Porous ceramic membranes for propane–propylene separation via the π-complexation mechanism: unsupported systems

Separation of propylene/propane mixtures by titanosilicate ETS-10 membranes prepared in one-step seeded hydrothermal synthesis

“…The final repeated experiment at the lowest temperature (30 • C) corroborates the already discussed deactivation of propylene permeance and selectivity with time on stream, which can be reversed by treatment in air at higher temperatures. [15]), Ag/SiO 2 (asterisk symbol [14]), Ag/Al 2 O 3 (rhomb closed symbol [14]), carbon membranes (cross symbol [18][19][20]), ETS-10 membrane (closed triangle symbol [10]), AM-6 membrane (closed circle symbol [10]) and membranes in the present work (open square symbol, inside the synthesis time).…”

“…Membrane separation is an interesting alternative for alkenes/alkanes separations on account of a potentially high selectivity and low energy consumption. Polymeric membranes have been used for this purpose [13], but they have strong limitations in terms of mechanical and chemical stability [14]. On the other hand, inorganic membranes have a much wider range of operation, and therefore constitute suitable candidates for processes in which chemical environment and mechanical restrictions prevent the use of polymeric membranes.…”

“…On the other hand, inorganic membranes have a much wider range of operation, and therefore constitute suitable candidates for processes in which chemical environment and mechanical restrictions prevent the use of polymeric membranes. However, up to now the studies concerning the use of inorganic membranes to separate propylene/propane mixtures are rather scarce [14], and involve alumina-silica microporous membranes [15], zeolite membranes [16,17], carbon membranes [18][19][20] and mesoporous alumina or microporous silica membranes modified with Ag [14]. Different investigations have found that ETS-10 is capable of adsorbing alkenes with preference to alkanes.…”

Propylene/propane Permeation Properties of Metal-doped Organosilica Membranes with Controlled Network Sizes and Adsorptive Properties

“…Several studies have reported enhanced C3H6 adsorptive properties when metal ions such as Ag and Cu were incorporated in the SiO2 structure 26) 28) . Stoitsas et al 28) evaluated the C3H6 and C3H8 adsorptive properties of micro porous SiO2 and Ag /SiO2 gels, and confirmed an enhanced C3H6/C3H8 adsorption selectivity. They concluded that the incorporation of Ag ions created π-complexation interactions between the double bond in C3H6 and transition metal cations; also, the diffusion and/or sorption of C3H8 molecules was hindered by the introduction of a C3H6 selective adsorption site.…”

Material properties and operating configurations of membrane reactors for propane dehydrogenation

“…Various types of ceramic or metallic membranes for propylene-selective or hydrogen-selective separation have been reported. [32][33][34][35] One of the promising candidates are zeolite membranes, which have well-defined crystalline pore structures and for which membrane fabrication processes have been developed over two decades. Detailed studies of hydrogen-selective 36,37 and propylene-selective 38-41 zeolite membranes have been published.…”