Prev. Article Next Article Table of Contents

Article

Packing Effects in the Liquid-Phase Adsorption of C₅_-C₂₂ n-Alkanes on ZSM-5

Kurt M. A. De Meyer,^† Shaji Chempath,^‡ Joeri F. M. Denayer,*^† Johan A. Martens,^§ Randall Q. Snurr,^‡ and Gino V. Baron^†

Department of Chemical Engineering, Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussel, Belgium, Department of Chemical Engineering, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Center for Surface Science and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium

J. Phys. Chem. B, 2003, 107 (39), pp 10760–10766

DOI: 10.1021/jp0354144

Publication Date (Web): September 10, 2003

†

Vrije Universiteit Brussel.

‡

Northwestern University.

Corresponding author. E-mail: Joeri.denayer@vub.ac.be.

Katholieke Universiteit Leuven.

Abstract

The liquid-phase adsorption of C₅_-C₂₂ linear alkanes on ZSM-5 was studied using a batch adsorption technique. Saturation capacities of the alkanes depend strongly on the chain length. The number of −CH_x groups adsorbed per unit cell drops steeply between C₇ and C₈ and then increases steadily to reach a plateau of 53−54 for C₁₄−C₂₂. In this plateau region, the pores of ZSM-5 are densely packed with alkane molecules. The mechanisms of packing in liquid-phase adsorption were studied using configurational-bias grand canonical Monte Carlo simulations. These simulations revealed that the probability of bending and crossing in the intersections increases with chain length, explaining the very good packing of long-chain alkanes. Short alkanes tend to stay away from the intersections, resulting in a lower packing density.

View: Full Text HTML | Hi-Res PDF