Chemical Engineering Commons^™

Microporous Polymeric Membranes Via Melt Processing, Chaiya Chandavasu

Dissertations

Novel ultraporous and microporous membranes from immiscible polymer blends were produced via melt processing and post-extrusion treatments. Polystyrene (PS)/polypropylene (PP) and poly(ethylene terephthalate) (PET)/polypropylene (PP) blend systems with different rheological properties were studied. The blends were first compounded in an intermeshing co-rotating twin-screw extruder and subsequently extruded through a sheet die to obtain the precursor films. These were post treated by uniaxial or biaxial deformation (100-500%) with respect to original dimensions to induce a microporous structure. The porosity is induced by drawing the precursor film at a temperature below the glass transition temperature (T_g) of the minor …

Structures, Intramolecular Rotation Barriers, And Thermodynamic Properties Of Methane And Ethylene Carbons Bonding To Two Unsaturated Groups : Ethylene, Acetylene, Phenyl And Carbonyl, Manish H. Gurbani

Theses

Enthalpy, ΔH_f°₂₉₈, entropy, S°₂₉₈ and heat capacities C_p(T) (300 ≤ T/K ≤ 1500) are determined for Methane, bi-phenyl (CCB2H2); Methane, phenyl-vinyl (CCBCDH2);Toluene, 1-formyl (CCBCOH2), Propyne, 3-phenyl (CCBCTH2); 1,4-pentadiene (CCD2H2); Propene, 3-formyl (CCDCOH2); Methane, di-formyl (CCO2H2); Propyne, 3-formyl (CCOCTH2); Methane, di-ethynl (CCT2H2); Ethene, bi-phenyl (CDCB2); 1,4 Butadiene, 3-phenyl (CDCBCD); Ethene, I-ethynl-l-phenyl (CDCBCT); 1,4 Butadiene,3-vinyl (CDCD2); 1,4 Butadiene, 2-ethynl (CDCDCT) and Ethene, 1,1di-ethynl(CDCT2) using density functional B3LYP/6-31G(d) calculation method. Molecular structures and vibration frequencies are determined at the B3LYP/6-31G(d) density functional calculation level. Evaluation of data from the isodesmic reactions results in ΔH_f° …

A Laboratory And Field Study Of The Attenuation Of Sound Intensity Using A Whistle As The Sonic Generator, Navneet Kumar

Theses

This study investigated the attenuation of sound intensity using a whistle as the sonic generator along with the detailed analysis of all the previous studies. Attenuation of sound in air studies were performed in Otto H. York Center for Environmental Engineering and Science at New Jersey Institute of Technology. Sound attenuation through air was measured by doubling the distance for each of five whistles. It was concluded that Whistle No.5 gives the highest sound intensity of 140.54 dB at a distance of 0.75 ft , the closest distance used for measurement, at a air flow rate of 7.5 SCFM. These …

Testing Of Semiconductor-Based Adsorption Modified Photosensitive (Samp) Sensor For Response To Toluene, Ashish Agrawal

Theses

The response of semiconductor-based adsorption modified photosensitive sensor is based on the dye-enhanced photoconductivity of a CdS semiconducting film. The change in this photoconductivity is brought about when organic molecules are sorbed onto the dye-coated surface. The response is related to the overlap in the infrared spectrum of the dye with that of the analyte.

This research was carried out to study the response of the sensor to a typical hydrocarbon, toluene. The sensor was tested for its response to concentrations of toluene ranging from 2.6 ppm to 200 PPM in nitrogen. The sensor was tested under non-flow conditions and …

Turbulent Mixing And Chemical Reaction In Baffled Stirred Tank Reactors : A Comparison Between Experiments And A Novel Micromixing-Based Computational Fluid Dynamics Model, Otute Akiti

Dissertations

The optimization of reaction processes to maximize the yield of a desired product while minimizing the formation of undesired by-products is one of the most important steps in process development for drug manufacturing or fine chemical production. In many situations the kinetics of product formation can be quite complex and involve a number of intermediate steps as well as parallel and serial reactions. This renders the systems sensitive to the operating conditions. Often, upon scale-up, a decrease in the yield of the desired product is experienced, while more undesired by-products are produced. A large number of interrelated variables influence the …

Nanofiltration-Based Diafiltration Process For Solvent Exchange In Pharmaceutical Manufacturing, Jignesh P. Sheth

Theses

Commercially available solvent stable polymeric nanofiltration membranes were used to study the nanofiltration and diafiltration operations in the context of the pharmaceutical industry. Experimental results are presented for a two-step operation involving the preconcentration of a feed solution via nanofiltration followed by the replacement of the first stage solvent with a second solvent via diafiltration in two stages. Membranes MPF-50 and MPF-60, having molecular weight cut-offs of 700 and 400 respectively, were used in the present study. A solution of erythromycin (MW 734) in ethyl acetate was preconcentrated via nanofiltration followed by replacement of ethyl acetate with methanol via batch …

Endotoxin Removal From Protein Solutions By Immobilized Metal Ion Affinity Chromatography, Yun Kang

Dissertations

In the biotechnology/pharmaceutical industry, the removal of endotoxins from final protein product has always been a challenge. A novel method for endotoxin removal from protein solutions, immobilized metal (ion) affinity chromatography (IMAC) has been developed in this study. Fe³⁺ was charged to a chelating gel that contains iminodiacetic acid (IDA). The IDA- Fe³⁺ IMAC column was exploited to remove endotoxin from protein solutions. This method involves the adsorption of the endotoxin on IMAC column. More than 99% endotoxin is removed and protein yield is higher than 90%. IDA-Fe³⁺ IMAC has proved to be an economical and efficient …

Fluidization And Soot Filtration In A Rotating Fluidized Bed, Gui-Hua Qian

Dissertations

A horizontal rotating fluidized bed (RFB) has been investigated for the removal of soot from diesel engine exhaust. This requires necessitating an understanding of the nature of fluidization, particle mixing and filtration in the RFB.

In an RFB, particles are subject to a centrifugal force which can be much larger than the force of gravity. Therefore the Geldart classification for conventional fluidized beds must be modified for rotating fluidized beds. A theoretical analysis shows that group A particles (minimum bubbling velocity U_mb > minimum fluidization velocity U_mf can shift to group B U_mb = U_mf and group …

An Integrated Membrane-Based Chromatographic Process For Biomolecule Isolation And Purification, Xiaoping Dai

Dissertations

Biomolecules obtained from fermentation and cell-culture processes are present in low concentrations in a complex medium/broth. For intracellular products, cells are first harvested. Subsequently, cell lysis and homogenization are undertaken to produce a homogenate. The biomolecules are next separated from the cell debris by lysate clarification. For extracellular products, the biomolecules are separated from the whole cells by clarification. The overall yield is reduced with each additional step. As the cost of bioseparation process accounts for 50-80% of the final product cost, innovations in and improvement of bio-downstream processing are greatly needed.

In this research, a cyclic process integrating a …

Feasibility Study Of Rotating Fluidized Bed As A Dry Coater And Granulater, Manish Sawhney

Theses

This study is directed at enhancing our understanding of the mechanism of dry coating and granulation in a rotating fluidized bed (RFB). The main objective was to study the feasibility of the coating and granulation processes using an REB, both quantitatively and qualitatively.

A force balance and kinetic model is applied to explain the coating phenomenon and also to investigate why coating takes place in certain particle material systems and not in others. An equation for the resultant velocity with which one particle collides with another has been suggested for the rotating fluidized bed coater. A condition, which predicts whether …

Numerical Studies Of Deep Bed Filtration, Chan-Gyun Shin

Theses

Deep bed filtration is a process used to separate small solid particles suspended in a fluid by using granular solids as the collecting medium. The filter efficiency depends on many parameters such as the Reynolds number, particle drag coefficient, the ratio of the diameter of injected, and filter particles, etc.

In the present work we model the porous media flow (solution of the Navier-Stokes equations) by using a computer code developed by Dr. P. Singh and we restrict our analysis to the case of two dimensional periodic porous media. The computational domain is discretized using the finite element method. In …

The Impact And Fate Of Aqueous Sodium Nitrate On Hydrocarbon Flames, Ann Marie Flynn

Dissertations

This study examined the impact and fate of sodium (fed as an aqueous nitrate solution) in fuel-rich methane/air and methane/methyl chloride/air flames as a function of equivalence ratios that experienced diffusion of air from the surroundings. The flames were stabilized on a slotted, uncooled burner. The data set was divided into profiles of relative sodium atom concentrations, temperatures, and selected stable species concentrations. The flames were simulated using a modified version of the Sandia FORTRAN program for modeling steady laminar one-dimensional premixed flames complete with detailed mechanisms. The results showed that maximum sodium atom concentration in the flame is decreased …

In-Line Measurement Of Solibility Of Physical Blowing Agents In Thermoplastic Melts As Related To Extrusion Foaming, Qiang Zhang

Dissertations

A novel in-line method for measuring physical blowing agent solubility in thermoplastic melts in extrusion foaming equipment has been developed in this study. This method uses video microscopy in connection with a foaming extruder (single or twin-screw) to generate solubility data by observing the onset of gas bubble formation/dissolution. This method offers a number of advantages over the existing conventional methods. It can be easily used to obtain solubility data for many foamable thermoplastic-physical blowing agent systems at high pressure and temperature near actual foaming conditions. Data generated using this method could be directly used to characterize and control a …

A Study Of Sound Attenuation Using Sonic Energy Focussed At An Artificial Soil Fracture, Minhaz Bootwala

Theses

Several laws have been passed over the past two decades to control contamination and to remediate already existing contaminated sites. There are a large number of these sites and several ex-situ and in-situ techniques have been developed to decontaminate these sites. These techniques can be quite expensive, especially the ex-situ clean-up operations, and there has always been a need for cheap, quick remediation methods.

This study investigates the attenuation of sound used in the in situ remediation technique coupling Sonic Energy with Pneumatic Fracturing and Vapor Extraction. Preliminary attenuation studies were performed in the laboratory with a microphone made at …

Study Of The Effects Of Deuterium Implantation Upon The Performance Of Thin-Oxide Cmos Devices, Sumit Kishore

Theses

The use of ultra thin oxide films in modem semiconductor devices makes them increasingly susceptible to damage due to the hot carrier damage. Deuterium in place of hydrogen was introduced by ion implantation at the silicon oxide-silicon interface during fabrication to satisfy the dangling bonds. Deuterium was implanted at energies of 15, 25 and 35 keV and at a dose of 1x10¹⁴/cm². Some of the wafers were subjected to N₂O annealing following gate oxide growth. It was demonstrated that ion implantation is an effective means of introduction of deuterium. Deuterium implantation brings about a …

Chemical Volatilization Of Heavy Metals For Waste Separation And Real Time Metals Analysis, Mohammad Nasr Ul-Alam

Theses

One of the major challenges in environmental analysis concerns the rapid and sensitive detection of metals emitted from combustion stacks. An interesting concept for real time analysis is to convert airborne metal oxide particles in a flow reactor into relatively volatile compounds of a single class, and then analyze in the gas phase. In this project, kinetics of chemical volatilization reaction between Sb₂O₃ and HCl was investigated. To achieve this a laboratory volatilization flow reactor was built and data was collected for the volatilization reaction in terms of conversion, inlet and outlet concentrations and flow rates. A …

Chemical Reactions And Mass Transport In Emulsion Liquid Membrane, Huifang Fan

Dissertations

Emulsion liquid membrane (ELM) systems are an important technique for wastewater cleanup. For this purpose, emulsion globules are dispersed in wastewater (external phase), each emulsion globule consisting of many tiny aqueous droplets (internal phase) enclosed in oil (membrane phase). Hazardous chemicals in the wastewater are transported into the internal droplets by mass transfer mechanisms.

Since Li first invented an ELM system in the 1960s, much research effort has been devoted to experimentally finding the optimal conditions for ELM recovery of various chemicals. Such studies would have benefited greatly from the guidance of mathematical models, especially those that provide analytical predictions. …

Study Of Reactive Media For Chromium Removal From Groundwater By Permeable Barriers, Hemant S. Desai

Theses

The purpose of the study was to select reduction media for application in permeable barriers for removing chromate ions from groundwater emanating from chromium refining sites in New Jersey. The high pH condition of groundwater in such sites is expected to pose limitations on the use of metallic iron (Fe⁰) as the sole reductive medium.

Reasonable reduction kinetics was achieved using iron at pH < 9.2. Several pH lowering media were investigated and were found to have either very slow or very fast dissolution kinetics, which rendered them impractical for use in passive permeable barriers. Two other media, namely: pyrite and siderite minerals have shown promising results, but fell short of achieving the required performance. Detailed investigation of interfacial processes in a batch reactor have shown that the addition of a small amount of a neutral salt can significantly improve chromate reduction kinetics, even at high pH conditions around 10.9.

The formation of passivating layers, which can slowdown the reaction significantly, was found to be important at high pH conditions. It is recommended that an injection system be used with the reactive barrier to …

Fundamentals Of Dry Coating In Fluidized Bed, Rakesh Iyer

Theses

This thesis is devoted to the study of a novel dry coating method in fluidized bed - Dry Coating of Particles in Spouted bed (DCPS). The main objectives of this work were to study the feasibility of the process, both quantitatively and qualitatively, and to compare the results with coating by conventional mechanical mixing. Aerosol mechanics is applied to account for the following: 1) collision between the guest and host particles in a spouted bed (analysis of guest-host particle inertial fluid-dynamic interaction), and 2) to show how collision efficiency of guest particles with host particles affects the coating efficiency. An …

Thermodynamic And Kinetic Analysis On Cl.+Rci -- Cl2+R.Reactions, Ch3cjo+O2= Products And Cjcho+O2= Products, Jongwoo Lee

Theses

Thermodynamic Parameters, ΔH°_f(298), S°₍₂₉₈₎ and Cp(T) are evaluated for C₁ and C₂ chlorocarbon molecules and radicals. These thermodynamic properties are used in evaluation and comparison of R.+ Cl₂ => R-Cl + Cl. (defined forward direction) reaction rate constants from the kinetics literature. Data from some 20 reactions in the literature show linearity on a plot of Ea_fwd vs. ΔH_rxn,fwd, yielding a slope of (0.38 ± 0.04) and intercept of (10.10 ± 0.77) kcal/mole. Thermodynamic properties (ΔH°₍₂₉₈₎, S°₍₂₉₈₎ and Cp(T) from 300 to 1500 K) for reactants, adducts, transition …

A Field Study Coupling Soil Fractionation And Sonic Energy For Enhancing The In Situ Removal Of Volatile Organic Compounds In The Vadose Zone, Hassan Kaleem

Theses

Remediation of sites contaminated with hazardous wastes could be an expensive endeavor. There is, therefore, the need to explore techniques, which can reduce the remediation time and achieve regulatory specifications, thus reducing the cost involved in a site remediation exercise.

In this work, we investigated the use of sonic energy to enhance the in situ removal rate of trichloroethylene and dichloroethylene from a site in Hillsborough Township. New Jersey. The experiments were performed with and without sonic energy and each time the concentration of the trichloroethylene swept out from the site and the flowrate of the effluent gas were measured. …

Low Pressure Chemical Vapor Deposition (Lpcvd) Of Titanium Nitride : Synthesis And Characterization, Sameer Narsinha Dharmadhikari

Theses

Titanium tetrachioride and ammonia were used as precursors in a Jow pressure chemical vapor deposition process to deposit titanium nitride films on silicon wafers. The process was carried out at temperatures from 450 to 850 C and the activation energy for the reaction was determined. The order of the reaction, with respect to the partial pressures of the reactant gases, was determined by carrying out the reaction at varying partial pressures of the reactant gases. The following rate equation was established for the reaction:

rate = 4.35*10^-5exp(-5150/T)*(P_NH3)^1.37(P_Ticl4)^-0.42

The titanium nitride thin …

Nanofiltration With Organic Solvents And Its Possible Applications To Organic Syntheses, Jose Antonio Whu

Theses

Experimental results on the nanofiltration (NF) separation behavior of three different solvent- compatible membranes are presented for three organic solutes of molecular weights 351, 826 and 1355 in methanol; the manufacturer-specified molecular weight cut-offs (MWCO) of the membranes are 250, 400 and 700. Membranes were primarily tested at 440 psig, at different concentrations of the solutes in methanol; the effect of varying the applied pressure was also briefly explored. The solvent permeation flux and the solute rejection were time dependent for an extended initial period; the membranes had to be compacted to achieve steady-state results. Furthermore, the manufacturer-specified MWCO was …

Removal Of Volatile Organic Compound (Voc) Vapors In Biotrickling Filters : Process Modeling And Validation With Chlorinated Aromatic Compounds, Christos J. Mpanias

Dissertations

This study dealt with the removal of vapors of volatile organic compounds from airstreams in biotrickling filters (BTFs). A detailed general model was developed for describing the process under steady-state conditions. The model accounts for mass transfer between phases (air, liquid, biofilm) and biodegradation of pollutants in the biofilm. It also accounts for potential kinetic interactions among pollutants as well as potential process limitations by oxygen availability.

The general model was experimentally validated using mono-chlorobenzene (m-CB) and ortho-dichlorobenzene (o-DCB) as model compounds either alone or in mixture with each other. Before BTF experiments were undertaken, a systematic kinetic study was …

Modelling Of In-Situ Bioremediation With Emphasis On Inhibitory Kinetics And Biomass Growth, Dilip Kumar Mandal

Dissertations

This thesis was motivated by the need for better engineering tools to predict the extent of contaminant plume migration in the saturated zone. The principal result was a mathematical model analogous to a catalytic packed-bed reactor, in which the subsurface was considered to be composed (conceptually) of soil aggregates (the "catalyst" particles, in which biodegradation, diffusion, and sorption take place), and a mobile phase (groundwater) passing around the aggregates, in which convection, axial diffusion, and mass transfer from the aggregates take place.

The modelling emphasis was on a more detailed exposition of the biokinetics of the system (including an inhibitory …

Rheological Characterization Of Unmodified And Chemically Modified Poly (Ethylene Terephthalate) Resins, Jorge Quintans

Theses

Intrinsic viscosity (IV) has often been misused for estimating both melt viscosity and elasticity of poly(ethylene terephthalate) (PET). A rheological study was conducted to determine the variations between a virgin unmodified PET and a recycled and chemically modified PET, both having a reported nominal IV of 0.95.

The modified material had a larger melt viscosity (capillary and dynamic) than the virgin material (by an average of 61%). The extrudate swell, a better indicator of melt elasticity, of the modified was more than 110% greater than that of the unmodified material. Activation energies for melt viscosity and extrudate swell were found …

An Experimental Study On Removal Cadmium From Wastewater By Emulsion Liquid Membrane, Jing-Chi Shiu

Theses

Research was conducted on cadmium, a heavy metal pollutant, extraction out of wastewater by means of an emulsion liquid membrane system. The emulsion liquid membrane was made of a carrier (di(2-ethylhexyl) phosphoric acid), a surfactant (ECA 4360J), and a stripping agent (sulfuric acid). The effects of using the following parameters on the membrane to optimize the operating conditions were investigated: type of buffer solutions, initial external phase pH, initial cadmium concentration, internal sulfuric acid concentration, impeller stirring speed, carrier concentration, surfactant concentration, and selectivity between cadmium and sodium ion.

The best performance for the system presented in this thesis was: …

Molecular Modelling Studies Of Acetylcholinesterase, Charilaos E. Linaras

Dissertations

The controversial role of electrostatic interactions in the process of steering of acetylcholine into the active site of acetylcholinesterases was investigated in this study. A novel methodology was implemented to simulate the process of recognition of acetylcholine by Torpedo Californica and both wild type and charge neutralized mutated Human AChE. The obtained results suggest the important role of coulombic interactions in the steering process. The steering process of selected irreversible AChE inhibitors was also simulated supporting the role of electrostatic interactions in the recognition process.

A novel methodology was also employed to model the covalent adducts of Torpedo Californica and …

Introduction To Pollution Prevention Concepts In Freshman Chemistry Through Simulations And Hypermidia, Aniraban Bhaumik

Theses

As citizens of the 20th century, a key issue we all are aware of is degradation of the environment. In the interest of teaching the environmental issues to freshmen engineers, this study develops a computer aided learning/teaching (CAL/T) tool.

This CAL/T tool consists of Internet based multimedia courseware and intelligent simulations. The courseware assembles the fundamentals of chemistry associated with current environmental issues such as air pollution, stratospheric ozone layer depletion and environmentally sensitive or 'clean' manufacturing. The courseware targets early and comprehensive understanding of pollution prevention concepts with a focus on environmentally friendly manufacturing. The courseware includes: on-line text, …

Removal Of Vocs From Superfactant-Flushed Wastewater By Membrane Based Modified Pervaporation Process, Anirban Das

Theses

An aqueous solution of a volatile organic compound (VOC) e.g. trichloroethylene (TCE) is passed through the bores of hydrophobic microporous polypropylene hollow fibers having a plasma polymerized silicone coating on the fiber outside diameter; a vacuum is maintained on the shell side of the fiber to remove the VOC and recover it by condensation. Process performance has been obtained over a range of feed flow rates, concentrations of VOC and the surfactant (sodium dodecyl sulfate (SDS)). In solutions without surfactant or low surfactant concentrations, the pores are not wetted and remain gas-filled. The VOC is stripped from the solution into …