saponification of ethyl acetate by sodium hydroxide in a continuous stirred reactor cstr

1. Saponification of Ethyl Acetate by Sodium Hydroxide in a Continuous Stirred Reactor (CSTR) Kurt Spies Trevor Carlisle ChE 414 Winter 2005

3. Requested Information Information Contained The procedures and results of the saponification experiment Audience Peers Supervisors Educational Leaders Peers- for information about the process and success for possible experimental recreation Supervisors- for information about how successful the lab was and to confirm the correct lab format was followed Educational Leaders- to verify the education of senior engineers and to thoroughly test their understanding of the lab Peers- for information about the process and success for possible experimental recreation Supervisors- for information about how successful the lab was and to confirm the correct lab format was followed Educational Leaders- to verify the education of senior engineers and to thoroughly test their understanding of the lab

4. Objectives Develop calibration curves for conductivity Determine rate constant using batch reactor Evaluate the CSTR reaction rate as a function of residence time

5. Project Planning and Execution Planning Developed initial project plan Only deviation included an additional lab session Execution Lessons/Thoughts Plan first lab session before entering the room Prepare to put in sufficient out of lab time into project to make lab time efficient

6. Team member roles Trevor- Operations Manager Responsible for the operation of the CSTR accountable for data collection In charge of making sure experiment is accurate and follows correct procedures Kurt- Team Leader/Safety Manager Identify safety issues Develop the safety plan Monitor safe lab behavior Develop project plan Ensure lab work moves forward Responsible for the operation of batch reactor

7. Background and Experimental Methods The Irreversible Reaction

8. Logical Experimental Organization Calibration Batch Experiment CSTR Experiment

9. Conductivity Calibration

10. Calibration Procedure Prepared and standardized 0.1M NaOH Solution Diluted solution to various concentrations Fine-tuned conductivity using calibration probe Measured Conductivity of different solutions

11. Calibration Data/Results

12. Calibration Conclusions 1) Calibration curves for conductivity cells match well with a linear approximation [concentration NaOH M] = 0.00440*[conductivity]

13. Batch Reactor

14. Theoretical Batch Calculation Alkaline Hydrolysis of Ethyl Acetate is a second order reaction To solve using graphical methods

15. Experimental Batch Design Three Experimental Types Equal molar concentrations Significant excess Sodium Hydroxide Significant excess Ethyl Acetate Erlenmeyer Flask ~100 mL solution Hot water bath ~50OC Mixed with conductivity probe

16. Equal Molar Concentrations

17. Equal Molar ConcentrationsResults Experimental Rate Constant from Data Theoretical Experimental Rate Constant from Tsujikawa and Inoue Theoretical Experimental Rate Constant from Mata-Segreda

18. High Concentration of Sodium Hydroxide

19. High Concentration of Sodium Hydroxide Results Slope of experimental line excluding bottom points m=k(CB0-CA0)=0.00760 (+/- 0.000129)

20. High Concentration Ethyl Acetate

21. High Concentration of Ethyl Acetate Results Slope of experimental line only including reaction region of first few points m=k(CB0-CA0)=0.0374 (+/- 0.0044)

22. What accounts for theoretical and empirical differences? Overall rate constant consistent with theoretical data Initial concentration different then planned

23. Equal Molar Concentrations

24. The Continuous Stirred Tank Reactor Add picture of TowerAdd picture of Tower

25. Theoretical CSTR Calculation Second order mixed flow reactor Graphical Solution

26. Experimental Design for CSTR Filled chemical reservoirs with equal concentration sodium hydroxide and ethyl acetate Preformed experiment with different flow rates with different concentrations

27. CSTR Data

28. CSTR Results The theoretical information for the CSTR should be the same rate constant Our experimental data contains considerable noise and does not conform to any experimental trend for determining the order of reaction

29. CSTR Data

30. CSTR Results Our experimental data can be approximated by a inverse relationship This makes sense because as the resonance time increases the rate should approach that of the batch reactor

31. What accounts for theoretical and empirical differences? The CSTR reaction has significant noise in the reaction and the order is difficult to experimentally confirm The flow rates for the CSTR feeds may not be correctly calibrated

32. Experimental Conclusions 2) Batch reaction information suggests the reaction rate constant is 3) Experimental data suggests the correlation between resonance time and reaction rate is

33. Recommendations Leave more time for CSTR data collection Flow rate calibrations Solution prep Temperature adjustment Use volumetric glassware as much as possible Gather sufficient technical information about experiment

34. Questions?...

35. References �Density of Water: Vapor Pressure of Water�. Retrieved February 15, 2005 from the World Wide Web: http://www.ncsu.edu/chemistry/resource/ H2Odensity_vp.html �Kinetics: Alkaline Hydrolysis of Ethyl Acetate�. Retrieved January 29, 2005 from the World Wide Web: Http://www.uni-regensburg.de/fakultaeten/nat_fak_IV/ organische_chemie/didaktik/keusch/chembox_etae_e.htm Levenspiel, Octave. 1999. Chemical Reaction Engineering (3rd Ed). United States of America: John Wiley & Sons Inc. Segreda-Mata, Julio F., �Hydroxide as General Base in the Saponification of Ethyl Acetate�. Journal of American Chemical Society, 124: 10: 2259-2262 Traceable Expanded Range Digital Conductivity Meter Instructions. Model VWR 23226-523. 2000 Control Company. Tsujikawa, Hiroo, and Inoue, Hakuai. �The Reaction Rate of Alkaline Hydrolysis of Ethyl Acetate�. Bulletin of the Chemical Society of Japan, 39: 1837-1842