Saponification of Ethyl Saponification of Ethyl acetate by Sodium acetate by Sodium

hydroxide in a Plug Flow hydroxide in a Plug Flow ReactorReactor

Lindsey KatoLindsey KatoShawna TogiokaShawna Togioka

Luke SugieLuke SugieFebruary 2, 2005February 2, 2005

Overview

Project ObjectivesProject Objectives Project Planning and ExecutionProject Planning and Execution Background and Experimental MethodsBackground and Experimental Methods Results and ConclusionsResults and Conclusions Recommendations and Future WorkRecommendations and Future Work

Project Objectives

Develop reaction kinetic data for the Develop reaction kinetic data for the saponification of ethyl acetate by sodium saponification of ethyl acetate by sodium hydroxide.hydroxide.

1.1. Develop calibration curves for electric Develop calibration curves for electric conductivity cell, using known concentrations conductivity cell, using known concentrations of reactants and productsof reactants and products

2.2. Calibration of pump settings on Plug Flow Calibration of pump settings on Plug Flow Reactor (PFR).Reactor (PFR).

3.3. Ran Batch Reactor and PFR and gathered Ran Batch Reactor and PFR and gathered kinetic rate data kinetic rate data

Project PlanningProject Planning

Roles & ResponsibilitiesRoles & Responsibilities Team Leader – Lindsey KatoTeam Leader – Lindsey Kato

• Planning agenda, Assigning tasks and goals, presentationPlanning agenda, Assigning tasks and goals, presentation Operations Coordinator – Shawna TogiokaOperations Coordinator – Shawna Togioka

• Knowledge of equipment, data collections and laboratory Knowledge of equipment, data collections and laboratory documentationdocumentation

Safety Coordinator – Luke SugieSafety Coordinator – Luke Sugie• Hazards of the Lab, chemical safety, MSDSHazards of the Lab, chemical safety, MSDS

Group: Background data collection and analysisGroup: Background data collection and analysis

Key Planning ElementsKey Planning Elements

1.1. Project Plan / Time TableProject Plan / Time Table

2.2. Learn about the lab, equipment, safety, hazardsLearn about the lab, equipment, safety, hazards

3.3. Calibration TestsCalibration Tests

4.4. Batch Reactor TestsBatch Reactor Tests

5.5. PFR TestsPFR Tests

6.6. AnalysisAnalysis

7.7. Oral PresentationOral Presentation

8.8. Written ReportsWritten Reports

Lessons LearnedLessons Learned

Some activities take longer than expectedSome activities take longer than expected Experiments don’t always run smoothly. Experiments don’t always run smoothly.

Must rethink the experimental design.Must rethink the experimental design.

Overall – Lab time was utilized and Overall – Lab time was utilized and original project plan didn’t need to be original project plan didn’t need to be altered.altered.

Background InformationBackground Information

Reaction:Reaction:Ethyl acetate+Sodium Hydroxide Ethyl acetate+Sodium Hydroxide → Sodium acetate+Ethanol→ Sodium acetate+Ethanol

CC22HH55OO22CCHCCH33 + Na-OH → CH + Na-OH → CH33COCO22Na + HNa + H33C-CHC-CH22-OH-OH

Theory: Theory:

-r-rOHOH = -dC = -dCOHOH/dt = -dC/dt = -dCEt-O-AcEt-O-Ac/dt = k*C/dt = k*COHOH*C*CEt-O-AcEt-O-Ac

A second order bimolecular reaction.A second order bimolecular reaction.

Literature ValueLiterature Value1,21,2::

kkOHOH = 0.111 L/mole-sec at 25°C = 0.111 L/mole-sec at 25°C

Irreversible reactionIrreversible reaction

EquipmentEquipment

Conductivity MeterConductivity MeterUses: measuredUses: measured

the conductivitythe conductivity

in the batch reactions in the batch reactions

and PFR experimentsand PFR experiments

Preparation: calibrated atPreparation: calibrated at

beginning of every labbeginning of every lab

period.period.

Calibration curves were constructedCalibration curves were constructed

with different concentrations ofwith different concentrations of

reactants and products.reactants and products.

EquipmentEquipment

Constant Water BathConstant Water Bath-Batch Reaction-Batch Reaction

experiments doneexperiments doneat at 25°C25°C

-Reactants were -Reactants were submerged in thesubmerged in thebath to reach temp. bath to reach temp. and then put together and then put together for the experiment.for the experiment.

EquipmentEquipment

Plug Flow ReactorPlug Flow Reactor-Packed with small-Packed with small

spherical ballsspherical balls-Bed Void Fraction-Bed Void Fraction33, , εε, of, of

~0.41 ~0.41 -Equimolar concentrations of -Equimolar concentrations of NaOH and Ethyl AcetateNaOH and Ethyl Acetate

were pumped into PFRwere pumped into PFR-Conductivity meter used to -Conductivity meter used to determine the composition determine the composition of the product stream. of the product stream. -Experiment finished once -Experiment finished once reaction reached equilibrium.reaction reached equilibrium.

ExperimentsExperiments

1.1. Testing was done on the PFR pumps to Testing was done on the PFR pumps to determine the resonance time for each pump determine the resonance time for each pump at different settings.at different settings.

2.2. Calibration curves were generated for the Calibration curves were generated for the conductivity meter for known concentrations of conductivity meter for known concentrations of reactants and products.reactants and products.

3.3. Batch reactions were done using equimolar Batch reactions were done using equimolar concentrations of reactantsconcentrations of reactants..

4.4. PFR experiments were done using equimolar PFR experiments were done using equimolar concentrations and approx. equal molar flows.concentrations and approx. equal molar flows.

Batch Reactor ExperimentsBatch Reactor Experiments

• Bath was set to 25Bath was set to 25°C°C• Reactants were measured and put in bath Reactants were measured and put in bath

separately to heat.separately to heat.• Combined reactants and conductivity Combined reactants and conductivity

measurements taken at 5 and 10 second measurements taken at 5 and 10 second intervals.intervals.

• Batches were constantly stirred for the Batches were constantly stirred for the duration of the experiment.duration of the experiment.

PFR ExperimentsPFR Experiments

• Large quantities of equimolar mixture of Ethyl Large quantities of equimolar mixture of Ethyl acetate and NaOH were prepared and placed at acetate and NaOH were prepared and placed at the inlet for each pump.the inlet for each pump.

• The pumps were set so that the flow rates of The pumps were set so that the flow rates of each of the reactants would be equal.each of the reactants would be equal.

• Conductivity Meter was connected to the PFR at Conductivity Meter was connected to the PFR at the outlet and readings were taken during the the outlet and readings were taken during the experiment.experiment.

• Experiment was finished once the conductivity Experiment was finished once the conductivity reached a steady state.reached a steady state.

Key EquationsKey Equations

Batch ReactorBatch Reactor

CCOHOH=C=CEt-O-AcEt-O-Ac

Relationship:Relationship: 1 1 = k*t + = k*t + 1 1

CCOH OH CCOHOHoo

PFRPFR

CCOHOH=C=CEt-O-AcEt-O-Ac

Relationship:Relationship:

1 1 * * X XOHOH = k* = k*ττ ττ = V/v = V/voo (Space- (Space-time)time)

CCOH OH 1-1- XXOHOH

Results – Conductivity CalibrationResults – Conductivity Calibration

Measurements were taken with pure NaOH, 50-50% Measurements were taken with pure NaOH, 50-50% concentration NaOH and Sodium acetate, and pure concentration NaOH and Sodium acetate, and pure sodium acetate.sodium acetate.

y = 106167x + 7070

R2 = 1

0

2000

4000

6000

8000

10000

12000

14000

16000

0 0.01 0.02 0.03 0.04 0.05 0.06 0.07

Results – Batch ReactorResults – Batch Reactor

The kinetic rate constant is the initial slope at The kinetic rate constant is the initial slope at the start of the experiment.the start of the experiment.

Batch Reactor Trial 5

0200400600800

100012001400

0 100 200 300 400

Tim e (s )

1/C

OH

Batch Reactor Trial 7y = 0.1737x + 16.382

R2 = 0.9965

0

5

10

15

20

25

30

35

40

0 20 40 60 80 100 120

Time (s)

Batch Reactor Trial 5 y = 0.1975x + 16.045R2 = 0.9909

0

5

10

15

20

25

30

35

40

0 20 40 60 80 100 120

Tim e (s )

1/C

OH

Batch Reactor Trial 6 y = 0.2136x + 15.436R2 = 0.9823

05

10152025

3035404550

0 50 100 150

Tim e (s)

1/C

OH

Results – Batch ReactorResults – Batch Reactor

Results - PFRResults - PFR

The flow rate of the pumps was varied to five The flow rate of the pumps was varied to five different settings for data collection.different settings for data collection.

Rlug Flow Reactor Trialsy = 0.2431x

R2 = 0.6406

12

13

14

15

16

17

18

19

20

21

22

23

60 65 70 75 80 85 90

V/Vo (s)

XO

H/(

CO

Ho

*(1-

XO

H))

Results – Batch and Plug Flow ReactorResults – Batch and Plug Flow Reactor

• Batch Reactor showed a kinetic rate Batch Reactor showed a kinetic rate constant of ~0.19 L/mole-secconstant of ~0.19 L/mole-sec• Tests showed the rate constant to be 2 times Tests showed the rate constant to be 2 times

higher than literary value, but was consistent higher than literary value, but was consistent for all trials.for all trials.

• Plug Flow Reactor showed the kinetic rate Plug Flow Reactor showed the kinetic rate constant to be ~0.24L/mole-secconstant to be ~0.24L/mole-sec• The experimental value was 2.5 times higher The experimental value was 2.5 times higher

than the literary value.than the literary value.

Major ConclusionsMajor Conclusions

1.1. The kinetic rate constant for batch is 0.19 L/mole-The kinetic rate constant for batch is 0.19 L/mole-sec sec

2.2. The kinetic rate constant for a PFR is 0.24 L/mole-The kinetic rate constant for a PFR is 0.24 L/mole-sec.sec.

3.3. The literary value was 0.111 L/mole-secThe literary value was 0.111 L/mole-sec4.4. Discrepancies in the experiment and literature could Discrepancies in the experiment and literature could

be caused from slightly unequal concentrations, be caused from slightly unequal concentrations, incorrect molar flow rates, or conductivity incorrect molar flow rates, or conductivity calibration problems.calibration problems.

5.5. Reaction data showed characteristics of being Reaction data showed characteristics of being second order as theory predicted.second order as theory predicted.

Lessons LearnedLessons Learned

Some activities take longer than expectedSome activities take longer than expected Experiments don’t always run smoothly. Experiments don’t always run smoothly.

Must rethink the experimental design.Must rethink the experimental design.

Overall – Lab time was utilized and Overall – Lab time was utilized and original project plan didn’t need to be original project plan didn’t need to be altered.altered.

Future RecommendationsFuture Recommendations

• More careful research done early on, so More careful research done early on, so work in the lab could go more smoothly.work in the lab could go more smoothly.

• Run more trials on the PFR and batch to Run more trials on the PFR and batch to confirm data.confirm data.

• Plan out your lab times carefully and set Plan out your lab times carefully and set reasonable goals and be safe.reasonable goals and be safe.

ReferencesReferences

1.1. Bamford, C.H. and C.F.H. Tipper. 1970. Bamford, C.H. and C.F.H. Tipper. 1970. Comprehensive Chemical Kinetics v.10Comprehensive Chemical Kinetics v.10. Elsevier . Elsevier Publishing Company. New York. p.169.Publishing Company. New York. p.169.

2.2. Batch Reactor Kinetic Analysis. Jan 15, 2005. Batch Reactor Kinetic Analysis. Jan 15, 2005. www.csupomona.edu/~tknguyen/che435/Notes/P5www.csupomona.edu/~tknguyen/che435/Notes/P5-kinetic.pdf-kinetic.pdf

3.3. Levenspiel, Octave. 1998. Engineering Flow and Heat Levenspiel, Octave. 1998. Engineering Flow and Heat Exchange. Plenum Press. New York. p.128.Exchange. Plenum Press. New York. p.128.

Questions?Questions?