Page 207 - Elements of Chemical Reaction Engineering 3rd Edition

See. 4.6 Using CA (liquid) and FA (gas) in the Mole Balances and Rate Laws 179

TABLE 4-6. (continued)
then

r,
r, = b -rA rc = -; r, =I -;
r,
d
C
a
Concentrations:

Tatat molar flow rate: F, = FA + F, + F, + F,
4. Combine: For an isothermal operation of a PBR wlth no AP
Mewures
other than
conversion

1. Specify parameter values: k,, C,,, a, p, To,a, b, c,d
2. Specify entenhg numbers: FAO, F,,, F,,, F, and final values: Vfina,
5. Use an ODE solver.

Emmple 4-9 Working in Terms of Molar Flow Rates in a PFR

The gas-phase reaction
A I
28
is carried out isothermally (T = 500 K) and isobarically (Po = 4.1 atm) in a PFR
qnd follows an elementary rate law. Express th,e r+te law and mole balances in terms
of the molar flow rates and solve the combined equations to determine the molar
flow rates along the length of a IOO-drn' PFR.

Additional infomation:
k:, = 2.7 min- l, K, = 1.2 mol/dm3, FAo = 10 mQYmin

Solution

dEA -
The algorithm Mole1 balance: -_ (EA-9.1)
dV

(E4-9.2)

Rate law: (E4-9.3)