The DOI (Digital Object Identifier) link for this article is http://dx.doi.org/10.1017/S1446181100008348.
The DOI (Digital Object Identifier) link for this article is http://dx.doi.org/10.1016/j.cej.2005.04.012.
The DOI (Digital Object Identifier) link for this article is http://dx.doi.org/10.1017/S1446181100009974.
Abstract
We extend an investigation into the static and dynamic
multiplicity exhibited by
the reaction of a fuel/air mixture in a continuously stirred tank
reactor by considering the effect of adding a chemically inert species
to the reaction mixture.
The primary bifurcation parameter is taken to be the
fuel fraction as this is the most important case from the perspective of
fire-retardancy. We show how the addition of the inert species progressively
changes the steady-state diagrams and flammability limits. We
also briefly
outline how heat-sink additives can be incorporated into our scheme.
M.I. Nelson. Bifurcation phenomena for an oxidation reaction in a continuously stirred tank reactor. III The inhibiting effect of an inert species. The ANZIAM Journal, 46(3), 399-416, March 2005. http://dx.doi.org/10.1017/S1446181100008348.
Abstract
The dynamics of a non-isothermal bi-molecular gas-phase reaction in a
semi-batch reactor is investigated. It is assumed that one of the
reactants flows into a reactor containing the second. A reduced model
is obtained by making a `pool-chemical' approximation on the
concentration of the reactant initially in the reactor.
The region in parameter space in which oscillations are observable in the full
transient model is estimated by determining the Hopf bifurcation locus
in the reduced system. The contribution of the current work is its
comparative study of the behaviour of the full system to that of the
pool-chemical model. Although the reaction scheme is symmetric with
respect to the reactants the regions of oscillatory behaviour are not
identical because the reactants have different heat capacities.
Keywords: Semi-batch reactor; Gas-phase oxidation reaction; Pool-chemical approximation; Oscillations; Hopf bifurcation.
H.S. Sidhu and M.I. Nelson. Behaviour of an elementary oxidation reaction in a semi-batch reactor. Chemical Engineering Journal, 110(1-3), 31-39, 2005.
The DOI (Digital Object Identifier) link for this article is http://dx.doi.org/10.1016/j.cej.2005.04.012.
Abstract
We investigate a bioreactor cascade consisting of two reactors. For a given
total residence time, we study how the performance of the reactor
(measured either as the cell mass concentration or the reactor productivity)
depends upon the feed substrate concentration and the residence time in the
first reactor. The bioreactor model in this study uses a growth rate
that is given by a Monod expression with a yield coefficient that is a linear
function of the substrate concentration. Previous researchers have compared
the performance of a two-reactor system against a single reactor with the same
total residence time. The main focus of this paper is to show that the
performance of a two-reactor cascade should not be gauged in this manner,
as comparisons using this criterion can give grossly misleading results.
Our analysis shows that before maximising the performance of a cascade, we
must first consider the performance of a single reactor system as a
benchmark.
H.S. Sidhu and M.I. Nelson. Improving Bioreactor Performance: Are Two CSTBs Always Better Than One? In Proceedings of the 33rd Australasian Chemical Engineering Conference, CHEMECA 2005, 6 pages (on CDROM). Institute of Engineers, Australia, 2005. ISBN 1-86499-832-6.
Abstract
We investigate a chemostat model in which the growth rate is given by
a Monod expression with a variable yield coefficient. This model has
been investigated by previous researchers using numerical integration.
We combine analytical results with path-following methods. The conditions
for washout to occur are found. When washout does not occur we establish
the conditions under which the reactor performance is maximised at
either a finite or infinite residence time. We also determine the
parameter region in which oscillations may be generated in the reactor,
which was the primary feature of interest to earlier workers on this
problem.
Keywords: bioreactors, Non-linear dynamics,
reaction engineering
.
AMS Subject classification: 34Cxx, 92C45, 92E20.
M.I. Nelson and H.S. Sidhu. Analysis of a chemostat model with variable yield coefficient. Journal of Mathematical Chemistry, 38(4): 605-615, 2005.
Abstract
We investigate the behaviour of a reaction described by Michaelis-Menten
kinetics in an immobilised enzyme reactor (IER). The IER is treated
as a well-stirred flow reactor, with the restriction that
bounded and unbounded enzyme species are constrained to remain within
the reaction vessel. Our aim is to identify the best operating conditions for
the reactor.
The cases in which an IER is used to either reduce pollutant emissions or to synthesise a product are considered. For the former we deduce that the reactor should be operated using low flowrates whereas for the latter high flowrates are optimal. It is also shown that periodic behaviour is impossible.
M.I. Nelson, X.D. Chen and M.J. Sexton. Analysis of the Michaelis-Menten mechanisms in an immobilised enzyme reactor. The ANZIAM Journal, 47(2): 173-184, 2005. http://dx.doi.org/10.1017/S1446181100009974.