A molecular simulation approach to the study of adsorption of hydrogen cyanide and methyl ethyl ketone in silicalite, mordenite and zeolite beta structures

Abstract

In the present research study the primary aim is to understand and characterize the physical adsorption of polar molecules such as hydrogen cyanide (HCN) and methyl ethyl ketone (MEK), in silicalite-1, mordenite, and zeolite beta structures through detailed Monte-Carlo simulation studies. The sorption capacity and affinity of the different zeolites is compared by simulating single component isotherms for different Si/Al ratios at 298 K. It was found that the number of the Na⁺ cations has an important effect on adsorption characteristics at lower pressures. In particular, within the range of [Na⁺] studied, the adsorption capacity of these zeolites was found to be independent of the [Na⁺], except in the case of zeolite beta. Furthermore, the MEK sorption capacity of zeolite beta was found to be the highest, followed by silicalite and mordenite respectively. The HCN sorption capacity of silicalite was shown to be greater than mordenite due to the presence of the 10-membered ring channels of silicalite.

Keywords:

• Hazardous molecules
• Adsorption
• Molecular modeling
• Molecular simulation
• Hydrogen cyanide
• Methyl ethyl ketone

Acknowledgements

The authors gratefully acknowledge the support provided by the National Science Foundation (NSF) through grant: NSF NIRT award DMI-0210258. This work was also supported by the following NSF programs: Partnerships for Advanced Computational Infrastructure, Distributed Terascale Facility (DTF), and Terascale Extensions: Enhancements to the Extensible Terascale Facility. Technical help on computing platforms from Josh Brandt, WPI Computing and Communications Center, Senior UNIX Systems Administrator, is gratefully acknowledged as well.