Date

2017

Document Type

Dissertation

Degree

Doctor of Philosophy

Department

Chemical Engineering

First Adviser

Kothare, Mayuresh V.

Other advisers/committee members

Gilchrist, James F.; Hsu, James T.; Golden, Timothy C.

Abstract

An isothermal-isobaric column dynamic test apparatus was built to measure equilibrium adsorption isotherms of pure N2, O2, Ar and N2-O2 mixtures at 0, 30 and 65 oC in the pressure range of 0 – 6 atm on LiLSX zeolite. New experimental data successfully passed an integral and a differential thermodynamic consistency test between pure and binary gas isotherms. Three analytical adsorption isotherm models were tested. Pure gas isosteric heats of adsorption and model analysis of the data indicate that the zeolite behaved like a nearly homogeneous adsorbent for Ar adsorption while it exhibited substantial heterogeneity for adsorption of N2 and milder heterogeneity for adsorption of O2. Effective mass transfer coefficients (k^e,s^(-1)) for adsorption of pure N2, O2 and Ar into LiLSX zeolite were estimated. The over-all mass transfer coefficient for N2, O2 and Ar adsorption were comparable in magnitude and a large skin resistance at the adsorbent particle surface was observed.The measured binary selectivities of N2 over O2 were functions of gas phase mole fraction and pressure and the performance of a MOC- RPSA process using a LiLSX zeolite was improved when the adsorbent exhibited higher selectivity of adsorption of N2 over O2. The results of a literature search (1995 – 2015) for experimental data on binary and ternary gas adsorption selectivity and their estimation from the corresponding pure gas adsorption isotherms by Ideal Adsorbed Solution Theory (IAST) are summarized which indicate the selectivity of adsorption of a component of a binary or a ternary gas mixture can be a complex function and it must be experimentally measured for reliable design of adsorptive gas separation processes.

Available for download on Wednesday, March 06, 2019

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