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1996

Series

Chemical and Biochemical Engineering Faculty Research & Creative Works

Articles 1 - 6 of 6

Full-Text Articles in Engineering

Dynamics Of An Adsorbed Patch And A Model For Spreading Of Films Of Ultralow Thicknesses, Partho Neogi Nov 1996

Dynamics Of An Adsorbed Patch And A Model For Spreading Of Films Of Ultralow Thicknesses, Partho Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamics of ultrathin films of liquids with vanishing 3D volatility, on solid surfaces, has been modeled by assuming that the films can be taken to be adsorbed patches spreading under surface diffusion. when the phase behavior of the adsorbed films is taken into account, it is seen that a vapor patch will spread without limits and evolve into a Gaussian profile. For a liquid film which has low 2D volatility, a patch will appear to equilibrate and the surface ahead will remain dry. This is the "pancake," a case where a wetting liquid stops spreading. the spreading kinetics is …


Modified Contactor For Experimental Studies Of Mass Transfer And Chemical Reaction Across A Liquid-Liquid Interface, Muthanna H. Al-Dahhan, Charles E. Wicks Jan 1996

Modified Contactor For Experimental Studies Of Mass Transfer And Chemical Reaction Across A Liquid-Liquid Interface, Muthanna H. Al-Dahhan, Charles E. Wicks

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Modified Stirred-Cell Type Contactor Has Been Designed and Tested for its Use in Experimental Investigations of Mass Transfer and Chemical Reaction in Liquid-Liquid Systems. its Design overcomes the Shortcomings of Previously Proposed Contactors. It is Easy to Operate and Has the Ability to Investigate the Effect of a Wide Range of Operating Conditions. the Mixing Performance of the Contactor Was Tested using a Dye Injection and a Tracer Technique. Experiments to Evaluate Mass-Transfer Coefficients Across a Liquid-Liquid Interface Have Been Conducted to Determine its Effectiveness. the Results Verified that the Contactor Could Be Successfully Employed as a Useful Experimental …


Catalyst Bed Dilution For Improving Catalyst Wetting In Laboratory Trickle-Bed Reactors, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 1996

Catalyst Bed Dilution For Improving Catalyst Wetting In Laboratory Trickle-Bed Reactors, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Catalyst Bed Dilution Technique Has Found Rather Widespread Applications as a Means of Producing Reliable and Reproducible Results for Successful Scale-Up and Scale-Down When Testing Commercially Used Catalyst Particle Sizes and Alternative Feedstocks in Small-Scale Laboratory Trickle-Bed Reactors. in Such Small-Diameter Laboratory Units When the Catalyst Used in Commercial Units is Employed as the Only Packing, Low Liquid Velocities Lead to Incomplete Catalyst Utilization Due to Incomplete External Catalyst Wetting, Liquid Maldistribution, and Wall Effects. Diluting the Bed with Fines is Recommended to Remedy These Shortcomings. the Effect of the Bed Dilution with Fines on Catalyst Wetting Efficiency, Pressure …


Evaluation Of Trickle Bed Reactor Models For A Liquid Limited Reaction, Yuanxin Wu, Muthanna H. Al-Dahhan, Mohan R. Khadilkar, Milorad P. Dudukovic Jan 1996

Evaluation Of Trickle Bed Reactor Models For A Liquid Limited Reaction, Yuanxin Wu, Muthanna H. Al-Dahhan, Mohan R. Khadilkar, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Isothermal Decomposition of Hydrogen Peroxide on a CuCr Catalyst in a Laboratory Scale Trickle Bed Reactor Was Used to Test Model Predictions of the Dependence of Liquid Reactant Conversion on Space Time for Different Operating Conditions. It is Assured that the Decomposition of Hydrogen Peroxide is a First Order Liquid-Limited Reaction. Comparison of Model Predictions and Experimental Data Indicates that Both External Mass Transfer Effects and Incomplete External Catalyst Wetting Need to Be Accounted For. Dudukovic's (1977) Approximate Model for the Catalyst Effectiveness Factor Adequately Simulates Both Effects.


Comparison Of Upflow And Downflow Two-Phase Flow Packed-Bed Reactors With And Without Fines: Experimental Observations, Yuanxin Wu, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Duduković Jan 1996

Comparison Of Upflow And Downflow Two-Phase Flow Packed-Bed Reactors With And Without Fines: Experimental Observations, Yuanxin Wu, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

This Study Compares the Performance of Laboratory Trickle-Bed and Upflow Reactors over a Range of Operating Conditions, using the Hydrogenation of Α-Methylstyrene to Cumene in Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. It is Shown that the Trickle Bed Performs Better Than the Upflow Reactor at Low Pressures When the Reaction is Gas Limited, Due to Ready Access of the Gas to the Incompletely Externally Wetted Catalyst, While the Upflow Reactor Performs Better at High Pressures When the Liquid Reactant Limitation Controls the Rate, Due to the Completely Wetted Catalyst. Comparison of the Two …


Comparison Of Trickle-Bed And Upflow Reactor Performance At High Pressure: Model Predictions And Experimental Observations, M. R. Khadilkar, Y. X. Wu, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic, M. Colakyan Jan 1996

Comparison Of Trickle-Bed And Upflow Reactor Performance At High Pressure: Model Predictions And Experimental Observations, M. R. Khadilkar, Y. X. Wu, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic, M. Colakyan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Comparison of Laboratory Trickle-Bed and Up-Flow Reactors over a Range of Operating Conditions, Which Cover Both Gas and Liquid Reactant Limitations, Has Been Investigated using Hydrogenation of Alpha-Methylstyrene to Cumene in a Hexane Solvent over 2.5% Pd on Alumina Extrudate Catalyst as a Test Reaction. the Results Show that When the Reaction is Gas Limited at Low Pressure and High Liquid Feed Concentration, Trickle Bed Reactor Outperforms the Upflow Reactor. at High Pressure and Low Liquid Feed Concentration, the Reaction Becomes Liquid Limited and Upflow Reactor Performs Better. It is Concluded that the Advantage of Upflow or Downflow Depends on …