Page 544 - Elements of Chemical Reaction Engineering Ebook

514 Steady-State Nonisothermal Reactor Design Chap. 8

(g) What do you believe to be the point of this problem?
(h) Ask another question or suggest another calculation for this reaction.

Additional information:
Hi(273) = -20 kcal/mol
HBO(273) = - 15 kcal/mol
H,"(273) = -41 kcal/mol'
c,, = 0.1 km0i/m3
CpA = Cp, = 15 cal/mol-K Cpc = 30 cal/mol. K

at
k = 0.01 - 300 K E = 10,000 cal/mol
dm3
mol. s
P8-6* The elementary irreversible gas-phase reaction
Before solving the A-+B+C
problems, state or
sketch qualitatively is carried out adiabatically in a PFR packed with a catalyst. Pure A enters the
the expected results reactor at a volumetric flow rate of 20 dm3/s at a pressure of 10 atm and a tem-
or trends. perature of 450 K.
(a) Plot the conversion and temperature down the plug-flow reactor until an
80% conversion (if possible) is reached. (The maximum catalyst weight
that can be packed into the PFR is 50 kg.) Assume that AP = 0.0.
(b) What catalyst weight is necessary to achieve 80% conversion in a CSTR?
(c) What do you believe to be the point of this problem?
(d) Write a question that requires critical thinking and then explain why your
question requires critical thinking. [Hint: See Preface p.xx]
Additional information:
Cp, = 40 J/mol. K Cp, = 25 J/mol. K Cpc = 15 J/mol. K

Hi = -70 kJ/mol Hi = -50 kJ/mol H," = -40 kJ/mol
All heats of formation are referenced to 273 K.

k = 0.133 exp - --- ___ with E = 31.4 kJ/mol
[:(4:0 k)lkgd$-s

P8-7B Repeat Problem P8-6 by taking pressure drop into account in the PFR.

The reactor can be packed with one of two particle sizes. Choose one.
a = 0.019/kg cat. for particle diameter D,

(Y = 0.0075/kg cat. for particle diameter D,
(a) Plot the temperature, conversion, and pressure along the length of the reactor.
(b) Vary the parameters a and R, to learn the ranges of values in which they
dramaticelly ziTeci the corrversion.