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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.
1

Assessing the potential and limitations of heavy oil upgrading by electron beam irradiation

Zhussupov, Daniyar 25 April 2007 (has links)
Radiation technology can economically overcome principal problems of heavy oil processing arising from heavy oil’s unfavorable physical and chemical properties. This technology promises to increase considerably yields of valuable and environmentally satisfying products of thermal cracking; to simplify complexity of refinery configuration; and to reduce energy expenses of thermal cracking. Objectives of the present study are: ● Evaluate heavy oil viscosities with respect to absorbed dose and effect of different solvents on the viscosity of irradiated crude oil by comparing selected physical properties of irradiated samples to a non-irradiated control group; ● Investigate effect of e-beam radiation on the yields of light fractions comparing yields of radiation-thermal cracking to yields of conventional thermal cracking. The viscosity was used as an indicator of the change in the molecular structure of hydrocarbons upon irradiation. We found that the irradiation of pure oil leads to the increase of the molecular weight calculated from the Riazi-Daubert correlation. Thus, irradiation up to 10 kGy resulted in a 1.64% increase in the molecular weight, 20 kGy ─ 4.35% and 30 kGy ─ 3.28%. It was found that if irradiated oil was stored for 17 days, its viscosity increased by 14% on average. The irradiation of samples with added organic solvent in the following weight percentages 10, 5, 2.5wt.% resulted in the increase in the viscosity by 3.3, 3.6 and 14.5%, respectively. The irradiation of the sample with added distilled water also resulted in an increase in the viscosity. This increase mainly happened because the thermal component was absent in the activation energy and hydrogen, produced from radiolysis of solvent and water molecules in mixture with crude oil, and was not consumed by hydrocarbon molecules and no reduction in molecular size occurred. Implementation of radiation to the thermal cracking increased yields of light fractions by 35wt.% on average compared to the process where no radiation was present. The last chapter of this thesis discusses a profitability of installation the hypothetical radiation-thermal visbreaking unit. The calculation of profitability was performed by a rate of return on investment (ROI) method. It showed that implementation of radiation-thermal processing resulted in an increase of ROI from 16 to 60%.
2

Experimental investigation of in situ upgrading of heavy oil by using a hydrogen donor and catalyst during steam injection

Mohammad, Ahmad A A 10 October 2008 (has links)
Experiments were conducted to investigate the feasibility of in situ upgrading of heavy oil by the use of an orgametallic catalyst and a hydrogen donor (tetralin). The experiments used a vertical injection cell into which a mixture of sand, water, and Jobo oil was thoroughly mixed and packed. Two types of runs were conducted: a run where the tetralin and catalyst were mixed within the mixture before packing into the cell, and the other was conducted by injecting a slug of the tetralin-catalyst solution before commencing with the steam injection. The Jobo oil used had an oil gravity of 12.4° API and a viscosity of 7800 cp at 30°C. The injection cell was placed in a vacuum jacket and set to a reservoir temperature of 50°C. Superheated steam at 273°C was then injected into the injection cell at a rate of 5.5 cc/min (cold water equivalent). The cell outlet pressure was maintained at 500 psig. Produced liquid samples were collected periodically through a series of separators. The produced oil was divided into two halves and several measurements and analyses were carried out on them. These included viscosity, density, elemental analysis and liquid composition. Experimental results indicated that tetralin alone was a worthy additive and increased recovery by 15% compared to that of pure steam. The premixed tetralincatalyst run showed improved recovery to that of pure steam by 20%. Experiments also showed that, when the tetralin-catalyst solution was injected rather than mixed, the results were equivalent to tetralin injection runs. Oil production acceleration was displayed by all the runs with tetralin and tetralin-catalyst but was more pronounced with the availability of catalyst.
3

"To Upgrade or Not to Upgrade?" : A comparative study of Adobe CS5 & CS6 software

Omolo, Lilian, Dicheva, Maria January 2013 (has links)
Abstract For a long time, human beings have believed that only the best of the best is what counts as quality.  This has led to a consumer mentality where as soon as a new or an upgraded version of a product comes out, everybody rushes to get it without hesitating. This has resulted in producers rushing to produce new products in order to be able to compete with the rest, and to maintain their stronghold in the market.  It has therefore become more and more difficult for us to keep up with the fast changing technology, which is steered by the need to make a quick buck (the suppliers) and the need to be in with the times (users).  The questions we are trying to answer in this document are:  Is it really necessary to upgrade or buy the new item?  What value does it add to our lives when we upgrade? Is there a significant improvement to the product that warrants us getting the newer or latest version?  Through our user study, we try to bring out a clear distinction between the different versions of the same product, that will give a clearer understanding of the idea behind the upgrade and our need to have it. Thus we want to help people to make the right decision in considering of buying a new software. The results that we got showed that the latest and the greatest is not always the best, and in some cases it might be better to just stick to the older version than getting the newer.
4

Experimental Study of In-Situ Upgrading for Heavy Oil Using Hydrogen Donors and Catalyst under Steam Injection Condition

Zhang, Zhiyong 2011 May 1900 (has links)
This research is a study of the in-situ upgrading of Jobo crude oil using steam, tetralin or decalin, and catalyst (Fe(acac)₃) at temperatures of 250 °C, 275 °C and 300 °C for 24 hours, 48 hours and 72 hours using an autoclave. Viscosity, API gravity and compositional changes were investigated. We found that tetralin and decalin alone were good solvents for heavy oil recovery. Tetralin or decalin at concentrations of 9% (weight basis) could reduce the Jobo crude oil viscosity measured at 50 °C by 44±2% and 39±3%. Steam alone had some upgrading effects. It could reduce the oil viscosity by 10% after 48 hours of contact at 300°C. Tetralin, decalin or catalyst showed some upgrading effects when used together with steam and caused 5.4±4%, 4±1% and 19±3% viscosity reduction compared with corresponding pre-upgrading mixture after 48 hours of reaction at 300°C. The combination of hydrogen donor tetralin or decalin and catalyst reduced the viscosity of the mixture the most, by 56±1% and 72±1% compared with pre-upgrading mixture. It meant that hydrogen donors and catalyst had strong synergetic effects on heavy oil upgrading. We also found that 300 °C was an effective temperature for heavy oil upgrading with obvious viscosity reduction in the presence of steam, hydrogen donors and catalyst. Reaction can be considered to have reached almost equilibrium condition after 48 hours. The GC-MS analysis of the gas component showed that light hydrocarbon gases and CO₂ were generated after reaction. The viscosity reduction from decalin use is larger than that of tetralin because decalin has more hydrogen atoms per molecule than tetralin. A mechanism of transferring H (hydrogen atom) from H₂O and hydrogen donors to heavy oil, which can lead to structure and composition changes in heavy oil, is explained. The study has demonstrated that in-situ heavy oil upgrading has great potential applications in heavy and extra heavy oil recovery.
5

THE SELECTIVE SULPHIDATION AND PHYSICAL UPGRADING OF NICKEL FROM A NICKELIFEROUS LATERITIC ORE

HARRIS, CHRIS 30 January 2012 (has links)
The processing of nickeliferous laterites to produce nickel metal is both complex and energy intensive. Since most laterites are found in remote regions, the capital costs for the infrastructure can exceed those for the process itself. The low temperature sulphidation of lateritic ores to produce an intermediate nickel concentrate for further processing offers a number of potential advantages, such as lower energy consumption and a relatively simple flowsheet. In this research, the sulphidation of a nickeliferous lateritic ore was investigated between the temperatures of 450-1100oC and sulphur additions of between 25-1000 kg of sulphur per tonne of ore. The experiments demonstrated that the nickel oxide within the ore can be selectively sulphidized to a nickel-iron sulphide. It was found that both the grade and the sulphidation degree largely depended upon the temperature and the sulphur additions, with temperatures above 550oC exhibiting the highest nickel sulphidation extents and grades. A DTA/TGA with mass spectrometer was used to further elucidate the nature of the phase transformations that occur upon heating of the ore, in the presence of sulphur. It was found that the Fe-Ni-S phase formed at low temperatures was submicron in nature and heating to temperatures of 1050oC-1100oC allowed for the growth of the sulphides to a d80 of up to 14 µm due to increased sulphide mobility, associated with the formation of a liquid sulphide matte with dissolved oxygen. Flotation studies conducted on 60 g samples showed that the sulphides formed respond to flotation with maximum grades of up to 6-7 wt% nickel being achieved and average grades of between 4-5 wt% nickel. Recoveries were approximately 50% on a sulphide basis and it was determined that the low nickel grades were due to the entrainment of magnetite fines. / Thesis (Ph.D, Mining Engineering) -- Queen's University, 2012-01-29 14:14:18.704
6

Heavy Oil Upgrading from Electron Beam (E-Beam) Irradiation

Yang, Daegil 2009 December 1900 (has links)
Society's growing demands for energy results in rapid increase in oil consumption and motivates us to make unconventional resources conventional resources. There are enormous amounts of heavy oil reserves in the world but the lack of cost effective technologies either for extraction, transportation, or refinery upgrading hinders the development of heavy oil reserves. One of the critical problems with heavy oil and bitumen is that they require large amounts of thermal energy and expensive catalysts to upgrade. This thesis demonstrates that electron beam (E-Beam) heavy oil upgrading, which uses unique features of E-Beam irradiation, may be used to improve conventional heavy oil upgrading. E-Beam processing lowers the thermal energy requirements and could sharply reduce the investment in catalysts. The design of the facilities can be simpler and will contribute to lowering the costs of transporting and processing heavy oil and bitumen. E-Beam technology uses the high kinetic energy of fast electrons, which not only transfer their energy but also interact with hydrocarbons to break the heavy molecules with lower thermal energy. In this work, we conducted three major stages to evaluate the applicability of E-Beam for heavy oil upgrading. First, we conducted laboratory experiments to investigate the effects of E-Beam on hydrocarbons. To do so, we used a Van de Graff accelerator, which generates the high kinetic energy of electrons, and a laboratory scale apparatus to investigate extensively how radiation effects hydrocarbons. Second, we studied the energy transfer mechanism of E-Beam upgrading to optimize the process. Third, we conducted a preliminary economic analysis based on energy consumption and compared the economics of E-Beam upgrading with conventional upgrading. The results of our study are very encouraging. From the experiments we found that E-Beam effect on hydrocarbon is significant. We used less thermal energy for distillation of n-hexadecane (n-C16) and naphtha with E-Beam. The results of experiments with asphaltene indicate that E-Beam enhances the decomposition of heavy hydrocarbon molecules and improves the quality of upgraded hydrocarbon. From the study of energy transfer mechanism, we estimated heat loss, fluid movement, and radiation energy distribution during the reaction. The results of our economic evaluation show that E-Beam upgrading appears to be economically feasible in petroleum industry applications. These results indicate significant potential for the application of E-Beam technology throughout the petroleum industry, particularly near production facilities, transportation pipelines, and refining industry.
7

Philosophical perspectives on sustainable development with a focus on the urban poor

Bäcklund, Anna January 2014 (has links)
The study discusses sustainable development related to the urban poor in informal settlements. It includes also a case study of how the Municipality of Taboão da Serra, a city in the periphery area to SaoPaulo, work for upgrading the favelas. It discusses issues such as which strategies for slum upgrading that are used and which philosophical theories the upgrading projects are related to. The study is based on literature studies and a two and a half month long field study at the municipal office at Taboão da Serra. During the field studies, a number of interviews and informal conversationswere held. Also visits to favelas and participation observations were made. The municipality has many projects aimed at upgrading the favelas. Many measures are about a better infrastructure and physical environment, for example waste management, land regularization andbetter roads. There are also measures both at municipal and national level to promote primary education. The municipality also runs programs to reduce unemployment. The upgrading projects have connectionsto both different kinds of utilitarianism and Rawls theory of justice.
8

Catalytic cracking and upgrading of oilsands bitumen using natural calcium chabazite

Christopher, Street Unknown Date
No description available.
9

Natural Zeolite Catalysts for the Integrated Cracking, Waterless Extraction and Upgrading of Oilsands Bitumen

Junaid, Abu Unknown Date
No description available.
10

Solubility Modeling of Athabasca Vacuum Residue

Zargarzadeh, Maryam Unknown Date
No description available.

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