Page 558 - Elements of Chemical Reaction Engineering Ebook

528 Steady-State Nonisothermal Reactor Design Chap, 8

(a) Find the ideal inlet temperature for the production of styrene for a
steam/ethylbenzene ratio of 58: 1. (Hint: Plot the molar flow rate of
stryrene versus To. Explain why your curve looks the way it does.)
(e) Find the ideal steam/ethylbenzene ratio for the production of styrene at
900 K. [Hint: See part (d).]
(0 What do you believe to be the points of this problem?
(g) Ask another question or suggest another calculation that can be made for
this problem.
Additional information:
Heat capacities
Methane 68 J/mol. K Styrene 273 J/mol.K
Ethylene 90 J/mol. K Ethylbenzene 299 J/mol *K
Benzene 201 J/mol.K Hydrogen 30 J/mol-K
Toluene 249 J/mol.K Steam 40 J/mol.K
p = 2137 kg/m3 of pellet
+ = 0.4
AHRxlEB = 118,000 kJ/kmol ethylbenzene
AHRx2EB = 105,200 kJ/kmol ethylbenzene
AH,,,,, = -53,900 kJ/kmol ethylbenzene
I
{ ;
+
K~, exp b, + 3 + b3 In (TI + [(b,~ b,) T + b6] T atm
=
b1 = -17.34 b4 = -2.314 X lo-''
b2 = -1.302X lo4 b5 = 1.302 X
b3 = 5.051 bs = -4.931 X low3
The kinetic rate laws for the formation of styrene (St), benzene (B), and tolu-
ene (T), respectively, are as follows. (EB = ethylbenzene)

(
rZB = p (1 - +) exp 13.2392 -

r3T = p (1 - 4) exp (F'EBPH2) (kmol/m3 * S)

The temperature T is in kelvin.
P8-31B The liquid-phase reactions

(1) A+3 > D (desired reaction)
(2) A+B k2 > U (undesiredreaction)