodynamics Ki with multicomponent flash: Into MB: Sequential solution: suggestions p 35-37 (Rachford-Rice Eqn) Simultaneous solution technique: suggestions p 40-43

24. Sizing Flash Drums

25. Simulators Flash input: Sensitivity Analysis: Design Spec:

26. Questions?