Jump to main content
Jump to site search

Issue 19, 2001
Previous Article Next Article

Separation of linear, mono-methyl and di-methyl alkanes in the 5–7 carbon atom range by exploiting configurational entropy effects during sorption on silicalite-1

Author affiliations

Abstract

We have developed a novel concept for separating alkane mixtures, in the 5–7 carbon atom range, into three separate fractions consisting of linear, mono-methyl and di-methyl alkanes by adsorption on silicalite. We make use of the fact that with increased degree of branching, the “ packing efficiency” within the silicalite matrix is significantly lower. This configurational entropy effect comes into play when the loading exceeds 4 molecules per unit cell, when all the intersection sites are occupied, and results in the following hierarchy of sorption strengths: linear alkanes[double greater-than, compressed]mono-methyl alkanes[double greater-than, compressed]di-methyl alkanes. To demonstrate the feasibility of the entropy-based separation concept we carried out configurational-bias monte carlo simulations for a variety of binary, ternary and quaternary mixtures of alkanes, n-pentane (n-C5), 2-methylbutane (2MB), n-hexane (n-C6), 2-methylpentane (2MP), 3-methylpentane (3MP), 2,2-dimethylbutane (22DMB), n-heptane (n-C7), 2-methylhexane (2MH), 2,2-dimethylpentane (22DMP). The entropy-driven separation concept has been verified, in part, by comparison with the experimental sorption data of Santilli (J. Catal., 1986, 99, 335) for the mixture n-C6–3MP–22DMB.

Back to tab navigation

Article information


Submitted
05 Apr 2001
Accepted
02 Aug 2001
First published
12 Sep 2001

Phys. Chem. Chem. Phys., 2001,3, 4390-4398
Article type
Paper

Separation of linear, mono-methyl and di-methyl alkanes in the 5–7 carbon atom range by exploiting configurational entropy effects during sorption on silicalite-1

S. Calero, B. Smit and R. Krishna, Phys. Chem. Chem. Phys., 2001, 3, 4390
DOI: 10.1039/B103118J

Social activity

Search articles by author

Spotlight

Advertisements