Carbon dioxide separation zeolite membranes

Carbon dioxide separation from nitrogen using Y-type zeolite membranes... 

This cost differential can be tolerated only in applications in which polymeric membranes completely fail in the separation [78]. Demanding separation applications, where zeolite membranes could be justified, due to the high temperatures involved or the added value of the components, and have been tested at laboratory scale, are the following separation of isomers (i.e., butane isomers, xylene isomers), organic vapor separations, carbon dioxide from methane, LNG (liquefied natural gas) removal, olefines/paraffins and H2 from mixtures. In most cases, the separation is based on selective diffusion, selective adsorption, pore-blocking effects, molecular sieving, or combinations thereof. The performance or efficiency of a membrane in a mixture is determined by two parameters the separation selectivity and the permeation flux through the membrane. 

Kusakabe K, Kuroda T, and Morooka S. Separation of carbon dioxide from nitrogen using ion-exchanged faujasite-type zeolite membranes formed on porous support tubes. J Membr Sci 1998 148(l) 13-23. 

The Sandia aluminosilicate zeolite membranes have fluxes on the order of 10-6 mole/mole per meter squared Pascal secont (flux unit) (m Pa sec) and pure gas separations of H2/N2 >61, H2/CO2 >80, H2/ CH4 =7, CH4/CO2 >11. H2 (hydrogen), N2 (diatomic nitrogen),C02 (carbon dioxide), CH4 (methane). 

MFl has been extensively studied in zeolite membranes preparation due to its pore size suitable for several industrially important separations." " Using MFl supported membranes it was demonstrated that the CO2/N2 separation factor increases with CO2 feed composition because of the higher CO2 adsorption on the zeolite wall, which consequently limits the N2 transport in zeolitic channels." The selectivity of this gas species reaehes the value of 20 at 180 °C when the carbon dioxide composition is higher than 60% in the feed. Other researchers using membranes with the same topology found the same effect of the CO2 feed concentration on its separation from nitrogen." ... 

Some of the available membrane separation processes can already be applied on an industrial scale. Hence, inorganic ceramic membranes (zeolites and their derivatives, e.g. silico aluminophosphates), organic polymer membranes and facilitated transport membranes, which rely on a carrier molecule with high CO2 affinity to achieve selective CO2 transport (such as metallic ions or liquid amines), have been used in separating CO2 from flue gas in post-combustion. As single-stage separation with these membranes is still difficult, new membrane materials are being developed [1]. Typically, the initial separation of carbon dioxide accounfs for 60-80% of the total cost of CO2 sequestration [24,25]. 

White J C, Dutta P K, Shqan K and Verweij H (2010), Synthesis of nltrathin zeolite Y membranes and their apphcation for separation of carbon dioxide and nitrogen gases , Langmuir, 26,10287-10293. 

The book explores various examples of these important materials, including perovskites, zeolites, mesoporous molecular sieves, silica, alumina, active carbons, carbon nanotubes, titanium dioxide, magnesium oxide, clays, pillared clays, hydrotalcites, alkali metal titanates, titanium silicates, polymers, and coordination polymers. It shows how the materials are used in adsorption, ion conduction, ion exchange, gas separation, membrane reactors, catalysts, catalysts supports, sensors, pollution abatement, detergency, animal nourishment, agriculture, and sustainable energy applications. 

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