High purity separation of n-pentane from neopentane using a nano-crystal of zeolite Y

Nag, S and Ananthakrishna, G and Maiti, PK and Subramanian, Y (2021) High purity separation of n-pentane from neopentane using a nano-crystal of zeolite Y. In: Journal of Chemical Physics, 155 (1).

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Abstract

A method for the separation of a mixture of n-pentane and neopentane using a nano-crystallite of zeolite Y is reported. This method judiciously combines two well-known, counter-intuitive phenomena, the levitation and the blowtorch effects. The result is that the two components are separated by being driven to the opposite ends of the zeolite column. The calculations are based on the non-equilibrium Monte Carlo method with moves from a region at one temperature to a region at another temperature. The necessary acceptance probability for such moves has been derived here on the basis of stationary solution of an inhomogeneous Fokker-Planck equation. Simulations have been carried out with a realistic and experimentally relevant Gaussian hot zone and also a square hot zone, both of which lead to very good separation. Simulations without the hot zones do not show any separation. The results are reported at a loading of 1 molecule per cage. The temperature of the hot zone is just �30 K higher than the ambient temperature. The separation factors of the order of 1017 are achieved using single crystals of zeolite, which are less than 1 μm long. The conditions for including the hot zone may be experimentally realizable in the future considering the rapid advances in nanoscale thermometry. The separation process is likely to be energetically more efficient by several orders of magnitude as compared to the existing methods of separation, making the method very green. © 2021 Author(s).

Item Type:	Journal Article
Publication:	Journal of Chemical Physics
Publisher:	American Institute of Physics Inc.
Additional Information:	The copyright for this article belongs to American Institute of Physics Inc.
Keywords:	Fokker Planck equation; Monte Carlo methods; Nanocrystallites; Paraffins; Zeolites, High purity; Nanoscale thermometries; Non equilibrium; Orders of magnitude; Separation factors; Separation process; Stationary solutions; Two-component, Separation
Department/Centre:	Division of Chemical Sciences > Materials Research Centre Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Physical & Mathematical Sciences > Physics
Date Deposited:	14 Sep 2021 11:33
Last Modified:	14 Sep 2021 11:33
URI:	http://eprints.iisc.ac.in/id/eprint/69595

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