Dense ceramic membranes membrane reactors fabrication

There are three main types of dense ceramic membranes disk/flat sheet, tubular, and hollow fibers. The disk/flat sheet membranes are applied mostly in research work because they can be fabricated easily in laboratories with a small amount of membrane material. Comparatively, the hollow fiber membranes can provide the largest membrane area per volume but low mechanical strength, while the tubular membranes possess a satisfactory specific membrane area, high mechanical strength, and are easy to assemble in membrane reactors. Dense ceramic MRs can be constructed and operated in either packed bed MR or catalytic MR configurations. 

Abstract Dense ceramic membrane reactors are made from composite oxides, usually having perovskite or fluorite structure with appreciable mixed ionic (oxygen ion and/or proton) and electronic conductivity. They combine the oxygen or hydrogen separation process with the catalytic reactions into a single step at elevated temperatures (>700°C), leading to significantly improved yields, simplified production processes and reduced capital costs. This chapter mainly describes the principles of various types of dense ceramic membrane reactors, and the fabrication of the membranes and membrane reactors. 

Disc/flat-sheet-shaped membranes are mostly applied in dense ceramic membrane reactors due to the ease of the fabrication process the ceramic material powder is pressed into discs in a stainless steel mould under an isostatic or hydraulic pressure, followed by sintering at a high temperature. Such disc-shaped membranes usually have a thickness of about 1 mm so as... 

Dense ceramic membranes allow oxygen or hydrogen permeation in a dissociated or ionized form other than the conventional molecular diffusion, and thus exhibit extremely high selectivity (up to 100%). They can be incorporated into membrane reactors for a variety of oxidation and dehydrogenation reactions where the membrane functions as either a product extractor or a reactant distributor. Three configurations, that is, disc/flat-sheet, tubular and hollow fibre membranes have been applied in membrane reactors. They exhibit respective advantages/disadvantages in terms of the ease and cost of fabrication, the effective membrane area/volume ratio, and... 

This chapter will describe extensively the dense ceramic oxygen permeable membrane reactors from their principles, fabrication, and design to their applications. The prospects and critical issues of the dense... 

High-temperature sealing and connection. For the fabrication of industrial dense ceramic MRs, a key problem is the development of seals for membrane integrity with other reactor components that are able to operate at high temperatures. One solution to seal ceramic membranes with metal is the use of ceramic glass. These materials usually require high temperatures to melt, and creep of the membrane can be detrimental to the sealing [5]. 

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