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Authors
Advisor(s)
Abstract(s)
The mass balances on substrate in each unit of a series of CSTRs performing an enzyme-catalyzed reaction described
by Michaelis-Menten kinetics (with parameter K,,,)a re written and the necessary and sufficient condition that must be
satisfied by the intermediate concentrations in order to obtain a minimum overall capital investment is found on the
assumption that the cost of each reactor unit scales up on its capacity according to a fractional factor exponential rule
(with parameter n). The asymptotic situations of pseudo-zero order and pseudo-first order behavior are explored. The
ratio between consecutive concentrations leading to a minimum overall capital investment decreases as K,,, decreases at
a rate that is slower for higher n, and tends to unity as the pseudo-first order situation is approached. If fractional values
of n are considered, local minima of the capital investment associated with the overall reactor cascade exist only in certain
ranges of substrate conversion; below the lower limits of such ranges, the number of reactor units should actually
be decreased. A graphical procedure aimed at obtaining the intermediate optimal concentrations is presented.
Description
Keywords
Capital investment Exponential factor rule Michaelis-Menten reactions Optimization
Pedagogical Context
Citation
MALCATA, F. Xavier - Economic Criteria in the Design of Cascades of CSTR’s for the Performance of Enzyme -c at a1 yzed Reactions. The Canadian Journal of Chemical Engineering. ISSN 1939-019X. Vol. 75, n.º 5 (1997), p. 984-989
Publisher
Chemical Institute of Canada