Chemical Engineering Commons^™

Cfd Of Multiphase Flow In Packed-Bed Reactors: I. K-Fluid Modeling Issues, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Eulerian K-Fluid CFD Model Was Used to Simulate the Macroscale Multiphase Flow in Packed Beds. the Geometric Complexity of the Bed Structure is Resolved by Statistically Describing the Porosity Distribution. the Complicated Multiphase Interactions Are Computed using the Ergun Type of Formula Developed based on Bench-Scale Hydrodynamic Experiments. the Work is Presented in Two Sequential Articles. Part I Discusses Implementation Issues of the K-Fluid CFD Model for Packed Beds. the Drag Exchange Coefficients Are Obtained from the Model of Holub Et Al. for the Particle-Fluid Interfaces Xks and from the Model of Attou Et Al. (1999) for the Gas …

Cfd Of Multiphase Flow In Packed-Bed Reactors: Ii. Results And Applications, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Numerical Simulations of Multiphase Flow using the K-Fluid CFD Model Described in Part I of This Issue Are Presented for Packed Beds at Various Operating Conditions. Both Steady-State and Unsteady-State (E.g., Periodic Operation) Feed Conditions Were Studied Numerically. Predictions of the K-Fluid CFD Model Are Comparable with the Experimental Data in the Literature for Liquid Upflow in a Cylindrical Packed Bed. in Addition to the Mean Porosity and the Longitudinally Averaged Radial Porosity Profile, the Variance of the Porosity Distribution is Needed for Predicting the Probability Density Function of the Sectional Flow Velocity. in the Trickling Flow Regime, the K-Fluid …

Ethylene Oxide And Propylene Oxide Random Copolymer/Sodium Chloride Aqueous Two-Phase Systems: Wetting And Adsorption On Dodecyl-Agarose And Polystyrene, Yingqing Huang, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Liquid/liquid partition chromatography is a mild yet powerful separation method for a variety of biological materials. This work demonstrates that it should be feasible to immobilize an ethylene oxide-propylene oxide (EO/PO) random copolymer solution and to use a solution of NaCl equilibrated against the polymer solution as the mobile-phase (poly (EO-PO) [P(EO-PO)] and NaCl form two aqueous phases known as aqueous two-phase systems). Three random copolymers with different molecular weights and EO/PO ratios were used. Dodecyl-agarose and polystyrene were tested as possible supports. The wetting energies of the aqueous two-phase systems on these two kinds of surfaces were calculated as …

Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ashes exist as a mixture of major amorphous phases and minor crystalline phases. For commercial applications, such as in concretes and for the production of zeolites, it would be desirable to be able to predict the reactivity of fly ashes. The amorphous phase dominates degradation behaviour, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. Despite the large quantities of fly ash produced annually by coal-burning power plants, there have been very few studies investigating the microstructure and composition of …

Studies On Use Of Carbon Slurry, A Waste From Fertilizer Plant, In Treatment Of Waste Water, Sanjay Tewari

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

"Non biodegradable materials like heavy metals, refractory organics are not removed during the conventional treatment process. In order to meet the regulatory standards and for safe disposal, it is necessary to go for tertiary treatment. Various tertiary treatment methods include adsorption, membrane separation process, ultra filtration, reverse osmosis etc. Adsorption has been found to be efficient for the removal of most of heavy metals in waste water at lower concentrations. Activated carbon is commonly used adsorbents, however, due to its high cost and loss in regeneration, various low cost adsorbents have been investigated during recent years.

The aim of the …

Field Analyses Of Rdx And Tce In Groundwater During A Gcw Pilot Study, Andrew Curtis Elmore, Lisa A. Travaglin, Jennifer L. Triplett

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Contaminant concentrations in groundwater are typically analyzed using traditional laboratory analytical procedures approved by the Environmental Protection Agency (EPA) or state regulatory agencies. The use of off-site laboratories provides very high-quality water quality data at a relatively high cost in terms of time and money. Yet there are many instances when it is desirable to have water quality data measured in the field. The field methods for measuring water quality typically cost much less than the corresponding laboratory methods. However, the usability of the field data may be uncertain when the results are qualitatively compared to duplicate laboratory results. Groundwater …

Incorporation Of Cerium And Neodymium In A Uranyl Hydroxide Solid, Chang-Soo Kim, David J. Wronkiewicz, R. J. Finch, E. C. Buck

Electrical and Computer Engineering Faculty Research & Creative Works

The migration behavior of radionuclides in a nuclear-waste repository will be influenced, in part, by their equilibrium solubilities in the presence of radionuclide-bearing solids and/or adsorption affinities as trace components onto the surfaces of solid host phases. Uranium phases that precipitate on the surface of altered spent nuclear fuel may thus influence the mobility of radionuclides released in the near-field environment, since by proximity, these will be the first phases that the radionuclides encounter following their release from the spent fuel matrix. We have evaluated the potential for incorporating radionuclides into crystalline compounds by precipitating uranyl phases from aqueous solutions …

Remediation Of Trapped Free-Phase Lnapl, T. M. Whitworth, Andrew Curtis Elmore

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Free-phase light nonaqueous phase liquids (LNAPLs) may be trapped in certain stratigraphic and structural features near or at contaminated sites due to seasonal or other variations in the water table elevation. The purpose of this article is to point out particular subsurface conditions that are conducive to trapping of free-phase LNAPLs and to suggest approaches to remediating LNAPL-contaminated sites exhibiting similar subsurface geometry and stratigraphy. To trap free-phase LNAPL, a structure must have, in addition to closed contours, an upper boundary with pores small enough so that the LNAPL will not enter them. This boundary usually consists of clay-rich sediments. …

Best Available Treatment Technologies Applied To Groundwater Circulation Wells, Andrew Curtis Elmore, Thomas Graff

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Groundwater circulation wells (GCWs) are a quasi-in-situ method for remediating groundwater in areas where remediation techniques that limit the water available for municipal, domestic, industrial, or agricultural purposes are inappropriate. The inherently resource-conservative nature of groundwater circulation wells is also philosophically appealing in today's culture, which is supportive of green technologies. Groundwater circulation wells involve the circulation of groundwater through a dual screen well, with treatment occurring between the screens. The wells are specifically designed so that one well screen draws in groundwater and the second returns the groundwater after it has been treated within the well. Historically, the treatment …

Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous phase of fly ash dominates degradation behaviour because glass has a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. It would be advantageous to predict the presence and subsequent degradability of glass on the basis of the solid-state chemistry of the fly ash. To this end, and inorganic polymer model was applied to a selection of European fly ashes to determine the value known as cross-link density (CLD). A cross-link density value of less than two implies that the material is amorphous …

A Unified Theory On Residual Oil Saturation And Irreducible Water Saturation, Nick P. Valenti, R. M. Valenti, Leonard Koederitz

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In many mature fields, there is a growing debate as to how much of the remaining oil is mobile in the unswept regions versus immobile in the swept regions. Log measured oil saturations behind the flood front are substantially lower than the residual oil saturations measured from special core analysis. In order to explain this contradiction, data from several fields is analyzed with special emphasis on capillary pressure. The concept of irreducible water saturation, connate water saturation, residual oil saturation and "critical water saturation" are discussed. The conclusions which are supported by experiment and theory, have substantial commercial implications concerning …

Inferring Liquid Chaotic Dynamics In Bubble Columns, M. Cassanello, F. Larachi, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experiments Carried Out to Study the Liquid Displacements in Bubble Columns Via the Computer Automated Radioactive Particle Tracking Technique Are Analyzed by Means of Lagrangian and Qualitative Dynamics Tools. the Lagrangian Approach Yields the Detailed Motion Sequences of the Tracer as Entrained by the Fast Ascending Bubbles or by the Liquid Flow Alongside the Column Walls. the Qualitative Dynamics Tools, on the Other Hand, Provide Prima Facie Corroboration of Chaos in Liquid Motion based on an Analysis of the Volume-Averaged Kolmogorov Entropy and the Mutual Information Function. Other Features of the Chaotic Motion, the Reconstructed Attractors and the Radial and …

Monte Carlo Simulations Of Peptide Adsorption On Solid Surfaces (Monte Carlo Simulations Of Peptide Adsorption), D. Song, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Monte Carlo (MC) simulations of a short peptide in bulk water and at charged and neutral surfaces were performed. To pursue the objective of finding whether or not the water structure around the peptide changes upon adsorption and how these changes affect the orientation of the peptide at the surface, the water structure around the peptide in the bulk and at charged and neutral surfaces were compared by analyzing the pair correlation functions (PCFs) between selected groups in the peptide and the surrounding water. In general, evidence was obtained that water is not homogeneously distributed over the peptide surface.

The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effect of low levels of zirconia addition on the mechanical properties of hydroxyapatite was analyzed. Optimum amount of zirconia required to prevent decomposition of hydroxyapatite during sintering was determined. The particle size, morphology and surface area were measured and calcium to phosphorus ratio and trace element impurity content were determined by x-ray fluorescence. Low level addition of zirconia resulted in composites with better mechanical properties and minimum levels of decomposition.

The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study of glasses from the ternary system CaF₂-CaAl₂Si₂O₈-P₂O₅ has been carried out. It has been shown that glasses with low phosphorus contents and high fluorite contents crystallise to fluorite. Fluorine reduces the glass transition temperature and is also required for the formation of fluorapatite (FAP). In the absence of fluorine in the glass no apatite phase is formed. Bulk nucleation of FAP is favoured for glasses with Ca:P ratios close to the apatite stoichiometry of 1.67 and with low crosslink densities. Thermal gravimetric analysis showed significant weight losses …

Modeling The Ultraviolet Photodegradation Of Rigid Polyurethane Foams, C. R. Newman, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Before the Montreal Protocol of 1987 and the subsequent phasing-out of chlorofluorocarbons (CFCs) in industrial applications, rigid polymer foams were made using these compounds as secondary blowing agents. The CFCs remain trapped in the gaseous part of the cellular foam structure, and once discarded these foams constitute a significant reservoir for the environmental release of ozone-depleting chemicals. Environmental degradation of the foam accelerates this process. Of particular interest in this work is the degradative effect of ultraviolet (UV) light on rigid polyurethane foams. Foams were subjected to accelerated weathering conditions and then viewed with a scanning electron microscope. The thin …

A Preliminary Comparison Of The Mechanical Properties Of Chemically Cured And Ultrasonically Cured Glass Ionomer Cements, Using Nano-Indentation Techniques, Mark R. Towler, A. J. Bushby, R. W. Billington, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is a requirement for a dental cement with properties comparable or superior to conventional glass ionomer cements (GICs) but with the command set properties of the resin modified GICs. The objective of this work was to show that the application of ultrasound to conventional Fuji IX commercial glass ionomer cement imparts a command set, whilst improving the short-term surface mechanical properties. Nano-indentation techniques were employed to highlight the improvements in hardness and creep resistance imparted to the cement through the application of ultrasound. The instant set imparted by the application of ultrasound provides improved surface hardness and creep, particularly …

Quantitative Analysis And Synthesis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamic mathematical model of Grimes and Liapis [J. Colloid Interf. Sci. 234 (2001) 223] for capillary electrochromatography (CEC) systems operated under frontal chromatography conditions is extended to accommodate conditions in CEC systems where a positively charged analyte is introduced into a packed capillary column by a pulse injection (analytical mode of operation) in order to determine quantitatively the electroosmotic velocity, electrostatic potential and concentration profiles of the charged species in the double layer and in the electroneutral core region of the fluid in the interstitial channels for bulk flow in the packed chromatographic column as the adsorbate adsorbs onto …

A Lagrangian Description Of Flows In Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (Carpt), A. R. Rammohan, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

In This Study, Computer-Automated Radioactive Particle Tracking (CARPT) is Implemented for the First Time in the Characterization of Flows in Stirred Tanks. Both the Experimental Set-Up Are Discussed. the CARPT Technique is Seen to Capture Qualitatively Most of the Important Flow Phenomena Observed in Stirred Tank Flows, Like the Two Recirculating Loops above and Below the Impeller and the Dead Zones at the Bottom of the Tank. the CARPT Data is Also Used to Extract ''Sojourn'' Time Distributions in Different Zones of the Reactor. These Distributions Are Used to Partially Quantify the Observed Dead and Active Zones in the Tank. …

Particle Motion In Packed/Ebullated Beds By Ct And Carpt, Jinwen Chen, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković, Duyen Nguyen, Krishniah Parimi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computed Tomography (CT) and Computer-Automated Radioactive Particle Tracking (CARPT) Were Used to Study the Gas Distribution and Incipient Particle Motion in a Packed/ebullated Bed in Which Gas and Liquid Are in Cocurrent Upflow. CT Scans Were Performed to Evaluate the Gas-Liquid Distributor and Gas Sparger for the Experiments, using a Perforated Plate Gas-Liquid Distributor (With 96 1-Mm Holes, Open Area of 0.1%) and a Gas Sparger (Cross-Shaped, with 16 3-Mm Holes), the Cross-Sectional Gas Holdup Distribution in the Packed/ebullated Bed Was Relatively Uniform, with Gas Holdup of About 0.11 in the Center and 0.09 Near the Wall of the Bed …

Cfd Modeling Of Multiphase Flow Distribution In Catalytic Packed Bed Reactors: Scale Down Issues, Y. Jiang, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Flow Maldistribution in Either a Bench-Scale or Commercial Scale Packed Bed is Often Responsible for the Failure of the Scale Down Unit to Mimic the Performance of the Large Reactor. the Modeling of Multiphase Flow in a Bench-Scale Unit is Needed for Proper Interpretation of Reaction Rate Data Obtained in Such Units. Understanding the Mechanism of Flow Maldistribution is the First Step to Avoiding It. in Order to Achieve This Objective, Computational Fluid Dynamic (CFD) Simulations of Multiphase Flow under Steady State and Unsteady State Conditions in Bench-Scale Cylindrical and Rectangular Packed Beds Are Presented for the First Time. the …

Statistical Characterization Of Macroscale Multiphase Flow Textures In Trickle Beds, Y. Jiang, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental Studies (Lutran Et Al., Ind. Engng Chem. Res. 30 (1991) 1270; Ravindra Et Al., Ind. Engng Chem. Res. 36 (1997) 5133) and Numerical Simulation (Jiang Et Al., Chem. Engng Sci. 54 (1999) 2409-2419) Lead to the Conclusion that Fluid Flow Distribution in Trickle Beds is a Function of Bed Structure (I.e. Porosity Distribution), Particle External Wetting and Inlet Superficial Velocities of the Two Fluids. in This Study, Quantitative Relationships among the above Parameters Are Developed in a Statistical Manner through a Series of Computational Fluid Dynamics Simulations. the Contribution of Capillary Forces to Liquid Maldistribution is Significant in the …

Prediction Of Axial Liquid Velocity Profile In Bubble Columns, Yuanxin Wu, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Liquid Flow and Mixing Behavior in Bubble Columns is Partially Described by Means of Global Liquid Recirculation Velocity Profile. Due to the Complex Character of the Flow in Bubble Columns, the Prediction of the Axial Liquid Circulation is Still a Difficult Task. in This Work, the Following Correlation is Proposed for the Liquid Recirculation Profile: VLO/ VL(R)= 1 - 2.65 * N0.44 * C[R/r] 2.65, N0.442,c , Where N and C Are the Gas Radial Holdup Profile Parameters Evaluated by the Correlations Proposed by Wu, Ong and Al-Dahhan (Chemical Engineering Science, 56 (2001) 1207-1210). N = 2.188 X 103 …

Gas Holdup In A Trayed Cold-Flow Bubble Column, A. Kemoun, N. Rados, F. Li, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic', P. L. Mills, T. M. Leib, J. J. Lerou

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Study Was Performed to Investigate the Effect of Sieve Trays on the Time-Averaged Gas Holdup Profiles and the overall Gas Holdup in a Cold-Flow Bubble Column that Was Scaled-Down from a Commercial Unit. Γ-Ray Computed Tomography (CT) Was Used to Scan the Column at Several Axial Locations in the Presence and Absence of Trays from Which the Local Variation of the Gas Holdup Was Extracted. the overall Gas Holdup Was Also Determined using the Same Configuration by Comparing the Expanded and Static Liquid Heights. Air and Water Were Used as the Gas-Liquid System. the Superficial Gas and Liquid …

Modeling And Analysis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Nonporous Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mass-transfer systems based on electrokinetic phenomena (i.e., capillary electrochromatography (CEC)) have shown practical potential for becoming powerful separation methods for the biotechnology and pharmaceutical industries. A dynamic mathematical model, consisting of the momentum balance and the Poisson equations, as well as the unsteady-state continuity expressions for the cation and anion of the background electrolyte and of a positively charged analyte (adsorbate), is constructed and solved to determine quantitatively the electroosmotic velocity, the electrostatic potential, the concentration profiles of the charged species in the double layer and in the electroneutral core region of the fluid in the interstitial channels for bulk …

Comparison Of Single- And Two-Bubble Class Gas-Liquid Recirculation Models - Application To Pilot-Plant Radioactive Tracer Studies During Methanol Synthesis, Puneet Gupta, Muthanna H. Al-Dahhan, Milorad P. Dudukovic, Bernard A. Toseland

Chemical and Biochemical Engineering Faculty Research & Creative Works

Radioactive Gas Tracer Measurements Conducted during Liquid-Phase Methanol Synthesis from Syngas in a Pilot-Scale Slurry Bubble Column at the Alternate Fuels Development Unit (AFDU), La Porte Have Been Compared with Simulations from Two Mechanistic Reactor Models - Single-Bubble Class Model (SBCM) and Two-Bubble Class Model (TBCM). the Model Parameters Are Estimated from an Independent Sub-Model Gas and Liquid Recirculation, and the Long-Time-Averaged Slip Velocity between the Gas and Liquid/slurry in the Column Center Can Be as High as 50-60 Cm/s Depending on the Operating Conditions. Comparison of Experimental Data with Simulation Results from the Two Models Indicates that Accurate Description …

Predictions Of Radial Gas Holdup Profiles In Bubble Column Reactors, Yuanxin Wu, Boon Cheng Ong, M. (Muthanna) H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Gas Holdup and its Profile Are Important Parameters to Be Characterized in Bubble Column Reactors. Proper Prediction of the Radial Gas Holdup Profiles is Necessary for Determining Liquid Mixing, Flow Regime Transition, Heat and Mass Transfer. in This Study, the Following Gas Holdup Profile Form, Which Can Be Fitted to the Observed Holdup Profiles, is Proposed: EG = EG (N + 2/n + 2 - 2c) [1 - C(R/R)n]. the Parameters N and C Needed to Describe the Gas Holdup Profile Are Correlated with Appropriate Dimensionless Groups. N = 2.188 X 103 ReG-0.598 Frg0.146 MoL-0.004, C = 4.32 X 10-2 …

Hydrodynamics Of Churn Turbulent Bubble Columns: Gas-Liquid Recirculation And Mechanistic Modeling, Puneet Gupta, Booncheng Ong, Muthanna H. Al-Dahhan, Milorad P. Dudukovic, Bernard A. Toseland

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Phenomenological (Mechanistic) Model Has Been Developed for Describing the Gas and Liquid/slurry Phase Mixing in Churn Turbulent Bubble Columns. the Gas and Liquid Phase Recirculation Rates in the Reactor, Which Are Needed as Inputs to the Mechanistic Reactor Model Are Estimated Via a Sub-Model Which Uses the Two-Fluid Approach in Solving the Navier-Stokes Equations. This Sub-Model Estimates the Effective Bubble Diameter in the Reactor Cross-Section and Provides a Consistent Basis for the Estimation of the Volumetric Mass Transfer Coefficients. the Strategy for the Numerical Solution of the Sub-Model Equations is Presented Along with the Simulation Results for a Few …

A Case Study Of The Beneficial Reuse Of Treated Groundwater, Andrew Curtis Elmore, Thomas Graff

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The future disposal of treated groundwater at the former Nebraska Ordnance Plant (NOP) Superfund site has been a topic of interest to the local property owners, the U.S. Army Corps of Engineers, and the local regulatory agencies. The Record of Decision for the site includes the extraction, treatment, and disposal of almost 3,000 gpm of groundwater with an estimated restoration time period exceeding 100 years. Interest from property owners and the Nebraska agency charged with regulating groundwater supply prompted the Corps of Engineers to consider several strategies for beneficially reusing the treated water. Alternatives included the establishment of a rural …

Purification And Characterization Of Crystallins By Aqueous Two-Phase Extraction, Ondrea Bermudez, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Crystallins are a family of water-soluble proteins that constitute up to 90% of the water-soluble proteins in mammalian eye lenses. We present in this paper an alternative purification method for these proteins using polyethylene glycol/dextran aqueous two-phase extraction. Under the appropriate conditions, we were able to recover the γ-crystallin fraction essentially free of the remaining proteins. High concentrations of salt at a neutral pH maximize the recovery of γ-crystallins in the top phase and minimize the contamination by the other proteins present in the lenses. The proposed protocol decreases the separation time by about 50%. The complex partition behavior observed …