Page 574 - Elements of Chemical Reaction Engineering Ebook

544 Unsteady-State Nonisothermal Reactor Design Chap. 9

with

NBO
@ =-
B
NAO
Combine:
(E9-2.5)
k = 0.00017 exp[ E (A i)]
-

Energy Balance:

(E9-2.6)

For ACP = 0,

Let Q, be the heat generated [Le., Q, = (rAv)(c(ff&)] and let Q, be the heat
removed [Le., Q, = UA(T - TJI:
-e, Q,

(E9-2.7)

Then (E9-2.8)

Parameter evaluation for day of explosion:
- 1 NCp = NAOOICpr = (9.0448)(40) + (103.7)(18) + (33)(8.38)

A. Isothermal Operation Up to 45 Minutes

We will first darry out the reaction isothermally at 175°C up to the time the cooling
was turned off at 45 min. Combining and canceling yields

-- - kCAo(1 -x)(@B-2x) (E9-2.9)

33
-
@ B -- g.04 = 3.64
At 175°C = 448 K, k = 0.0001167m3/kmol~min. Integrating Equation (e9-2.9)
gives us

(E9-2.10)