Membranes ceramic

Because membranes appHcable to diverse separation problems are often made by the same general techniques, classification by end use appHcation or preparation method is difficult. The first part of this section is, therefore, organized by membrane stmcture preparation methods are described for symmetrical membranes, asymmetric membranes, ceramic and metal membranes, and Hquid membranes. The production of hollow-fine fiber membranes and membrane modules is then covered. Symmetrical membranes have a uniform stmcture throughout such membranes can be either dense films or microporous. 

Although hollow fibers are thought to be an excellent candidate to be used as support-they are cheap and have a very high surface area to volume (>1000 m m ) - very few reports on hollow-fiber-supported zeolite membranes exist in the open literature. For zeohte membranes, ceramic hollow fibers are preferred because of their mechanical and thermal stability. Recently, Alshebani... 

Electrolyte Potassium hydroxide Polymer membrane Immobilized liquid molten carbonate Immobilized hquid phosphoric acid Ion exchange membrane Ceramic... 

Elmer, T. H. 1978. Evaluation of porous glass as desalination membrane. Ceramic Bull. 57(11) 1051-53, 60. 

Membrane Ceramic, polypropylene (PP), Thin film of ceramic. Thin film of CA Thin film of CA... 

In this chapter membrane preparation techniques are organized by membrane structure isotropic membranes, anisotropic membranes, ceramic and metal membranes, and liquid membranes. Isotropic membranes have a uniform composition and structure throughout such membranes can be porous or dense. Anisotropic (or asymmetric) membranes, on the other hand, consist of a number of layers each with different structures and permeabilities. A typical anisotropic membrane has a relatively dense, thin surface layer supported on an open, much thicker micro-porous substrate. The surface layer performs the separation and is the principal barrier to flow through the membrane. The open support layer provides mechanical strength. Ceramic and metal membranes can be either isotropic or anisotropic. 

Due to their greater chemical and thermal stabilities and narrower pore size distributions compared to polymer membranes, ceramic membranes are attractive in a number of filtration applications related to the fermentation broths. They can be used for either upstream or downsueam processing. 

Content of Some Radioisotopes in the Process Streams in UF/Complexation Experiments. Membrane CeRam Inside 15 kDa... 

Typical UF performance for pyrogen removal with a polymeric and ceramic membrane is shown in Table 13. It can be seen that both types of UF membranes can adequately remove pyrogens. The choice of UF membrane (ceramic or polymeric) will depend on operating conditions or other special process requirements. Ceramic membrane ultrafiltration can achieve a 5 log reduction in pyrogen level. These UF membranes have been validated for the production of water meeting the requirements of pyrogen-free water for injection (WFI) standards.f ... 

Figure 9.10a shows a concept for scale-up of cermet (ceramic-metal) type membranes. Ceramic closed-one-ended tubes coated with thin, dense hydrogen permeable materials are envisioned for the cermet-type membranes (Fig. 9.10a) As with the all-metal systems, the closed-one-ended tube arrangement allows free chemical and thermal expansion and minimizes the seal area. CoorsTek has had previous...

For laboratory research, various types of membranes mentioned earlier are used without any support in PV cells. For large-scale applications, where the membrane sizes are larger, the reinforcement of this top skin layer by an appropriate support is required to maintain dimensional stability. These types of membranes consisting of a skin layer (permselective layer) supported by a suitable support are called composite membranes. Ceramic-supported membranes already have a support, and hence, no additional support is required. 

Proven integrity of membranes albeit with a limited life span of 3—5 years for polymeric membranes. Ceramic membranes, which last longer, are also being deployed but are expensive. 

Zeolite membrane Ceramic membranes made up of a micro-porous support layer and a meso- or micro-porous active layer. Made from alumina, silica, titania, zirconia, or any other mixtures of these materials. 

Vladisavljevic, G.T., Lambrich, U., Nakajima, M., and Schubert, H., Production of O/W emulsions using SPG membranes, ceramic a-Al203 membranes, microfluidizer and a microchannel plate — a comparative study. Colloid Surface A, 232 (2-3), 199-207, 2004. 

Pelaez, L., Vdzquez, M.I. and Benavente, J. 2010. Interfacial and fouling effects on diffusional permeability across a composite ceramic membrane. Ceram. Int. 36 727 801. 

It goes in the same direction as the possibility of using porous inorganic-membrane supports modified with nanosized metaUocomplex components, distributed into the membrane pores (Tsodikov et al., 2011). The kind of possible supports are of a different nature, but they must be chosen with respect to rules of acceptable resistance and capacities. This is why a preliminary study of four types of membrane ceramic supports was done, to identify their main features before any other kind of modifications (Table 4.17) (Tsodikov et al., 2011). 

Mikulasek, P., Dolecek, P., Rambousek, V., Cakl, J. and Sed H., Testing of Micro-filtration Ceramic Membranes , Ceramics—Silikdty, 38(2), 99 (1994)... 

An emerging new group of lithium-ion separator comprises of inorganic composite membranes ( ceramic separators ) with their excellent wettability and exceptional thermal stability properties. Most of ceramic separators are porous mats made of ultrafine inorganic particles bonded using a small amount of binder. 

Dual-phase transport membrane (ceramic-ceramic and metal-ceramic)... 

In the 25 years that have passed since 1972 the field of defect chemistry in oxides has grown and developed in many ways. New and improved measurement techniques, new synthesis techniques, as well as skilled and devoted investigators have produced better data for many oxides, partly encouraged by industrial developments in the use of solid electrolytes (solid oxide fuel cells, gas separation membranes, ceramic electrodes, catalysts, etc). Computer modelling enables detailed analysis of defect chemistry and transport processes, and helps us interpret experimental data. Although the increasing accuracy and complexity is welcome and unavoidable, the sound overview and ability to analyse a situation may be obscured or lost. The newcomer may find the field difficult to enter. 

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