Hollow fiber contained liquid membranes for separations

Gabelman, A. and Hwang, S.T. (1999) Hollow-fiber membrane contactors. Journal of Membrane Science, 159, 61. Sirkar, K.K. (1996) Hollow fiber-contained liquid membranes for separations - an overview, in Chemical Separations with Liquid Membranes (eds R.A. Bartsch and J.D. Way), ACS, p. 222. 

Sirkar KK. Hollow fiber-contained liquid membranes for separations—an overview, In Bartsch, RA and Way, JD, eds. Chemical Separations with Liquid Membranes, ACS, 1996, p. 222. 

Sirkar KK. Hollow Fiber-Contained Liquid Membranes for Separations An Overview. In Bartsch RA, Way JD. (Eds.). Chemical Separations with Liquid Membranes. American Chemical Society, Symposium Series 642, 1996 222-238. 

Hollow Fiber-Contained liquid Membranes for Separations An Overview... 

SIRKAR Hollow Fiber-Contained Liquid Membranes for Separations 223... 

Papadopoulos T and Sirkar KK. A modified hollow fiber contained liquid membrane technique for gas separation at high pressures. JMem Sci, 1994 94(1-3) 163-181. 

Figure 6.15 Schematic hollow-fiber contained liquid membrane permeator (HFCLMP) used for stereoisomers separation. From Ref. [93] with permission.

In Section 5.4.4, we studied a variety of chemical reaction facilitated separation where the reaction was taking place in a thin liquid layer acting as the liquid membrane Figure 5.4.4 illustrated a variety of liquid membrane permeation mechnisms. Here we will identify first the structural configuration of the liquid membranes as they are used in separators with countercurrent flow pattern (as well as for the cocurrent flow pattern). There are three general classes of liquid membrane structures emulsion liquid membrane (ELM) supported liquid membrane (SLM) or immobilized liquid membrane (ILM) hollow fiber contained liquid membrane (HFCLM). Each will be described very briefly. 

Facilitated transport of penicilHn-G in a SLM system using tetrabutyl ammonium hydrogen sulfate and various amines as carriers and dichloromethane, butyl acetate, etc., as the solvents has been reported [57,58]. Tertiary and secondary amines were found to be more efficient carriers in view of their easy accessibility for back extraction, the extraction being faciUtated by co-transport of a proton. The effects of flow rates, carrier concentrations, initial penicilHn-G concentration, and pH of feed and stripping phases on transport rate of penicillin-G was investigated. Under optimized pH conditions, i. e., extraction at pH 6.0-6.5 and re-extraction at pH 7.0, no decomposition of peniciUin-G occurred. The same SLM system has been applied for selective separation of penicilHn-G from a mixture containing phenyl acetic acid with a maximum separation factor of 1.8 under a liquid membrane diffusion controlled mechanism [59]. Tsikas et al. [60] studied the combined extraction of peniciUin-G and enzymatic hydrolysis of 6-aminopenicillanic acid (6-APA) in a hollow fiber carrier (Amberlite LA-2) mediated SLM system. 

Continuous fermentation processes can also be carried out in a hollow fiber fermentor (HFF).85 Cells are packed into the shell side of a hollow fiber module, while substrate solution is fed to the core of the fibers (Figure 7.41). Since the cell slurry is separated from the substrate solution by the membrane, HFFscan be used for fermentation of liquid streams containing low molecular weight fermentable substances. A careful choice of membrane molecular weight cut-off can also assure that the cell environment is fully sterilized. Figure 7.45 shows typical performance of an HFF for whey permeate fermentation to ethanol by... 

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