Network modeling of the pore structure of porous media for determining the diffusion and convective flow of a solute in monoliths and columns packed with chromatographic particles under unretained and adsorbing conditions -- comparison between theory and experiments

Author

John Joseph Meyers

Keywords and Phrases

Pore network modelling; Pore size distribution; Pore connectivity; Pore diffusion; Dynamic profiles of pore diffusion coefficient; Dynamic adsorptive capacity of column; Network model; Percolation threshold; Porous chromatographic particles; Chromatographic column; Liquid chromatography; Perfusion chromatography; Intraparticle convection; Intraparticle diffusion; Monoliths; Continuous bed; Film mass transfer coefficient; Pore spatial distribution; Nitrogen sorption experiments; Silica particles

Abstract

"A versatile pore network model (cubic lattice network) is constructed describing the void structure in monoliths and in porous chromatographic particles packed in a column with respect to pore size distribution, pore connectivity, and pore spatial distribution. Constitutive equations for mass transfer are developed for a single pore and are employed in the network model to determine a priori values of the intraparticle convective velocity and pore diffusivity for a given pore structure for different solutes of interest.

The network is employed to calculate intraparticle convective velocities and pore diffusivities for adsorbate molecules under retained (adsorption) and unretained conditions where the combined effects of steric hindrance at the entrance to the pores, frictional resistance within the pores, molecular size of the adsorbate and ligand (active site), and fractional saturation of active sites are considered. By obtaining the values of the pore diffusivity of a solute calculated in an a priori fashion from pore network model analysis for a given pore structure, a model was constructed and used to evaluate the dynamic behavior, scale-up, and design of monoliths and packed beds employing adsorbent particles. Breakthrough curves and dynamic adsorptive capacities were calculated based on different pore size distributions and pore connectivities for chromatographic systems operating under retained and unretained conditions.

Simulations of nitrogen adsorption/desorption, mercury intrusion, size exclusion chromatography and internal surface area accessibility were performed in order to determine the properties of different pore structures. Also, pore structure parameters (pore size distribution, pore connectivity, and pore spatial distribution) were determined by the comparison of experimental nitrogen adsorption and mercury intrusion data with pore network model simulations; the agreement between theory and experiment was found to be good"--Abstract, page iv.

Advisor(s)

Liapis, Athanasios I.

Committee Member(s)

Crosser, Orrin K.
Reed, X. B., Jr.
Neogi, P. (Partho), 1951-
Avula, Xavier J. R.

Department(s)

Chemical and Biochemical Engineering

Degree Name

Ph. D. in Chemical Engineering

Sponsor(s)

Monsanto Company
University of Missouri--Rolla

Comments

The second volume, attached as a supplementary document, contains Appendix D (Program source codes) and Vita.

Publisher

University of Missouri--Rolla

Publication Date

Summer 2000

Journal article titles appearing in thesis/dissertation

• Network modeling of the intraparticle convection and diffusion of molecules in porous particles packed in a chromatographic column
• Network modeling of the convective flow and diffusion of molecules adsorbing in monoliths and in porous particles packed in a chromatographic column
• Modeling and simulation of the dynamic behavior of monoliths: Effects of pore structure from pore network model analysis and comparison with columns packed with porous spherical particles
• Pore network modelling: Determination of the dynamic profiles of the pore diffusivity and its effect on column performance as the loading of the solute in the adsorbed phase varies with time
• Determination of the pore connectivity and pore size distribution and pore spatial distribution of porous chromatographic particles from nitrogen sorption measurements and pore network modelling theory

Pagination

2 volumes (xxi, 604 pages)

Note about bibliography

Includes bibliographical references.

Rights

© 2000 John Joseph Meyers, All rights reserved.

Document Type

Dissertation - Restricted Access

File Type

text

Language

English

Subject Headings

Molecules -- SeparationAdsorptionChromatographic analysisIon exchange chromatography

Thesis Number

T 7790

Print OCLC #

46655930

Electronic OCLC #

944951575

Recommended Citation

Meyers, John Joseph, "Network modeling of the pore structure of porous media for determining the diffusion and convective flow of a solute in monoliths and columns packed with chromatographic particles under unretained and adsorbing conditions -- comparison between theory and experiments" (2000). Doctoral Dissertations. 1371.
https://scholarsmine.mst.edu/doctoral_dissertations/1371