Chemical Engineering Commons^™

Multi-Component Perfusion Chromatography In Fixed Bed And Periodic Counter Current Column Operation, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model of multi-component dynamic adsorption in columns with spherical perfusive and spherical purely diffusive adsorbent particles with a bidisperse porous structure is constructed, solved, and used to study the performance of a binary adsorption system in a single-column fixed-bed process and in a two-column periodic countercurrent process in which the adsorbent is equally distributed over two beds. The total length of the two-column periodic counter-current system is equal to the length of the single-column fixed-bed system. The performance of fixed-bed and periodic counter-current systems with both perfusive and purely diffusive adsorbent particles is examined for different values of …

The Effects Of Multiple Electroplated Zinc Layers On The Inhibition Of Hydrogen Permeation Through An Iron Membrane, D. H. Coleman, G. Zheng, Branko N. Popov, Ralph E. White

Faculty Publications

The Devanathan-Stachurski permeation technique was used to investigate the rate of hydrogen permeation through an iron membrane with consecutively electroplated zinc layers. Hydrogen evolution rates and hydrogen permeation rates were followed as functions of time at different applied potentials. Hydrogen evolution and permeation decreased with each successive zinc layer until finally reaching an average decrease of 93 and 96%, respectively, as compared with bare iron. Hydrogen surface coverage, exchange current density, absorption-adsorption reaction constant, and hydrogen recombination constant were estimated on bare iron and on zinc-plated iron. It was found that the decrease in the permeation rate of hydrogen through …

Activity Coefficients Of Adsorbed Mixtures, Orhan Talu, Jianmin Li, Alan L. Myers

Chemical & Biomedical Engineering Faculty Publications

Experimental and simulated data for adsorption of gas mixtures on energetically heterogeneous surfaces like activated carbon and zeolites exhibit negative deviations from ideality. The deviations are large in some cases, with activity coefficients at infinite dilution equal to 0.1 or less. Similar molecules form ideal mixtures, but molecules of different size or polarity are nonideal. Equations for bulk liquid mixtures (Wilson, Margules, etc.) do not apply to isobars for adsorbed mixtures. A two-constant equation for activity coefficients as a function of composition and spreading pressure is in good agreement with theory, simulation, and experiment.

The Effect Of Inorganic Salts On Adsorption Of Organics By Fly Ash, Pai-Yuan Horng

Theses

Optimum amounts of inorganic salts ( monovalent, divalent, and trivalent chlorides ) added to various bituminous coal fly ashes in batch adsorption treatment experiments indicates the possibility of improving adsorption capacity.

Experiments were conducted on aqueous solutions of three priority pollutants : phenol, toluene, benzene. Both high fusion and low fusion fly ashes were used as sorbent materials. Removal of organic pollutants was measured using a total organic carbon analyzer.

Isotherm tests positively indicate that the addition of inorganic salts to fly ash significantly increases adsorption capacity. The study shows that removal of organic pollutants by fly ash depends on …

Mathematical Simulation Of Proteins Separation In A Packed Bed, Jing James Huang

Dissertations

The generalized adsorption models are developed to simulate the unsteady state mass transfer behavior in a packed column. Based on the nature of adsorbent particles, the adsorption models may be classified into two categories: (1) the surface adsorption model, (2) the pore diffusion model. In the first model, it is assumed that the internal diffusion is negligible, and the adsorption rate is determined by external diffusion and surface adsorption. In the second model, the effect of internal diffusion is considered as significant as that of external diffusion. For both models, the effect of axial dispersion in fluid phase is emphasized. …

Adsorption On Activated Flyash, John William Kubarewicz

Theses

An experimental study was undertaken to compare the adsorptive characteristics of activated carbon, flyash, and activated flyash. Due to the contradictory evidence available in the literature, emphasis was placed on the effect of acid activation on the physical properties of the adsorbent. The experiment consisted of two parts; batch isotherm studies, and continuous column operations. An artificial sewage composed of a mixture of deionized water and beef broth was used as the adsorbate. This solution was prepared daily and exerted a COD of 225 ± 30 mg/l. Flyash activation was found to increase the degree of adsorption indirectly rather than …

Exchange Adsorption Of Electrolytes On Titanium Dioxide, Richard Algimantas Slepetys

Theses

During the manufacture of titanium dioxide pigments many processing steps are carried out in solutions of electrolytes. Adsorption of these electrolytes strongly affects properties of the finished pigments.

Adsorption of electrolytes Was studied on titania samples prepared by controlled neutralization of titanium tetrachloride solutions with ammonium hydroxide, and one sample of commercial sulfate process rutile titania. In analogy to zirconia--as reported by Kraus and Phillips?^22,23 titania also behaved as a weak anion exchanger in acid solutions and as a weak cation exchanger in basic solutions. Acid or base liberated was approximately equivalent to ions exchanged. On the best sample …

Design Of Fixed Bed Absorbers For Drying Gases, Roger Emery Bibaud

Theses

No abstract provided.