Engineering Commons^™

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 …

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 …

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 …

Hydrolytic Depolymerization Of Lignin For The Preparation Of Polyols And Rigid Polyurethane Foams, Nubla Mahmood

Electronic Thesis and Dissertation Repository

This doctoral study was aimed to produce bio-polyols from Kraft lignin (KL) and hydrolysis lignin (HL) via depolymerization and utilize the lignin-derived bio-polyols in the preparation of bio-based rigid polyurethane (BRPU) foams at high percentage of bio-contents (50-70 wt.%). This study demonstrated that depolymerization is a practical and effective approach to unleash the potential of utilization of lignin, of complex structures and low reactivity/functionality, for bioproducts and biomaterials.

Depolymerization of KL was realized in alkaline medium using water alone as a solvent or employing water-ethylene glycol (EG) mixture via a low pressure (psig) proprietary process, both effective for producing low …

Impact Of Local Bed Hydrodynamics On Jet-Bed Interaction, Maryam Mohagheghi Dar Ranji

Electronic Thesis and Dissertation Repository

In Fluid Coking^TM or Fluid Catalytic Cracking liquid feedstocks are injected into a bed of fluidized particles. Uniform distribution of liquid feed on fluidized particles increases the yield of valuable products and improves operability in these processes. Contact between the injected liquid and the bed particles can be greatly affected by the liquid properties and local bed hydrodynamics.

The impact of parameters such as liquid properties, fluidization velocity, nozzle atomization gas flowrate, nozzle location and inclination were investigated on the distribution of liquid sprayed into a fluidized bed with a reliable and fast response capacitance meter. This method was …

Studies Of Anode Electrodes For The Biogenerator, Vahid Vajihinejad

Electronic Thesis and Dissertation Repository

The BioGenerator as a fundamentally new type of H₂-to-electricity conversion system offers a quite sustainable and cost effective solution to the challenges associated with the use of fuel cells in renewable power grids.The development of an anode electrode for the BioGenerator was subject of this work. The unique features of the BioGenerator require unique electrodes, and more specifically anode. The combination of biological cathodic liquid and the hydrogen gas fuel require specific hydrophobic/hydrophilic properties of the anode. Several different methods for anode formation were studied. The spreading technique was found to be most appropriate for the conditions in …

Surfactant Assisted Dispersion Of Single-Walled Carbon Nanotubes In Polyvinylpyrrolidone Solutions, Tennison Yu

Electronic Thesis and Dissertation Repository

Obtaining stable aqueous dispersions is one of the main challenges hindering a widespread and effective use of single-walled carbon nanotubes (SWNT) in many applications. Although it has been recognized that their versatility makes them an extremely attractive material, the unique molecular structure that gives SWNTs their unmatched electronic, mechanical, and thermal properties is also responsible for strong van der Waals interactions. This, combined with extremely high aspect ratios and flexibility, causes SWNTs to adhere strongly into tightly bundled ropes. In these bundles, SWNTs are not as useful as their linearized unbundled equivalents. Thus, in order to take advantage of their …

Hydrodynamics In Recirculating Fluidized Bed Mimicking The Stripper Section Of The Fluid Coker, Francisco J. Sanchez Careaga

Electronic Thesis and Dissertation Repository

The stripper section of a Fluid Coker^TM consists of a system of baffles (sheds) that enhances the removal of interstitial and adsorbed hydrocarbon vapors from the fluidized coke-particles. Most of the hydrocarbon-vapors released below a stripper shed flow up to the stripper shed, where they may crack and form coke deposits that foul the shed. Extensive fouling changes the shapes of the sheds, makes them thicker and reduces the free-space between the adjacent sheds until downward solids flow is so impaired that the Coker has to be shut down.

The Radioactive Particle Tracking (RPT) technique allows the determination of …

Treatment Of Combined Sewer Overflows Using Ferrate (Vi), Rohan Gandhi

Electronic Thesis and Dissertation Repository

Prevention of pollution from combined sewer overflows (CSOs) is currently a major concern due to their impact on aquatic and human environment. With the stringent regulations related to the CSOs treatment, it is necessary to develop an efficient, fast and low cost treatment technique that meets the applicable criteria. In this work, the comprehensive study was done to determine the efficiency of ferrate (VI) for the treatment of CSOs. At a Fe (VI) dose of 0.24 mg/l, TCOD, SCOD, TBOD₅, SBOD₅, TSS, VSS, TP, TN and soluble TN removal efficiencies of 71%, 75%, 69%, 68%, 72%, …

Study On Fine Powder Coating With Modified Additive, Dangchen Xue

Electronic Thesis and Dissertation Repository

Powder coating is a dry coating technology competing with conventional liquid coatings and offers many benefits such as the elimination of volatile organic compounds, high efficiency of material usage and improved coating durability. However, the rough and thick film surface restricts its wide application. The fine powder coating, which can solve the film quality issues, also has its own limitation: the powder is too cohesive to handle. Although, nanoparticle flow additives can significantly improve the flowability of fine powders, it leads to another obstacle at the same time. Since the inorganic nano additives are not fully compatible with the organic …

Optimisation Of The Transesterification Stage Of Biodiesel Production Using Statistical Methods, Arnold Paintsil

Electronic Thesis and Dissertation Repository

The present research examines solely the transesterification stage of the biodiesel production process. Six process variables that affect the yield of biodiesel at this stage are examined using the 12 run Plackett-Burman Design. To study the effect of FFA[1] and to replicate real life situations where oil (feedstock) contain varying amounts of FFA, linoleic acid is used as FFA and intentionally added to high oleic acid canola oil containing less than 0.07% FFA. The process is catalyzed with potassium carbonate and evaluated at varying temperatures, stirring rates, reaction times and methanol oil ratios. The yields at the end of …

Aging And Stabilization Of Pyrolitic Bio-Oils And Model Compounds, A. G. Manjula Taranganie Siriwardhana

Electronic Thesis and Dissertation Repository

When compared to conventional liquid fuels, bio-oil has several undesired properties such as high viscosity, high acidity, high molecular weight, instability, and phase separation upon aging. Therefore, bio-oil needs further stabilization and upgrading before it can be used as a fuel in engines. Phase separation is considered as one of the major issues because it is detrimental to any fuel application and creates problems in storage, transportation and upgrading of bio-oils. This thesis investigates the phase separation of hardwood derived bio-oil under accelerated aging conditions. Different alcohols are used as stabilizing agents and the minimum required amount of alcohol for …

Fate Of Estrogens In Anaerobic Digestion And Their Removal In Advanced Oxidation, Shubhajit Sarkar

Electronic Thesis and Dissertation Repository

Estrogenic compounds are most significant endocrine disrupting compounds (EDC), which are of primary concern due to their widespread presence in the aqueous environment and also due to their adverse impact both on aquatic life and potential risk to human health. Conventional wastewater treatment plants are not designed to remove EDC, with biosorption on biosolids as the predominant removal mechanism. Anaerobic digestion is one of the most preferred processes employed for sludge stabilization in wastewater treatment plants. Advanced oxidation processes (AOPs) are seen as promising technologies for removal of estrogens from the environment. In this research, a controlled degradation study of …

Development And Application Of An Experimental Model For The Fluid Coking Process, Carolina B. Morales

Electronic Thesis and Dissertation Repository

Liquid injection into a fluidized bed is used in industrial applications such as the Fluid Coking^TM process for heavy oil thermal cracking. Poor initial liquid-solid contact results in the formation of agglomerates that limit heat and mass transfer processes, reduce the yield of valuable compounds and create operating problems. The present study develops a new experimental model to simulate the complex phenomena that occur when heavy oil is injected in a Fluid Coker through two-phase nozzles. The model is applied in a pilot scale fluidized bed using scaled-down industrial spray nozzles. The experimental results indicate that agglomerate formation slows …

Carbon Dioxide Adsorption By Metal Organic Frameworks (Synthesis, Testing And Modeling), Rana Sabouni

Electronic Thesis and Dissertation Repository

It is essential to capture carbon dioxide from flue gas because it is considered one of the main causes of global warming. Several materials and various methods have been reported for the CO₂ capturing including adsorption onto zeolites, porous membranes, and absorption in amine solutions. All such methods require high energy input and high cost. New classes of porous materials called Metal Organic Frameworks (MOFs) exhibit excellent performance in capturing carbon dioxide from a gas mixture.

In the course of the current research, a novel MOF synthesis method using combined microwave and ultrasound, and microwave only was introduced and …

Effect Of Liquid-Solid Contact On Thermal Cracking Of Heavy Hydrocarbons In A Mechanically Fluidized Reactor, Mitesh C. Chaudhari

Electronic Thesis and Dissertation Repository

The aim of the thesis was to study the effect of liquid-solid contact on the thermal cracking of heavy hydrocarbons carried out in Fluid Cokers. The research has been carried out using a Mechanically Fluidized Reactor (MFR) in which the operating conditions of the Fluid Coking^TM reactions can be simulated and monitored. The first part of the research, aimed at investigating the effect of agitation on liquid-solid contact, which was carried out by changing the rotation speed of the agitator of the MFR for both non-reactive as well as for reactive systems. In both situations, it was observed that …

Production Of Bio-Coal And Activated Carbon From Biomass, Diana C. Cruz

Electronic Thesis and Dissertation Repository

The slow pyrolysis of different biomasses (maple wood, birch bark, switch grass, coffee pulp and corn stalk) was studied with the aim to produce a solid pyrolysis product (bio-coal) with promising properties and potential for use in traditional fossil-coal applications. Batch pyrolysis experiments were conducted in a Mechanically Fluidized Reactor (MFR) at temperatures ranging from 143 to 665 ^oC, which includes the torrefaction temperature range (200-300 ^oC). The effects of temperature and holding time on bio-coal mass yields were determined. The bio-coals were characterized in detail and a highly-controlled study on bio-coal hygroscopicity is presented. Optimal conditions for …

Fractional Condensation Of Bio-Oil Vapors, Akhil Tumbalam Gooty

Electronic Thesis and Dissertation Repository

The research project described in this thesis deals with an investigation on the fractional condensation of bio-oil vapors to improve the separation of some of the key components of the bio-oil and, consequently, improve the properties and the value of each of the separated product streams.

In the first part, the separation of a mixture of three model compounds of bio-oil from a vapor and carrier gas stream was investigated with the help of a series of three condensers maintained at different temperatures. The practical performance of the fractional condensation train was improved by comparing the experimental results with the …

Preparation And Formulation Of Powder Coating For Application Of Enamelled Wire, Liuyin Xia

Electronic Thesis and Dissertation Repository

Enamelled wire is a conductive wire coated with a very thin layer of insulation, widely used in the field that requires tight coils of wire. The traditional enamelled wire is produced by liquid paint, which consists of resins, solvents, pigments, and additives. Organic solvent takes a relatively high content, normally of 75% to 90% by weight. Many efforts have been made to decrease the percentage of solvent in the insulation paint. On the other hand, increasing the solids content of given enamel results in the viscosity rises significantly, making it harder to flow. Therefore, powder coating technology as an alternative …

Calcium Phosphate-Based Resorbable Biomaterials For Bone Regeneration, Daniel O. Costa

Electronic Thesis and Dissertation Repository

Bone defects are a prevalent problem in orthopedics and dentistry. Calcium phosphate-based coatings and nanocomposites offer unique solutions towards producing scaffolds with suitable physical, mechanical and biological properties for bone regeneration.

We developed a novel method to synthesize hydroxyapatite (HA) particles with high aspect ratio using sol-gel chemistry and hydrothermal treatment. We obtained tunable pure-phase carbonated-HA in the form of micro/nanorods and nanowires (diameters 25-800 nm). To mimic the structure of bone, HA nanowires were homogenously mixed within poly(ε-caprolactone) (PCL) to produce nanocomposites with improved mechanical properties as determined by uniaxial tensile testing.

Surface chemistry and topography of biomaterials play …

Improved Non-Linear Solution Of Dip Coating Flow, Omar Bin Yusuf

Electronic Thesis and Dissertation Repository

A thin layer of film is developed on the surface of a substrate in the dip coating process where the substrate is initially immersed into the coating fluid and then withdrawn continuously from the coating fluid bath. In this study a two dimensional flow of the thin film for a Newtonian fluid is examined theoretically by dividing the film into three separate regions. A general formulation is developed for a thin film flow, which then simplifies for each region upon considering appropriate assumptions to each region. The influence of inertia and surface tension in the presence of gravity is investigated …

Experimental & Empirical Correlations For The Determination Of The Overall Volumetric Mass Transfer Coefficients Of Carbon Dioxide In Stirred Tank Bioreactors, Syeda Anam Kazim

Electronic Thesis and Dissertation Repository

One of the most important parameters to cultivate microalgae is carbon dioxide absorption by microalgae. Therefore, it is necessary to determine the overall volumetric mass transfer coefficient (K_La) of carbon dioxide to quantify CO₂ transfer from the gaseous to the liquid phase. Until now, finding K_La of CO₂ for microalgae cultivation has been a challenge as there is not much information available about it in the literature and most of the time the CO₂ transfer to microalgae is approximated. In this study, correlations to directly calculate K_La of CO₂ in …

Liquid Distribution From Industrial Scale Spray Jets In Fluidized Beds, Mohammadali Zirgachianzadeh

Electronic Thesis and Dissertation Repository

Liquid injections via spray nozzles are used in fluidized bed reactors such as Fluid Cokers. In such industrial processes, in order to maximize the product yields it is required to optimize the performance of the nozzle. Moreover parts of the bed might become defluidized, bogged, due to high liquid load. Then optimizing the performance of the nozzle and local bed bogging detection is the primary research objectives for this thesis work.

The first part of the research work was focused on developing a novel method employing electrical conductance to characterize the liquid distribution in a large scale fluid bed of …

Developing Novel Methods To Characterize Liquid Dispersion In A Fluidized Bed, Masoumeh Farkhondehkavaki

Electronic Thesis and Dissertation Repository

The performance of several important industrial processes, such as fluid coking or fluid catalytic cracking, is dependent on the good distribution of liquid feed sprayed into a fluidized bed of hot inert or catalytic particles, respectively.

Liquid injected into a fluidized bed is distributed in three different ways: (i) free moisture, or liquid coating individual particles; (ii) wet micro-agglomerates, which are fluidized; and (iii) wet macro-agglomerates, which settle to the bottom of the bed. This study develops and evaluates various methods for the determination of this moisture.

In the study using electrical techniques, two different kinds of electrodes geometries are …

Oxygen Delivery Strategies In Tissue-Engineering Constructs, Dawit Gezahegn Seifu

Electronic Thesis and Dissertation Repository

The supply of nutrients and the removal of waste products play a major role in tissue engineering. From all the nutrients necessary for cells seeded on scaffolds for tissue regeneration, oxygen is the limiting component due to its low solubility in culture media while cells consume five to six moles of oxygen for every mole of monosaccharide. The aim of the present work was to develop different strategies to improve the supply of oxygen to human coronary artery smooth muscle cells (HCASMC) seeded on three dimensional (3D) porous biostable polyurethane scaffolds. As a springboard for the study, the measured value …

Development Of A Novel Tio2-Polymeric Photocatalyst For Water Purification Both Under Uv And Solar Illuminations, Debjani Mukherjee

Electronic Thesis and Dissertation Repository

Comprising about 70% of the Earth’s surface, water is undoubtedly the most precious natural resource. According to the W.H.O, around 3.5 million people are dying every year from different water related diseases. Different kinds of dyes and pharmaceutical products have been detected in drinking water, all over the world. These organic compounds being non removable by traditional water purification processes, made advanced oxidation processes come into existence. Among all kind of advanced oxidation processes, photocatalytic oxidation is the most promising one. The photocatalytic process is based on aqueous phase hydroxyl radical chemistry and couples low energy UV light with semiconductors …

Audible Acoustic Emissions For Monitoring High-Shear Granulation, Erin M. Hansuld

Electronic Thesis and Dissertation Repository

High-shear wet granulation is a size enlargement process commonly used by the pharmaceutical industry to improve powder properties for downstream processes, such as tabletting. Granule growth however, is difficult to predict because the final product is sensitive to raw material properties and processing conditions. Development of process analytical technologies (PATs) is recommended by regulators to improve process understanding and monitor quality online.

This work investigates the robustness of AAEs as PAT for high-shear granulation. Condenser microphones suspended in the air exhaust were used to collect AAEs from granulation. Applying power spectral density (PSD) analysis, trends related to wetting and end-point …

Fabrication, Modification And Application Of Visible Light Responsive Tio2 Nanotubes, Tayirjan Taylor Isimjan

Electronic Thesis and Dissertation Repository

The highly ordered TiO₂ nanotube arrays have demonstrated remarkable properties that include solar cells, hydrogen sensors, drug eluting surfaces, hydrogen generation, and water purification along with numerous other applications. Built upon a suitable fabrication approach that enable significant differences in reproducibility as well as the large scale production with low cost plus investigation of the effective way to increase its visible light response so that create environmental friendly alternative energy sources were the motivations of this work, Since the field has grown so rapidly as to make it difficult to summarize the scope of all related work, some key …

Biological Nutrient Removal From Municipal And Industrial Wastewater Using A Twin Circulating Fluidized Bed Bioreactor, Mehran Andalib

Electronic Thesis and Dissertation Repository

Biological nutrient removal (BNR) refers to removal of carbon (C), nitrogen (N) and phosphorus (P) from wastewater (WW) by the aid of various microorganisms. Because of the public concern for the environment C, N and P effluent standards have become stricter. Different BNR processes such as suspended growth and attached growth have been studied during the last three decades in order to meet the increasingly stringent discharge standards.

In this work, two novel processes called Twin Fluidized Bed Bioreactor (TFBBR) and Twin Circulating Fluidized Bed Bioreactor (TCFBBR) were developed and tested for BNR from municipal WW. Both TFBBR and TCFBBR …