Zeolite catalysts in reaction of dimethyl ether production from CO and H ₂

Dimethyl ether; zeolite; synthesis gas, the acid-alkaline catalysis, dehydration of methanol.be easily transported, stored and processed in the same conditions. Perspective directions of application of the dimethyl ether are its use as a source of hydrogen for fuel cells in cars and other technics. The increasing demand for producing dimethyl ether from synthesis gas explains the renewed interest in studying the activity and stability of catalysts. In world practice most commonly used methanol catalysts and y-Al2O3 or molecular sieve type ZSM-5 for the production of dimethyl ether. According to the literature data Zeolite catalyst type ZSM-12, MFI, mordenite and beta are used in the synthesis of dimethyl ether and methanol dehydration. This paper presents the results obtained by combining of two process steps - the synthesis of methanol and methanol dehydration - in a single reactor and use a variety of industrial catalysts. We used an industrial methanol synthesis catalyst Katalco-58 firm «Johnson Matthey Catalysts», which, according to X-ray diffraction has a composition CuO/ZnO/Al2O3 (R-1), and industrial zeolite catalysts produced by «Angarsk plant of catalysts and organic synthesis OAO» (Open Joint-stock Company) -ZSM-12, MFI, Beta, mordenite used for the dehydration of methanol. Catalytic activity of zeolite catalyst ZSM-12, MFI, beta, mordenite as catalysts for the dehydration of methanol to dimethyl ether was investigated. Structural and acidic properties of zeolite catalysts were characterized by low-temperature adsorption of nitrogen, temperature-programmed desorption of ammonia and IR spectroscopy. It has been established that the production of dimethyl ether from CO and H2, is possible using industrial zeolite catalysts. It has been shown that the catalytic activity of the samples in the conversion of synthesis gas to dimethyl ether increases with the number of strong acid sites. It is suggested that zeolites having a sufficiently a developed surface, with high degree of crystallinity can be active in the reaction of the direct production of dimethyl ether from synthesis gas, and the presence of strong acid sites on the catalyst surface will provide a high conversion of carbon monoxide. The porosity of the zeolite provides selectivity to the desired reaction.

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