Page 364 - Elements of Chemical Reaction Engineering Ebook

Chap 6 CD-ROM Material 335

Additional information:
kl = 0.01 s-l k2 = 0.05 s-l k3 = 10 s-l k4 = 100 m3/kinol*s
C,, = 2 kmollm3 and uo = 0.2 m31s

Repeat for k2 = 0.002 s-l.
P6-;% The gas phase reactions take place isothermally in a membrane reactor packed
with catalyst. Pure A enters the reactor at 24.6 am and 500K and a flow rate
of A of 10 mollmin
A e ric = klc [ CA-- 23
B+C
A-D r;D = k2DCA
%C+D --+ 2E r;E = k3,C2cCD

Only species B diffuses out of the reactor through the membrane.
(a) Plot the concentrations down the length of the reactor.
(b) Explain why your curves look the way they do.
(c) Vary some of the parameters (e.g., kB, klc. Klc) and write a paragraph
describing what you find.
Additional Informatioa
Overel mass transfer coefficient kB = 1.0 dm3 1 kg cat min
klC = 2 dm3 I kg cat min
Klc = 0.2 mol I dm3
k2D = 0.4 dm3 I kg cat min
k3E = 400 dm2 / mol2 kg cat min
W,= 100 kg
(x = 0.008 kg-I
P6-29c Read the cobra module on the CD.
(a) Determine how many cobra bites are necessary in order that no amount
of anti-venom will save the victim.
(b) Suppose the victim was by a ahrmless snake and not bitten by a cobra
and anti-venom was injected. how much anti-venom would need to be
injected to cause death?
(c) What is the latest possible time and amount that anti-venom can be
injected after being bitten such that the victim would not die?
(d) Ask another question about this problem.
Hint: The Living Example Polymath Program is on the CD ROM.
P6-3OC Read over the oscillating reaction module. For the 4 reactionsinvolving I-
and IO-3 :
(a) What factors influence the amplitude and frequency of the oscillation
reaction?
(b) Why do you think that the oscillations eventually cease (in the original
experiment by Belousov, they lasted about 50 minutes)?
(c) What causes these oscillations? (In other words: What makes this reac-
tion different than others we have studied so far in Chapter 6?)
(d) What if ... play around with the Living Example Polymath Prol, 'ram on
the CD ROM - what are the effects of changing the values of k,, 141, kl,
and k,? Can you make the oscillations damped or unstable?