NATIONAL INSTITUTE OF TECHNOLOGY, TIRUCHIRAPPALLI – 15
DEPARTMENT OF CHEMICAL ENGINEERING
CHEMICAL REACTION ENGINEERING LABORATORY MANUAL
Experiments Order
1) Adiabatic Reactor
2) Batch Reactor –I
3) Batch Reactor –II
4) Mixed Flow Reactor
5) Mixed Flow Reactor in Series
6) Plug Flow Reactor
7) Mixed Flow Reactor followed by Plug Flow Reactor
8) RTD Studies in a Plug Flow Reactor
9) RTD studies in a Mixed Flow Reactor
10) Sono-chemical reactor
Department of Chemical Engineering
1
1. ADIABATIC REACTOR
Aim:
To study the effect of temperature on the rate of reaction between hydrogen peroxide
and sodium thiosulphate under adiabatic reaction conditions and to determine the activation
energy of the reaction.
Theory:
The effect of temperature on the reaction mixture consisting of hydrogen peroxide and
sodium thiosulphate when the reaction is carried out under adiabatic conditions, it can be
observed and correlation with the reaction rate is given. As the exothermic reaction proceeds,
the temperature increases and becomes constant after a certain time. The rate of the reaction
and temperature are correlated to various temperatures.
1
dT KC A0e − E RT
=
TF − T0
(Tf − T )2 dt
Where
TF – Final Temperature (°C)
T0 – Initial Temperature (°C)
K – Rate constant
CA0 – Initial concentration (moles/ litre)
A graph is drawn between lnA Vs.1/T and the slope is equated to -E/R.
Procedure:
Take 30 ml of hydrogen peroxide in a beaker and dilute it into 300 ml by using distilled
water and pour it into the reactor, 300 ml of sodium thiosulphate solution will also be added
in the reactor. Due to exothermic reaction, the temperature of reaction mixture starts
increasing, the rise in temperature is noted at different time intervals as the reaction proceeds.
Tabulation:
Time (sec) Temperature
(°C)
dT/dt
(Ts – T)2
1/(T+273)
(k-1)
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A
ln A
2
Model Graph:
T°C
lnA
Slope = -E/R
0
Time (s)
1/T (k-1)
x
Model Calculation:
1) t =
2) T =
dT
=
3)
dt
4) (Tf – T)2=
5) A =
dT
10 −3

=
dt (Tf − T) 2
6) lnA =
1
7)
=
(T + 273)
8) E= -slope x R=
Result and Inferences:
The activation of energy the reaction was found to be
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2. BATCH REACTOR -1
Aim:
To verify the order and to determine the rate constant for the reaction between equimolar
quantity of NaOH and ethyl acetate in a batch reactor.
Reaction:
NaOH + CH3COOC2H5
CH3COONa + C2H5OH
Theory:
For a second order reaction, the rate of reaction is as follows
dCA
= − KC A 2
dt
Integrating,
CA
CA
dCA
1
t= 
= −1
2
C
A
CA0
KC A
K
CA 0

t=

1  xA 


KC A0  1 − xA 
Procedure:
500 ml of NaOH and 500 ml of ethyl acetate of equimolar quantities are taken in the
batch reactor. Then, 10 ml of the reaction mixture is taken every 5 minutes of the reaction
followed by arresting of reaction by adding 10 ml of 0.05N acetic acid to the reaction
mixture. The reaction mixture is titrated against sodium hydroxide of known
normality(0.05N) and its concentration found. Samples are taken up to 50 minutes and the
concentration of the reactor is found.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Tabulation:
S.No.
1
2
3
4
5
6
7
8
9
10
Reaction
Volume of Naormality
Time (min) NaOH (ml) of NaOH (N)
5
10
15
20
25
30
35
40
45
50
CA
1/CA
-3
(mol/lit)×10
(lit/mol)
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XA
XA
1 − XA
4
Model Graph:
y
1
1
y
k
CA
kCA0
XA
1 - XA
C A0
0
x
0
t
x
t
Model Calculation:
NNaOH
1) CA0 =
=
2
moles of CH3COOH added − moles of NaOH added
2) CA =
=
Sample Volume
1
3)
=
CA
CA0 − CA
4) XA =
=
CA0
XA
=
5)
1 − XA
Result:
Thus, the experiment on batch reactor was performed. The value of K found from
graph.
1/CA vs t =
XA /(1-XA) vs t =
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3. BATCH REACTOR – II
Aim:
To verify the order and to determine the rate constants for the reaction between nonequimolar quantity of NaOH and ethyl acetate in a batch reactor.
Reaction:
NaOH + CH3COOC2H5
CH3COONa + C2H5OH
Theory:
In a batch reactor, the composition of the components is uniform throughout at any
instant of time
XA
kXA
t = CA0 
(-rA)
0
for (A + B) → Products
- rA = KC ACB
=
 (m − XA ) 
1
ln 
K(C B0 - CA0)  m(1 − XA )
Procedure:
400 ml of NaOH and 800 ml of ethyl acetate of equal concentration are taken in the
reactor. Samples (10ml) are drawn for every 5 minutes from the reactor followed arresting
the reaction by adding 10 ml of acetic acid of 0.05N. The concentration of reactants in the
sample is found out by adding 10 ml of acetic acid and titrating against sodium hydroxide.
Samples are drawn up to 50 minutes and these steps are repeated.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Tabulation:
S.No. Reaction Volume of Naormality CA
CBo
Time (min) NaOH (ml) of NaOH (N) (mol/lit)×10 -3 (mol/lit)
1
2
3
4
5
6
7
8
9
10
XA
 m − XA 
ln 

 m(1 − XA) 
5
10
15
20
25
30
35
40
45
50
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Model Graph:
y
 m − XA 

ln 
 m(1 − XA ) 
Slope = K (CB0 – CA0)
0
x
Time (min)
Model Calculation:
VNaOH  NNaOH
1) CA0 =
=
Vtotal
(N  V)A.A − (N  V )NaOH =
2) CA =
Total Volume
VEA  NEA
3) CB0 =
=
Vtotal
C B0
4) M =
=
CA0
CA0 − CA
5) XA =
=
CA0
Slope
6) K =
=
CB0 − CA0
Result:
Thus, the experiment on batch reactor – II was performed. The value of k found the
graph is
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4. MIXED FLOW REACTOR
Aim: To study the performance of a mixed flow reactor using second order saponification
reaction.
Reaction:
NaOH + CH3COOC2H5 → CH3COONa + C2H5OH
Theory:
In a mixed flow reactor, properties of the reaction mixture are uniform. Thus, for
example, concentration of the reactants at inlet of the second order reaction and outlet
concentration of the reactants remain the same. The design equation for above reaction in
mixed flow reactor is
CA0 − CA
=
CA0 = CB0,
CA = CB,
KC A 2
Experimental Setup:
It consists of a 500 ml flask with a flow stream and this is attached with the flow
meter for setting the flow rate.
Procedure:
The residence time of the reactor is adjusted by adjusting of reactants the flow rate
and keeping the reactor volume constant. The reaction is allowed to continue up to 50
minutes. After this reaction mixture of 5 ml is collected in measure jar having 5 ml of acetic
acid of normality 0.05N. Then, the resulting is mixture is titrated against 0.05N of sodium
hydroxide and the concentration unreacted sodium hydroxide was found out. If the titer value
is same for two subsequent collection, then the steady state is presumed to be reached.
Finally, theoretical and experimental conversion were found out by calculating the
concentration of unreacted sodium hydroxide at steady state condition using the MFR
performance equation.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Flow rate of NaOH
Flow rate of CH3COOC2H5=
Reaction Rate Constant =
Table: 1
S.No.
Volume of Sample
(ml)
Burette Reading (ml)
Initial
Final
Concordant Value (ml)
Model Calculation:
V
1)  = =

(V  N )CH3COOH − (V  N )NaOH
2) CA =
Vtotal
CA0 − CA
3) XAexp =
CA0
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4) XAtheo = kTCA0(1 − XA )
2
Result:
Thus, the experiment of mixed flow reactor is studied and the conversion is found to
be:
XATheo:
XAExp:
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5. MIXED FLOW REACTOR IN SERIES
Aim: To study the performance of a mixed flow reactors connected in series, using second
order saponification.
Reaction:
NaOH + CH3COOC2H5 → CH3COONa + C2H5OH
− rA = KCACB = KCA2
Theory: In a mixed flow reactor, properties of the reaction mixture are uniform and these
connected in series. Thus, we have the equimolar concentration of reactant at inlet of the first
reactor and the out let concentration of the first reactor will be the inlet concentration for the
second reactor for above second order saponification reaction. The outlet concentration and
conversion based on performance equation are as follows.
CA0 = CB0,
CA = C B,
CA1 − CA2
KC A2 2
τ = X( A )2
KC A0 1-XA
τ
2
=
Procedure:
The residence time of the reactor is adjusted by adjusting of reactants the flow rate
and keeping the reactor volume constant. The reaction is allowed to continue up to 70
minutes. After this reaction mixture of 5 ml is collected at the outlet of the second reactor in
measure jar having 5 ml of acetic acid of normality 0.05N. Then, the resulting is mixture is
titrated against 0.05N of sodium hydroxide and the concentration unreacted sodium
hydroxide was found out. If the titer value is same for two subsequent collection, then the
steady state is presumed to be reached. Similar procedure was followed for the out let of the
first reactor. Finally, theoretical and experimental conversion were found out by calculating
the concentration of unreacted sodium hydroxide at steady state condition using the MFR
performance equation.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Flow rate of NaOH
Flow rate of CH3COOC2H5=
Reaction Rate Constant =
Table: 1
S.No.
Volume of Sample
Burette Reading (ml)
Initial
Final
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Concordant Value (ml)
10
Table: 2
S.No.
Volume of Sample
Burette Reading (ml)
Initial
Final
Concordant Value (ml)
Model Graph
XA
2
1

Model Calculation:
VCH 3COOH  NCH 3COOH
NNaOH =
VNaOH
At steady state in Reactor I
CA1 =
(V  N )CH COOH − (V  N )NaOH
3
Volume
CA0 − CA1
XA1 =
CA0
At steady state in Reactor II
CA2 =
XA2 =
(V  N )CH COOH − (V  N )NaOH
3
CA0 − CA2
CA0
Volume
Theoretical conversion:
Reactor I:
τ
1
=
V1

τ
1
=
XA1
2
KC A0(1-XA )
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Reactor II:
τ
V2

τ2 = XA2 (- XA1 )2
KC A0 1-XA
2
=
Result:
Thus, the experiment of mixed flow reactor in series is studied and the conversion is
found to be:
Reactor 1
XA,Theo :
XA,Exp :
Reactor 2
XA,Theo :
XA,Exp :
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6. PLUG FLOW REACTOR
Aim:
To study the performance of the plug flow reactor for the second order reaction of
saponification of ethyl acetate.
Reaction:
NaOH + CH3COOC2H5 → CH3COONa + C2H5OH
CA
t=


dCA
1 − 1 CA
=
2
CA CA0
KC A
K
CA 0

1  xA 


KC A0  1 − xA 
KC A 0
XA =
1 + KC A 0
t=
Experimental setup:
It consists of a transparent tube provided with glass beads ( = 0.04) sampling can be
done at different points all along the length of the tube.
Procedure:
The residence time of the reactor is adjusted by adjusting of reactants the flow rate
and keeping the reactor volume constant. The reaction is allowed to continue up to 60
minutes. After this reaction mixture of 5 ml is collected at out let of PFR in measure jar
having 5 ml of acetic acid of normality 0.05N. Then, the resulting is mixture is titrated
against 0.05N of sodium hydroxide and the concentration unreacted sodium hydroxide was
found out. If the titer value is same for two subsequent collection, then the steady state is
presumed to be reached. Similar procedure was followed for all other out lets all along
length of the reactor. Finally, theoretical and experimental conversion were found out by
calculating the concentration of unreacted sodium hydroxide at steady state condition using
the PFR performance equation.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Flow rate of NaOH
Flow rate of CH3COOC2H5=
Reaction Rate Constant =
Tabulation:
S.No Reactor volume Space time
(ml)
 (min)
Titrant
volume (ml)
CA (N)
×10 – 3
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XA (%) XA (%)
(expt.) (theo)
13
Model Graph:
y
Theoretical
Experimental
XA
x
0
Time
Model Calculation:
1)
2)
3)
4)
5)
Initial Concentration= NNaOH/2
τ= V
V0
(V  N )CH3COOH − (V  N )NaOH
CA =
Volume
CA
XAexp = 1 −
CA0
KC A0τ
XAtheo =
1 + τKC A0
Result:
Thus, the performance of plug flow reactor under constant flow rate is studied and
necessary graphs are drawn.
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7. MIXED FLOW FOLLOWED BY PLUG FLOW REACTOR
Aim: To study the performance of a mixed flow followed by plug flow reactor using second
order saponification reaction.
Reaction:
NaOH + CH3COOC2H5 → CH3COONa + C2H5OH
Theory:
In a mixed flow reactor, properties of the reaction mixture are uniform. Whereas in
PFR the concentration is varying all along the length of the reactor. In this experimental set
up PFR having two out let volume connected in series with MFR. The design equation for
reaction
τ1 = CA0 − C2A1
τ 1 = V1
CA0 = CB0,
V
KC A1
Whereas in plug flow the concentration of the reactants are changing along with length and
hence the with residence time as volume of the reactor changing with the length for give a
flow rates of reactants
τ
2
=
KC A0τ2
V2
; XAtheo =
1 + τ2KC A0
V
Experimental Setup:
It consists of a 1000ml flask attached with stirrer and transparent tube provided with
glass beads ( = 0.04) sampling can be done at different points all along the length of the
tube.
Procedure:
The residence time of the reactor is adjusted by adjusting of reactants the flow rate
and keeping the reactor volume constant. The reaction is allowed to flow through MFR, then
through PFR and waiting for 60 minutes. After this reaction mixture of 5 ml is collected at
out let of PFR in measure jar having 5 ml of acetic acid of normality 0.05N. Then, the
resulting is mixture is titrated against 0.05N of sodium hydroxide and the concentration
unreacted sodium hydroxide was found out. If the titer value is same for two subsequent
collection, then the steady state is presumed to be reached. Similar procedure was followed
for other out of PFR and out let of the MFR. Finally, theoretical and experimental conversion
were found out by calculating the concentration of unreacted sodium hydroxide at steady
state condition using the PFR performance equation.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Flow rate of NaOH
Flow rate of CH3COOC2H5=
Reaction Rate Constant =
S.No Reactor volume Space time
(ml)
 (min)
Titrant
volume (ml)
CA (N)
×10 – 3
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XA (%) XA (%)
(expt.) (theo)
15
Model graph
XA
1

Model Calculation:
VCH 3COOH  NCH 3COOH
NNaOH =
VNaOH
At steady state in Reactor I
CA1 =
(V  N )CH COOH − (V  N )NaOH
3
Volume
CA0 − CA1
XA1 =
CA0
At steady state in Reactor II
CA2 =
XA2 =
(V  N )CH COOH − (V  N )NaOH
3
CA0 − CA2
CA0
Volume
Theoretical conversion:
Reactor I:
τ
1
=
V1
V
τ
1
=
XA1
2
KC A0(1-XA )
Reactor II:
τ
2
=
V2
V
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4) XAtheo =
KC A0τ2
1 + τ2KC A0
y
Theoretical
Experimental
XA
0
x
Time
Result:
Thus, the performance of mixed flow followed by plug flow reactor under constant
flow rate is studied and necessary graphs are drawn.
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8. RTD STUDIES IN A PLUG FLOW REACTOR
Aim:
To study the behavior of a plug flow reactor by RTD studies.
Theory:
Elements of fluid taking different routes through the reactor taking different lengths of
time to pass through the vessel. The distribution of these times for the stream of fluid leaving
the vessel is called the exit age distribution E, or the residence time distribution (RTD) of the
fluid. From E mean residence time, flow pattern, model parameters can be evaluated.
Procedure:
In a plug flow reactor, a tube packed with particles is used to give plug flow. To start
with 2 gms of NaOH was taken by accurate weighing, got dissolved in 10 ml of distilled
water and is kept ready. Then adjust the flow rate distilled water coming from an overhead
water tank above the reactor is adjusted at 25 ml/min reactor by Rotameter and allowed to
flow through PFR reactor. Then pipette out the prepared NAOH solution keep ready and
inject in the reactor while starting stop watch in your mobile. Then, dilute sodium hydroxide
coming out from the exit of the reactor is collected for every three minutes for five seconds
and titrated against the dilute acetic acid. This procedure is repeated for 45 minute for every
3 minutes interval. Then, E data is prepared using formulas given below.
Standard Data:
Normality of CH3COOH =
Flow rate of Water
=
Normality of NaOH (Nmax)
Formulae:
1)
2)
,
=
2
3) σ2 =  ti 2EiΔti − t
σ2
4) σ0 2 = 2
t
D
σ0 2
5)
=
UL
2
1
6) σ0 2 =
N
where,
t = mean residence time
σ 2 = variance
∆ti = time interval
D
= Dispersion number
UL
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Tabulation:
Time
VCH3COOH
(min)
(ml)
NNaOH
Eiti
Eiti2
Model Graph:
y
E=C
x
Result:
Thus, the experiment of plug flow RTD was conducted and the dispersion number and
N were calculated.
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9. RTD STUDIES IN MIXED FLOW REACTOR
Aim:
To study the behavior of the mixed flow reactor through RTD studies.
Theory:
Elements of fluid taking different routes through the reactor taking different lengths of
time to pass through the vessel. The distribution of these times for the stream of fluid leaving
the vessel is called the exit age distribution E, or the residence time distribution (RTD) of the
fluid. From E mean residence time, flow pattern, model parameters can be evaluated.
Experimental setup and procedure:
Reactor consists of 500 ml beaker attached with stirrer. To start with 2 gms of NaOH
was taken by accurate weighing, got dissolved in 10 ml of distilled water and is kept ready.
Then adjust the flow rate distilled water coming from an overhead water tank above the
reactor is adjusted at 25 ml/min reactor by Rotameter and allowed to flow through MFR
reactor. Then pipette out the prepared NAOH solution keep ready and inject in the reactor
while starting stop watch in your mobile. Then, dilute sodium hydroxide coming out from the
exit of the reactor is collected for every three minutes for five seconds and titrated against the
dilute acetic acid. This procedure is repeated for 45 minutes for every 3 minutes interval.
Then, E data is prepared using formulas given below.
Standard Data:
Normality of CH3COOH =
Flow rate of Water
=
Normality of NaOH (Nmax)
Formulae:
1)
2)
=
,
2
3) σ =  ti EiΔti − t
σ2
2
4) σ0 = 2
t
D
σ0 2
5)
=
UL
2
1
6) σ0 2 =
N
where,
t = mean residence time
2
2
σ 2 = variance
∆ti = time interval
D
= Dispersion number
UL
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Tabulation:
Time
VCH3COOH
(min)
(ml)
NNaOH (C i) Ei = Ci/Q
Ei ti
Eiti2
Model Graph:
y
E=C
x
y’
Model Calculation:
1)
2)
3)
σ2
4) σ0 2 = 2
t
D
σ0 2
5)
=
UL
2
1
6) σ0 2 =
N
Result:
Thus, the experiment of mixed flow RTD was conducted and the dispersion number
and N were calculated.
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10. SONOCHEMICAL REACTOR
Aim:
To verify the order and to determine the rate constants for the reaction between
equimolar quantity of NaOH and ethyl acetate under sono-conditions.
Reaction:
NaOH + CH3COOC2H5
CH3COONa + C2H5OH
Theory:
For a second order reaction, the rate of reaction is as follows
dCA
= − KC A 2
dt
Integrating,
CA
CA
dCA
1
t= 
= −1
2
CA CA0
KC A
K


CA 0
t=
1  xA 


KC A0  1 − xA 
Procedure:
200 ml of NaOH and 200 ml of ethyl acetate of equal normalities around 0.05N are
taken in a 500 ml beaker and kept in the sono-chemical reactor. Then each 5 ml of the
reaction mixture is taken for every 2 minutes followed by arresting of reaction by adding 5 ml
0.05 N acetic acid to the sample. The reaction mixture is titrated against sodium hydroxide of
normality around 0.05 N and its concentration found. Samples are taken up to 20 minutes and
the concentration of the reactor is found.
Standard Data:
Normality of NaOH=
Normality of CH3COOC2H5=
Normality of CH3COOH=
Tabulation:
S.No.
1
2
3
4
5
6
7
8
9
10
Reaction
Volume of Naormality
Time (min) NaOH (ml) of NaOH (N)
2
4
6
8
10
12
14
16
18
20
CA
1/CA
-3
(mol/lit)×10
(lit/mol)
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XA
XA
1 − XA
22
Model Graph:
y
1
1
y
k
CA
kCA0
XA
1 - XA
C A0
0
x
0
t
x
t
Model Calculation:
NNaOH
1) CA0 =
=
2
moles of CH3COOH added − moles of NaOH added
2) CA =
=
Sample Volume
1
3)
=
CA
CA0 − CA
4) XA =
=
CA0
XA
=
5)
1 − XA
Result:
Thus, the experiment on sono-chemical reactor was performed. The value of K found
from graph. The higher value give the effect of sonication on the rate of chemical reaction
1/CA vs t =
XA /(1-XA) vs t =
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