n-Butene Synthesis in the Dimethyl Ether-to-Olefin Reaction over Zeolites

Catalysts

Yusuke Edashige¹  Masaru Aoyagi²  Toshiaki Hanaoka² 

[1] Faculty of Agriculture, Ehime University, Matsuyama 790-8566, Japan;Organic Materials Diagnosis Group, Research Institute for Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Hiroshima 739-0046, Japan;

关键词: dimethyl ether;    n-butene;    zeolite;    strong acid;    micropore;   

DOI  :  10.3390/catal11060743

来源: DOAJ

【 摘 要 】

Zeolite catalysts that could allow the efficient synthesis of n-butene, such as 1-butene, trans-2-butene, and cis-2-butene, in the dimethyl ether (DME)-to-olefin (DTO) reaction were investigated using a fixed-bed flow reactor. The zeolites were characterized by N₂ adsorption and desorption, X-ray diffraction (XRD), thermogravimetry (TG), and NH₃ temperature-programmed desorption (NH₃-TPD). A screening of ten available zeolites indicated that the ferrierite zeolite with NH₄⁺ as the cation showed the highest n-butene yield. The effect of the temperature of calcination as a pretreatment method on the catalytic performance was studied using three zeolites with suitable topologies. The calcination temperature significantly affected DME conversion and n-butene yield. The ferrierite zeolite showed the highest n-butene yield at a calcination temperature of 773 K. Multiple regression analysis was performed to determine the correlation between the six values obtained using N₂ adsorption/desorption and NH₃-TPD analyses, and the n-butene yield. The contribution rate of the strong acid site alone as an explanatory variable was 69.9%; however, the addition of micropore volume was statistically appropriate, leading to an increase in the contribution rate to 76.1%. Insights into the mechanism of n-butene synthesis in the DTO reaction were obtained using these parameters.

【 授权许可】

Unknown