Chemical Engineering Commons^™

The Interpretation Of Infrared And Raman Spectra Using Pattern Recognition, John Martin Comerford

Dissertations

An automatic classification of chemical compounds by computer processing of digitized spectral data is presented. The classification system is based on a branch of artificial intelligence known as supervised learning, and used binary linear classifiers to identify compounds as alcohols, esters, ethers, ketones or compounds containing double bonds.

Each of the 1117 spectra in volume one of Sadtler's Standard Raman Spectra was coded using a scale from 0 to 9 in the range from 4000 to 200 cm^-1. One hundred and twelve readings were taken on each spectrum. These data were then examined using pattern recognition techniques, and …

A Nonlinear Viscoelastic Model, Yon-Li Shangkuan

Dissertations

A nonlinear viscoelastic model has been developed to describe the non-Newtonian viscosities and the primary normal stress differences of high polymers at steady-state shearing flow.

It has been demonstrated that the Huang-Shangkuan model gives the best representation of the experimental data for a wide range of shear rates. In the high shear rate region the Huang-Shangkuan model is distinguished among other models by its capability to predict the nonNewtonian viscosities and the primary normal stress differences Which the other models fail to predict.

Continuum mechanics, Lodge's network theory and Rouse's theory provide specific information in developing our model. The theoretical …

Effect Of Gas Temperature Gradients And Radiant Heat Transmission On Kinetic Model Behavior, Richard W. J. Robertson

Dissertations

Satisfactory methods to predict radiant heat transmission in enclosures containing a radiating gas at uniform temperature are available. These methods have been traditionally used in solutions of kinetic models.

Kinetic models are strongly temperature dependent with a difference of 10°K able to double the reaction rate. In the present investigation, calculation techniques which make allowance for the non-uniformity of gas temperatures in an enclosure are applied to the kinetic models. The furnace problem considers only the radiation section with the assumption that detailed knowledge of combustion and fluid flow pattern within the enclosure is available.

If the gas space in …

Representation And Characterization Of Thixotropic Fluids, Huei-Hsiung Wang

Dissertations

Thixotropy is a time-dependent rheological behavior of a group of fluids which are characterized by an isothermal reversible breakdown induced by a mechanical disturbance. Based on this definition, a mathematical model of reversible degradation kinetics is set up. Its development leads to two equations which represent quantitatively the hysteresis loop and torque-decay curve. These equations consist of five independent parameters with their physical meanings. These parameters can be used to characterize the properties of thixotropic materials.

The original Weissenberg Rheogoniometer was modified to measure the thixotropic behavior of blood with the step change and the ramboid change of shear rate. …

The Effect Of Ultrasonic Vibrations On Heterogeneous Catalysis, William Lintner

Dissertations

The effect of ultrasonic vibrations on the vapor phase decomposition of cumene to benzene and propylene was investigated employing silica-aluminum cracking catalyst.

The catalytic reactor consisted of a 1 cm. diameter stainless steel tube containing a 20 in. long preheater and a 4 in. long catalyst chamber. The catalyst bed was irradiated from above by means of an ultrasonic horn which transmitted acoustical energy directly into the vapor.

The reactor was run at temperatures of 650°F. and 1050°F., frequencies of 26,000 cps and 39,000 cps, feed rates of 20 to 600 gms./hr., power outputs of 0.5 to 1.3 watts/cm.^{2 …}

The Preparation Of Cis- And Trans-1,2-Dimethoxyethylene. The Study Of The Cis-Trans-Rearrangement And Evaluation Of Equilibrium Constants, James T. Waldron

Dissertations

Equilibrium constants for the mercuric acetate-catalyzed reaction, cis-CH₃ OCH=CHOCH₃ D trans-CH₃ OCH=CHOCH₃, have been determined in the liquid and vapor phase over the temperature range 30° - 175°C by gas chromatography analysis. A novel synthesis of the cis- and trans-isomers of 1,2-dimethoxyethylene is discussed. From a screening of 29 catalysts, mercuric acetate, mercuric benzoate, and mercuric salicylate were found to be favorable isomerization catalysts. For the liquid phase reaction,

ln K = -779.8/T + 0.6748

with ΔH° = +1.549 ± 0.019 Kcal/mole
and ΔS° = +1.34 ± 0.05 e.u./mole

Similarly, for the vapor phase reaction, …

Structure And Magnetic Properties Of Rare Earth Garnets, Milan R. Kokta

Dissertations

This study deals with preparation and magnetic properties of garnet compounds containing rare earth ions and scandium ions on two crystallographic sites: the dodecahedral and the octahedral. A number of compounds of the types {R_3-yr_y}[r_x Ga_2-x](Ga₃) O_12' {R₃}[Sc₂](Fe_z Ga_3-x) O_12' {R_3-y Sc_y}[Sc₂] (Fe₃) O_12' and {R_3-y r_y)[r₂ (Fe_z Ga_3-z) O_12' where R stands for large rare earth ions such as Nd³⁺ and Pr³⁺, …

The Oxidation Of Carbon Monoxide By Magnesium Aluminate, James A. Whelan

Dissertations

In this research the catalytic oxidation of carbon monoxide was investigated on magnesium aluminate catalysts, MgO:xAl₂O₃, with five different compositions, x, ranging from 1.0 to 3.0. The reaction was run at temperatures ranging from 500 to 600 °C. with radioactive carbon monoxide as the tracer. An experimental technique has been devised for the analysis of unreacted CO which takes into account a correction for the solubility of CO in CO₂.

Four mathematical models were postulated to explain the mechanism of reaction. The models were examined against experimental data by means of non-linear least squares …

Local Mole Fraction Equations For The Excess Free Energy Of Mixing, Jose Mario Marina

Dissertations

An extensive study of local mole fraction equations aimed at obtaining a two parameter expression for the Excess Free Energy of miscible and immiscible systems has been undertaken.

Initially our approach was to modify existing equations by substituting those parameters reflecting interaction between like molecules by the pure component energies of vaporization. This resulted in a one parameter modification of the three parameter Wilson equation, which correlates data poorly and a two parameter modification of the NRTL equation which correlates binary miscible data with fair accuracy. A modification of the Scatchard-Hildebrand equation, where mole fractions are substituted by local mole …

A Kinetic Study Of The Anionic Polymerization Of Neopentylethylene Oxide, Albert Edward Meisinger

Dissertations

Kinetic data for the anionic polymerization of bulk neopentylethylene oxide were determined. The initiator used for this study was potassium t-butoxide. Polymerization runs were made at temperatures of 39.9, 60.0 and 80.3°C using monomer to initiator ratios of 50/1 and 20/1.

The polymerization reaction was found to follow pseudo first order kinetics up to about 60% polymerization and second order after this. The energy of activation for the propagation reaction was found to be 17.4 ± 1.2 K cal/mole and 18.5 ± 1.5 K cal/mole, respectively, for the pseudo first order and second order portions of the polymerization. The value …

Continuous Esterification Of Lactic Acid With N-Butyl Alcohol, Robert Dix

Dissertations

A model is proposed for the reactions occurring when an aqueous 30% lactic acid solution is contacted with a primary alcohol, normal butanol. Kinetic and equilibrium data for the esterification reactions of monomeric lactic acid and dimeric lactic acid were determined in a series of experiments using an ideal overflow back-mix reactor. The variables studied were reaction temperature and catalyst concentration.

It was determined that the significant reactions occurring within this system are the esterification of monomeric lactic acid with n-butanol and the esterification of dimeric lactic acid with n-butanol. Other reactions that may be postulated to occur within the …

A Study Of The Dynamics Of Gas Adsorption In An Air Fluidized Bed, William Charles Zalewski

Dissertations

The dynamics of gas adsorption was studied in an air fluidized bed containing activated alumina particles. The adsorption studies made with a fixed bed and in the transition region between minimum fluidization velocity and 2.0 times minimum fluidization velocity, compliment work done at higher velocities. With adsorption, particle motion controlled the overall dynamics of the fluidized bed. A different approach in applying the two phase fluidization model was necessary to satisfactorily describe unsteady state adsorption in fluidized beds. Experimental and theoretical results were compared in frequency response plots to obtain a rigorous comparison. Good agreement was obtained for flow rates …

Simulation Of Periodic Tank Reactors, Noshir Pirojshaw Mistry

Dissertations

Normally it is assumed that the steady state mode of operation is most desirable for the design of the chemical reactor system. However it appears that this assumption may not be correct in many cases.

In the present work disturbances of various types were externally created and forced on a system comprising an isothermal continuous stirred tank reactor. The effects of these purposefully created disturbances were investigated by mathematically modelling the system and simulating it on a digital computer.

The change in reactor performance, as defined by the percentage change in the production rate from the steady state value, can …

Boiling Heat Transfer In The Presence Of Electric Fields, Ronald Francis Lovenguth

Dissertations

The effects of a non-uniform, radial D.C. electric field on the natural convection and nucleate boiling regimes in saturated pool boiling and on the peak heat flux phenomenon were determined for trichlorotrifluoroethane, carbon tetrachloride, dichloromonofluoromethane and chloroform using as a heat transfer surface a 0.02 inch diameter platinum wire.

Bubble departure diameters for the nucleate boiling region were measured by photographic means as a function of the electric field intensity at the heat transfer surface.

The application of an electric field was found to have a significant effect on the natural convection mode of heat transfer and also the peak …

Viscosity-Density Correlation Of Newtonian Liquids, Melvin Leonard Druin

Dissertations

The viscosity of monatomic liquids was modeled by an equation derived from the kinetic theory of gases. Viscosities may be calculated from data on density and molecular weight of the liquid. In adapting this relationship to polyatomic liquids, a single correction factor was developed for each of five series of homologues; n-paraffins, n-1 -alkenes, n-alkylcyclohexanes, n-alkylbenzenes and n-alcohols, to account for the deviations of the calculated viscosities from those reported, extending over a one- to three-hundred degree range. The factor is a function of reduced temperature relative to the normal boiling point, T_rB. A single equation for each …

The Generalized Virial Equation Of State, Ghanshyam R. Patel

Dissertations

A generalized three parameter virial equation of state has been developed and tested for seven pure gases having different molecular characteristics. The equation has also been tested for more than thirteen binary gas mixtures using three different mixture rules. The final equation is as follows:

Z = 1 + B(T)/V + C(T)/V² + D(T)/V³ + E(T)/V⁴ + VF(T)/e^aV + VG(T)/e^bV

The expressions for E(T), F(T), and G(T) along the critical isotherm were derived in terms of critical properties and two constants, a and b which appear in the sixth and seventh terms in the above …

Relationships Between Some Properties Of Pure Homologous Organic Liquids, Herbert Rudolph Kemme

Dissertations

The vapor pressures of eleven primary straight chain alkyl chlorides and eleven primary straight chain alcohols between C3 and C16 were determined within a range of 5 to 760 mm Hg. These data were obtained by determining the boiling points of the pure materials at various pressures by using differential thermal analysis. The boiling points were determined with a precision of -.1 degree Centigrade at a 95 per cent C.I. The Antoine equation was used to analytically describe the data. The constants for this equation were determined by a multiple linear regression technique for each individual compound. The heats of …

Kinetics Of Hydrogen Reduction By Manganese Dioxide, Herbert Eugen Barner

Dissertations

Samples of synthetic pyrolusite were reduced in hydrogen at various partial pressures in the temperature range of 200° to 500°C. Most reduction experiments were conducted using a Pyrex vertical-tube reactor, in which small beds of porous particles (0.07 to 0.21 mm.) or single porous pellets of the oxide were suspended. The reaction kinetics were followed by recovering and weighing the water product formed during measured time intervals, and the intermediate reduction products were identified by X-ray diffraction analysis.

The data show that reduction proceeds through the sequence MnO₂->Mn₂O₃->OMn₃O₄- …

Kinetics Of The Lactic Acid-Butyl Alcohol Esterification Reaction, Joel Howard Kaplan

Dissertations

Kinetic and equilibrium data for the esterification reaction of monomeric lactic acid with normal butanol were determined in a series of experiments utilizing a batch stirred tank reactor. The variables studied were temperature and catalyst concentration. The kinetic data were successfully represented by the integrated equation for a second order reversible reaction.

Rate constants were obtained at three temperature levels and four catalyst levels. The observed rate constants in the catalytic reaction were linearly correlated with catalyst concentration and also satisfied the Arrhenius criterion. The activation energy and frequency factor for the uncatalyzed reaction were determined to be 13,190 calories …

Hydrotropic Extraction Of Hydrocarbon Mixtures, Michael Jay Ram

Dissertations

The solubilities at 25°C of selected aromatics and straight chain alkanes in hydrotropic solutions of sodium xylene sulfonate and sodium cymene sulfonate were studied. The results of this investigation are shown on distribution diagrams relating the solubilities of alkane and aromatic in each phase.

Two methods were investigated to predict the experimentally determined solubilities. The semi-empirical solubility parameter approach resulted in answers that were extremely low. A purely theoretical approach involves the calculation of dispersion forces between molecules. An equation for predicting solubilities has been derived so that it is applicable to four component systems. This method results in values …

A Systematic Evaluation Of Alternate Chemical Routes, Arthur H. Bobis

Dissertations

A systematic method for selecting from among alternative routes for chemical synthesis is developed and presented. Consideration is given not only to making the best decision, but of reaching that decision with a minimum of experiments.

A method is developed whereby the calculated differences in process cost due to variations in the levels of such responses as chemical yield, usage and recovery are displayed graphically. Such a representation by indicating the potential worth of any experiment focuses attention on those parts of the synthesis which have an economic bearing on the ultimate process cost.

The probability of achieving a particular …

Prediction Of Batch Heat Transfer Coefficients For Pseudoplastic Fluids In Agitated Vessels, Donald William Hagedorn

Dissertations

Experimental batch heat-transfer data were obtained for both Newtonian and pseudoplastic liquids in a baffled agitated vessel. The fluids tested had flow behavior in-dexes between 0.36 and 1.0; and the apparent viscosity ranged from 1 to 1200 centipoise. Four types of impellers (anchor, paddle, propeller, and disk and vane turbine) were studied using eleven separate impellers. The probable error in the measured heat transfer coefficient was ± 20 percent.

The effects of the generalized Reynolds number, generalized Prandtl number, and viscosity ratio were studied. In addition the effect of impeller diameter was studied for paddles, propellers, and turbines; and the …

The Electrochemical Oxidation Of Cholesteryl Acetate Dibromide, Abraham Cooper

Dissertations

Cholesteryl Acetate Dibromide was dissolved in carbon tetrachloride, suspended with mixing in 4.5 molar solution of sulfuric acid and electrolyzed at a lead dioxide anode. The anodically prepared film of lead dioxide, when maintained at potentials (relative to a calomel electrode) above 1.5 volts, was a catalyst for the oxidation. A new and mild oxidation took place at the catalytic electrode surface that resulted in attack on the tertiary hydrogen atom at the 25 carbon. The mildness of the oxidation prevented the decomposition of the unconverted raw material and permitted the recovery of up to 96% of the cholesteryl acetate …

Current-Potential Effects Of Trace Impurities In Manganese Electrowinning, George Robert Ferment

Dissertations

The purpose of this investigation was to study the effects of trace metallic impurities, found in manganese electro-winning solutions, on cathode current-potential curves.

This investigation led to the development of a novel analytical tool, emphasizing polarization curves as a means of detecting trace metallic impurities in manganese sulfate electrolytes. The method possesses two distinguishing features: (a) it uses the competing hydrogen evolution reaction as a means of detecting metallic impurities, and (b) it enables one to establish if the electrolyte is sufficiently pure for efficient electrolysis.

Nine metallic impurities were studied, consisting of: nickel, cobalt, silver, copper, zinc, molybdenum, cadmium, …

Salt Effects In Liquid-Liquid Equilibria, Edwin Otto Eisen

Dissertations

The effect of lithium chloride, sodium chloride and potassium chloride on the distribution of acetic acid, propionic acid and butyric acid between benzene and water at 25° C has been studied. The method of Hand, which has previously been used to correlate tie line data in salt-free ternary systems, has now been successfully employed to correlate distribution data for quaternary systems containing salt.

The slope and intercept of the Hand equations have been expressed as linear functions of the salt concentration in each system studied. Equations for slope and intercept possessing high statistical significance have been formulated using a linear …