
260 Green Chemical Engineering
constant k = 0.1 m
3
/kmol/min is carried out. Concentration of A in the feed solu-
tion is 1 kmol/m
3
. A total of 80% conversion of A is to be achieved in the two
CSTRs. What is the conversion of A in the rst CSTR corresponding to the optimal
space time?
(Answer: Optimal space times are 37.5 and 50; conversion in the rst CSTR is 60%)
11. Calculate the conversion of A (X
Af
) and the overall selectivity of B (Ø) achieved
in a space time of 5 min in the CSTR and in the PFR for a rst-order series reac-
tion
. The values of kinetic rate constants are k
1
= 0.5 min
−1
and
k
2
= 0.1 min
−1
.
(Answer: For CSTR, X
Af
= 71 ...