Chemical Engineering Commons^™

Enhanced Pervaporation Using A Novel Pump Configuration, Donough Patrick Shanahan

Theses

The pervaporation process is investigated in this work under the guises of process design improvements and process performance. Several avenues of research were investigated.

The main aim of the project was to investigate the use of liquid ring vacuum pumps for permeate recovery at laboratory and industrial scales. Due to technical and economical issues, these pumps were deemed unsuitable. This analysis then had to be extended further. Previous work investigated the use of dry vacuum pump systems on a lab scale and this work was extended to industrial scale simulations. Results from the lab scale process particularly those relating to …

Experimental Investigation Of Mixing Time In A Stirred, Torispherical-Bottomed Tank Equipped With A Retreat-Blade Impeller, Nonjaros Chomcharn

Theses

Glass-lined reactors are typically used in the pharmaceutical and specialty chemicals industries because of their material compatibility with most reactants and their cleanability. These reactors are typically equipped with a retreat-blade impeller placed close to the bottom of the tank a single baffle mounted from the top. The mixing performance of such reactors has not received significant attention in the literature, despite their ubiquitous presence in the pharmaceutical industry. In particular, mixing time, i.e., the time required by the system to achieve a predefined level of homogeneity, has not been studied to any significant degree.

In this work, the mixing …

Mixing Performance Of A Novel, Continuous Confined Impinging Jets Mixer Using Competitive Reactions, Han Zheng

Theses

In this work, a novel continuous flow apparatus featuring the impingement of fluid jet streams in the presence of ultrasonic energy provided by an ultrasonic probe was tested using competitive reactions in order to determine its mixing effectiveness. The ultrasonic energy enhances micromixing of the fluid jet streams, which results in an overall mixing effectiveness improvements in different physical and chemical processes.

In the competitive reactions system used here (third Bourne reaction), one stream containing sodium hydroxide was continuously fed to the first impinging jet, while an aqueous solution of hydrochloric acid and ethyl chloroacetate was fed to the second …

Preparation Of Nanovehicles For Targeted Drug Delivery, Anagha Avinash Bhakay

Theses

Application of nanotechnology in pharmaceutical research has opened new frontiers for drug development and its efficient delivery. In recent years, the focus of the research has been on the engineering of nano/micro-particulate structures for efficient and targeted delivery of drugs for selective and enhanced absorption. This work throws light on the preparation of biodegradable and non-toxic nanoparticulate systems for targeted drug delivery. The drug vehicles were made by two different processes namely electrostatic interactions and desolvation process. The drug carriers made by these processes were found to be in the size range of 150-200nm which is necessary for cellular uptake …

Carbon Dioxide Capture From Flue Gases, Mohamed Rashid Al Rashid

Theses

Global warming and climate change are believed to be caused by the greenhouse effect. CO₂ has been regarded as the main contributor to global climate change which directly results in serious environmental problems. Half of the anthropogenic CO₂ emission sources are emitted from the combustion of fossil fuels in industries and power plants worldwide. The absorption behavior of Carbon dioxide from flue gases can be studied using conventional absorber and polymeric hollow fiber membrane contractors. An industrial absorber data was compared with simulated data using hollow fiber membrane contractor using the gPROMs software package. In this analysis, with …

Optimum Non Hydrocarbon Gas Injection Development Process And Ultimate Recovery Maximization., Abdulla A.F. Abed

Theses

A multi layered heterogeneous reservoir was selected for this study. The integrated reservoir characterization model and the pertinent transformed reservoir simulation history matched model were quality assured and quality checked.

The development scheme was identified and selected where the pattern and completion of the wells were defined to fit the heterogeneity of the reservoir characterization model. Lateral and maximum block contact holes were investigated.

The development processes studied were mainly hydrogen sulphide, carbon dioxide, nitrogen and rich hydrocarbon gas. The Water Alternating Gas/ Simultaneous Water Alternating Gas (WAG/SWAG) processes were also assured. In addition to the main gas and WAG/SWAG …

Experimental Investigation Of The Effect Of Sonication On The Precipitation Of Grieseofluvin By Impinging Jets, Ankit H. Patel

Theses

Almost 80% of drugs on the market are manufactured as solid dosage forms, such as tablets. Drug bioavailability increases as the particle size decreases and the surface area per unit volume of drug increases. Therefore, there is a keen interest by the pharmaceutical industry to develop techniques that can be used to manufacture particles of active pharmaceutical ingredients (API) in the nano/micro particle range. Impinging jets is one of the most promising techniques to do so.

In this work, a submerged impinging jet system coupled with an ultrasonic probe (sonicator) was used to precipitate Griseofulvin, a common, poorly water-soluble antifungal …

Precipitation Of Ultrafine Particles Using Liquid Antisolvent With Concentric Ultrasonic Nozzle And Subcritical Co2, Satya Chaitanya Kunchala

Theses

Nanotechnology has become more relevant in the pharmaceutical industry. Almost 40% of the drugs developed by pharmaceutical industries are poorly soluble in water which limits the bioavailability of these drugs in body fluids. Hence, it is necessary to reduce the particle size, which increases the interfacial surface area. This work focuses on micronization of class ii drug Griseofulvin which is poorly water soluble. Two processes namely, liquid antisolvent precipitation using ultrasonic nozzle and other process using subcritical CO₂ have been used to produce ultrafine particles of this drug.

In liquid antisolvent precipitation, a combination of ultrasound, polymer and surfactant …

Experimental Investigation Of The Fluid Velocity Distribution In Stirred Tank Reactors Equipped With Retreat-Blade Impellers Using Laser Doppler Velocimetry, Deepak Rajesh Madhrani

Theses

Stirred tank reactors are commonly used in the pharmaceutical industry for synthesis of Active Pharmaceutical Ingredients (API's) and their intermediates. Typically, these vessels are glass-lined and are provided with a single retreat-blade glass-lined impeller and a single baffle. Despite their ubiquitous utilization in the pharmaceutical industry for at least the past 40 years, the mixing characteristics of these systems have not been studied to any great extent, making it difficult to predict mixing performance in any given operation.

In this work, the velocity distribution inside the typical glass-lined vessel/impeller system was experimentally quantified using Laser Doppler Velocimetry (LDV), which is …

Ultra-Fine Particle Formation Using Principle Of Rapid Expansion Of Supercritical Solutions`, Miraj Minesh Sheth

Theses

There are indications in the chemical and pharmaceutical industries that the reduction in size of a crystalline particle can lead to better performance of the drug compound, particularly for water insoluble drugs, in the final dosage form. Many particle formation techniques have been investigated in recent years by researchers to obtain desired particulate sizes and size distributions. Supercritical fluid technologies have been successfully investigated for particle formation due to its unique gas/liquid properties in the supereritical state. In this report, results of particle formation using the principles of Rapid Expansion of Supercritical Solutions (RESS) have been documented.

In the RESS …

Mixing Of Nanoparticles In A Stirred Tank In High Pressure Carbon Dioxide, Nitin Aggarwal

Theses

Mixing of nanoparticles of different compositions offers wide opportunities in manufacturing new nanocomposite materials with unique electronic, optical, mechanical, and chemical properties. However, due to large cohesive forces between nanoparticles, they often form large micron-sized agglomerates, thus losing their main advantage of small size and high surface area. Therefore, breaking of these agglomerates is necessary prior to mixing. One of the techniques to achieve deagglomeration and mixing of nanoparticles is based on rapid depressurization/expansion of supercritical suspensions. where the suspension of initially premixed agglomerates in supercritical CO₂ pass through the nozzle undergoing deagglomeration as a result of rapid expansion …

Magnetically Assisted Impaction Mixing Of Nanosize Particles, James V. Scicolone

Theses

Magnetically assisted impaction mixing (MAIM) is a novel dry mixing technique, which can be used to mix nanoparticles. Mixing of nanoparticles is usually conducted in solvent-based mixing techniques. The solvents used in these techniques are usually organic, which can be expensive and harmful to the environment. MAIM creates homogeneous nanoparticle mixtures while eliminating conditioning and drying steps associated with wet mixing techniques. To create the best mixing quality of nanoparticles, MAIM was optimized by studying the effects of magnet-to-sample ratio, time, magnet size, and constituents of the mixture. The results were then compared with other well-known mixing techniques.

To characterize …

Treatment Of Aqueous Waste Streams At Eli Lilly - Alternatives To Incineration, Barry Hennessy

Theses

The aim of this project was to investigate the potential to treat liquid waste (secondary) from production processes at Eli Lilly with the emphasis on minimising the volume of waste sent for thermal oxidation. In addition, the project aimed to investigate if the chosen technology was diverse and potentially capable of handling waste streams from different processes. Membrane technology was identified as one of the most suitable technologies and trials were carried out on secondary waste from three production processes. The literature review and practical thrials aswell as assessment of trial results ran from October 2003 to June 2005.

All …

Solubility In Supercritical Carbon Dioxide, Syed Asif Abdullah

Theses

The different techniques used for the determination of the solubility of compounds in supercritical carbon dioxide are described. A comparative study is made of the methods used in the measurement of the concentration of benzoic acid and caffeine in supercritical carbon dioxide. The difference in measurement techniques did not have much effect on the solubility data at lower pressures. However, at higher pressures, the solubility data obtained by different techniques began to deviate from each other.

Further, the method used by different researchers in generating the solubility data in supercritical carbon dioxide is also discussed. A number of data sheets …

Functionalization Of Nanoclays Through Exchange Reactions, Jin Uk Ha

Theses

A cationic clay (sodium-montmorillonite, MMT) and an anionic clay (hydrotalcite, HT) were treated with two phosphonium based ionic liquids (ILs) and a commercial corrosion inhibitor. Clay modification was examined by TGA, FTLR and WXRD. The cationic clay modified with both ILs had similar thermal stabilities since they contained the same cation although the original anions were different. The thermal stability of the modified clays was higher than that of a commercial organoclay and of clays modified in our group with smaller MW pyridinium and imidazolium based cations. 10 wt% of interchanged cation was found under selected time/temperature treatment conditions.

Clays …

Jet Assisted Fluidization Of Nanoparticle Agglomerates, Ayokunle O. Omosebi

Theses

Fluidization serves as a primary operation used to disperse, handle and process nanoparticles, but due to the complications involved with achieving homogenous fluidization of the agglomerates of nanoparticles, several methods have been developed to assist their conventional mode of fluidization.

In this work, the conventional mode of fluidization was coupled with secondary gas flow emerging from a micro jet nozzle. The effect of the jet on the fluidization behavior of various APF and ABF nanopowders was studied and compared with the pure conventional fluidization mode. Generally, experiments were conducted to find the optimal operation of the jet by varying parameters …

Inverse Solid-Liquid Fluidization Of Aerogel Granules And Its Application In Removing Oil From Water, Gaurav Babubhai Patel

Theses

Fluidization is a very well known unit operation used in the chemical industry for various purposes. Inverse solid-liquid fluidization, where the solid particles to be fluidized are less dense than the fluid, is one of the several different kinds of fluidization being studied for its potential in industrial applications. The present work focuses on finding the hydrodynamic characteristics (minimum fluidization velocity, bed expansion and pressure drop) of an inverse fluidized bed of aerogel granules and using this system to remove oil from an oil-water mixture. The solid particles employed for this study are low density (100 kg/m³) surface …

Synthesis Of Polymeric Nanocomposites In Supercritical Carbon Dioxide, Hongta Yang

Theses

Supereritical carbon dioxide has been of great interest in various areas of chemical science and engineering during the last decade. In this thesis, the properties of poly (methyl methacrylate) (PMMA)/silica nanocomposites with different surfactant and filler concentrations synthesized through in-situ polymerization in supercritical carbon dioxide were investigated. In addition, ferromagnetic nano-particles were synthesized and functionalized for the preparation of nanocomposites. The thermal stability and surface morphology of PMMA/iron oxide nanocomposites synthesized in supercritical carbon dioxide were first studied in the work.

The scanning electron microscopy micrographs show that higher surfactant concentration results in higher number density of polymeric nanocomposite particles …

Modification Of Clays With Ionic Liquids For Polymer Nanocomponents, Neung Hyun Kim

Theses

In attempts to prepare nanofillers with enhanced compatibility with a polymer matrix, cationic and anionic clays susceptible to exchange of their interlamellar ions with a variety of other cations or anions, were selected.

In order to treat cationic clay, montmorillonite, which contains sodium ions as interlayer ions, reagents having cations differing in size and structure included three ionic liquids ([EMIM]⁺ [Br]^-, [HXMIM]⁺ [Cl]^-, and [Epty]⁺ [BF4]^-). Results indicated that cationic exchange did occur from aqueous solution as confirmed by FTIR, EDX, WAXS, TGA, and elemental analysis. WAXS indicated a significant increase …

Investigation Of Solid Polymeric Hollow Fiber Heat Exchange Devices For Use In Thermally-Driven Desalination Processes, Saskia Christian

Theses

The heat exchange between hot brine (4 wt% NaCl) and cold water as well as between condensing steam and cold water without direct fluid-fluid contact using modules made out of solid polymeric hollow fibers of polypropylene (PP) and polyetheretherketone (PEEK) has been studied. The solid hollow fiber dimensions were 425μm/575μm (ID/OD) for PP and 420μm/570μm (ID/OD) for PEEK. Extensive heat transfer measurements have been performed and the experimentally-determined overall heat transfer coefficients utilized to isolate the wall heat transfer coefficient, the inside heat transfer coefficient and the outside heat transfer coefficient. The heat exchange between hot brine and cold water …

Synthesis And Characterization Of Polymer Nanocomposites, Nirav S. Patel

Theses

Polymer nanocomposites were produced by solution mixing of a commercial flexible acrylic polymer paint, with nanofillers of different size, shape, aspect ratio and purity such as hydrotalcite (HT), sodium montmorillonite (MMT), single wall carbon nanotubes (SWNT) and fullerenes (FUL), at 5 and 10 wt% loading. Structural characteristics and mechanical, thermal and barrier properties of the nanocomposites were characterized by different techniques and compared to those of the unfilled polymer.

The presence of partially exfoliated and intercalated nanoplatelets in the polymer resulted in increased 2% secant tensile modulus, and decreased tensile strength and elongation at break, to different extents. While the …

Evaluation Of Unifac Group Interaction Parameters Usijng Properties Based On Quantum Mechanical Calculations, Hansan Kim

Theses

Current group-contribution methods such as ASOG and UNIFAC are widely used for approximate estimation of mixture behavior but unable to distinguish between isomers. Atoms in Molecules (AIM) theory can solve these problems by using quantum mechanics and computational chemistry to compute atomic contributions to molecular properties and to intermolecular interactions. Rigorously defined properties available through AIM theory and new functional group definitions are used for the UNIFAC model to predict the behavior of various mixtures. Results are presented for various mixtures with nine regressed global parameters to optimize model's predictive capability. The results are also compared to analogous results for …

Evaluation Of Knox Group Contribution Parameters Using Quantum Based Molecular And Group Properties, Myriam Carrillo

Theses

Thermodynamic property prediction through the group contribution methods has been improving. However, the approaches considered in the past present not only limitations on the physical basis but often have restrictions as to certain substances, such as isomers. A new group contribution method is proposed that uses AIM theory, which is based on computational chemistry and quantum mechanics, to overcome these limitations by treating each molecule individually. An evaluation of this method as applied to the Knox model is proposed and analyzed for Vapor Liquid Equilibrium (VLE) of mixtures with the help of nine global parameters that are obtained by correlation. …

Pervaporation Of Water From Solvent Solutions, Richard Manning

Theses

Pervaporation is an emerging membrane technology which has found acceptance as a method for the dehydration of organic solvents.

An existing pervaporation apparatus was modified to accommodate a new type of pervaporation membrane. The instrumentation used with the pervaporation apparatus was upgraded to include a Keithley Data Logger. A HAZOP was carried out on the modified pervaporation apparatus to ensure the apparatus was safe to operate after the modifications were completed.

The pervaporation apparatus was initially tested using screening experiments to verify that changing the operating parameters produced a measurable response which could be recorded. The pervaporation apparatus was successfully …

Fluidization Of Agglomerates Of Nanoparticles Under Different Force Fields, Jose A. Quevedo

Theses

Nanoparticles are the focus of many research activities, and in the near future they will be handled in large amounts by industry. Fluidization is a very important unit operation which is applied in several industrial processes.

In the present work, fluidization experiments with agglomerates of nanoparticles were done under different force fields: (1) gravity force or conventional fluidization; (2) a magnetic force field, which uses magnetic particles under the influence of a magnetic field; and (3) a centrifugal force, generated by a rotating frame that simulates higher gravity conditions.

Among the significant results with agglomerates of nanoparticles, conventional fluidization was …

Mathematical Modeling Of Transient State Transdermal Drug Delivery, Alison Nickol Weltner

Theses

In this work, a two-pathway mathematical model for transdermal drug delivery with iontophoresis is presented. The partial differential equations are described and then solved. An alternative, two-pathway, three-layer model is also presented, and the implications of the coefficients within the equation are discussed. Using Franz cell iontophoretic delivery data from three drug substances (amitriptyline HCl, clomipramine HCl, and nortriptyline HCl), the two-pathway model is regressed to determine the diffusion coefficient and the concentration within the skin at the drug reservoir interface. ANOVA analysis indicates a correlation between iontophoretic current and concentration of drug within the stratum corneum.

Kinetics Of Ho2 Abstraction Of H Atoms From Hydrocarbons And Thermochemical Properties Of Urethane Monomers And Radicals, Rajul Shah

Theses

SECTION I: Kinetics of HO₂ Abstraction of H Atoms From Hydrocarbons

Structures, internal rotational barriers and ideal gas thermochemical properties, ΔH^°_f98 for representative series of transition states for abstraction of H atoms from primary, secondary and tertiary hydrocarbons by the HO₂ radical, TC-HOOH (1), TCC-HOOH (2), TC₂C-HOOH (3), TC₃C-HOOH (4), TC₂CC-HOOH (5), TC₂CC-HOOHC (6) and TC₃CCC-HOOH (7) are analyzed in this study. Molecular structures and vibrational frequencies are determined at the B3LYP/6-3111G(d,p) density functional level. The S°₂₉₈ and C_p(T) values (300≤T/K≤1500) from vibrational, …

Closed Material Cycles And Organic Solvent Recovery, Tim De Jong

Theses

A survey was conducted of the pharmaceutical sector in Ireland to establish organic solvent usage, recovery and treatment practices. The eleven companies covered by the survey, which included several of the worlds largest multinational companies, consumed in the region of 122,000 tonnes of organic solvent in 2002. Approximately 53,000 tonnes was recovered on-site while 69,000 tonnes of virgin solvent was brought on-site to replace that which was lost through wastewater treatment, incineration, fugitive emissions and off-site treatment or reuse. The total quantity of virgin solvent consumed by the eleven companies accounted for 75.4 % of organic solvent imports to Ireland. …

Production Of Nanocrystalline Nitramine Energetic Materials By Rapid Expansion Of Supercritical Solutions, Victor Stepanov

Theses

Nanotechnology is a rapidly evolving field and has been characterized as "the next industrial revolution". Nanostructured materials are receiving increasing amount of attention in fields ranging from electronics to metallurgy due to their novel and unique properties. This work was focused on exploring the benefits of nanofabrication of high density energetic materials. The work primarily focused on the feasibility and viability of recrystallization of nitramine explosives down to the nanometer crystal size (<100 nm). It is anticipated that properties of the high density energetic materials such as sensitivity, packing density, crystal quality, energetic performance will be benefited.

Rapid Expansion of Supercritical Solutions was chosen as the process most appropriate to realize the objective. Solubility of CL-20 in supercritical solutions was studied. Nitramine crystals with …

Modification Of Biodegradable Polyesters With Inorganic Fillers, Georgia Chouzouri

Theses

In attempts to address the growing need of materials with controlled degradation characteristics and good mechanical properties for tissue engineering applications, composites based on biodegradable polymers and a potentially bioactive novel inorganic synthetic filler were produced and characterized. Composites were produced by solution mixing of a commercial polylactic acid, as well as a biodegradable thermoplastic polyester based on butylene adipate/succinate, with synthetic magnesium/aluminum carbonate minerals, known as hydrotalcites. Two types of hydrotalcites, at 30 wto/o filler level, were used: surface coated and uncoated. Composites were also melt-mixed in a twin-screw extruder for comparison.

Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), …