Determining Reaction Rate Constant in A Continuous Stirred Tank Reactor Report u will find my report u should complete it.

attached u will find 2 example reports, use them only to know how to write the report, how to format the report, and dont copy from them. u may paraphrase but i need new ideas not only ideas on example reports. u will talk about my results and analyze it in technical way. ( u should be familiar with excel and its analysis)

Don't use plagiarized sources. Get Your Custom Essay on

Determining Reaction Rate Constant in A Continuous Stirred Tank Reactor Report u will find my report u should complete it.
attached u will find 2 example

Just from $13/Page

all data and results are done by me and they are attached in excel file, dont use other results from web or example reports!

sections should be completed: Abstract, Results and conclusion.

abstract:

Key features of the report in about 250 words (quarter page, single spaced.)

Reason for the study (often left out, especially when it was assigned is the reason)

Experimental objective

Equipment and methods used think unique and novel, think scale

Types and ranges of data collected think experimental design

Principal results

Major conclusions

——————————————————————————————————–

Results and Discussion (can be two sections) .

Presentation of the data

Presentation of all calculated results

Discussion of the meaning of the results

——————————————————————————————————

conclusion

A conclusion paragraph contains a description of the purpose of the experiment, a discussion of your major findings, an explanation of your findings, and recommendations for further study

please add data and results to the appendix section just like the way its done in example reports

u need to talk in past tense in all sections. dont forget to number tables and figures the same way in example reports.

if the report is a paraphrase only from examples, i will not accept it at all.

just add more, fix things, ask if you lost Saponification of Ethyl Acetate by

Sodium Hydroxide in a CSTR

Abstract

This comprehensive lab report is prepared to demonstrate the reaction rate constant (k) as a

function of temperature. It also assesses the optimal temperature required to run the continuously

stirred tank reactor (CSTR). The lab experiment is aimed at determining the reaction rate

constants at different temperatures between 30o and 40o. For this, saponification of ethyl acetate

by sodium hydroxide is conducted using a continuously stirred tank reactor (CEM-MLII CSTR).

In this lab, the Arrhenius equation is applied to determine both the activation energy and the

frequency factor. The experimental results of the activation energy are then compared with the

activation energy from theoretical calculations and finally, the percentage errors calculated. This

report presents the introduction, theory, methodology, collection of raw data, analysis of data

collected, calculations of experimental results, discussions, and lastly the conclusions. The

conclusions provided herein are based on the experimental results obtained and how this

laboratory activity fulfilled the intended objectives.

Table of Contents

Introduction ……………………………………………………………………………………………………. 4

Objective ………………………………………………………………………………………………………… 4

Theory ……………………………………………………………………………………………………………. 5

Experimental Method ………………………………………………………………………………………. 9

Equipment …………………………………………………………………………………………………… 9

Experimental Design…………………………………………………………………………………… 10

Anticipated Results/Discussion
..
..
..11

Conclusion
14

2

Appendix
.
..16

Introduction

When designing a chemical reactor, there are three common reactors to choose from: a batch

reactor, a plug flow reactor (PFR), and a continuously stirred tank reactor. A batch reactor has no

flow in or out of the reactor, a plug flow reactor has continuous flow through a tube, and a CSTR

has continuous flow in a tank that is being constantly stirred to create a uniformly mixed solution.

The reaction kinetics varies in each of these reactor types, resulting in different reaction rates and

sizing equations. In this lab, the reaction kinetics of a CSTR were investigated. What makes the

CSTR unique is the constant flow and the continuous mixing of the chemicals during the reaction.

Continuously stirred tank reactors are common throughout the chemical industry and are regularly

seen in both the pharmaceutical, gas, and oil industries. However, experimental researches indicate

that CSTR has the lowest conversion per unit volume as compared to all the other reactors (Fogler,

1999).

The lab results are important because they demonstrate the reaction rate constant (k), as a function

of temperature and thus changes as reaction temperature increases or decreases (Dios, 2002). This

is important for anyone who is attempting to use this reaction to create valuable products, because

of the higher conversion rates, the higher the profit. The data obtained from this experiment could

be used to determine the optimal temperature required to run the reactor. This is achieved by

3

comparing the same reaction using different types of reactors such as batch or packed bed reactor

with an objective of determining the reactor with the highest conversion.

Objective

In this lab, the saponification of ethyl acetate using sodium hydroxide was completed in a

continuously stirred tank reactor. Using the conventional kinetic equations for a CSTR, the

objective of this experiment was to determine the reaction rate constant at different temperatures

between 30o and 40o. Once the reaction rate constants were calculated, the next objective was to

find the relationship between the reaction rate constant and temperature and to determine if the

relationship is linear on an Arrhenius plot. Using this Arrhenius equation described in the theory

section, both the frequency factor and activation energy were calculated for the reaction in the

CSTR.

In order to ensure the experimental readings and calculations are reasonably accurate, a simple

statistical analysis of the data was performed. The experimental calculation of the activation

energy was compared with the activation energy from the instruction manual by calculating the

percent error and ensuring the error wasnt too large.

Theory

The saponification of ethyl acetate using sodium hydroxide is defined by the following chemical

equation:

NaOH + H3COOC2H5 ? CH3COONa + C2H5OH

(Eq. 1)

In which sodium hydroxide reacts irreversibly with ethyl acetate to create both sodium acetate and

ethyl alcohol. This reaction can be considered to be equimolar and first order for both sodium

hydroxide and ethyl acetate. Overall, the reaction can then be considered to be second order

between the concentration limits of 0.0 M – 0.1 M and the temperature limits of 20o 40o.

4

In a CSTR, the reaction will eventually reach a steady state once a certain conversion of the

starting reagents, sodium hydroxide, and ethyl acetate, has taken place. Steady-state conditions

can vary based on multiple factors including the volume of the reactor, reactor temperature, flow

rate, and concentration of reagents. Once steady state is reached, the reaction rate constant can be

calculated using reactor kinetics

In order to calculate the specific reaction rate constant (k), consider the overall mass balance for

the reactor. The overall mass balance at steady state may be written as:

Input + Generation Output – Consumption = Accumulation

(Eq.2)

For reactant a in a reactor of volume V, the accumulation terms go to zero in the mass balance,

such that,

??(????1 )

????

=0

(Eq. 3)

The reaction rate is given as r = k[A]m[B]n and therefore,

??(????1 )

????

= ?? ? ??0 ? ?? ? ?? ? ??1 2

(Eq. 4)

Where F is the total flow rate, V is the reactor volume, a0 is the sodium hydroxide concentration

in the mixed feed, and ??1 is the sodium hydroxide concentration in the reactor at time t which was

squared since both sodium hydroxide and ethyl acetate were an equimolar feed. This can be

simplified further to solve for the specific rate constant, k, using the following notations:

??=

??

?

??

??0 ???1

??1

2

=

(???? +???? )

??

?

(??0 ? ??1 )

??1 2

(Eq.5)

5

where Fa is the volumetric flow rate of sodium hydroxide, and Fb is the volumetric flow rate of

ethyl acetate. This simplification is possible because it is assumed that the volume of species ?? in

the reactor remains constant with respect to V due to continuous mixing, making the left side of

Eq. 4 equal to zero. The reaction term in Eq. 4 is based on the reaction kinetics of a CSTR and is

simplified on the assumptions that the reactor is well mixed (allowing the volume to be assumed

to act as a constant) and that the concentration of species a and species b are equal to each other.

The concentrations in the reaction were measured using conductivity measurements with a

conductivity probe placed inside of the reactor. The following equations convert the conductivity

measurements to concentrations:

?0 = 0.195[1 + 0.0184(?? ? 294)] ? ??0

(Eq.6)

?? = ???? = 0.070[1 + 0.0284(?? ? 294)] ? ???

(Eq.7)

? ??

??1 = (??? ? ??0 ) [? 0? ? 1 ] + ??0

0

?

(Eq.8)

Where ?0 is the initial conductivity of the solution, a0 is sodium hydroxide concentration in the

feed stream, T is the temperature, ?? is the total conductivity measured at time infinity, ?c? is the

conductance of sodium acetate at time infinity, c? is the concentration of sodium acetate at time

infinity, a1 is the concentration of sodium hydroxide in the tank at time t, an? in the reactor at time

infinity, and ?1 is the conductivity at time t. These equations are derived from experimental data

from the same CSTR reactor and are used to solve for a1.

The total conductivity at time infinity is equal to ?c? because ?a? is equal to zero. The conversion

can be calculated for every time point by using a set of known constants Fa, Fb, a?, b?, c?, T and V.

Where Fa is the volumetric flow rate of sodium hydroxide, Fb is the volumetric flow rate of ethyl

acetate, a? is the concentration of sodium hydroxide in the feed vessel, b? is the concentration of

ethyl acetate in the feed vessel, c? is the concentration of sodium acetate in the feed vessel, T is

the temperature and V is the reactor volume. Note that the concentration of the incoming reagents

is calculated using the following equation:

6

??0 = ??

????

?? +????

? ????

(Eq 9)

Since both sodium hydroxide and ethyl acetate are being fed at the same rate, reaction order, and

concentration, neither is limiting so the concentration of sodium hydroxide in the mixed feed (a0)

is assumed to equal the concentration of sodium acetate at time infinity (c?) since the reaction is

irreversible. The conductivity of the initial sodium hydroxide concentration (?0) can be calculated

using the relationship seen in (Eq. 6).

This is equal to the conductivity of the initial solution before any reaction occurs because ethyl

acetate does not contribute any conductance. When t equals infinity, it is assumed that the

concentration of sodium acetate is equal to the initial concentration of sodium hydroxide and at

time infinity the concentration of sodium hydroxide equals zero. Therefore, the conductivity of

sodium hydroxide at t equals infinity is equal to zero. The conductivity of sodium acetate at t

equals infinity can be calculated using the relationship seen in (Eq. 7). These variables can then be

used to calculate the sodium hydroxide concentration at a given time t (a1) using (Eq. 8).

The conversion of sodium hydroxide (xa) can then be calculated using the following:

???? =

??0 ? ??1

??0

(Eq.10)

The conversion values calculated can be used to determine when the reaction has reached a steady

state. Steady state can be identified when the conductance and conversion plateau for an extensive

amount of time. Once at steady state, the specific reaction rate constant can then be calculated

using (Eq. 5).

Using the reaction constant k calculated for three different temperatures, the Arrhenius equation

can be applied to determine the activation energy. The Arrhenius equation is commonly written as

follows:

7

???

?? = ???? (????)

(Eq. 11)

Where k is the reaction constant, A is the Arrhenius constant, E is the activation energy, R is the

gas constant, and T is the temperature that the k value was calculated at. This equation can be

rearranged to produce the following:

??

1

ln ?? = ln ?? ? (??) ? (??)

(Eq. 12)

By plotting ln k vs 1/T for each temperature, a linear relationship should be formed with a slope

equal to -E/R and a y-intercept equal to ln A. Therefore the activation energy (E) is equal to the

following:

?? = ?(??)(??)

(Eq.13)

Where R is the gas constant and m is equal to the slope of the fitted linear trend line. Note that the

Arrhenius constant (A) is equal to the following:

?? = ????

(Eq.14)

Where b is the y-intercept of the fitted linear trend line

Experimental Method

Equipment

8

Figure 1: apparatus for CEM MKII Continuous stirred tank reactor (Armfield, 2013).

The reactor was set up on a stand consisting of three pillars, with one pillar facing forward in the

proper configuration. The reactor encapsulates a heat exchange coil that was used to heat the fluid

contained within the reactor. Two reagent feed tubes were attached to the bottom left of the reactor

which allowed the reagents to be added to the reactor from two reagent bottles situated next to the

reactor. The amount of each reagent added to the reactor was controlled by adjusting the flow rate

of each reagents peristaltic pump. An adjustable standpipe situated within the reactor could be

used to change the volume of the reactor from a minimum volume of 1.0 liters to a maximum of

2.0 liters. To measure the volume of the reactor at a given standpipe height, water was added to

the reactor until it overflowed through the standpipe. Once the water had stopped flowing into the

pipe, the water was released through the valve on the underside of the reactor into a graduated

cylinder. An agitator connected to a stirrer shaft was run by a stirrer motor to mix the reagents in

the reactor. Four baffles were placed along the outside of the reactor to prevent a vortex from

forming within the reactor. Both temperature and a conductivity sensor were attached to the top of

the reactor so that they were submerged when the reactor was filled with the reagents. These were

attached by loosening the appropriately sized gland and inserting the sensor until it lightly rested

on the bottom of the reactor and before retightening the gland. Note that the temperature sensor

9

gives an accurate temperature reading so that the heat of the heat exchange coil can be modified

and the conductivity sensor gives readings of ion concentration which enables the extent of

reaction to be determined.

Experimental Design

Ethyl acetate and sodium hydroxide, each at a concentration of 0.1 M, were added to the reactor

at a rate of 40 mL/min each. Within the reactor, the solution was mixed and heated to maintain a

constant temperature. In order to calculate the specific rate constant, k, the conductivity, and

conversion were recorded every 30 seconds until steady state was reached. The reaction was

assumed to be at steady state once the conductivity and conversion reached a constant value. Note

that the conductivity and conversion will be considered constant when it stays within a ±1% margin

for longer than two minutes. It was estimated that the reaction would take somewhere between 30

and 45 minutes to reach a steady state, so the CSTR was set to run for 1 hour. The conductivities

were recorded on an excel spreadsheet and later evaluated to calculate the rate constant. This

process was completed for the same reaction at three different temperatures of 30o, 35o and 40o.

While collecting data, the group of engineers prepared the solutions to be used for other

temperatures so as to complete the experiment swiftly.

Anticipated Results/Discussion

The conductivity was measured at various times during the reaction in order to determine the

specific rate constant. The initial conductivity was measured and the reaction run until the

conductivity measurements remained constant for around three to four minutes. Table 1 indicates

the different state conductivities of the reaction.

Table 1: Initial, infinite, and steady-state conductivities of the reaction

T

30°C

35°C

40°C

10

?ao [mS]

11.27

11.34

12.9

?a? [mS]

4.34

4.39

5.25

?1 [mS]

5.80

6.80

6.86

The steady state and initial conductivity and concentrations were utilized in order to solve for the

value of a1 which is the sodium hydroxide concentration at time t (Eq. 8). The conversion can also

be found at each data point for all three trials for a1 (Eq. 10) in order to demonstrate the temperature

effect on conversion at each given time in a reaction (Figure 2). Note, when conversion stops

increasing, steady state has been achieved.

Conversion of Naoh

1

0.9

0.8

X NaOH

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0

0

200

400

600

800

1000

1200

1400

time/sec

* T29.5°C * T33.9°C * T38.6°C

Figure 1: Conversion of NaOH at various times in the reaction for each trial.

11

The concentration of sodium hydroxide at steady state was found at each temperature (Table 2),

and the specific rate constant calculated for each trial (Eq. 5).

Table 2: Concentration and conversion of sodium hydroxide and the specific rate constant at

various temperature

T

30°C

35°C

40°C

a1 [mol/dm³]

0.011

0.007

0.011

Xa

0.79

0.86

0.79

K [M-1s-1]

0.38

0.91

0.38

From there the Arrhenius relationship (Eq. 12) produces a linear plot of ln (k) vs. 1/T (Figure 3).

12

k = f (tempreture)

y = -10796x + 5.0427

0

0.00047

0.00048

0.00049

0.0005

0.00051

0.00052

0.00053

R² = 1

0.00054

0.00055

0.00056

-0.2

ln k

-0.4

-0.6

-0.8

-1

-1.2

1/T

Figure 2: The linear relationship between ln (k) and 1/T used to determine the frequency factor

(A) and activation energy (E)

The activation energy and frequency factor was found via the utilization of linear regression. Using

the regression line, the value of the activation energy was found based on the slope (Eq. 12) and

the frequency factor was found based on of the y-intercept (Eq. 13). From Figure 3, R was obtained

as 1 and thus the activation energy was calculated as

??

??

= 10796.

Therefore, the activation energy for the reaction was obtained as E = 107.96 KJ/mol. However, a

the first trial had to be removed due to abnormalities with the data.

?????????? % =

10796 ? 10849

? 100% = 0.5 %

10849

13

Conclusion

Both the experimental results and theoretical calculations for the determination of reaction rate

constants which were 0.3849

??

?????????

, 0.9066

??

?????????

, and 0.3848

??

?????????

for 30°C, 35°C, and 40°C

respectively and the activation energy matched up within the range of experimental uncertainty

with an error % of 0.5%. This concludes that either theoretical calculations or experimental results

can be applied when dealing with activation energies and frequency factors. The experimental

outcomes in this laboratory exercise were in agreement with what was predicted from the

theoretical models of activation energies in reactions. However, it had to be noted rerun of the

experiment is highly needed since only two runs were used due to abnormalities with the data in

run 1. Possible causes of that could have contributed is malfunction with the equipment,

specifically the probe during the first run. Besides that, this lab exercise is thus regarded as a

seamless and intriguing addition to the study of activation energies, frequency and reaction rate

factors

References

Sodium Hydroxide; MSDS No. 21300; Fisher Scientific: Fair Lawn, NJ, Feb 2, 2008.

14

Ethyl Acetate; MSDS No. 08750; Fisher Scientific: Fair Lawn, NJ, June 29, 2007.

Dios, Angel C. Temperature Dependance of Rate Constants. Bouman Georgetown. 2002.

https://bouman.chem.georgetown.edu/S02/lect4/lect4.htm

Fogler, H. Scott. (1999). Elements of chemical reaction engineering. Upper Saddle

River, N.J. :Prentice Hall PTR

Armfield. Continuous Stirred Tank reactor Instruction Manual. 2013

Appendix

15

Experimental Protocol:

1. Wear proper personal protective equipment before entering the lab.

2. Determine the volume of the reactor by filling the reactor with deionized water until the

overflow is achieved.

3. Once the water has stopped flowing out of the overflow tubing, empty the water in the reactor

into a graduated cylinder using the reactor release.

4. Open the Armfield software and choose the experiment with heater option.

5. Turn on the circuit breakers and RCD device then turn on the CEXC unit.

6. Prepare a 0.1M solution of ethyl acetate and a 0.1M solution of sodium hydroxide in two

separate 2.5L reagent bottles via dilution from 1.0M

7. Attach the reagent bottles to the feed tubes but do not completely tighten …

Purchase answer to see full

attachment

Why should I choose Homework Writings Pro as my essay writing service?

We Follow Instructions and Give Quality Papers

We are strict in following paper instructions. You are welcome to provide directions to your writer, who will follow it as a law in customizing your paper. Quality is guaranteed! Every paper is carefully checked before delivery. Our writers are professionals and always deliver the highest quality work.

Professional and Experienced Academic Writers

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Reasonable Prices and Free Unlimited Revisions

Typical student budget? No problem. Affordable rates, generous discounts - the more you order, the more you save. We reward loyalty and welcome new customers. Furthermore, if you think we missed something, please send your order for a free review. You can do this yourself by logging into your personal account or by contacting our support..

Essay Delivered On Time and 100% Money-Back-Guarantee

Your essay will arrive on time, or even before your deadline – even if you request your paper within hours. You won’t be kept waiting, so relax and work on other tasks.We also guatantee a refund in case you decide to cancel your order.

100% Original Essay and Confidentiality

Anti-plagiarism policy. The authenticity of each essay is carefully checked, resulting in truly unique works. Our collaboration is a secret kept safe with us. We only need your email address to send you a unique username and password. We never share personal customer information.

24/7 Customer Support

We recognize that people around the world use our services in different time zones, so we have a support team that is happy to help you use our service. Our writing service has a 24/7 support policy. Contact us and discover all the details that may interest you!

Try it now!

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Our Services

Our reputation for excellence in providing professional tailor-made essay writing services to students of different academic levels is the best proof of our reliability and quality of service we offer.

Essays

When using our academic writing services, you can get help with different types of work including college essays, research articles, writing, essay writing, various academic reports, book reports and so on. Whatever your task, homeworkwritingspro.com has experienced specialists qualified enough to handle it professionally.

Admissions

Admission Essays & Business Writing Help

An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.

Reviews

Editing Support

Our professional editor will check your grammar to make sure it is free from errors. You can rest assured that we will do our best to provide you with a piece of dignified academic writing. Homeworkwritingpro experts can manage any assignment in any academic field.

Reviews

Revision Support

If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.