Inorganic membranes hollow fiber

The phase inversion method is developed to prepare hollow fiber inorganic membranes. Since the porous substrate and the separation layer are formed in a single step for this method, the preparation process can be... 

Figure 8.7. Shell-and-tube membrane module containing either hollow-fiber polymeric membranes or tubular inorganic membranes.

M. Hassan, J.D. Way, P.M. Thoen and A.C. Dillon, Separation of gas mixtures using hollow fiber silica membranes, in Y.H. Ma (Ed.), Proceedings of 3rd International Conference on Inorganic Membranes (ICIM3), July 10-14,1994, Worcester, MA, USA. Distributed by Worcester Polytechnic Institute, 100 Institute Rd. Worcester, MA 01609, USA. pp. 325-335. 

Membrane Processes in Separation and Purification published in 1993, contains chapters on pervaporation, facilitated transport membrane processes, membrane gas absorption processes, hollow fiber contactors, membrane reactors, and the preparation and application of inorganic membranes. In addition to an introductory chapter by the editors. Polymeric... 

Hollow fiber membrane(s), 70 766 76 1-31 additional types of, 76 24 advantages of, 76 3 categories of, 76 2-3 in desalination, 76 22 development of, 76 1 extractors, 70 787 fiber treatment for, 76 12-18 future prospects for, 76 26-28 glass and inorganic, 76 23-24 handling and unit assembly of, 76 15-18 interpenetrated wall matrix in, 76 15 low pressure, 76 24-26 macrovoids in, 76 12 materials associated with, 76 18-24 melt spinning of, 76 9-10... 

Inorganic glass systems, 12 568t Inorganic halogen compounds, hydrogen chloride reaction with, 13 820 Inorganic hollow-fiber membranes, 16 23-24... 

Although the pyrolysis of organic materials (organic hollow fibers) is used in the commercialization of a new family of inorganic membranes (Fleming 1988) there are only a few descriptions in the open literature. Koresh and Soffer (1980, 1986, 1987) have published a series of articles on this subject. There is also a paper by Bird and Trimm (1983) which is based on a previously described preparation procedure of Trimm and Cooper (1970, 1973). 

In this last section some recent developments are mentioned in relation to gas separations with inorganic membranes. In porous membranes, the trend is towards smaller pores in order to obtain better selectivities. Lee and Khang (1987) made microporous, hollow silicon-based fibers. The selectivity for Hj over Nj was 5 at room temperature and low pressures, with permeability being 2.6 x 10 Barrer. Hammel et al. 1987 also produced silica-rich fibers with mean pore diameter 0.5-3.0nm (see Chapter 2). The selectivity for helium over methane was excellent (500-1000), but permeabilities were low (of the order of 1-10 Barrer). 

Zeolite/polymer mixed-matrix membranes can be fabricated into dense film, asymmetric flat sheet, or asymmetric hollow fiber. Similar to commercial polymer membranes, mixed-matrix membranes need to have an asymmetric membrane geometry with a thin selective skin layer on a porous support layer to be commercially viable. The skin layer should be made from a zeohte/polymer mixed-matrix material to provide the membrane high selectivity, but the non-selective porous support layer can be made from the zeohte/polymer mixed-matrix material, a pure polymer membrane material, or an inorganic membrane material. 

Inorganic membranes Glass hollow fiber Glass hollow fiber Graphite, oxidized Schott A Gen. Westinchouse (Union Carbide Comp.) SO 98 80 120 41 0.5 0.5 ... 

Different membrane shapes are used, such as plates, foils, spirals, hollow fibers, tubes, and even monilithic multichannel elements have been mentioned in the context of membrane reactors. In the following section, a general survey will be given indicating the main characteristics of the different types of inorganic membranes used in CMRs. More details can be found elsewhere [13-15]. 

Current commercial inorganic membranes come in a limited number of shapes disk, tube and monolithic honeycomb. Compared to other shapes such as spiral-wound and hollow-fiber that are available to commercial organic membranes, these types of membrane elements have lower packing densities and, therefore, lower throughput per unit volume of membrane element or system. 

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