609-26-7Relevant articles and documents
Catalyst and process for contacting a hydrocarbon and ethylene
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Page 17-18, (2008/06/13)
A process of contacting at least one feed hydrocarbon, containing three to about seven carbon atoms per molecule, and ethylene in a hydrocarbon-containing fluid in the presence of a catalyst composition to provide at least one product hydrocarbon isomer containing about four to about nine carbon atoms per molecule is provided. The at least one feed hydrocarbon can be selected from paraffins, isoparaffins, and the like and combinations thereof. The catalyst composition contains a hydrogen halide component, a sulfone component, and a metal halide component.
Effect of zeolite structure and acidity on the product selectivity and reaction mechanism for n-octane hydroisomerization and hydrocracking
Zhang, Wenmin,Smirniotis, Panagiotis G.
, p. 400 - 416 (2007/10/03)
The activity, product selectivity, and stability of a series of bifunctional zeolite catalysts, primary ZSM-12, USY, and β-zeolite, with different Si/Al ratios were compared for the hydroisomerization and hydrocracking of n-octane. The performance of L-zeolite and mordenite was examined to a lesser extent as well. It was found that the activity per acidic site decreases at the initial stage (1 h on stream) in the following order: ZSM-12 > β-zeolite > mordenite > USY > L-zeolite. For extended periods of operation, the activity of ZSM-12 remains unchanged. The superior stability of ZSM-12 even under accelerating coking conditions results from its unique pore structure, which does not favor coke formation. Its one-dimensional noninterpenetrating puckered channels (5.5 × 6.1 A) act as perfect tubes, which do not trap coke precursors. The branched product selectivity increases with the increase in Bronsted acid site strength of the zeolite catalysts, and thus hydroisomerization is favored at the expense of cracking at a higher Bronsted acid strength. USY-5.8 (CBV-712) showed relatively high initial activity with respect to other USYs. This is probably related to its high surface Al content. The Bronsted acid strength of the USY zeolites decreases in the order USY-2.6 > USY-28 > USY-5.8. The 2,2-DMC6 and 3,3-DMC6 isomers are not favored as final products due to their bulky molecular size even in USY. In addition, the 2,2-DMC6 species is more abundant than 3,3-DMC6 because the rate of isomerization by PCP intermediates decreases in the following order: 2-MC7 > 3-MC7 > 4-MC7. The 2,3-DMC6 concentration is much higher than that predicted by equilibrium, which indicates that the interconversion of 2,3-DMC6 to other dibranched isomers is not preferred. The i-C4/n-C4 ratio detected depends on both the reaction temperature and zeolite pore structure/acidity. Aluminium content determines the type of β-scission. For zeolites with a high concentration of acid sites (Si/Ai about 30), type A β-scission dominates at low temperature, while at lower Al content, type A, B, and C β-scissions are equally important.
