Mass Transfer Coefficient For Extraction Research Articles

Phenol recovery with tributyl phosphate in a hollow fiber membrane contactor: Experimental and model analysis

The extraction and stripping of phenol using a solution of tributyl phosphate in kerosene in a hydrophobic polypropylene hollow fiber membrane contactor has been studied. The effect of the aqueous and the organic phase flow rates on the overall mass transfer coefficient for both extraction and stripping steps was investigated. Experimental values of the overall mass transfer coefficient were determined and compared with predicted values from the resistance in series model. Results showed that the overall mass transfer coefficients for extraction were about one order of magnitude greater than those measured during the stripping process. The experimental values were in good agreement with the predicted values for the extraction module. However, the predicted values were slightly overestimated for the stripping module. The individual mass transfer resistances were analyzed and the rate-controlling steps of mass transfer were also identified in both extraction and stripping modules. The major resistance in extraction and stripping was in the aqueous phase and in the membrane phase, respectively.

Recovery of copper from ammoniacal medium using liquid membranes with LIX 54

The recovery of copper from ammoniacal medium using non-dispersive solvent extraction (NDSX) with hollow fibres as contactors was studied. The β-diketone LIX 54 was used as an extractant. The influence of the flow rates, initial concentration of copper in the aqueous feed phase and concentration of extractant on the extraction rate was examined. The experimental values of the overall mass transfer coefficients for extraction were compared with the ones predicted by the resistance in series model. Simultaneous extraction and stripping experiments were carried out using two hollow fibre modules under several operating conditions. The results obtained showed that practically all the copper content was removed from the ammoniacal feed solutions. The recovery of copper attained 96–100% and concentration ratios of about 40-fold could be achieved. These results were then compared with the ones obtained by applying the emulsion liquid membranes separation technique.

Recovery of phenol from aqueous solutions using liquid membranes with Cyanex 923

The recovery of phenol from aqueous solutions using hydrophobic polypropylene membrane contactors with Cyanex 923 as an extractant was studied. The effect of the aqueous and organic flow rates on the overall mass transfer coefficient for extraction was determined. The experimental values of the overall mass transfer coefficient for extraction were found in agreement with the ones predicted from the conventional resistance in series model. Integration of the extraction and stripping stages was carried out using different volume phase ratios and stripping reagent concentrations. Concentration ratios of about 39-fold with 98% of phenol recovery could be achieved. The results were then compared with the ones obtained by applying the emulsion liquid membranes separation technique.

A new model for estimating mass transfer coefficients for the extraction of ethanethiol with alkaline solutions in packed columns

The mathematical model for estimating the mass transfer coefficients for the ethanethiol extraction from gasoline, with alkaline solutions was established by processing the data obtained in a laboratory and in a pilot plant experiment. It allows the estimation of overall mass transfer coefficients, taking into account the dispersed phase velocity, the concentration of NaOH solution, the specific area and the porosity of the packing. The model’s parameters were statistical tested in order to confirm the accuracy of the model.

Studies on extraction IV. Relationship between the efficiency and mass transfer coefficient for extraction with back-mixing

Studies on extraction IV. Relationship between the efficiency and mass transfer coefficient for extraction with back-mixing