Page 233 - Elements of Chemical Reaction Engineering Ebook

204 Isothermal Reactor Design Chap. 4

dCA - rA - - (S4- 16)
--
cAuO
dt V
(S4-17)

(S4- 18)

Equations (S4-12), (S4-13), and (S4-16) to (S4-18) are solved simul-
taneously.
4. Simultaneous reaction and separation
a. Membrane reactors:
RB = k,CB (S4-19)

b. Reactive distillation:
v = V,( 1 + ELX) (S4-20)

ODE SOLVER ALGORITHM

When using an ordinary differential equation (ODE) solver such as
POLYMATH or MATLAB, it is usually easier to leave the mole bal-
ances, rate laws, and concentrations as separate equations rather than
combining them into a single equation as we did to obtain an analytical
solution. Writing the equations separately leaves it to the computer to
combine them and produce a solution. The formulations for a packed-bed
reactor with pressure drop and a semibatch reactor are given below for
two elementary reactions.

Gas Phase Liquid Phase
A+B+3C A+B+2C
Packed-Bed Reactor Semibatch Reactor
- - - dN~ rAv
--
dX - -IA
-
dW F A, dt
-- '2 - rAV + FBo
l - x
CA=c - u1
1 + EXY
e,- x dt
cB = c.40s+Y v = v, + UOt