Effect of the Si/Al ratio and of the zeolite structure on the performance of dealuminated zeolites for the reforming of hydrocarbon mixtures

Journal Article · Sun Sep 01 04:00:00 EDT 1996 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie9507639· OSTI ID:376243

Smirniotis, P G; Zhang, W ^[1]

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1. Univ. of Cincinnati, OH (United States). Chemical Engineering Dept.

Various 12-membered ring pore zeolites were employed for the reforming of synthetic hydrocarbon mixtures which simulate industrial naphthas. All the zeolites were dealuminated to various extents. It was found that, under the present conditions over the samples which are slightly dealuminated, bimolecular-condensation reactions followed by recracking are responsible for the relatively large selectivities of C{sub 4} paraffins. The monomolecular cracking (via pentacoordinated carbonium ions) of the latter hydrocarbons is responsible for the large generation of CH{sub 4} from the cracking of C{sub 4} paraffins. When the Si/Al ratio increases, the selectivity of methane passes through a steep minimum, while those of C{sub 3}, C{sub 4}, and C{sub 5} pass through a maximum. It was also found that the zeolite pore structure is a very important factor for the time on stream activity of zeolite-based catalysts. Zeolites with reduced aluminum content and pore structures, which do not favor the formation of coke precursors in their cavities, can lead to very promising catalysts for acid-catalyzed reactions. From this study a 12-membered ring pore zeolite, which demonstrates minimal coke deactivation, was identified.

• OSTI ID: 376243
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 9 Vol. 35; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
ALKANES
ALUMINIUM
CATALYTIC CRACKING
CATALYTIC EFFECTS
CATALYTIC REFORMING
CHEMICAL COMPOSITION
CHEMICAL REACTION YIELD
DEMETALLIZATION
METHANE
NAPHTHA
PORE STRUCTURE
SERVICE LIFE
ZEOLITES