Separation using supported liquid

Di Luccio M, Smith BD, Kida T, Borges CP, and Alves TLM. Separation of fructose from a mixture of sugars using supported liquid membranes. J. Membr. Sci. 2000 174 217-224. 

M., ViUora, G. (2007). Integrated reaction/separation processes for the kinetic resolution of rac-l-phenylethanol using supported liquid membranes based on ionic liquids. Chem. Eng. Process., 46, 818-24. 

Bara JE, Gabriel CJ, Carlisle TK, Camper DE, FinoteUo A, Gin DL, Noble RD (2009) Gas separations in fluoroalkyl-functionalized room-temperature ionic liquids using supported liquid membranes. Chem Eng J 147 43-50... 

El-Said, N., Rahman, N.A., Borai, E.H., Modification in Purex process using supported liquid membrane separation of cerium(III) via oxidation to cerium(IV) from fission products from nitrate medium by SLM, J. Membr. Sci. 198, 23, 2002. 

Mohapatra, P.K., Bhattacharyya, A., Manchanda, V.K., Selective separation of radio-cesium from acidic solutions using supported liquid membrane containing chlorinated cobalt dicarbollide (CDD) in phenyltrifluoromethyl sulphone (PTMS), J. Hazard. Mater. 181, 679, 2010. 

The removal of actinides from reprocessing acidic waste solutions is advantageous in terms of minimizing the radioactive discharge to the natural environment. The separation of plutonium using supported liquid membranes was extensively studied, as well as U(V1) and Pu(lV) selective transport over fission products and minor actinide contaminants (Lakshmi et al. 2004 Sriram et al. 2000 Kedari et al. 1999). 

Jiang YY, Zhou Z, Jiao Z, Li L, Wu YT, Zhang ZB (2007) SOj gas separation using supported ionic liquid membranes. J Phys Chem B 111 5058-5061... 

The enantiomer separation with the use of membranes is a promising technique, more convenient than traditional methods, due to its high processing capacity, continuous operation mode and low energy consumption allowing its use in a large scale enantiomer separation processes. Supported liquid membranes show high chiral selectivity, however they are not stable on the contrary, solid membranes with immobilized chiral carrier polymer are stable and therefore able to a durable enantiomer separation [100]. 

Adsorbers, distillation colunuis, and packed lowers are more complicated vessels and as a result, the potential exists for more serious hazards. These vessels are subject to tlie same potential haz. uds discussed previously in relation to leaks, corrosion, and stress. However, llicse separation columns contain a wide variety of internals or separation devices. Adsorbers or strippers usually contain packing, packing supports, liquid distributors, hold-down plates, and weirs. Depending on tlie physical and chemical properties of the fluids being passed tlirough tlie tower, potential liazards may result if incompatible materials are used for llie internals. Reactivity with llie metals used may cause undesirable reactions, which may lead to elevated temperatures and pressures and, ullinialely, to vessel rupture. Distillation columns may contain internals such as sieve trays, bubble caps, and valve plates, wliicli are also in conlacl with tlie... 

As described above, the application of classical liquid- liquid extractions often results in extreme flow ratios. To avoid this, a completely symmetrical system has been developed at Akzo Nobel in the early 1990s [64, 65]. In this system, a supported liquid-membrane separates two miscible chiral liquids containing opposite chiral selectors (Fig. 5-13). When the two liquids flow countercurrently, any desired degree of separation can be achieved. As a result of the system being symmetrical, the racemic mixture to be separated must be added in the middle. Due to the fact that enantioselectivity usually is more pronounced in a nonaqueous environment, organic liquids are used as the chiral liquids and the membrane liquid is aqueous. In this case the chiral selector molecules are lipophilic in order to avoid transport across the liquid membrane. 

ILs, on the other hand, are uniquely suited for use as solvents for gas separations. Since they are non-volatile, they cannot evaporate to cause contamination of the gas stream. This is important when selective solvents are used in conventional absorbers, or when they are used in supported liquid membranes. For conventional absorbers, the ability to separate one gas from another depends entirely on the relative solubilities (ratio of Henry s law constants) of the gases. In addition, ILs are particularly promising for supported liquid membranes, because they have the potential to be incredibly stable. Supported liquid membranes that incorporate conventional liquids eventually deteriorate because the liquid slowly evaporates. Moreover, this finite evaporation rate limits how thin one can make the membrane. This... 

The solubilities of the various gases in [BMIM][PFg] suggests that this IL should be an excellent candidate for a wide variety of industrially important gas separations. There is also the possibility of performing higher-temperature gas separations, thanks to the high thermal stability of the ILs. For supported liquid membranes this would require the use of ceramic or metallic membranes rather than polymeric ones. Both water vapor and CO2 should be removed easily from natural gas since the ratios of Henry s law constants at 25 °C are -9950 and 32, respectively. It should be possible to scrub CO2 from stack gases composed of N2 and O2. Since we know of no measurements of H2S, SO, or NO solubility in [BMIM][PFg], we do not loiow if it would be possible to remove these contaminants as well. Nonetheless, there appears to be ample opportunity for use of ILs for gas separations on the basis of the widely varying gas solubilities measured thus far. 

Ionic liquids have already been demonstrated to be effective membrane materials for gas separation when supported within a porous polymer support. However, supported ionic liquid membranes offer another versatile approach by which to perform two-phase catalysis. This technology combines some of the advantages of the ionic liquid as a catalyst solvent with the ruggedness of the ionic liquid-polymer gels. Transition metal complexes based on palladium or rhodium have been incorporated into gas-permeable polymer gels composed of [BMIM][PFg] and poly(vinyli-dene fluoride)-hexafluoropropylene copolymer and have been used to investigate the hydrogenation of propene [21]. 

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