Hollow fibre supported liquid membranes

Keller, O.C., Poitry, S. and BufHe, J. (1994) A hollow fibre supported liquid membrane system for metal speciation and preconcentration calculation of the response time. J. Electroanal. Chem., 378, 165-175. 

Lezamiz, J. and J.A. Jonsson. 2007. Development of a simple hollow fibre supported liquid membrane extraction method to extract and preconcentrate dinitrophenols in environmental samples at ng L-1 level by liquid chromatography. J. Chromatogr. A 1152 226-233. 

D. S. Flett and D. Pearson, Role of Hollow Fibre Supported Liquid Membranes in Hydrometallurgy, in Extraction Metallurgy 85, Inst. Min. Metall., London, UK, 1985, pp. 1-21. 

A simple model for predicting the flux of CO2 through hollow fibre supported liquid membranes has been presented. It has been shown that radial geometry must be considered in order to accurately simulate the flux of the gas through the walls of a hollow fibre and that a flat sheet model is not able to capture this. However, because of... 

Ansari, S.A., Gujar, R.B., Mohapatra, P.K., Kandwal, R, Sengupta, A., Thulasidas, S.K. Manchanda, V.K. (201 lb) A cold actinide partitioning run at 20 L scale with hollow fibre supported liquid membrane using diglycolamide extractants. RadiocMmicaActa, 99 (12), 815-821. 

Patil, C.B., Mohapatra, P.K., Lakshmi, D.S., Venugopalan, A.K., Manchanda, VK. Mohan, D. (2003)Trans-port of uranium from HCl medium using hollow fibre supported liquid membrane containing Alamine 336 in toluene as flie carrier. Paper presented at the 22nd Annual Conference of the Indian Council of Chemists, 17-19 October 2003, ET Roorkee, Roorkee, India. 

Supported ionic liquid membranes have also found application in analytical chemistry, specifically in the trace determination of toxic substances. Several examples of the application of ionic liquids as liquid membrane in hollow fibre-supported liquid-phase nuCToextraction have been reported [50,51 ]. This technique, combined with high-performance liquid chromatography was used for (he determination of chlorophenols and sulphonamides in environmental water samples. 

Parthasarathy, N., Pelletier, M. and Buffle, J. (1997) Hollow fibre based supported liquid membrane a novel analytical system for trace metal analysis. Anal. Chim. Acta, 350, 183-195. 

Simulation of Supported Liquid Membranes in Hollow Fibre Configuration... 

Supported liquid membranes offer excellent selectivity for use in gas separation. The transport of CO2 through an aqueous diethanolamine solution held within a hollow fibre membrane is modelled in this paper. When compared with flat-sheet models, the results demonstrated that radial geometry has to be taken into account in a hollow fibre model. The model was used to simulate the CO2 separation in membrane contactors and the results were compared with experimental data. The discrepancy between the results and the experimental data is thought to be due to the conditions within the membrane contactors, which are far from ideal. 

In general, membrane-supported liquid-liquid extraction is offered as a micro-porous hollow fibre module (Fig. 2.23). The membrane contactor contains thousands of micro-porous hollow fibres knitted into an array that is wound around a distribution tube with a central baffle. The hollow fibres are arranged in a uniform open packing allowing the utilisation of the total membrane surface area. The liquid flows over the shellside (outside of the hollow fibre), is introduced through the distribution tube and moves radially across the array of hollow fibres and then around the baffle and is carried out by the collection tube. 

A MC module contains thousands of microporous hollow fibres, which are knitted into a fabric that is wound around a distribution tube with a central baffle as shown in Figure 1.15. The baffle ensures the water is distributed across the fibres, and also results in reduced pressure drop across the contactor. The hollow fibres are packed densely in a membrane module with a surfrce area of up to 4000 n / m. The liquid flows outside (shell side) the membrane, while vacuum is appHed on the inside of the fibre (tube side) forming a film across the pores of the membrane. Mass transfer takes place through this film and the pores due to the difference in the gas partial pressure between the shell side and tube side. Since the membranes are hydrophobic, they are not wetted by water, thereby, efiectively blocking the flow of water through the membrane pores. The membrane provides no selectivity. Rather its purpose is to keep the gas phase and the Hquid phase separated. In effect, the membrane acts as an inert support that allows intimate contact between gas and liquid phases without dispersion. Vacuum on the tube side of the membrane increases the mass transfer rate as in a vacuum tower. The efficiency of the process is enhanced with the aid of nitrogen sweep gas flowing on the permeate side of the membrane. 

---