DEPARTMENT OF CHEMICAL ENGINEERING
REACTION ENGINEERING
(RCNE101)
TEST 1
Date: 4 April 2022
Duration: 1hr 15 min : 8h30 to 9h45
Total Marks: 40
Examiner: Ms S Vallabh
Moderator: Mr N Brijmohan
Please write your name and student number on your answer script.
All scripts must be scanned, converted to PDF and emailed to me by 10h00. Test scripts
received after 10h00 will not be marked irrespective of the reason given.
My email is
There are two (2) questions in total.
The standard integral table is given on Page 3.
Page 1 of 3
, QUESTION 1
The following elementary irreversible liquid phase reaction takes place in an isothermally
operated CSTR:
A + B → C
The feed enters the 175 L CSTR at a temperature of 27oC. The volumetric flow rate to the reactor
is 2 L/s. The feed is composed of 50% species A and the rest species B. The feed concentration
of species A is 0.1 mol/L. The pressure drop across the reactor is negligible.
The same reaction is to be carried out in a 100 L CSTR with the same feed flow rate, composition
and concentration as the 175 L CSTR.
(a) Determine the temperature at which the 100 L CSTR should be operated at in order to achieve
the same conversion as the 175 L CSTR.
(b) Is the 100 L CSTR suitable if the maximum operating temperature of the reactor is 45oC.
Additional Data
K = 0.83 L/mol.s at 293 K
E = 41 850 J/mol
R = 8.314 J/mol.K = 0.082 L.atm/mol.K = 0.082 m3.atm/kmol.K [17]
QUESTION 2
The following elementary irreversible gas phase reaction takes place in an isothermally operated
flow reactor:
A + B → C + D
The feed enters the reactor at a temperature of 250oC and a pressure of 1300 kPa. The feed
composition is 30% species A and 70% species B. The feed flow rate of species A is 200 mol/s.
The volume of the flow reactor is 200 L. The rate constant, k, at 250 oC is 110 L/mol.s. The pressure
drop across the flow reactor is negligible.
(a) Determine the conversion achieved in the flow reactor if it were a PFR.
(b) Determine the conversion achieved in the flow reactor if it were a CSTR.
Additional Data
R = 8.314 J/mol.K = 8.314 L.kPa/mol.K [23]
Page 2 of 3
REACTION ENGINEERING
(RCNE101)
TEST 1
Date: 4 April 2022
Duration: 1hr 15 min : 8h30 to 9h45
Total Marks: 40
Examiner: Ms S Vallabh
Moderator: Mr N Brijmohan
Please write your name and student number on your answer script.
All scripts must be scanned, converted to PDF and emailed to me by 10h00. Test scripts
received after 10h00 will not be marked irrespective of the reason given.
My email is
There are two (2) questions in total.
The standard integral table is given on Page 3.
Page 1 of 3
, QUESTION 1
The following elementary irreversible liquid phase reaction takes place in an isothermally
operated CSTR:
A + B → C
The feed enters the 175 L CSTR at a temperature of 27oC. The volumetric flow rate to the reactor
is 2 L/s. The feed is composed of 50% species A and the rest species B. The feed concentration
of species A is 0.1 mol/L. The pressure drop across the reactor is negligible.
The same reaction is to be carried out in a 100 L CSTR with the same feed flow rate, composition
and concentration as the 175 L CSTR.
(a) Determine the temperature at which the 100 L CSTR should be operated at in order to achieve
the same conversion as the 175 L CSTR.
(b) Is the 100 L CSTR suitable if the maximum operating temperature of the reactor is 45oC.
Additional Data
K = 0.83 L/mol.s at 293 K
E = 41 850 J/mol
R = 8.314 J/mol.K = 0.082 L.atm/mol.K = 0.082 m3.atm/kmol.K [17]
QUESTION 2
The following elementary irreversible gas phase reaction takes place in an isothermally operated
flow reactor:
A + B → C + D
The feed enters the reactor at a temperature of 250oC and a pressure of 1300 kPa. The feed
composition is 30% species A and 70% species B. The feed flow rate of species A is 200 mol/s.
The volume of the flow reactor is 200 L. The rate constant, k, at 250 oC is 110 L/mol.s. The pressure
drop across the flow reactor is negligible.
(a) Determine the conversion achieved in the flow reactor if it were a PFR.
(b) Determine the conversion achieved in the flow reactor if it were a CSTR.
Additional Data
R = 8.314 J/mol.K = 8.314 L.kPa/mol.K [23]
Page 2 of 3
