| dc.description.abstract | The aim of this work is the experimental and theoretical characterization of the mass transfer in a
membrane-based dense gas extraction of metal ions from aqueous solutions using a hollow fiber contactor.
Extractions of Cu(II) were conducted in a single fiber membrane contactor operating under steady
state conditions. Aqueous CuSO4 solutions were treated using a CO2 phase containing 1,1,1-trifluoro-
2,4-pentanedione (TFA) or 1,1,1,5,5,5-hexafluoro-2,4-pentanedione (HFA) at 40 ◦C and pressures ranged
between 70 and 90 bar.
Experiments show that the use of dense CO2 as extraction solvent of Cu(II) ions reaches extraction
efficiencies valued up to 98.7%. Simultaneously, a mass transfer model was proposed correlating an
effective rate function of the complex formation at the aqueous-CO2 interface.
The highest extraction efficiencies were observed at higher pressures and lower pH values, which could
confirm that a high content of protons is required to facilitate and stabilize the formation complex by
means of keto-enol tautomerism.
This work represents the first step in order to propose a novel intensified operation, which could be
applied for high valued metals or hazardous materials. | |
