Page 522 - Elements of Chemical Reaction Engineering Ebook

492 Steady-State Nonisothermal Reactor Design Chap. 8

Heat-removed curve
RtT)

T
Figure 8-18 Variation of heat removal line with inlet temperature.

TO
T
Figure 8-19 Variation of heat removal line with K (K = UA/CpoFA0).

8.6.2 Heat of Generation, G(T)

The heat-generated term, Equation (8-68), can be written in terms of
conversion, (recall: X = -rAV/FAo)
G( T) = ( - AHo,,)X (8-70)
To obtain a plat of heat generated, G(T), as a function of temperature, we must
solve for X as a function of T using the CSTR mole balance, the rate law, and
stoichiometry. For example, for a first-order liquid-phase reaction, the CSTR
mole balance becomes
v=-- FAOX - uOcAOx,
kC, kC,( 1 - X)

Solving for X yields
x= -
zk
I st order reaction
1 +zk
Substituting for X in Equation (8-70), we obtain
-AH;,zk
G(T) = (8-71)
1 +zk