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Advisor(s)
Abstract(s)
Solvent extraction is considered as a multi-criteria optimization problem, since several chemical species with
similar extraction kinetic properties are frequently present in the aqueous phase and the selective extraction
is not practicable. This optimization, applied to mixer–settler units, considers the best parameters and
operating conditions, as well as the best structure or process flow-sheet. Global process optimization is
performed for a specific flow-sheet and a comparison of Pareto curves for different flow-sheets is made. The
positive weight sum approach linked to the sequential quadratic programming method is used to obtain the
Pareto set.
In all investigated structures, recovery increases with hold-up, residence time and agitation speed, while the
purity has an opposite behaviour. For the same treatment capacity, counter-current arrangements are shown
to promote recovery without significant impairment in purity. Recycling the aqueous phase is shown to be
irrelevant, but organic recycling with as many stages as economically feasible clearly improves the design
criteria and reduces the most efficient organic flow-rate.
Description
Keywords
Solvent extraction Mixer–settlers Modelling Multi-criteria optimization Pareto curves
Citation
Publisher
Elsevier