Page 476 - Elements of Chemical Reaction Engineering Ebook

Sec. 8.3 Nonisothermal Continuous-Flow Reactors 447
This equation relates X and T through the energy balance. We see that there
are two equations [Equations (E8-4.5) and (E8-4.6)] that must be solved for
the two unknowns, X and 1:
7. Calculations:
a. Heat of reaction at temperature T:7

(8-27)

Hi(68"F) : -66,600 Btu/lb mol
Calculating the H; (68°F) : - 123,000 Btu/lb mol
parameter values
Hg(68"F) : -226,000 Btu/lb mol

(
NiX(6$"F) = -226,000- - 123,000) - -66,600)
(
= -36,400 Btu/lb mol propylene oxide
ACp = Cpc - CpB - CpA (E8-4.7)
L
.
A
= 46 - 18 - 35 = -7 Btu/lb mol."F
AH;, (T) = -36,400 - (7)(T - 528)
,
b. Stoichiometry ( CAo , 0, 7): The total liquid volumetric flow rate entering
the reactor is
uo = L'AO +uMO +vBO
= 46.62 + 46.62 + 233.1 = 326.3 ft3/h (E8-4.8)
V = 300 gal = 40.1 ft3

= 0.132 lb moi/ft3 (ER-4.9)

FMO 71.87 lb mol/h = 1.67
For methanol: 0, = - =
F, 43.04 lb mollh

-
-
For water: - 50 - 802.8 lb mol/h = 18.65
FA0 43.04 Ib mol/h
C. Energy balance terms:
-
C@icPl= + + @#ep,
b
= 35 +(18.65)(18)+(1.67)(19.5)
= 403.3 Btu/lb mol. "F (E8-4.10)

~__^__
Hi and Hg are calculated from heat-of-combustion data.