부산대학교 도서관

The formation and subsequent transformation of light olefins is a crucial subject to optimize the production and use of this important intermediate in refining and petrochemical industry. Here a ferrierite zeolite and its mesoporous derivatives obtained by caustic post-treatment ( meso -FER) were tested in the transformation of propylene in a flow reactor under atmospheric pressure. The catalysts were compared at iso conversion and characterized by textural, chemical composition and n -hexane cracking. The higher the area of the mesoporous, the higher was the initial catalytic activity for propylene conversion and the selectivity to products containing six or more carbons. Similar results are observed by increasing the propylene partial pressure. Notably, meso -FER formed high amounts of mono-aromatics and branched olefins in the gasoline range, thus improved the gasoline octane number. Moreover, improving the mesoporous area hindered the formation of heavy products. However, propylene conversion showed a plateau limited to 25–30%. In contrast, other zeolites such as ZSM-5, Beta, and USY tested under the same conditions did not show conversion limitation. In contrast, all these later zeolites were less selective to mono-aromatics compared to FER. We proposed that this limitation was probably a result of the narrow canals the FER structure that limited the type of products formed coupled with the constrain imposed by the thermodynamic equilibrium between feed and permissible products inside the zeolite. [ABSTRACT FROM AUTHOR]