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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

A New Technology for the Anaerobic Digestion of Organic Waste

Guilford, Nigel 19 January 2010 (has links)
The development and patenting of a new technology for the anaerobic digestion of solid waste is described. The design basis is explained and justified by extensive reference to the literature. The technology was specifically designed to be versatile, robust and affordable and is directly derived from other proven processes for organic waste management. The ways in which environmental regulations directly affect the development and commercialization of organic waste processing technologies are described. The great differences in regulations between Europe and North America are analyzed to explain why anaerobic digestion is common in Europe and rare in North America and why this is the result of waste management economics which are driven by these regulations. The new technology is shown to be competitive in the Province of Ontario in particular and North America in general; a detailed financial analysis and comparison with European technologies is provided in support of this conclusion.
22

Task-ambient lighting: a sustainable design method investigation

Caton, Nicholas A January 1900 (has links)
Master of Science / Department of Architectural Engineering and Construction Science / Raphael A. Yunk / Today's engineers of building lighting systems must maintain a careful balance between the demands of accepted standards of practice, the necessity of life safety, the system performance needs of the client, and the developing national energy standards and certifications gaining prominence in the public eye. These sources of influence on the design process can create conflicts between the pressing need to conserve system energy usage and a costlier and perhaps unacceptable end-result for the client. In this climate, various governmental organizations and industry cooperatives have been funding published research and case-studies in order to promote sustainable design practices. Within these publications are repeated references to a "Task-Ambient" lighting fixture layout strategy. Multiple recent publications cite profound energy-saving benefits attainable using this design method. However, there is a noticeable lack of measured data concerning other qualities of this layout scheme, such as the end-user's comfort and ability to perform tasks under the resulting light distributions. Whether this lack of data resulted from the added complexity associated with such non-numerical measurements, or for some other unknown reason, this report explores this gap in the available data. An extended survey procedure was developed to approach the problem of measuring these unknown qualities of the Task-Ambient design strategy. This involved constructing multiple physical lighting layout mockups, defining the features of the Task-Ambient strategy which necessitated measurement, and designing objective tasks tailored to measure each of these non-numerical qualities. The careful analysis of this study's data results yields trends indicative of the Task-Ambient strategy, relative to a standard uniform layout, adversely affecting productivity, concentration, and the participants' subjective perceptions of the space's light distribution. The lowered level of energy use was however affirmed. The implications of these results are that the Task-Ambient strategy, while an efficient method of lighting system layout design, may not be beneficial for the client in other respects.
23

Intelligent dispatch for distributed renewable resources

Hopkins, Mark January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / Anil Pahwa / A time may soon come where prices of electricity vary by time of day or season. Time of Day (TOD) pricing is considered by many to be a key part of creating a more energy-efficient and renewable-energy friendly grid. TOD pricing is also an integral part of Smart Grid and is already available to some customers. With TOD pricing becoming a reality, intelligent dispatching systems that utilize Energy Storage Devices (ESDs) to maximize the use of renewable resources, such as energy produced by small, customer owned wind generators and roof-top solar generators, and grid energy while determining the most economical dispatch schedule could play an important role for both the customer and the utility. This purpose of this work is to create an algorithm upon which these dispatching systems can be based. The details of one proposed algorithm are presented. The full development of the algorithm from its most simplistic form into a much more complex system that takes into account all of the major nonidealities of a real system is given. Additionally, several case studies are presented to show the effectiveness of the algorithm from both a technical standpoint and an economic standpoint. The case studies simulated both wind and solar powered devices using data taken in the state of Kansas, but case studies to emulate electric rates and renewable resources in other areas of the country are presented as well. For each of these case studies, 20 year net present value calculations are presented to determine the economic viability of both the renewable energy production and the dispatching systems.
24

The economics of an alternative bio-energy feedstock – the case of Jatropha curcas

Tee, Meng Y. January 1900 (has links)
Master of Agribusiness / Department of Agricultural Economics / Vincent R. Amanor-Boadu / Biofuels such as ethanol and biodiesel are looked upon as the future source of alternative energy. These biofuels will supplement the needs of the ever increasing demand for fuel. Bio-energy feedstock is in high demand and current bio-crude oil prices such as soybeans and palm oil are higher than fossil fuel crude oil prices. Unless the price of fossil fuel crude oil increases beyond that, it would not be economically viable to produce biofuels from these feedstock. Jatropha curcas has been touted as the future of biodiesel. The seeds from the Jatropha curcas are crushed and processed using transesterification. The product of the chemical reaction results in bio-oil and glycerin. The objective of this paper is to study the economics of Jatropha curcas as an alternative bio-energy feedstock. Comparisons are done on Jatropha curcas oil, soybean oil, and palm oil. The Jatropha curcas industry is at its infancy, and crude Jatropha curcas oil is either not available in the open market or extremely difficult to find in any significant amount. However, soybean oil and crude palm oil are traded commodities and their prices are dependent on their demand and supply pressures. Given these conditions, the approach adopted here involved the establishment of a vertically integrated company that grows and harvests the Jatropha curcas feedstock and crushes the seeds to obtain the crude oil, and finally processes it to obtain biodiesel and glycerin. The financial analysis provided results that indicate that the Jatropha curcas has the potential to be a successful feedstock. The conclusion after conducting net present value comparisons shows that the price per kilogram of the Jatropha curcas seed would be the determining factor in the success of this bio-fuel feedstock. As more work goes into the genetic selection of Jatropha curcas for high yield varieties, the feedstock’s potential increases and its potential as a solution to the search for the competitive sources of biodiesel becomes more real.
25

Economic analysis and Monte Carlo simulation of community wind generation in rural western Kansas

Halling, Todd January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / Anil Pahwa / Energy costs are rising, supplies of fossil fuels are diminishing, and environmental concerns surrounding power generation in the United States are at an all-time high. The United States is continuing to push all states for energy reform and where better for Kansas to look than wind energy? Kansas is second among all states in wind generation potential; however, the best wind generation sites are located predominantly in sparsely populated areas, creating energy transportation problems. Due to these issues interest in community wind projects has been increasing. To determine the economic potential of community wind generation a distribution system in rural western Kansas where interest in community wind exists was examined and a feasibility study based on historical data, economic factors, and current grid constraints was performed. Since the majority of the load in this area is from pivot-point irrigation systems, load distributions were created based on temperature ranges instead of a linear progression of concurrent days. To test the economic viability three rate structures were examined: flat energy rate, demand rate, and critical peak pricing. A Monte Carlo simulation was designed and run to simulate twenty-year periods based on the available historical data; twenty-year net present worth calculations were performed to ensure economic viability. A sensitivity analysis was then performed to examine the effects of change in turbine size and energy rate scale. Finally, an energy storage analysis was performed to examine the economic viability of various sizes of battery storage systems.
26

Modeling power system load using intelligent methods.

He, Shengyang January 1900 (has links)
Master of Science / Department of Electrical Engineering / Shelli K. Starrett / Modern power systems are integrated, complex, dynamic systems. Due to the complexity, power system operation and control need to be analyzed using numerical simulation. The load model is one of the least known models among the many components in the power system operation. The two different load models are the static and dynamic models. The ZIP load model has been extensively studied. This has widely applied to composite load models that could maintain constant impedance, constant current, and/or constant power. In this work, various Neural Networks algorithms and fuzzy logic have been used to obtain these ZIP load model coefficients for determining the percentage of constant impedance, current, or power for the various load buses. The inputs are a combination of voltage, voltage change, and power change, or voltage and power, and the outputs consist of the ZIP load model coefficients for determining the type and the percentage of load at the bus. The trained model is used to predict the type and percentage of constant load at other buses using simulated transient data from the 16-generator system. A small study was also done using a dynamic induction machine model in addition to the ZIP load model. As expected, the results show that the dynamic model is more difficult to determine than the static model.
27

A techno-economic analysis of ethanol production from hydrolysis of cellulose with nanoscale magnetic solid acid catalysts

Ault, Trevor Joseph January 1900 (has links)
Master of Science / Department of Chemical Engineering / Keith Hohn / Acid catalysts have been shown to be very successful in the pretreatment of cellulosic biomass to improve glucose yield and improve overall yield of ethanol. This report presents the results of a techno-economic study that looks into the use of nanoscale magnetic solid acid catalysts for glucose production. Magnetic solid acid catalysts are an improvement over using diluted acid due to eliminating acid-waste generation and corrosion hazards. Their magnetic nature also allows them to be easily separated from reaction products by an external magnetic force. After the technology is analyzed, a series of unit operations is proposed to go from the laboratory scale to the industrial plant scale. The next step was to develop material and energy balances using HYSYS process simulation software. Capital and operating costs are estimated and all the information is combined into a discounted cash flow economic model. The economic portion of the report uses a probabilistic cost assessment. It is used to quantify the range of risks in the project from swings in feedstock costs, differences in yield from catalysts, and any other significant variables. Both capital costs (initial equipment & construction investment) and operating costs (feedstock supply, chemicals, and personnell) are included with ranges of error based on databases and expert opinion. This method of evaluating investment efficiency can be helpful for predicting the cost benefits of proposed future research. The yield and percent catalyst magnetically recovered is assumed based on laboratory research to simplify the model. A 2000 metric tons of biomass per day facility was analyzed. Using the magnetic solid acid catalyst technology, the capital costs are estimated to be $160 million and this technology saves around 10% of capital costs compared to ethanol plants that uses conventional acid hydrolysis. The yield of the magnetic solid acid catalysts should be around 75% to compete with existing ethanol technologies. The metric used for this report is the discount profitability index (DPI) which is the ratio of future cash flows divided by investment. A DPI “hurdle rate” of 1.3 is used, which is similar to industry economic metrics of projects that include new process plants. The calculated DPI for the project is 1.38 DPI which is higher than using conventional cellulose treatment technologies. The recommendation is continue to study this technology’s large scale applicability before attempting any plant pilot studies.
28

Real-time simulation of shipboard power system and energy storage device management

Li, Dingyi January 1900 (has links)
Master of Science / Department of Electrical and Computer Engineering / Noel Schulz / Many situations can cause a fault on a shipboard power system, especially in naval battleships. Batteries and ultra-capacitors are simulated to be backup energy storage devices (ESDs) to power the shipboard power system when an outage or damage occurs. Because ESDs have advantages such as guaranteed load leveling, good transient operation, and energy recovery during braking operation, they are commonly used for electrical ship applications. To fulfill these requirements, an energy management subsystem (EMS) with a specific control algorithm must connect ESDs to the dc link of the motor drive system. In this research, the real-time simulation of shipboard power system (SPS), bidirectional DC-DC converter, EMS, and ESDs are designed, implemented, and controlled on OPAL-RT system to test SPS survivability and ESD performance in various speed operations.
29

Hybrid core-shell nanowire electrodes utilizing vertically aligned carbon nanofiber arrays for high-performance energy storage

Klankowski, Steven Arnold January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Jun Li / Nanostructured electrode materials for electrochemical energy storage systems have been shown to improve both rate performance and capacity retention, while allowing considerably longer cycling lifetime. The nano-architectures provide enhanced kinetics by means of larger surface area, higher porosity, better material interconnectivity, shorter diffusion lengths, and overall mechanical stability. Meanwhile, active materials that once were excluded from use due to bulk property issues are now being examined in new nanoarchitecture. Silicon was such a material, desired for its large lithium-ion storage capacity of 4,200 mAh g[superscript]-1 and low redox potential of 0.4 V vs. Li/Li[superscript]+; however, a ~300% volume expansion and increased resistivity upon lithiation limited its broader applications. In the first study, the silicon-coated vertically aligned carbon nanofiber (VACNF) array presents a unique core-shell nanowire (NW) architecture that demonstrates both good capacity and high rate performance. In follow-up, the Si-VACNFs NW electrode demonstrates enhanced power rate capabilities as it shows excellent storage capacity at high rates, attributed to the unique nanoneedle structure that high vacuum sputtering produces on the three-dimensional array. Following silicon’s success, titanium dioxide has been explored as an alternative highrate electrode material by utilizing the dual storage mechanisms of Li+ insertion and pseudocapacitance. The TiO[subscript]2-coated VACNFs shows improved electrochemical activity that delivers near theoretical capacity at larger currents due to shorter Li[superscript]+ diffusion lengths and highly effective electron transport. A unique cell is formed with the Si-coated and TiO[subscript]2-coated electrodes place counter to one another, creating the hybrid of lithium ion battery-pseudocapacitor that demonstrated both high power and high energy densities. The hybrid cell operates like a battery at lower current rates, achieving larger discharge capacity, while retaining one-third of that capacity as the current is raised by 100-fold. This showcases the VACNF arrays as a solid platform capable of assisting lithium active compounds to achieve high capacity at very high rates, comparable to modern supercapacitors. Lastly, manganese oxide is explored to demonstrate the high power rate performance that the VACNF array can provide by creating a supercapacitor that is highly effective in cycling at various high current rates, maintaining high-capacity and good cycling performance for thousands of cycles.
30

Sol-gel synthesized nanomaterials for environmental applications

Yang, Xiangxin January 1900 (has links)
Doctor of Philosophy / Department of Chemical Engineering / Larry E. Erickson / Over the past decade, nanomaterials have been the subject of enormous interest. Their defining characteristic is a very small size in the range of 1-100 nm. Due to their nanometer size, nanomaterials are known to have unique mechanical, thermal, biological, optical and chemical properties, together with the potential for wide-ranging industrial applications. Here, we synthesized nanocrystalline metal oxides through the sol-gel process and used these materials as desulfurization adsorbents and photocatalysts. Deep desulfurization of fuels has received more and more attention worldwide, not only because of health and environmental consideration but also due to the need for producing ultra-low-sulfur fuels, which can only be achieved under severe operating conditions at high cost using hydrodesulfurization (HDS). Consequently, development of new and affordable deep desulfurization processes to satisfy the decreasing limit of sulfur content in fuels is a big challenge. Sol-gel derived Cu/Al[subscript]2O[subscript]3 and Zn/Al[subscript]2O[subscript]3 adsorbents have been demonstrated to be effective in the removal of thiophene from a model solution. Results showed that Cu[superscript]+ was the active site and thermal treatment under vacuum was critical for Zn/Al[subscript]2O[subscript]3 since a defective, less crystalline spinel led to stronger interaction between zinc ions and thiophene molecules in the adsorption process. The kinetic study suggested that most of the adsorption occurred in the first 30 min, and adsorption equilibrium was attained after 1.5 h. Both adsorbents showed good regenerative property. TiO2 is considered the most promising photocatalyst due to its high efficiency, chemical stability, non-toxicity, and low cost for degradation and complete mineralization of organic pollutants. However, the use of TiO[subscript]2 is impaired because it requires ultraviolet (UV) activation ([Lambda]<387 nm). The shift of optical response of TiO[subscript]2 from the UV to the visible light region would have a profound positive effect on the efficient use of solar energy in photocatalytic reactions. We shifted the optical response of TiO[subscript]2 and improved the photocatalytic efficiency through size modification and transition metal ion and nonmetal atom doping. Experimental results showed that C and V co-doped TiO[subscript]2 catalysts had much higher activity than commercial P25 TiO[subscript]2 towards the degradation of acetaldehyde under visible light irradiation. For the first time, we reported that activities were comparable in the dark and under visible light irradiation for co-doped TiO[subscript]2 with 2.0 wt% V. C and N co-doped TiO[subscript]2 exhibited higher activity for the degradation of methylene blue than pure TiO[subscript]2 under visible light and UV irradiation. Possible mechanisms were discussed based on the experimental results.

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