TAP Study of Adsorption and Diffusion of 2,2,4-Trimenthylpentane and 2,5-Dimethylhexane on β and USY Zeolites

The dimensionless equilibrium constant, apparent heats of adsorption, intraparticle diffusivities, and activation energies are determined under high vacuum conditions for 2,2,4-trimethylpentane and 2,5-dimethylhexane. These are representative of the products formed in the alkylation process of isobu...

Full description

Saved in:
Bibliographic Details
Published in:Industrial & engineering chemistry research 2012-02, Vol.51 (4), p.1570-1578
Main Authors: Nayak, Subramanya V, Ramachandran, Palghat A, Dudukovic, Milorad P
Format: Article
Language:English
Subjects:
Adsorption
Alkylation
Applied sciences
Cages
Catalysis
Catalysts
Channels
Chemical engineering
Diffusion
Diffusion rate
Exact sciences and technology
Kinetics, Catalysis, and Reaction Engineering
Zeolites
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The dimensionless equilibrium constant, apparent heats of adsorption, intraparticle diffusivities, and activation energies are determined under high vacuum conditions for 2,2,4-trimethylpentane and 2,5-dimethylhexane. These are representative of the products formed in the alkylation process of isobutane–butene mixtures on solid acid catalysts such as β and USY zeolites. It is observed that in the straight and zigzag channels of β zeolites, dimethyl-branched C8 isoalkane is strongly adsorbed and diffuses at a slower rate in comparison to trimethyl-branched C8 isoalkane. In contrast, in the super cages of USY zeolites, both C8 isoalkanes demonstrate similar sorption and transport properties. On the basis of this understanding, it is concluded that the ideal solid acid catalyst for alkylation processes requires super cages of USY zeolite rather than zigzag channels of β-zeolites in order to increase product selectivity, decrease catalyst deactivation, and decrease the energy requirement for regeneration.
ISSN:0888-5885
1520-5045
DOI:10.1021/ie200558e