Conversion of dimethyl ether to liquid hydrocarbons on zeolite catalysts: Influence of a base admixture in the zeolite

• Published in: Catalysis communications 2021-01, Vol.149, p.106210, Article 106210
• Main Authors: Kolesnichenko, Natalia V., Bondarenko, Galina N., Matieva, Zareta M., Snatenkova, Yulia M., Arapova, Olga V., Maksimov, Anton L.
• Format: Article
• Language: English
• Subjects: Dimethyl ether; Drift; Hydrocarbons; Synthesis gas; Zeolite
• ISSN: 1566-7367; 1873-3905
• DOI: 10.1016/j.catcom.2020.106210

This paper presents comparative data on the selectivity and gasoline fraction composition for commercial catalysts based on Zn- and Pd-modified zeolites with the same MFI structural type, but produced by different manufacturers. The data are obtained in the operation of a two-reactor micropilot unit in a flow circulation mode. The relationship and differences between the character and type of Brønsted acid site were investigated using in situ high-temperature diffuse reflectance IR spectroscopy during annealing of the catalysts in dry argon, hydrogen, and dimethyl ether flows. It was found that catalysts contain organic ammonium cations with different structures of organic substituents, which decompose to give a very strong nitrogen-containing acid site. This site can promote the formation of branched paraffins and light aromatics from dimethyl ether. Under the action of these sites, methanol can be rapidly converted to DME, which is more reactive towards the production of gasoline fraction. [Display omitted] •Using DRIFT method the nature and type of the Bronsted acid sites on the MFI was studied.•Organic compounds are present, which are ammonium cations with long organic substituents.•Organic ammonium cations begin to decompose with the formation of light organic substances.•Formation of branched hydrocarbons and light aromatic compounds from DME.