Download SGBAU (Sant Gadge Baba Amravati university) B-Tech/BE (Bachelor of Technology) 7th Sem Chemical Engineering Chemical Reaction Engineering I Previous Question Paper
B.chh. Seventh Semester (Chemical Engineering) (CGS)
11658 : Chemical Reaction Engineering - I : 7 CH 02
. AW ? 3377
I 1 'i I
Time : Tlu?ee Hours 'm?llhlg??gmllu Max. Marks : 80
Notes :
41.
AW - 3377 1 P.T.O
1 Answer three question from Section A and three question from Section B.
2 Due credit will be given to neatness and adequate dimensions.
3. Assume suitable data wherever necessary.
4 Diagrams and chemical equations should be given wherever necessary.
SECTION - A
For irr, cversible reactions in series
Obtain the expression for
l =1n(k2/1? I
1max _
klogmean k2 'kl
rmd also for the maximum concentration of R.
0R
Aqueous A at a concentration C A0 = 1 mol/liter is introduced into a batch reactor where it
reacts away to form product R accnrding to stuichiometry A -> R . The concentration of
A in the reactor is monitored at various times. as shown below:
t. min 0 100 200 300 400
CA m0} ,? m3 1000 500 333 250 200
For C A0 = 500 mol / m3 ?nd the conversion of reactant after 5 hours in the batch reactor.
Obtain the relation between concentration. time mid rate constant for the Autocatalytic
reactions. Plot conversion - time and ratc- concentration curves for autocalalytic reaction.
OR
The following data are obtained at 0? C in a constant - volume batch reactor using pure
gaseous A:
Time, min 0 2 4 6 8 10 12 14 cc
Partial pressure oI?A, mm 760 600 475 390 320 275 240 215 150
The stoichiometry of the decomposition is A ?> 2.5 R. F ind a rate equation which
satisfactorily represents this decmnpositiou.
Find the ?rst-order rate constant for the disappearance of A in the gas reaction 2A ~> R if?
on holding the pressure constant. the volume of the reaction mixture, starting with 80% A.
decreases by 20% in 3 min.
OR
14
13
6.
10.
ll.
12.
AW - 3377
b)
Find the ?rst-order rate eonuant for the disappearance of A in the gas reaction A-?) 1.6R if
the volume of the reaction mixture mtumng with pure A increases by 50% in 4 min. The
total pressure within the s) stem stay: cnnslunt :u 1.2 atm. and the temperature is 25? C.
SECTION ? B
Den'w performance equations for plug ?ow reactor. Explain graphically the representation
ufthe performance cquatmn fur plug 110w reactor.
OR
A gaseous feed ot?pure At 1 molrliter} enters :1 mixed flow reactor (2 liters) and reacts as
follmw:
? mnl
2A "?)? R, -fA =U.05( 32? 1*?
llter-sec
Find what feed rate (liter?mim will give an ?Jut1et concentration (?A = 0.5m01/1iter.
Litcr/s ofa 20% ozone - 80% air mixture at 1.5 mm and 93?C passes through a plug ?ow
reactor. Under these conditions ozone decomposes by homogeneous reaction.
w liter
?9 _ ~ _ , u . _ -
?03 " ?02 v ru/nne ? kC 01.0116? 1? ' 0")?
m0! - 5
What size reactor is needed for 50% decomposition of ozone?
We plan to replace our present mixed ?ow reactor with one having double the volume. For
the same aqueous feed (10 mo] A/Iitcr) tmd the
A ~91, ? rA =kc'k5
and present conversion is 713%
OR
Explain the size comparison OfSi?glc? reactors. mixed versus plug ?ow reactors, for ?rst
and second order reactions.
The kinetics of the aqueous?phase dccumpusilion of A is investigated in two mixed ?ow
reactors in series. the second having twice the volume of the ?rst reactor. At steady state
with a feed concentration of 1 mo! A/liter and mean residence time of 96 sec in the ?rst
reactor. the concentration in the ?r>t r'eactur is 0.5 mol A/liter and in the second is 0.25 mol
A/liter. Find the kinetic equation for the decomposition.
OR
Consider the autoeatalytie reaction A ?>1{.with ? FA = 0.001 CACR mol / liter-s . We wish
to process 1.5 liters?s ot?u C A0 = ltJmumiter t'ccd to the highest conversion possible in the
reactor system consisting of four 100-Iiter mixed ?ow reactors connected as you wish and
any feed arramgcmen: Sketch )0ur recommended design and feed arrangement and
determine C M from this system.
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This post was last modified on 10 February 2020