Engineering Commons^™

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 …

Effects Of Internals Configurations On Heat Transfer And Hydrodynamics In Bubble Columns - With And Without Solid Particles, Anil Kumar Jhawar

Electronic Thesis and Dissertation Repository

Internals of different types are required in a number of industrial applications of bubble columns to achieve the desired mixing or to remove the heat of reaction to maintain desired temperature and isothermal conditions of operation. Some of these applications include Fischer-Tropsch synthesis, methanol synthesis, and production of dimethyl ether (DME). The presence of internals however can alter the column hydrodynamics and mixing patterns which could influence reactor performance. A fast response probe capable of capturing bubble dynamics, as well as detecting flow direction is used to study the effect of internals on local heat transfer and column hydrodynamics in …

Investigations Of Transesterification Of Canola Oil With Methanol And Ethanol For A New Efficient Method Of Biodiesel Production, Krupal Pal

Electronic Thesis and Dissertation Repository

Transesterification of vegetable oil to biodiesel is a multistep process affected by mass transfer, mixing and chemical reaction equilibrium. Attempts have been made in this study to overcome these limitations by gradually feeding oil into a pool of alcohol. This approach provided large excess of alcohol to allow reaction to proceed further as well as allowed easy dispersion of oil into the alcohol. As a result improved conversion of feed, higher yield and better product quality were achieved. Comparisons have been made with other methods to show the differences and highlight improvements. Reactions were conducted at various reaction conditions for …

Photocatalytic Degradation Of Phenolic Compounds In Water: Irradiation And Kinetic Modeling, Jesus Moreira Del Rio

Electronic Thesis and Dissertation Repository

Scaling up a photoreactor requires both knowledge of optical properties of the slurry medium and an established kinetic model. Measuring the scattering and absorption coefficients of particles suspended in water involves the use of specialized optical equipment, as well as the partial solution of the radiative transfer equation (RTE). In addition, modeling of the radiation field in photoreactors with complicated geometries offers special challenges.

On the other hand, most of the kinetic models (KM) for phenol photodegradation reported in the literature were obtained for a single organic chemical species only. In fact, neglecting all the intermediate species generated during the …

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 …

Functional Coatings: Superhydrophopbic And Conductive Coatings, Seyed Amirhossein Seyedmehdi

Electronic Thesis and Dissertation Repository

The natural world has many superhydrophobic and self-cleaning surfaces such as butterfly wings and lotus plant leaves, both well known examples of self-cleaning surfaces. Water droplets on these surfaces can pick up dirt particles and remove contamination. The significant self-cleaning ability of these surfaces has inspired many researchers to attempt to fabricate these superhydrophobic coatings, mimicking their self-cleaning properties, using different methods. Most of the superhydrophobic coatings described in current literature need to be cured in ovens and thus difficult to be applied and/or be maintained in the work place. Therefore, there is a need to develop room temperature curing …

Supercritical Water Gasification Of Biomass & Biomass Model Compounds, Emhemmed A.E.A Youssef

Electronic Thesis and Dissertation Repository

Supercritical water gasification (SCWG) is an innovative, modern, and effective destruction process for the treatment of organic compounds. Hydrogen production using SCWG of biomass or waste feedstocks is a promising approach towards cleaner fuel production while simultaneously providing novel solution for hard-to-treat organic wastes. The main premise of this work was to experimentally examine real waste biomass sources i.e. hog manure and waste biomass model compounds using SCW gasification while examining various commercial catalysts. The improvement of the SCWG process requires an understanding of the waste/biomass reaction chemistry, and thus the knowledge of the reaction mechanisms is critically important for …

Particle Attrition With Supersonic Nozzles In A High Temperature Fluidized Bed, Feng Li

Electronic Thesis and Dissertation Repository

Fluidized beds are widely used for a variety of processes such as food, pharmaceutical, petrochemical and energy production. As a typical application of fluidized beds, the fluid coking process uses thermal cracking reactions to upgrade heavy oils and bitumen from oil sands. In order to maintain a well fluidized bed and a satisfactory operation, a series of supersonic nozzles are used to inject high pressure steam in the bed to maintain the coke particle within an optimal range. Currently, the attrition nozzles consume a large florwrate of high pressure and superheated steam, which accounts for about 40 % of the …

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 …

Investigation Of Ash Deposition During Co-Firing Biomass/Peat With Coal In A Pilot-Scale Fluidized-Bed Reactor, Yuanyuan Shao

Electronic Thesis and Dissertation Repository

Biomass, a promising alternative to fossil fuels, has been applied widely for energy generation by co-firing technology in recent year particularly in the EU countries. In this thesis, a key issue of biomass co-firing technology - ash deposition in combustion, co-combustion and gasification, was comprehensively investigated in a pilot-scale bubbling fluidized bed reactor. A custom-designed, air-cooled probe was installed in the freeboard zone of the reactor to simulate the heat-transfer surface and collect ash deposits from the process. A local lignite coal, a woody biomass (white pine), and a Canadian peat were involved in the tests. The main varying operating …

A Step Towards Continuous Production Of Nay Zeolite In Amorphous Silica Particles Using A Dry Process, Syed Sameen Ali Zaidi

Electronic Thesis and Dissertation Repository

This thesis is focused on the synthesis of nano-size (50-100nm) NaY zeolite crystals inside the micro/meso pores of preshaped amorphous silica particles of size 50 micrometer using a dry process, which reduced several operational steps and the zeolite synthesis time that are generally required for current in-practice processes. Three types of reactors namely; polypropylene bottles, a stainless steel tubular reactor, and a novel vibrated baffles fluidized bed (VBFB) reactor coupled with infrared radiation emitters were used to evaluate the effects of different operating parameters on the synthesis of NaY zeolite. The synthesis process took place without using any structure directing …

Nickel-Based Catalysts For Gasification Of Glucose In Supercritical Water, Muhammad Badrul Islam Chowdhury

Electronic Thesis and Dissertation Repository

Gasification of waste biomass to form hydrogen, H2, is a promising new source of green energy; while providing the additional benefit of treating challenging and hazardous waste streams that pollute the environment. Gasification of biomass in supercritical water (SCW) offers an attractive alternative to avoid the energy intensive drying process. In this approach, biomass is hydrolyzed by water into smaller molecules in the presence of a suitable catalyst. This study was aimed at developing an alumina supported nickel based non-noble metal catalyst suitable for biomass gasification in SCW. A lack of detailed characterization on fresh and spent catalysts in SCW …

The Effect Of Particle Size On Hydrolysis And Modeling Of Anaerobic Digestion, Saad Aldin

Electronic Thesis and Dissertation Repository

Batch experiments were performed to investigate the effect of particulate protein particle size on the hydrolysis of casein in anaerobic degradation. While particle size did not affect the ultimate protein degradation efficiency, the hydrolysis rate coefficient increased from 0.034 to 0.298 d-1 with the change in specific surface area from 0.01 to 0.192 m2/g. The maximum methane production rate was affected by the particle size change, although the ultimate amount of methane produced was approximately the same despite the change in specific surface area. A mathematical relationship between the hydrolysis rate coefficient and specific surface area was developed and a …

Catalytic Steam Gasification Of Biomass Surrogates: A Thermodynamic And Kinetic Approach, Enrique Salaices

Electronic Thesis and Dissertation Repository

Gasification of biomass is an environmentally important technology that offers an alternative to the direct use of fossil fuel energy. Steam gasification is getting increased attention as a potential source of renewable energy since it produces a gaseous fuel suitable for industrial applications in highly efficiently power/heat energy production, transport fuel, and as a feedstock for chemical synthesis. Furthermore, catalytic steam gasification has other advantages hence (i) it produces a gas with higher heating value; (ii) it reduces the diluting effect of N2 from air; (iii) it eliminates the need of cleaning, upgrading and/or conditioning the product gas for certain …