1. Composition of Methanol- Water Batch Distillation Prepared by: Jason Hixson Don Scott Michael Hickey September 20, 2005

2. Objective Determine the composition of liquid methanol-water binary system at equilibrium based on temperature in a distillation column.

3. Vapor-Liquid Equilibrium Diagram Antoine Equation Vapor Pressure in mmHg of methanol and water. T is the absolute temperature A, B, and C are constants.

4. Antoine Constants Are calculated using using the known temperatures and vapor pressures from Perry’s Chemical Engineers Handbook. WaterMethanol

5. Antoine Constants Arbitrary values are then chosen for A, B, and C giving an incorrect vapor pressure. Excel solver is then used to find values of A, B and C for both methanol and water which gives the correct pressure.

6. Van Laar’s Model Gamma correction factors for non-ideal system.

7. Gamma Correction Factor Ideal Gas Constant = 1.987 cal/K*g-mol Temperature (K) A and B are constants

8. Using data from Perry’s where P is 760 mmHg the constants A and B can be calculated using solver in Excel Gives

9. Raoult’s Law Vapor Liquid

10. Set Up Set arbitrary temperature = (P calc -P actual ) Use Solver to minimize DIF cell by changing T(C).

11. Liquid Vapor VLE Diagram

12. Composition Calculation Using WFIT Program 0.38652+0.39727*B2-0.012737*B2^2+0.00013528*B2^3-(0.00000048036)*B2^4)+1%

13. Reboiler Composition vs Time 0% Reflux 75% Reflux 2500 W Initial x m : 23%Initial V m : 16.86 L

14. Tray # 12 Composition vs Time 0% Reflux 75% Reflux 2500 W

15. Tray # 11 Composition vs Time 0% Reflux 75% Reflux 2500 W

16. Tray # 10 Composition vs Time 0% Reflux 75% Reflux 2500 W

17. Tray # 9 Composition vs Time 0% Reflux 75% Reflux 2500 W

18. Tray # 8 Composition vs Time 0% Reflux 75% Reflux 2500 W

19. Tray # 7 Composition vs Time 0% Reflux 75% Reflux 2500 W

20. Tray # 6 Composition vs Time 0% Reflux 75% Reflux 2500 W

21. Tray # 5 Composition vs Time 0% Reflux 75% Reflux 2500 W

22. Tray # 4 Composition vs Time 0% Reflux 75% Reflux 2500 W

23. Tray # 3 Composition vs Time 0% Reflux 75% Reflux 2500 W

24. Tray # 2 Composition vs Time 0% Reflux 75% Reflux 2500 W

25. Tray # 1 Composition vs Time 0% Reflux 75% Reflux 2500 W

26. Reflux Composition vs Time 0% Reflux 75% Reflux 2500 W Collected 1.69 LCollected 6.38 L

27. Conclusions At 0% reflux the amount of distillate collected was larger than 75% reflux. At 75% reflux the purity of methane was a much higher quality. If quality is more important then a high reflux percentage is needed. If quantity and timeliness is more important then a low reflux is needed.

28. QUESTIONS ?