PTU Punjab Technical University B-Tech May 2019 Question Papers 4th Semester Petroleum Engineering
Total No. of Pages : 03
Total No. of Questions : 09
B.Tech.(Petroleum Refinary Engineering) (2013 Batch) (Sem.?4)
CHEMICAL REACTION ENGINEERING-I
Subject Code : BTPC-406/BTCH-405
M.Code : 72429
Time : 3 Hrs. Max. Marks : 60
INSTRUCTION TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
SECTION A
Q1.
Answer briefly :
a) Give the variables affecting the rate of reaction.
b) Give the characteristics of plug flow reactor.
c) Differentiate between space time and residence time.
d) What will be the effect of increase in reaction order on the ratio of mixed flow reactor
and plug flow reactor volumes?
e) Define the terms ``Selectivity'' and ``Yield''.
f) How does the concentration level of reactants affect the product distribution in
parallel reactions?
g) Give the applications of RTD.
h) What is the effect of temperature on equilibrium conversion?
i) The rate constants of a certain reaction are 1.6 ? 10?3 and 1.625 ? 10?2 s?1 at 10?C and
30?C, respectively. Calculate activation energy of this reaction.
j) A 2nd order reaction is to be carried out in 3 CSTR's of Volume 100 liter, 150 liter
and 200 liter. How these should be connected?
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SECTION B
Q2.
The rate of homogeneous decomposition nitrous oxide, N2O N2 + ? O2 has been
found to be represented by
2
k [N O]
1
2
r
N O
2
1 k [N O]
2
2
Suggest a reaction mechanism which is in consistent with this rate law.
Q3.
Derive the performance equation for a recycle reactor. Write the performance equation
for the two extremes of the recycle ratio.
Q4.
An aqueous phase reaction A2R is carried out in a CSTR having volume of 5 liters and
the following data is obtained.
Temperature of
Concentration of R in
Run Feed rate (cm3/sec)
the run (?C)
the effluent (mol/liter)
1
2
13
1.8
2
15
13
1.5
3
15
84
1.5
Find the rate equation for this reaction and also evaluate the activation energy of the
reaction, assuming the applicability of Arrhenius law.
Q5.
An aqueous feed of A and B (400 liter/min, 100 mmol A/liter, 200 mmol B/liter) is to be
converted to product in a plug flow reactor. The kinetics of the reaction A + B R; is
represented as
? rA = 200 CACB mol/(liter-min)
Find the volume of reactor needed for 90% conversion of A to product.
Q6.
Explain the stimulus response techniques for study of flow pattern in reaction vessels.
Obtain the relation between E, F and C curves.
SECTION C
Q7.
A series reaction
1st order
Zero order
A B
C is taking place in a CSTR. Derive the
concentrations of A and B as functions of residence time , the rate constants (k1 and k2)
and the initial concentration of A (CA0). Assume that the concentrations of B and C in the
reactor entrance stream are zero.
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Q8.
An irreversible gaseous reaction A B at 10 atm and 144?C has to be carried out in two
reactor system. The volumetric feed (360 liter/min) contains 50 mole% A, and 50 mole%
inerts is required to be processed. The laboratory measurement of rate of reaction (?rA) as
a function of conversion (XA) at 10 atm and 144?C is as follows :
XA
0
0.2
0.4
0.6
0.8
0.9
?rA (mol/liters)
0.0053 0.005
0.004
0.0025
0.00125
0.0006
If the reaction is carried out in two reactor system in series with XA1 = 0.40 as
intermediate conversion (from 1st reactor) and XA2 = 0.85 as final conversion, estimate
the total volume of two reactors when :
i) The reactors are both mixed flow
ii) He reactors are both plug flow.
Q9.
75% conversion for a liquid phase reaction A + B 2C has been achieved in a 300 liter
CSTR. Equal mass flow rate of A and B (1.5 mol/s) at a temperature of 27?C and fed to
the reactor. Specific heats (in J/mol-K) of A, B and C are 200, 180 and 190, respectively.
The reactor is jacketed by water at a temperature of 20?C. The overall heat transfer
coefficient has been estimated at 225 J/(m2.s.K), and the heat transfer area is 1m2. Mixing
is ensured through an agitator, which contributes a work of 15 KW to the reactor. The
heat of reaction is ?35,000 J/mole of A. Calculate the steady state temperature in the
reactor by assuming that the heat of reaction is independent of temperature.
NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any
page of Answer Sheet will lead to UMC against the Student.
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This post was last modified on 04 November 2019