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

Autor: Giulia Baracchini, Albert G. F. Machoke, Wilhelm Schwieger, Michael Klumpp, Patrick Arnold, Ruoxi Wen, Roland Dittmeyer
Rok vydání: 2020
Předmět:
Zdroj: Catalysis today, 342, 46-58
ISSN: 0920-5861
1873-4308
DOI: 10.1016/j.cattod.2019.07.016
Popis: The direct synthesis of dimethyl ether (DME) from synthesis gas via methanol as an intermediate is a promising process for realizing a decentralized, small-scale Power-to-X concept. The efficient realization of this coupled process depends to a large extent on the appropriate catalyst configuration, i.e. the combination of the catalyst for methanol formation with the one for the subsequent dehydration step. In this work, two catalyst configurations were compared in terms of CO-conversion and DME-selectivity using modelling and experiments. Catalysts for methanol formation (Cu/ZnO/Al2O3, CZA) and dehydration (Zeolite H-ZSM-5, Z) prepared via flame spray pyrolysis and hydrothermal synthesis, respectively, were combined in the form of hybrid pellets (CZA&Z) and CZA-core@zeolite-shell (CZA@Z) particles. During the synthesis of the CZA@Z system, alteration of the CZA core in terms of CuO-reducibility and activity in methanol synthesis were found after individual steps of calcination and hydrothermal shell synthesis. In contrast, the preparation of the CZA&Z system presents an easy and tunable method with promising catalytic properties in terms of CO-conversion and DME-selectivity, once the proper mass ratio of the two catalysts was set. From modelling, for the same CZA/Z ratio in general higher CO-conversion was found for the CZA&Z system as compared to the CZA@Z, while the latter system shows higher DME-selectivity.
Databáze: OpenAIRE
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