Chemical Engineering Commons^™

Role Of Catalyst And Substrate In Synthesis Of Single Wall Carbon Nanotubes, Amit Goyal

Theses

The synthesis of single wall carbon nanotubes (SWNTs) by the catalyticdisproportionation of carbon monoxide (CO) (i.e., Boudouard reaction) at I atm pressureand 700-800 C, has been systematically investigated in order to determine whether theprocess can be used for the large scale production. SWNT diameter distribution andmorphology were studied by Raman scattering, and scanning and transmission electronmicroscopy, respectively. X-ray diffraction was used to determine levels of the remnantcatalyst and support. Synthesis experiments were conducted using a three-stage processwith hydrogen to reduce the catalyst-precursor and argon to cool the system. Two typesof catalyst/support synthesis were studied: (1) Combustion synthesis to form catalyst …

Liquid-Liquid Mixing In Stirred Tanks With Varying Liquid Depths, Sunil Mehta

Theses

Considerable attention has been devoted in the past to the determination of the minimum agitation speed, N_cd, required for the complete dispersion of two immiscible liquids in mechanically stirred tanks. When this situation is achieved the dispersed phase is no longer present as a distinct layer, such as a light oil phase above an aqueous solution, but becomes completely dispersed, in the form of droplets, throughout the continuous phase. The achievement of the dispersed state is of significant importance in many industrial operations. Nevertheless, the effect on N_cd of a number of operating variables remains poorly understood. …

Environmental Management Of Waste Electrical & Electronic Equipment (Weee) In Ireland, Simon Wilkinson

Theses

This thesis follows two previous studies by the Author on the calculation of theoretical WEEE arisings, and an assessment of ecodesign practices in Ireland. It has established collection trials in five different locations throughout Ireland in order to characterise and quantify WEEE arisings, and to examine outlets for collected WEEE. Overall, during the twelve months of collection at the project locations, more than 450 tonnes of WEEE was collected from the public and recycled. Within the catchments of each facility, collection rates of between 2.1 and 3.5 kg/person/year were achieved during the twelve-month trial period. With further public awareness raising …

Extraction Of A Valuable Compound From A Waste Stream For Adm Ringaskiddy, Colin G. Burkley

Theses

This thesis was originally conceived as a potential Masters Degree research programme by the management of ADM Ringaskiddy as a means of maximizing throughput through the plant’s wastewater treatment facility. This facility is a major producer of citric acid using beet molasses and a fermentation process. It was proposed that removal of a compound, known as betaine, from the citric acid process waste stream would reduce the Chemical Oxygen Demand (COD) content of the waste requiring treatment before disposal. This would be achieved by using the citric acid process waste as the feedstock for a betaine extraction process. The wastewater …

Low Salinity Flooding In A Selected Carbonate Reservoir: Experimental Approach, Mohamed Yehia Mohamed Mahmoud

Theses

Low-salinity water flooding LoSal^TM has been used to improve oil recovery for many decades. Historically, the mechanisms behind this improvement in oil recovery were attributed to the pressure maintenance and displacement of oil by injected water, i.e. physical mechanism. Recently, evidence from laboratory and field tests indicated that water flooding also involves chemical processes and that modifying of the injection brine salinity and its ionic composition can significantly impact the oil recovery. Several theories regarding the mechanism of LoSal^TM flooding have been discussed in the literature. These include interfacial tension reduction, wettability alteration (cation exchange), change in pH …

Dry Particle Coating And Granulation In Rotating Fluidized Beds, Madhuri Kolli

Theses

The practicability of using rotating fluidized bed as dry particle coater and granulator is investigated in this study. Dry particle coating, in which fine guest particles are coated onto bigger host particles in the absence of binders or solvents, is studied for various systems of host and guest particles. Coating results are explained by considering the collisions between the host and guest particles and among themselves. Balance between collisional energy and adhesion energy is suggested to be the limiting condition for the adhesion and hence the coating of guest particles onto host particles. It is observed that the experimental and …

Absorption Of Co2 Through Hollow Fiber Membranes Using Aqueous Solutions Of Various Absorbents, Praveen Babu Kosaraju

Theses

Absorption behavior of CO₂ was studied in different hollow fiber membrane modules fabricated using Celgard (polypropylene) and poly(4-methylpentene-1) microporous hollow fibers. Pure water, aqueous solutions of poly(amidoamine) (PAMAM) dendrimer of generation zero and monoethanolamine (MEA) were used as the absorbent; the absorbent solution flowed through the fiber bore, the gas mixture of C02 and N2 flowed countercurrently on the shell side. The system consisted of absorption in one module and stripping with Helium in another module of the same fibers. The absorption characteristics of the dendrimer solution and the MEA solution were studied in the modules built of Celgard …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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 …

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. …

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 …

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: …

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 …

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 …

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, …

Development And Characteristics Of Carbon Nitride Thin Solid Films For Advanced Coating Applications, Muhammad A. Hussain

Theses

Carbon nitride films were synthesized on silicon substrate by reactive magnetron sputtering of graphite target in an environment of Ar and nitrogen gas. The performance of a negative carbon ion source was also investigated to use the source in negative ion-beam-assisted deposition. These films were synthesized at room temperature at a constant pressure of 5 mtorr and at 300 Watts R.17 power, but at different composition of nitrogen in Ar-N₂ gas mixture ranging from 0-53 percent. The films deposited were microscopically smooth, amorphous and their properties found to be varied with nitrogen composition in plasma. The deposition rate was …

Voc Removal From Nitrogen By A Membrane-Based Combined Absorption-Stripping Process, Boya Xia

Theses

A regenerative membrane-based absorption process has been extensively studied to remove volatile organic compounds (VOCs) from air/N₂ using silicone oil as absorbent. The absorbent liquid is regenerated by applying vacuum in a membrane-based stripper. In this process, there are no flooding, loading and entrainment, which limit the gas/liquid flow rate in the traditional absorption process. In the present study, attention has been focused on the removal of volatile component(s) from binary gas mixtures such as methanol-N₂, and toluene-N₂, and from a model multicomponent mixture of gasoline vapor constituents and nitrogen. The process performance was tested …

Recovery Of Intracellular Materials By Electroporation, Wendy Elaine Reid

Theses

Electroporation is commonly used to transfer genetic materials such as DNA into the cell by exposing the cell to a high electric field that momentarily permeabilizes the cell membrane. This premise was utilized to use electroporation as a means of releasing intracellular proteins. A procedure has been developed for the release of intracellular proteins through the use of electroporation. This procedure is a breakthrough. In general, industrial scale techniques to recover proteins from microorganisms are inefficient (Clarkson, 1993). A benefit of this electroporation-based mechanism would be the reduction of steps in the downstream processing required to purify the desired product. …

Mixed Metal Removal And Recovery By Hollow Fiber Membrane-Based Extractive Adsorber, Ramprakash Chilukuri

Theses

The feasibility and efficiency of simultaneous removal of multiple cations as well as anionic heavy metals from wastewater into a mixed extractant kept stagnant on the shell side of a 2-fiber-set hollow fiber membrane extractor operated as a fixed bed adsorber was explored. The novel extracting solvent was a mixture of an acidic or chelating extracting agent for one or more cations and a basic extracting agent, e.g., trioctylamine (TOA) for extracting anions; both were dissolved in the same diluent kerosene for simultaneous and synergistic extraction of cations and anions. In the stripping part of the fixed bed operation, alkaline …