Page 359 - Elements of Chemical Reaction Engineering Ebook

330 Multiple Reactions Chap. 6

All reaction steps are irreversible and first-order, except for the formation
of B from F, which is second-order in F. The liquid carrier for reactants and
products is an inert solvent, and no volume change results from the reaction:
k, = 0.01 min-I k, = 0.02 min-l
k, = 0.07 min-' k4 = 0.50 dm3/g mol. min

reactor volume = 120 L

(a) What is the maximum possible molar concentration of C in the product?
(b) If the feed rate is 2.0 dm3/min, what is the yield of C (expressed as a per-
centage of the maximum), and what is the mole fraction of C in the prod-
uct on a solvent-free basis? (Ans.: 0.583.)
(California Professional Engineers Exam)
P6-2OC The reaction sequence discussed in Example 6-8 is to be carried out in a
microscale "fluidized" CSTR. The CSTR catalyst weight is 3 g. All of the
conditions in the problem statement are the same except that the reaction is to
be carried out at a slightly higher temperature and the rate constants are:

k, = 10 rn9/(kmol2. kg cat. * min) k, = 4 m6/(kmol kg cat. . min)
k, = 15 m9/(kmo12. kg cat. min) k, = 10 m3(m3h01)2/3/kg cat. min

(a) What are the exiting molar flow rates of each species.
(b) What is the overall yield of
(1) A to E?
(2) B to F?
(3) A to C?
P6-21D (Flame retardants) We now reconsider a more comprehensive version of the
combustion of CO discussed in P7-3. The reactions and their corresponding
rate law parameters are given in Table P6-21. AI1 reactions are assumed to be
elementary [Combustion and Flame, 69, 113 (1987)l. The precombustion
compositions (mol %) are:

TABLE P6-21 RATE LAW PARAMETERS

Rate Parameters, k = ATn exp ( - E/ RT)
(cm3, s, cal, mol units)
Reaction A n E

A. Uninhibited
1. OH+CO+COz+H 4.40E06 1.5 -740
2. CO+O+M+CO,+M 5.30E13 0 -4,538
3. H+O,-+O+OH 1.20E17 -0.91 16,504
4. O+H,-+H+OH 1.50E07 2.0 7,547
B. Inhibited
5. ClZ+M+2C1+M 1 .OOE14 0 48,180
6. HCl+H+H,+Cl 7.94E12 0 3:400
7. H + CI,-+HCl+ C1 8.51E13 0 1,170