Page 149 - Elements of Chemical Reaction Engineering 3rd Edition

Chap. 3 Questions and Problems 121

A+B <I
C
with CAo = C,, = 2 mol/dm3 and Kc = 10 dm7/mol.

(b) The gas-phase reaction
A e 3C
can-ied out in a flow reactor with no pressure drop. Pure A enters at a tem-
perature of 400 EL and 10 atm. At this temperature, Kc = 0.25 dm3/mo12.
(c) The gas-phase reaction in part (b) carried out in a constant-volume batch
reaction.
(d) The gas-phase reaction in part (b) carried out in a constant-pressure batch
reaction.
B3-18, Consider a cylindrical batch reactor that has one end fitted with a frictionless
piston attached to a spring (Figure P3-18). The reaction

A+B __j 8C
with the rate expression
-rA = k,CiCB
is taking place in this type of reactor.
Reaction occurs -4

in

Figure P3-18 here

(a) Write the rate law solely as a function of conversion, numerically eviduat-
ing all possible symbols. (Ans.: -rA = 5.03 X [(l - X)3/(l + 3103/2]
lb mol/ft3. s.)
(b) What is the conversion and rate of reaction when V = 0.2 ft3? ('4ns.:
X = 0.259, -rA = 8.63 X 1Q-l0 lb mol/ft3.s.)
Additional information:
Equal moles of A and B are present at t = 0
Initial volume: 0.15 ft3
Value of kl: 1.0 (ft3/lb mol)2.s-1
The relationship between the volume of the reactor and pressure
within the reactor is
V = (o.l)(P) (Vin ft3, Pin atm)
Temperature of system (considered constant): 140°F
Gas constant: 0.73 ft3 atdlb mol. "R
P3-19c Find the reaction rate parameters (Le., reaction order, specific reaction rate at
one temperature, and the activation energy) for:
(a) Three industrial reactions
(b) Three laboratory reactions
(c) Three reactions discussed in the literature during the last year