Engineering Commons^™

Polyhydroxybutyrate Production In A Photobioreactor Using Spirulina Platensis, Adrianna Mika

Electronic Thesis and Dissertation Repository

Biopolymers and other naturally derived chemicals continue to gain attention over petrochemical based products due to the price volatility of crude oil, increasing need to reduce greenhouse gas emissions and public awareness of environmental issues. Cyanobacterium Spirulina (Arthrospira) platensis, a commercially feasible blue-green alga, is able to synthesize poly(3-hydroxybutyrate) (PHB), a biodegradable and biocompatible polymer, as an energy storage product of photosynthesis directly from CO₂. A flat plate photobioreactor (PBR) with LED illumination was designed for the cultivation of S. platensis. Computational fluid dynamics (CFD) software was used to improve airflow uniformity and mixing in the …

Slope Stability Enhancement Of An Upstream Tailings Dam: Laboratory Testing And Numerical Modelling, Yazeed A. Alsharedah

Electronic Thesis and Dissertation Repository

Mine tailings are the byproduct of mining activities, which need to be disposed of once the ore is extracted. They can be disposed of in either dry or wet forms. The latter is most common with the tailings being disposed of in the form of slurry inside retention structures. The retention structure may be a natural, manmade, or built dam, which is the case in most of nowadays mining locations. In this thesis, improving the stability of an upstream tailings dam using soil additives is investigated. The experimental phase of this study involved laboratory tests conducted to characterize mine tailings …

Doping Plasmon-Enhanced Tio2 With Zirconia To Improve Solar Energy Harvesting In Dye-Sensitized Solar Cells, Anastasia Pasche

Electronic Thesis and Dissertation Repository

Solar energy is a promising solution towards meeting the world’s ever-growing energy demand. Dye-sensitized solar cells (DSSCs) are hybrid organic-inorganic solar cells with potential for commercial application, but are plagued by inefficiency due to their poor sunlight absorption. Silver nanoparticles have been shown to enhance the absorptive properties of DSSCs, but their plasmonic resonance causes local hot spots, resulting in cell deterioration. This thesis studies the mitigation of thermal energy loss of plasmon-enhanced DSSCs by the co-incorporation of zirconia, a well-known thermostabilizer, into the cell’s photoactive material. TiO2 was also synthesized using green bio-sourced solvents in supercritical CO2 to compare …

Pyrolysis Based Biorefineries For The Production Of Fermentable Substrates, Luis Carlos Luque-Moreno

Electronic Thesis and Dissertation Repository

Fast pyrolysis is rapid thermal conversion process capable of transforming multiple feedstocks into various energy carriers, specifically pyrolysis oil, bio gas, and bio char. The oil phase is of high value due to its complex mixtures of organic molecules, along with large number of anhydrous carbohydrates, which can be easily transformed into glucose via acid hydrolysis. These carbohydrates can be either biocatalyzed into fuels and chemicals by microorganisms or converted after further treatment steps. However quantities of these carbohydrates in the oil are a function of feedstock composition and process parameters. The research presented in this thesis focuses on producing …

Application Of 3d Printing Technology In Porous Anode Fabrication For Enhanced Power Output Of Microbial Fuel Cells, Bin Bian

Electronic Thesis and Dissertation Repository

Microbial fuel cells (MFCs) are widely researched for application in wastewater treatment. However, the current anodes used in MFCs often suffer from high fabrication cost and uncontrollable pore sizes. In this thesis, three-dimensional printing technique was utilized to fabricate anodes with different micro pore sizes for MFCs. Copper coating and carbonization were applied to the printed polymer anodes to increase the conductivity and specific surface area. Voltages of MFCs with various anodes were measured as well as other electrochemical tests such as linear sweep voltammetry and electrochemical impedance spectroscopy. 3D copper porous anode produced higher maximum voltages and power densities …

Biohydrogen Production From Cellulose By Clostridium Termitidis And Clostridium Beijerinckii., Maritza Gomez-Flores

Electronic Thesis and Dissertation Repository

The purpose of this study was to determine Clostridium termitidis microbial kinetics on glucose, cellobiose, and cellulose, and to assess its co-culture with Clostridium beijerinckii for hydrogen production. Microbial kinetics parameters of the mesophilic, cellulolytic, and hydrogen producer C. termitidis were determined on glucose and cellobiose using MATLAB for modelling biomass growth and substrate consumption. Hydrogen yields on these substrates were 1.99 and 1.11 mol H₂ mol^-1 hexose equivalent, respectively. C. termitidis microbial kinetics in mono-culture and in co-culture with mesophilic hydrogen producer C. beijerinckii were also investigated under agitated and non-agitated conditions, with hydrogen yields of 1.46 …

Catalytic Conversion Of Glycerol To Value-Added Chemical Products, Malaya Ranjan Nanda

Electronic Thesis and Dissertation Repository

Rapid expansion of biodiesel industry has generated a huge amount of crude glycerol. This thesis aimed to explore utilization of glycerol for the production of solketal as an oxygenated fuel additive and 1, 2-propanediol as a pre-polymer via catalytic conversion.

The thesis work may be divided into two major parts. In the first part, the thermodynamics and kinetics of the glycerol ketalization for the synthesis of solketal were investigated in a batch reactor. From this information, a continuous-flow process was designed, developed and optimized using pure glycerol. Crude glycerol (13 wt% purity) was successfully upgraded into a purified crude glycerol …

Investigations In Hydrodynamics And Mixing Pattern In The Bubble Column Equipped With Internals, Keller J H George

Electronic Thesis and Dissertation Repository

Bubble column reactors, with or without solid particles, have a number of applications in the chemical, petrochemical, biochemical and environmental industries. A number of these industrial applications require internals such as baffles, heat transfer surfaces and special distributors to meet demands. Proper selection and design of these internals can lead to the improved performance and efficiency of a bubble column reactor. Several experiments are carried out in a bubble column equipped with a concentric tube bundle (CT) and an internal combination consisting of a concentric tube bundle and concentric baffle (or static mixer) (CTB) respectively. Neutrally buoyant particles are used …

Mercury Removal From Aqueous Solution Using Natural, Synthetic, And Modified Zeolites, Mahshid Attari

Electronic Thesis and Dissertation Repository

Mercury has been recognized as one of the most hazardous heavy metals. The discharge of effluents containing mercury in soil, sediments and water can inflict an irreversible harm to the environment and human health. In this work, zeolitized coal fly ash as well as gold and gold-iron modified zeolites were successfully employed for mercury removal from a typical industrial wastewater. X-ray diffraction (XRD), thermo-gravimetrical analyses (TGA), surface area measurement (BET), and scanning electron microscopy (SEM-EDX) were utilized to explore the characteristics of the raw and modified zeolites. A pseudo-second-order kinetic model was identified to best represent the kinetic data for …

Evaluation Of Filtration Performance Of A Rotating Belt Filter For Different Primary Wastewater Influents., Tulip Chakraborty

Electronic Thesis and Dissertation Repository

Human activities around the world are responsible for production of enormous amount of wastewater, which needs to be treated quickly and effectively to avoid environmental concerns and other health implications. As an alternative to primary settlers in treating municipal wastewater, Salsnes, a subsidiary company of Trojan Technologies offers rotating belt filters (RBF) to treat the wastewater. A bench scale filtration unit of the RBF was developed to investigate the effect of varying water qualities from several wastewater plants in London, Ontario on the performance of the filter. The unit can achieve up to 80% reduction in total suspended solids (TSS), …

Effect Of Spray Jet Interactions On The Liquid Distribution In A Fluidized Bed, Helal Elkolaly

Electronic Thesis and Dissertation Repository

Many processes use spray nozzles to introduce liquid into a fluidized bed. One such process is the Fluid Coking Process which is used to upgrade bitumen. Poor liquid distribution in a Fluid Coker proves detrimental as agglomerates form which introduce mass and heat transfer limitations. The main objective of this thesis is to determine the effect of interacting spray jets on the liquid distribution in a Fluid Coker. This was accomplished by using a low temperature experimental model of Fluid Coking to estimate the liquid distribution. Preliminary screening of nozzle positions was accomplished by the use of conductance measurements. A …

Process Control For Biological Nutrient Removal Processes In Fluidized Beds Treating Low Carbon To Nitrogen Municipal Wastewater, Joseph Donohue

Electronic Thesis and Dissertation Repository

Conventional wastewater treatment techniques - utilizing microorganisms to remove organics and nutrients (i.e. nitrogen and phosphorus) from a water stream and partially incorporate them into their cell structure - struggle to adapt with increased urbanization due to land and infrastructure requirements. The circulating fluidized-bed bioreactor (CFBBR) was developed as a way to provide biological treatment in an urbanized area by cultivating high-density bacteria on an inert media. The technology operates as a pre-anoxic nitrification/denitrification wastewater treatment process. The system is initially loaded with media, providing a platform for microbial growth. Internal recycle streams in the system provide the energy to …

Effect Of Temperature And Successive Sprays On Liquid Distribution In Fluidized Beds, Liliana Andrea Pardo Reyes

Electronic Thesis and Dissertation Repository

Liquid injection in gas-solid fluidized beds is used in several industrial processes including food additive production, manufacturing of fertilizers, intermediate processing of pharmaceutical capsules and oil refining (i.e., Fluid Coking^TM and Fluid Catalytic Cracking (FCC)). Good quality in the liquid distribution on the fluidized particles is fundamental in these processes either to ensure uniformity in the formation of desirable agglomerates, or to minimize their formation when undesirable. In the Fluid Coking process, for example, improving the liquid distribution and minimizing agglomerate formation will result in increasing the overall yield of the process and avoid operability problems.

A new experimental …

Production Of Activated Carbons From Pyrolytic Char For Environmental Applications, Anastasia Colomba

Electronic Thesis and Dissertation Repository

Biomass pyrolysis has the potential to become a major component of future biorefineries, since biomass is cracked to produce gases, liquid products (bio-oil) and solid products (bio-char). In order for the process to be economically feasible, it is necessary to obtain the maximum value from each stream, thus no by-product can be regarded as a waste.

Bio-char is normally regarded as a by-product of fast pyrolysis, which is optimized to target bio-oil production. However, there are many potentially attractive applications for it: for example, it can be used for the production of activated carbons, which are the most commonly used …

Hydrotreatment Of Lignin Into Green Fuels And Chemicals, Matthew Tymchyshyn

Electronic Thesis and Dissertation Repository

Concerns about declining non-renewable fossil resources, energy security, climate change and sustainability are increasing worldwide. This has resulted in an increased interest in the development of alternatives to fossil resources not only for energy, but particularly for chemical production on a global level. There are a number of promising alternatives to fossil resources, however, lignocellulosic biomass such as forestry residues and wood waste (limbs, bark, sawdust, etc.) seem to be the most promising. They are widely available, renewable and a non-food resource. Therefore woody biomass holds the promise of being a sustainable resources for both energy and chemical production.

The …

Biosorption Processes For Removal Of Toxic Metals From Wastewaters, Shahram Amirnia

Electronic Thesis and Dissertation Repository

Excessive and cumulative release of toxic metals from industrial effluents due to rapid industrialization has posed hazard to aquatic ecosystem integrity and environmental/ human health. The inadequacy and high cost of traditional metal treatment technologies coupled with the imposition of stricter environmental regulations and guidelines for industrial point source discharges have increased the demand for economically feasible alternative methods.

Application of natural and abundant sorption material known as biosorbents comprising microbial biomass, agriculture waste, and industrial waste biomass, has gained international attention in scientific world as a low-cost and effective method for removal of heavy metals from aqueous solutions. However, …

Synthesis, Characterization And Applications Of Lignin-Based Epoxy Resins, Fatemeh Ferdosian

Electronic Thesis and Dissertation Repository

Epoxy resin is one of the most versatile thermosetting polymers with diverse applications. Epoxy resins are mainly produced from the reaction of bisphenol-A (BPA) and epichlorohydrin. The consumption of bisphenol-A is facing growing concerns over its carcinogenic effects and its sustainability. Lignin can be a promising renewable substitute of bisphenol-A in the synthesis of epoxy resins.

In this thesis work, a novel method has been developed for the synthesis of bio-based epoxy resins with reduced side reactions, employing de-polymerized lignin from organosolv lignin (DOL), kraft lignin (DKL) and hydrolysis lignin (DHL) under alkaline condition in the presence of a phase …

Application Of Mechanically Fluidized Reactors To Lignin Pyrolysis, Valentina Lago

Electronic Thesis and Dissertation Repository

Lignin has great potential for the production of aromatics currently derived from petroleum, since it is the most abundant source of aromatics in nature. At present, Kraft lignin is used as fuel within the pulping process but, alternatively, it could be converted to high-value chemicals using thermochemical processes such as pyrolysis. Kraft lignin, however, is a very cohesive and thermally sensitive powder with foaming and agglomerating tendency under reaction conditions. Therefore, new reactor designs are necessary to efficiently process this raw material.

Consequently, a novel reactor design, designated as Mechanically Fluidized Reactor (MFR) has been developed to successfully process Kraft …

A Comprehensive Study Of Esterification Of Free Fatty Acid To Biodiesel In A Simulated Moving Bed System, Nillohit Mitra Ray

Electronic Thesis and Dissertation Repository

Simulated Moving Bed (SMB) systems are used for separations that are difficult using traditional separation techniques. Due to the advantage of adsorption-based chromatographic separation, SMB has shown promising application in petrochemical and sugar industries, and of late, for chiral drug separations. In recent years, the concept of integration of reaction and in-situ separation in a single unit has achieved considerable attention. The simulated moving bed reactor (SMBR) couples both these unit operations bringing down the operation costs while improving the process performance, particularly for products that require mild operating conditions. However, its application has been limited due to complexity of …

Towards Intensified Protein Refolding And Purification On Size Exlusion Chromatography: Fundamental Studies And Mathematical Modelling, Pegah Saremirad

Electronic Thesis and Dissertation Repository

For industrial recombinant-protein processes, protein refolding and purification are crucial steps towards the recovery of considerable numbers of active and safe therapeutic products. In this thesis, intensification strategies for protein refolding and purification processes are explored. Development of an intensified process aims at simultaneous optimization of process performance indicators, namely: refolding yield, product purity, volumetric productivity and solvent consumption which in turn decrease the cost and time constraints to market.

The first strategy investigated related to multivariable experimental work using size exclusion chromatography (SEC) as a refolding method and a denatured/reduced model protein (lysozyme). SEC was selected due to its …

Residence Time Distribution Measurements In A Downer Reactor & Gas-Solids Separator, Martin Huard

Electronic Thesis and Dissertation Repository

An integrated gas-solids separator and stripper was developed, tested, and optimized for a circulating fluidized bed (CFB) downer at the Institute for Chemicals and Fuels from Alternative Resources (ICFAR) at Western University. The downer, designed for pyrolytic co-processing of heavy oil and biomass to valuable liquid fuels and chemicals, capitalizes on the plug flow behavior of gravity-assisted downward gas-solids flow, which has been proven in previous work. However, the effect of the reactor exit on unit performance has not been studied. Therefore, a comprehensive assessment of the gas-solids separator performance in a 0.07 m diameter, 1.34 m tall cold model …

Disinfection And Advanced Oxidation Of Highly Absorbing Fluids By Uv/Vuv Light: Process Modeling And Validation, Ferdinando Crapulli

Electronic Thesis and Dissertation Repository

One of the limitations in treating highly absorbing fluids with ultraviolet photoreactors is the short light penetration into the fluid leading to the following issues: (a) if not engineered properly, ultraviolet photoreactors dealing with highly absorbing fluids are likely to be energy-inefficient due to a non-ideal use of emitted photons and non-uniform dose distribution (b) the quantification of photo-chemical rate constants could be a challenging task due to the severe mixing-limited conditions of the experimental apparatus used during the investigation. As a result, new lab-scale apparatus (alternative to the conventional collimated beam system) and modeling approaches are needed in order …

Solar Photocatalytic Reduction Of Zn2+ Using Graphene-Based Tio2 Composite Catalyst For Application To Cso Treatment, Gloria Kumordzi

Electronic Thesis and Dissertation Repository

The improvement of photocatalyst efficiency in utilizing the majority of wavelengths in the solar spectrum, an abundant natural resource, presents the next step in the large scale application of photocatalysis for the treatment of dissolved organic and inorganic pollutants in wastewater. In this study, a composite catalyst of TiO₂ and Graphene synthesized by a hydrothermal treatment method is used to photo-reduce Zn²⁺, the most abundant heavy metal found in combined sewer overflows (CSOs). The performance of this composite catalyst was assessed under various process conditions such as pH, light intensity, catalyst loading and light source. The TiO …

The Study Of Mixing And Initial Granule Formation During High Shear Granulation Of Pharmaceutical Powders, Aveen Alkhatib

Electronic Thesis and Dissertation Repository

Wet granulation is the agglomeration of particles using a liquid binder to form granules. The process is extensively used in the pharmaceutical industry to manufacture tablets, as granulation minimizes segregation, dust, and improves flowability. Granule uniformity is important in pharmaceutical manufacturing, as the tablet must contain a uniform distribution of excipients in the product in order to comply with United States Food and Drug Administration (FDA) regulations. The research presented in this thesis focuses on the influence of formulation and process parameters on granule formation. Sugar spheres were initially used to study segregation during the dry mixing phase of high …

Development And Study Of Measurement Methods For Jets And Bogging In A Fluidized Bed, Majid Hamidi

Electronic Thesis and Dissertation Repository

In the Fluid Coking process, if the local concentration of liquid is very high, particles may stick together which can eventually result in process upset because of poor fluidization or even defluidization, a condition commonly known in industry as "bogging".

Using a capacitance sensor, the void distribution in a bed of coke particles can be visualized. The voidage fluctuations caused by gas bubbles have been shown to change dramatically as the bed becomes bogged. Therefore, capacitance sensors should be able to predict the bogging condition in fluid cokers.

The first part of the thesis focused on designing noiseless capacitance sensors …

Cluster Fluid Dynamics In Down Flow Reactors: Experimental And Modeling Study, Angel Virgilio Lanza Soto

Electronic Thesis and Dissertation Repository

Gas–solid concurrent downers possess unique features when compared to other gas–solid systems. Establishing their fluid dynamic properties requires both experimental measurements of gas-solid flow properties and computational modeling.

Measuring gas-solid flow properties such as cluster solid concentrations, individual cluster slip velocities, and cluster sizes, involves the use of specialized optical equipment, as well as a rigorous data analysis methodology. In addition, the modeling of the fluid dynamics of gas-solid flows in downer units offers special challenges such as establishing a proper drag model, cluster configuration and sizes, sphericity, boundary conditions, among other issues.

In this PhD dissertation, the fluid dynamics …

Thermal Conversion Of Triglycerides Of Vegetable Oil For Production Of Renewable Lamp Fuel, Jamie A. Gregory

Electronic Thesis and Dissertation Repository

The thermal treatment of crop oils was investigated with the aim to produce a renewable, liquid fuel suitable for use in wick-based lighting systems. Specific objectives include reducing fuel viscosity and improving wickability in traditional flat cotton wicks. Pyrolysis and visbreaking processes were the two methods of thermal treatment that were studied. Visbreaking was a semi-batch process carried out in a stirred tank reactor at temperatures ranging from 300 to 500 °C. Pyrolysis utilized a continuous system with a mechanically fluidized bed reactor at temperatures ranging from 400- 650 °C. Initial testing with soybean oil feedstock demonstrated that pyrolysis was …