Structured catalysts for the direct synthesis of dimethyl ether from synthesis gas: A comparison of core@shell versus hybrid catalyst configuration

Sorption enhanced dimethyl ether synthesis under industrially relevant conditions: experimental validation of pressure swing regeneration

“…This deactivation can be caused by the competing adsorption of water, dimers, trimers, or even larger alcohol-water clusters, but also the (reversible) formation of (surface) boehmite was shown. 27 Despite the large attention for more active low-temperature methanol dehydration catalysts, 4,6,59,69,71,73,74,[76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95] γ-Al 2 O 3 remains the catalyst of choice for industrial DME production, due to its low cost, high surface area, good thermal and mechanical stability, and high selectivity to DME because its relatively weak Lewis acid sites do not promote side reactions. 4,70,96,97 In contrast to direct DME synthesis, SEDMES offers two specific advantages for the (γ-Al 2 O 3 ) catalyst: the system is operated at low steam pressures and is periodically regenerated due to its adsorptive nature.…”

Direct synthesis of dimethyl ether: A simulation study on the influence of the catalyst configuration

“…These configurations cover both, particulate and planar (coated) systems implemented in PFR and µ CR, respectively. The cat alysts were classified based on the structural parameters originating from the synthesis procedure (details on the synthesis can be found in [60] and in the Supporting Information S1). Fig.…”

“…In this context it is important to mention that for the hybrid systems with a medium proximity (in the micrometer scale), namely CZA + Z and CZA#Z, the arrangement of the CZA and zeolite cannot be controlled during the preparation (see (ii) in Section 1.1), while for the hybrid systems with close proximity (in the sub micrometer range), namely CZA&Z and CZA &/Z, and especially for CZA@Z and CZA//Z, the arrangement of the two catalytic species is predefined by the preparation principle applied (see (iii) in Section 1.1). Moreover, while the purpose of the CZA@Z system is to enwrap the CZA core with a dense zeolitic membrane (see also details in [60]) in order to maximize DME selectivity, in case of the coated CZA//Z the upper layer should consist of a non dense zeolitic film, aiming to enhance the diffusion of the reactants. Therefore, even if the arrangement of the two structures follows a similar approach in either a spherical (CZA@Z) or planar (CZA//Z) geometry, the specific concepts differ in the purpose of the zeolite layers' properties and in the preparation principles applied (see also Supporting Information S1).…”

“…In this work CZA and zeolite H ZSM 5 (Si/Al ratio = 50) catalysts, prepared via flame spray pyrolysis and hydrothermal synthesis, re spectively, were considered. In recent publications CZA@Z and CZA + Z have been synthesized [60,61], the preparation procedure of CZA&Z, CZA#Z and CZA//Z is reported in the Supporting Information S2, CZA&/Z is considered theoretically in the present study.…”

“…In order to represent the different catalyst configurations in a way that they could potentially be used in real applications and to obtain structural parameters crucial for the systematic modelling, model cat alysts have been prepared and characterized in recent studies [60,61]. Details on the characteristics of the individual catalyst systems in vestigated are given in the following sections.…”