CSTRs-in-Series A first order reaction of A in the liquid phase has a rate const
ID: 891283 • Letter: C
Question
CSTRs-in-Series
A first order reaction of A in the liquid phase has a rate constant of 0.020 min^-1. The reaction of A to product is to be carried out isothermally at 200oC in two identical CSTRs-in-series, each vessel having a volume of exactly 100 L. The feed rate of reactant liquid is 0.7884 L/min. You may assume there is no change of volume during reaction.
a.) Please calulate the conversion leaving the second CSTR.
b.) To achieve the same conversion in a single 200 L CSTR, what feed rate (in L/min) would be needed?
Explanation / Answer
The governing equation for 1st order reaction is :-
rate constant(k)*time(t) = ln(initial rate/rate after time't')
a) k = 0.02 min-1 ; t = 1 min
Thus, 0.02*1 = ln(0.784/x)
or, e0.02 = 0.784/x
or, x = 0.768 L/min
Thus, the conversion rate = feed rate - x = 0.0199 L/min