Hollow fiber contained liquid membrane HFCLM

The theory of a hollow-fiber contained liquid membrane (HFCLM) transport is described in detail by Sirkar et al. in Refs. [58,59,91]. Its modified model, (HELM), developed by Schlosser et al. [5,9-11,25,38,92] is presented below. 

Figure 7.4 Drawing of the hollow-fiber contained liquid membrane (HFCLM) (A) configuration of HFCLM in a permeator shell and (B) side-view of the permeator (after modification from Ref. [12] Copyright 1996, reprinted with permission from Francis and Taylor).

Other configurations reported for simultaneous extraction and stripping include hollow fiber-contained liquid membrane (HFCLM) and ELMs in hollow fiber contactors. Neither technique has used microemulsion phases as the liquid membrane. The HFCLM configur-... 

Hollow Fiber Contained Liquid Membrane (HFCLM)... 

Figure 1. Basic hollow fiber-contained liquid membrane (HFCLM) permeator structure.

The same group (62) employed a hollow fiber-contained liquid membrane (HFCLM) module for e removal of heavy metals, such as Cu, Cr, and Hg from waste water. HFCLM combines the two-step process of extraction and stripping into one module containing two bundles of hollow fibers through which the feed and strip solutions flow. Both bundles are present in a single case through which the liquid membrane solution flows. 

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. 

The third liquid-membrane technique is the hollow fiber contained liquid membrane (HFCLM). In the SLM/ ILM technique, the liquid membrane is in contact with the feed liquid/feed gas and the strip liquid/permeate gas. The membrane liquid may be lost by solubilization/volatiliza-tion in addition, there may be irreversible reactions with extractants, complexing agents inside the liquid membrane, which could reduce the performance over time. The HFCLM structure can take care of such problems. In this structure (Figure 8.1.50), the membrane module (cylindrical or otherwise) has two sets of porous hollow fiber membranes. The shell-side interstitial space between the fibers is filled with a liquid acting as the membrane. If this membrane liquid wets the membrane pores and is therefore present in the pores, the pressure conditions in the feed liquid and the sweep/strip fluid should be such (higher) that the membrane liquid is not dispersed in the feed/sweep/stilp fluids. If the membrane liquid does not wet the membrane pores, but the feed/sweep fluids do, then the membrane liquid pressure should be higher than the feed/sweep fluid pressures. 

HFCLM hollow-fiber contained liquid membrane MELM microencapsulated liquid membrane... 

A more recent liquid membrane technique is the hollow fiber-contained liquid membrane technique which is sometimes abbreviated as the CLM technique or the HFCLM technique. This technique has overcome most of the shortcomings of the SLM/ILM techniques. First introduced during 1986-1988 (, 5), the CLM-based permeation technique is undergoing evolution. This paper will provide a brief... 

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