Zeolite Membranes in Catalysis—From Separate Units to Particle Coatings

Abstract

Literature on zeolite membranes in catalytic reactions is reviewed and categorized according to membrane location. From this perspective, the classification is as follows: (i) membranes spatially decoupled from the reaction zone; (ii) packed bed membrane reactors; (iii) catalytic membrane reactors and (iv) zeolite capsuled catalyst particles. Each of the resulting four chapters is subdivided by the kind of reactions performed. Over the whole sum of references, the advantage of zeolite membranes in catalytic reactions in terms of conversion, selectivity or yield is evident. Furthermore, zeolite membrane preparation, separation principles as well as basic considerations on membrane reactors are discussed.

In Situ Spectroscopic Studies of Proton Transport in Zeolite Catalysts for NH3-SCR

“…The Brønsted acidity of zeolites, which results from the non-equivalent substitution of T-atoms (e.g., the substitution of Si by Al in TO 4 units as shown in Figure 3) and the subsequent charge-balancing by external, exchangeable cations (Na + , NH 4 + , H + , etc.) at the adjacent oxygen sites within the pore space, enables several characteristic functions, such as ion-exchange capacity, proton donating ability and ionic conductivity [3,[40][41][42]. These properties allow zeolites to be used as adsorbents, separators, ionic conductors, sensors, or catalysts [3,[40][41][42].…”

Potential of Pervaporation and Vapor Separation with Water Selective Membranes for an Optimized Production of Biofuels—A Review

“…Among them, some progress in zeolite materials has been made due to their high tailoring character, in terms of chemical properties, pore size, adsorption capacity, shape selectivity, and stability [1,49]. At high temperatures, silica-rich zeolites, such as faujasites, phillipsite or mordenite could be considered more suitable, even if their use is still limited by definition of proper preparation methods, which enable reproducible and long-term resistant materials to be obtained.…”

“…Some important reviews concerning the types of membrane, reactor configuration and modeling [21,35,[42][43][44][45][46][47][48][49], specific applications, and hybrid processes realized on an industrial scale [50] have been published [1,9,21,[41][42][43]47,[51][52][53][54][55][56]. In a hybrid process, several possibilities exist to implement the PV or VP modules and the membrane separation devices and the reactor can be separated into two units or integrated into a single one [53,55].…”

Computational study of the CO adsorption and diffusion in zeolites: validating the Reed–Ehrlich model

“…One of the most promising technologies employs inorganic membranes based on functional coatings to create a chemical environment in the form of a microporous zeolite coating (Dragomirova et al 2015;Feng et al 2015;Ackley et al 2003). Zeolites generally stand out as the most advantageous and competitive porous solids used for industrial applications based on physisorption for the selective capture of selected gases.…”

“…Various purification techniques to remove unwanted compounds may be used prior to the manufacture of methanol or dimethyl ether (Dragomirova et al 2015;Feng et al 2015). One of the most promising technologies employs inorganic membranes based on functional coatings to create a chemical environment in the form of a microporous zeolite coating (Dragomirova et al 2015;Feng et al 2015;Ackley et al 2003).…”