Chemical Engineering Commons^™

Further Studies Of The Catalytic Oxidation Of Ortho-Xylene To Phthalic Anhydride Using A Fluidized Bed Reactor., Richard Shih-Chun Chu

Masters Theses

"This investigation was conducted to further study the vapor-phase oxidation or o-xylene to phthalic anhydride in a fluidized bed catalytic reactor. Parameters investigated during the study were temperature, catalyst volume, and catalyst activated by use or different promoters. Two different vanadium pentoxide catalysts were used. One was a new catalyst(Catalyst I) supported on a silica base and diluted with potassium sulfate. The other catalyst(Catalyst II) was similar to the first one except that it had been used in a commercial fixed bed reactor operated by the Monsanto Company, St. Louis, Missouri, using naphthalene as a reed material. It had been …

The Anodic Dissolution Of Magnesium In Aqueous Solutions, Chen-I Lu

Masters Theses

"The anodic dissolution of magnesium was studied in MgCl₂-KC1 and MgBr₂-KBr mixtures at 25, 40, and 55 °C. The parameters of the study were current density, concentration of magnesium ion, and temperature. The concentration of magnesium ions was varied from 0.001 to 1 N holding the ionic strength constant at 1.5. The weight loss of magnesium from the electrode during electrolysis was determined by weighing the electrode both before and after electrolysis. The current was measured with a sensitive milliammeter. The range of the current densities was varied from 0.001 to 0.1 amps·cm^-2. The …

Anodic Dissolution Of Silver In Aqueous Solutions, B. W. Jong

Masters Theses

"The purpose of this investigation was to study the anodic dissolution of silver in various electrolytes to determine if there existed any deviations from Faraday’s law in nitric acid-silver nitrate solutions. The effect of small additions (10^-4 and 10^-5 N) of Cl^-, SO₄⁼, and CrO₄⁼ on the apparent valence and dissolution potential was also studied. Current densities were varied from 0.00 to 0.07 amp·cm^-2.

Based on the observed apparent valences and a grey film containing metallic particles on the anode surface, it was concluded that deviations from Faraday’s law …

A Study Of The Removal Of Alkyl Benzene Sulfonate By Means Of A Column Packed With Sand Coated With Ferric Oxide, Chang I. Fung

Masters Theses

"Iron, precipitated in the form of hydroxides on sand particles (-48 + 65 mesh) and stabilized by drying at 100°C for 10 hours, was utilized to remove alkyl benzene sulfonate (ABS) from aqueous solutions. Solutions containing a maximum of 5 mg/l ABS were passed through a glass column packed with treated sand. The ABS formed a complex with the iron precipitants which adhered to the sand particles.

Preliminary work, in which solutions containing 10 mg/l ABS were treated with various concentrations of FeCl₂ at the equivalence point (pH about 9.5), verified the fact that ABS could be removed by …

A Crystallographic Study Of The Pbzro₃-Pbtio₃-Bifeo₃ Ternary System., Dannie R. Clarida

Masters Theses

"The purpose of this investigation was to conduct a crystallographic study of the PbZrO₃-PbTiO₃-BiFeO₃ ternary system, where all three components are perovskites. Lead zirconate is antiferroelectric, lead titanate is ferroelectric, and bismuth ferrate is thought to be ferroelectric. X-ray diffraction analysis was employed to determine the crystallographic structure and lattice parameters.

A tetragonal region was found to exist in the area of high PbTiO₃ content. A rhombohedral region occurred in the remainder of the system with high BiFeO₃ and PbZrO₃ content, except for an orthorhombic envelope along the PbZrO₃-BiFeO₃ side of the diagram up to approximately 70 per cent BiFeO₃.The …

Study Of Heat And Mass Transfer Through Non-Wettable Porous Membrane, Rajender Kumar Rohatgi

Masters Theses

"The object of this investigation was to study the use of non-wettable porous membranes for simultaneous heat transfer and mass transfer of water from a hot salt solution stream to a cold distilled water stream, the streams being in countercurrent flow separated by the membrane. This type of mass transfer was achieved in the experiments, and mass and heat transfer coefficients were measured.

The membranes studied in this work were made of fiberglas treated with Teflon dispersion and aluminum sulphate. The fiberglas membranes yielded desired results. Empirical correlations were proposed which predict values of heat and mass transfer coefficients close …

Permeability And Additive Sorption And Extraction In Lubricating Greases, Hsiu-Hsiung Lin

Masters Theses

"An important goal in the study of lubricating greases is the determination of the mechanism of additive action in lubricating greases and the effect of additive concentration on the improvement of particular properties. As a step in this direction, one aim of this investigation was an attempt to determine whether grease additives are sorbed on the thickener surface, or are dissolved in the oil phase, or if a combination of these effects prevails. Exploratory sorption and extraction experiments were run by Tu using greases thickened with lithium hydroxystearate and Baragel and using only one concentration of additive. More detailed studies …

The Kinetics Of The Reaction Of M-Nitrobenzyl Bromide With Hydroxide Ion In Aqueous-Aprotic Solvent Mixtures, Ramesh Nagindas Sheth

Masters Theses

"The reaction between m-nitrobenzyl bromide and sodium hydroxide in homogeneous aqueous dioxane and aqueous tetrahydrofuran media was studied.

The product of the reaction was identified by infrared, gas chromatography and chemical tests as m-nitrobenzyl alcohol.
The kinetics of the reaction are second order with practically no variation in the rate constants as the % of the organic solvent was changed in the medium. This seems to imply hydrolysis of the organic halide by a process involving both bond-breaking and bond-formation in the transition state.
The activation energy, measured in 50% aqueous dioxane, between 20⁰ and 69.5⁰C at 5 different temperatures, …

Kinetics And Mechanisms Of Base-Catalysed Reactions, Rohit Panalal Sheth

Masters Theses

"Base-catalysed reactions normally involve complex series of transformations. their kinetics is usually governed by a variety of equilibria, participating in the overall and concurrent processes as well as by competitive side-reactions that interfere with the normal course of such reactions. Mechanisms which have been proposed, by and large, are primarily based on product, by-product and intermediate analyses together with some scattered kinetic and isotopic evidence. In the cases where kinetic studies have been attempted, highly complex mechanisms have usually been proposed due to the frequent necessity of using heterogeneous media or employing involved mathematical treatments to describe the kinetics of …

Decarboxylation Of Malonic Acid In Aqueous Solutions, Ramesh Natwarlal Gujarathi

Masters Theses

"The rate of decarboxylation of malonic acid in aqueous solutions was studied over a range of concentrations, pH's, and temperatures. The catalytic effect of various divalent metallic ions was also studied at a pH of 0.3. these studies did not support a truly unimolecular decomposition as the experimental order was found to be slightly greater than one. An empirical relation for the rate of decarboxylation was formulated in which the undissociated malonic acid and the monovalent malonate ion were the reactive species.

A possible mechanism of decarboxylation due to solvent activation was postulated. No pronounced catalytic effect due to the …

The Anodic Oxidation Of Crotonic Acid In Basic Solutions, Richard C. Porter

Masters Theses

"The purpose of this study was to investigate the anodic oxidation of crotonic acid in basic solutions. Potassium hydroxide solutions of pH 12.3 and KOH-K₂CO₃ solutions of pH 11.5 and 10.5 were used. The investigation was carried out on platinized-platinum anodes at 80°C.

Experimental studies were conducted to determine the effects of crotonic acid concentration, pH, and temperature on the current. Faradaic efficiency was determined by analysis of CO₂ produced and was approximately 100 per cent.

The results were interpreted in terms of a mechanism having the following characteristics:

1. The first electron transfer is the rate …

Correlation Of Drag Reducing Data In Dilute Polymer Solutions, Jorge Mario Rodriguez

Masters Theses

"The purpose of this investigation was to obtain a correlation for drag reducing solutions in circular tubes under turbulent conditions. Data were taken for three polymer-solvent systems: polymethyl methacrylate V-100 (M_v ~ 110,000) in toluene, polyisobutylene L-200 (M_v ~ 4,700,000) in toluene, and polyisobutylene L-200 in cyclohexane. The data from the two polyisobutylene systems, together with other data on polymethyl methacrylate G (M_v ~ 1,500,000) in toluene and polyisobutylene L-80 (M_v ~ 860,000) in cyclohexane, were used to attempt to obtain the correlation. The V-100 solutions were not used because they were not drag reducing.

The …

The Performance Of A Countercurrent Extraction Column With Vibrated Packing, Mehmet Uran ÖZsoy

Masters Theses

"The performance of a continuous countercurrent extraction column with a packing -- that could be vibrated vertically at various amplitudes and frequencies by a variable speed motor -- was investigated under both non-flooding and flooding conditions using the high interfacial tension benzene-acetic acid-water ternary system. In all the experimental runs, which were sequenced randomly with a full-factorial experiment design, mass transfer of the solute (acetic acid) from the aqueous to the organic phase was studied. Column performance was evaluated in terms of the height of an overall transfer unit, HTU, based on the benzene phase. The variables studied were: amplitude …

Nucleate-Boiling Heat Transfer To Water At Atmospheric Pressure, H. D. Chevali

Masters Theses

"The purpose of this investigation was to study the hysteresis effect, the effect of micro-roughness and orientation of the heat-transfer surface, and the effect of infra-red-radiation-treated heat-transfer surfaces on the nucleate-boiling curve.

It has been observed that there exists no hysteresis effect for water boiling from a cylindrical copper surface in the nucleate-boiling region over the range studied. The nucleate-boiling curve has been found to be independent of micro-roughness and orientation of the heat-transfer surface. There was no detectable change in the nucleate-boiling characteristics of the heat-transfer surface when the surface was treated with infra-red radiation"--Abstract, page ii.

Electrodialysis Of Tomato Juice, Raghunath R. Khetan

Masters Theses

"Thermal decarboxylation of carboxylic acids has been helpful in illustrating some fundamentals of reaction kinetics in solution. It has been important in formulation of the theory of unimolecular reactions. It is also used frequently in the synthetical methods of organic chemistry.

In a recent study of the anodic oxidation of malonic acid in sulfuric acid at 80⁰C using a platinum anode, the interpretation of some results was impossible due to the spontaneous decomposition of the malonic acid. As no information is available in the literature about decomposition rates of malonic acid in sulfuric acid at the concentrations used, it was …

Mass Transfer In Droplets With Turbulent Internal Circulation - Mathematical Description, Jayantilal Mohanbhai Patel

Masters Theses

"This investigation was carried out to check the accuracy of the eigenvalues, λ_n, calculated by Wellek and Skelland, using some method other than the Rayleigh-Ritz technique and also, to determine the coefficients, B_n in series solution, which were not calculated before.
The eigenvalues were obtained by trial and error procedure using the standard Runge-Kutta method. The coefficients B_n were obtained by using eigenvalues. By using this information the fractional extraction was calculated as a function of droplet contact time.

The Wellek-Skelland modification was also solved by finite difference technique to compute fraction extracted as a function …

Anodic Dissolution Of Lead In Aqueous Solutions, Christopher Kuo-Chieh Wu

Masters Theses

"The apparent valence of lead was determined in one normal solutions of potassium nitrate, ammonium acetate, lead nitrate, and lead acetate at temperatures of 25 and 50°C. The current density was varied from 0.001 to 1.00 amp•cm ^-2. The apparent valence of lead ranged between 1.90 and 2.00 in all solutions. The lower valences were reached at higher current densities. The amount of disintegration was very small, and was dependent upon film formation on the surface of the anode.

Potential-current density relationships for the anodic dissolution of lead were obtained in the electrolytes mentioned above. In potassium nitrate and …

Study Of Mass Transfer Through Porous, Water-Repellent Membranes, Virendra V. Tanna

Masters Theses

"A new method of desalination using a porous, water-repellent membrane was studied. The membrane utilized surface forces to support a vapor phase in its pores which separated the salt water from fresh water. The method used a vapor pressure difference across the membrane as the driving force for mass transfer of water from the salt water phase to the fresh water. This vapor pressure difference was obtained by maintaining a temperature difference between the two liquid phases.

The experimental data and results indicated the feasibility of vaporization through porous, water-repellent membranes. The flux of water through a membrane made of …

The Effect Of Concentration On The Viscosity Of Polyisobutylene Solutions, Lung-Yu Chou

Masters Theses

"In the past twenty years the viscosity of dilute polymer solutions (i.e., where the solute molecules are far apart) has been investigated in great detail, both theoretically and experimentally. The viscosity characteristics of such systems are well-understood.

Only a few studies have been made of the effect of concentration on the viscosity of polymer solutions in the concentration range where the polymer molecules begin to overlap. This range of concentrations is important in practical applications such as dry spinning of fibers, cross-graded automotive motor oils and in many industrial formulations where polymers are used to thicken solvent vehicles. Development of …

The Kinetics And Mechanisms Of The Reaction Of Benzyl Chloride With Potassium T̲-Butoxide In T̲-Butyl Alcohol, Der-Rong Chen

Masters Theses

"Benzyl chloride is a moderately reactive halide. Substitution of the Cl⁻ by other nucleophiles, e.g., HO⁻, AcO⁻, S₂O₃⁻, Br⁻ etc. proceeds almost quantitatively in solutions at convenient temperatures ... The object of this study was to investigate if the less basic t̲-butoxide in t̲-butyl alcohol would afford the same product, viz., stilbene; and, if so, by what mechanism. A study of the products and kinetics of the interaction between benzyl chloride and potassium t̲-butoxide in t̲-butyl alcohol therefore has been initiated"--Introduction, page 1.

Construction Of A Capillary Viscometer And The Study Of Non-Newtonian Liquids, Hsun Kuang Yang

Masters Theses

"A capillary tube viscometer was built for the purpose of investigating the fluid properties of non-Newtonian aqueous CMC and Carbopol solutions. The viscometer was tested with Newtonian liquids (glycerine, water and two different oils) having known viscosities to insure that the viscometer was operating correctly. The shear stress-shear rate data obtained for different concentrations of CMC and Carbopol solutions were correlated using the simple power law model. The power law constants were only slightly affected by saturating the solution with iodine and carbon tetrachloride. Aging had very little effect on the viscosities of the CMC solutions but had a considerable …

Thermal Degradation Of Poly (Methyl Methacrylate) In Solution In Various Solvents, Ya-Chih Chen

Masters Theses

"A study has been made of the thermal degradation of poly (methyl methacrylate) of different molecular weights in toluene, ethyl acetate and chloroform. Four poly (methyl methacrylate) samples having molecular weights of 2,210,000, 733,000, 320,000, and 43,00, respectively were studied in this investigation. The results indicated that the polymer having a molecular weight of 2,210,000 undergoes degradation while the low molecular weight polymers having molecular weights of 733,000, 320,000, 43,000 undergo reverse polymerization"--Abstract, page [ii].

The Design Of A Sensitive Probe For Mass Flux Measurements Of Water Vapor In Air, Devendra Vaikunthlal Mehta

Masters Theses

"This investigation pertains to the construction and investigation of a sensitive probe to determine the possibility of measuring the mass flux of water vapor in air under non-flow steady state conditions. The probe was a small electrolysis cell is which the electrolyte (partially hydrated phosphorus pentoxide) was used as the sensing element. The rate of mass transfer was determined by measuring the amount of direct current flowing through the acid film"--Abstract, page i.

The Anodic Dissolution Of Cadmium In Nitrate Solution, Eh Deng

Masters Theses

"It is only relatively recently that the immensity of the problem of corrosion prevention has begun to be realized. In times when materials were plentiful, the problem did not seem so pressing. Now that a finite limit can be seen for the world*s resources of metals, and the cost of finding, mining and extracting them has become ever more expensive, the problem of controlling the destructive processes of corrosion has become an urgent one.

The basic mechanism of the anodic dissolution of metals such as cadmium, zinc, silver and magnesium in salt solutions is not completely known. Although several mechanisms …

The Dissolution Of Magnesium In Strong Acids And Neutral Solutions, Cheng-Ken Chi

Masters Theses

"The increasing demand for magnesium and magnesium- base alloys in the manufacture of aircraft has stimulated a great amount of research into the corrosion characteristics of these materials. The result of such research has been the development of suitable magnesium alloys and protective coatings to retard corrosion.

The basic mechanism of the anodic dissolution of metals such as magnesium, zinc, and cadmium in salt solutions is not completely known. Several schools of investigators have proposed different and opposing theories to explain the discrepancies which often arise between coulometer data and the weight loss of metal electrodes in certain salt solutions. …

Anodic Dissolution Of Silver In Aqueous Solutions, Jagdish Shantilal Sanghvi

Masters Theses

"Silver and platinum, although not used extensively in industry, find considerable use in specialized work. Silver, because of its much lower cost, is used to a greater extent than platinum. Since silver has a high position in the electromotive series, it is very resistant to chemical attack. It is unaffected by alkaline conditions even at high temperatures and hence silver is used in ladles and molds for producing pure sodium and potassium hydroxides. This and its excellent electrical conductivity makes it a very useful material in circuitry.

It has been reported in the literature that when active metals such as …

Kinetics Of Base-Catalysed Reactions, Kunjvihari Ramanlal Mehta

Masters Theses

"The work of Wulfman on the mechanism of the Michael reactions suggests that the normal Michael reaction is second order kinetically, with the rate being proportional to the concentration of the acceptor and the active form of the addendum. A detailed reaction mechanism of normal Michael reaction was not proposed due to insufficient data which resulted from analytical difficulties. This investigation involves the study of the kinetics of normal Michael reaction from the stand point of base strength, solvent concentration and acidity of the reactants, solvent and products"--Experimental. A. Purpose of Investigation, page 17.

The Electrochemical Oxidation Of Crotonic Acid, John L. Cannaday

Masters Theses

"The purpose of this investigation was to explain the mechanism of the electrochemical oxidation of crotonic acid on platinized-platinum anodes at 80⁰C.

A current-potential study was conducted using the parameters of pH and crotonic acid concentration. Faradaic efficiency was determined by measurement of CO₂ production.

Oxidation occurred both in acidic and basic solutions.The Faradaic efficiency was approximately 100 per cent.

The results were interpreted in terms of a mechanism having the following characteristics.

(a) The first charge transfer is the rate determining step.

(b) The rate is the sum of the rates for two parallel reactions. In strongly acidic solutions, …

Mass Transfer In The Electrodialytic Desalination Of Brackish Water And A Correlation Of Experimental Data With Theory, James Shih-Jiann Yang

Masters Theses

"The object of this work is an experimental investigation into the possibility of obtaining an increase in mass transfer in the electrodialysis of brackish water by altering the physical character of the selective membrane, and a correlation of experimental mass transfer data with theory"--Introduction, page 1.

Study Of Deformation Of Non-Oscillating Droplets In Liquid Media, Arun Kumar Agrawal

Masters Theses

"The object of this investigation was to find a method for predicting the deformation of non-oscillating liquid droplets which are moving in liquid media, from a knowledge of droplet size and the physical properties of the continuous and dispersed phase systems. The deformation of thirteen liquid-liquid systems was experimentally studied in this investigation"--Abstract, page i.