Sustainability and Stability - Bioprocess Engineering: Kinetics, Biosystems, Sustainability and Reactor Design - page 853

is to be carried out adiabatically in a flow reactor. The feed consists of pure A at
a temperature of 298 K and a pressure of 1 bar. The feed rate is 0.1 mol/s. Neglect
the pressure drop in the reactor.
(a) Calculate the operating temperature and conversion from a CSTR of volume 2 m 3 .
Indicate the stability of your solution.
(b) Calculate the volume of a PFR for a conversion of 0.99. Comment on your findings.
(c) Recalculate the volume of the PFR for a conversion of 0.99, but the feed to the
reactor is preheated to 500 K.

The additional data are k ¼ 10 11 exp

s 1

E
RT

E
R ¼ 18

; 000 K; D H R ¼ 60 kJ/mol-A;

;

C PA ¼ 120 J/(mol $ K); C PB ¼ 80 J/(mol $ K); C PC ¼ 40 J/(mol $ K).
16.8. The elementary reversible liquid-phase reaction

A % B

is to be carried out in a CSTR with a heat exchanger. Pure A enters the reactor at
a molar flow rate of 10 mol/min. The inlet temperature is the same as the ambient
temperature of the fluid in the heat exchanger, T 0 ¼ T

N ¼ 320 K. For your convenience,
the fractional conversion of A is given as a function of the effluent temperature, T e ,in
Fig. P16.8 . Assume that the heat exchanger capacity, U 0 A, can be changed at will.
What is the value of U 0 A required to obtain the maximum conversion, and what is
the reactor temperature?
Additional data: M A ¼ M B ¼ 58 kg/kmol, C PA ¼ C PB ¼ 167.4 J/(mol $ K),
D H R ¼ 334.7 kJ/mol at 400 K, V ¼ 10 l and Q 0 ¼ 1 L/min.

FIGURE P16.8