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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

Posouzení metod CCS a CCU / Assessment of CCS and CCU methods

Kroupa, Zdeněk January 2020 (has links)
The thesis focuses on CCS and CCU technologies, which could find application in industry and other sectors in the future. These technologies are used to reduce CO2 emissions, mainly from point sources. This thesis provides a comprehensive overview and division of CCS and CCU technologies and points out negative effects of its installation. Part of the work is also a comparison of individual steps of technology, both from an energetic and financial point of view. The aim is to show a wide range of influences on the final price and a significant discrepancy in the results of some scientific works. At the same time, in some parts, you can find a detailed description of individual parts of the technology.
2

Optimization of a CO2 flood design Wesson Field - west Texas

Garcia Quijada, Marylena 30 October 2006 (has links)
The Denver Unit of Wasson Field, located in Gaines and Yoakum Counties in west Texas, produces oil from the San Andres dolomite at a depth of 5,000 ft. Wasson Field is part of the Permian Basin and is one of the largest petroleum-producing basins in the United States. This research used a modeling approach to optimize the existing carbon dioxide (CO2) flood in section 48 of the Denver Unit by improving the oil sweep efficiency of miscible CO2 floods and enhancing the conformance control. A full compositional simulation model using a detailed geologic characterization was built to optimize the injection pattern of section 48 of Denver Unit. The model is a quarter of an inverted nine-spot and covers 20 acres in San Andres Formation of Wasson Field. The Peng-Robinson equation of state (EOS) was chosen to describe the phase behavior during the CO2 flooding. An existenting geologic description was used to construct the simulation grid. Simulation layers represent actual flow units and resemble the large variation of reservoir properties. A 34-year history match was performed to validate the model. Several sensitivity runs were made to improve the CO2 sweep efficiency and increase the oil recovery. During this study I found that the optimum CO2 injection rate for San Andres Formation in the section 48 of the Denver Unit is approximately 300 res bbl (762 Mscf/D) of carbon dioxide. Simulation results also indicate that a water-alternating-gas (WAG) ratio of 1:1 along with an ultimate CO2 slug of 100% hydrocarbon pore volume (HCPV) willallow an incremental oil recovery of 18%. The additional recovery increases to 34% if a polymer is injected as a conformance control agent during the course of the WAG process at a ratio of 1:1. According to the results, a pattern reconfiguration change from the typical Denver Unit inverted nine spot to staggered line drive would represent an incremental oil recovery of 26%.
3

Spatial variations of carbonate parameters and CO2 flux in seawaters around Taiwan during summer 2006

Hsieh, Hsiu-Ling 10 September 2008 (has links)
Seawater samples around Taiwan were collected for pH, DIC, TA and fCO2 analyses. Results showed that their distributions closely related to the distribution of different water types. The high DIC and low pH but lower fCO2 values were found in the Shelf Surface Water (SSW) in the northern part of the study area, while the low DIC and TA but higher fCO2 values were found in the Luzon Coastal Current (LCC) in the northern Luzon Strait. The LCC was weak source under the influence of high temperature. Coastal Water (CW) and SSW represented two major sink areas due to the enhanced biological production stimulated by the high nutrient input from coastal and subsurface waters, respectively. Results also showed that high pH and TA but lower fCO2 were found in Kuroshio Surface Water (KSW) and KSW + Luzon Coastal Current (KSW+LCC) in the region off eastern Taiwan. The warm and saline KSW and KSW+LCC were weak sink owing to the elevated TA/DIC ratio, suggesting their CO2 uptake potential were influenced by biological production. The entire northern SCS represented a weak source under the influence of temperature. Finally, seawaters around Taiwan collectively acted as a sink of atmospheric CO2 with a flux of -0.12¡Ó0.43 mmol m-2 day-1 during the study period.
4

DETERMINATION OF CAPILLARY PRESSURE, RELATIVE PERMEABILITY AND PORES SIZE DISTRIBUTION CHARACTERISTICS OF COAL FROM SYDNEY BASIN-CANADA

Nourbakhsh, Anita 13 August 2012 (has links)
Global warming due to anthropogenic emission of greenhouse gases notably carbon dioxide, could lead to the irreversible melting of the polar ice and significant increases in global mean temperature. One of the mitigating strategies that can be carried out on a larger scale is the capture and geological sequestration of this gas. Notable among proven geological resources is deep unmineable coal seams. Geological sequestration in these systems has a value added advantage because of coal bed methane production which is a source of cleaner burning fuel than coal. Accordingly the injection of carbon dioxide to a coal seam for long term storage accompanied by the production of methane requires adequate knowledge of the two phase flow characteristics of the methane/brine and carbon dioxide/brine systems. The most important characteristics of the two phase flow are relative permeability and capillary pressure. The coal core was characterized by proximate and ultimate ASTM measurements, x-ray diffraction (XRD), and scanning electron microscopy (SEM) analyses. These analyses identify the existence of clay minerals in the coal structure, which shows that origin of coal formation was from swamp plants. These minerals were used to fill the pores and reduce the permeability. Relative permeability and capillary pressure data for Sydney basin coal samples were collected. This study has also obtained pore size distribution and its indexes both from capillary pressure data and statistical methods based on the hyperbolic model of capillary pressure versus saturation data. The elaborate experimental design and precise measurements using capillary pressure unit (TGC-764) with a pressure control module makes the acquired petro-physical data a valuable asset for future carbon dioxide enhanced coal bed methane production.
5

Reduction of CO2 Emissions from Cement Plants

Gante Caruso, Hernane 13 May 2007 (has links)
Reduction of CO2 Emissions from Cement Plants Governments around the world have been pressured by society to discuss environmental issues, and global warming is one of the most controversial debates. The Kyoto Protocol is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC). Under Kyoto protocol some countries committed to reduce their Greenhouse Gas (GHG) emissions. The Intergovernmental Panel on Climate Change (IPCC) has predicted global rise in temperature and carbon dioxide is a major greenhouse gas responsible for global warming. The cement industry contributes approximately five per cent of the total CO2 emitted worldwide. Currently Canada sustains a very aggressive objective to reduce GHG emissions to support the Kyoto Protocol. It is clear that international affairs and global polices will affect different sectors and even though cement production and distribution is constrained by location and natural resource availability, the major cement producers around the globe will be required to meet more stringent environmental regulations. Kyoto presents a ???cap and trade??? mechanism that requires countries to reduce, on average, 5.2 per cent below their 1990 baseline. This reduction must take place between 2008 and 2012. Although these caps are country specific, most countries are requiring industries to have particular objectives for reduction. This can be seen especially in European countries. The credit trade opportunity increases the possibility for an economical justification of new and environmentally friendly solution for GHG emissions abatement. St Marys Plant, located in St Marys, Ontario, was used as a case study to evaluate the results of various modifications on cement plants operation that can impact on the plant CO2 emissions. An economic model which objective is to highlight the best selection strategy to reduce CO2 emissions with the least cost was developed using St Marys Plant data as part of this thesis. St Marys Plant achieved a significant result of 23.6 per cent reduction in CO2 emissions per tonne of cement produced. The results were achieved mainly by applying a progressive approach prioritising project implementation effort and feasibility. St Marys main steps were 1) implementation of a more robust maintenance system, 2) plant optimization and Kiln expert system; 3) alternative fuels and 4) major equipment modifications.
6

Process Simulation of Impurity Impacts on CO2 Fluids Flowing in Pipelines

Peletiri, Suoton P., Mujtaba, Iqbal M., Rahmanian, Nejat 23 August 2019 (has links)
Yes / Captured carbon dioxide flowing in pipelines is impure. The impurities contained in the carbon dioxide fluid impact on the properties of the fluid. The impact of each impurity has not been adequately studied and fully understood. In this study, binary mixtures containing carbon dioxide and one impurity, at the maximum permitted concentration, flowing in pipelines are studied to understand their impact on pipeline performance. A hypothetical 70 km uninsulated pipeline is assumed and simulated using Aspen HYSYS (v.10) and gPROMS (v.5.1.1). The mass flow rate is 2,200,600 kg/h; the internal and external diameters are 0.711 m and 0.785 m. 15 MPa and 9 MPa were assumed as inlet and minimum pressures and 33 oC as the inlet temperature, to ensure that the fluid remain in the dense (subcritical or supercritical) phase. Each binary fluid is studied at the maximum allowable concentration and deviations from pure carbon dioxide at the same conditions is determined. These deviations were graded to rank the impurities in order of the degree of impact on each parameter. All impurities had at least one negative impact on carbon dioxide fluid flow. Nitrogen with the highest concentration (10-mol %) had the worst impact on pressure loss (in horizontal pipeline), density, and critical pressure. Hydrogen sulphide (with 1.5-mol %) had the least impact, hardly changing the thermodynamic properties of pure carbon dioxide.
7

Experimental and Simulation Studies to Evaluate the Improvement of Oil Recovery by Different Modes of CO2 Injection in Carbonate Reservoirs

Aleidan, Ahmed Abdulaziz S. 2010 December 1900 (has links)
Experimental and numerical simulation studies were conducted to investigate the improvement of light oil recovery in carbonate cores during CO2 injection. The main steps in the study are as follows. First, the minimum miscibility pressure of 31ºAPI west Texas oil and CO2 was measured using the slimtube (miscibility) apparatus. Second, miscible CO2 coreflood experiments were carried out on different modes of injection such as CGI, WF, WAG, and SWAG. Each injection mode was conducted on unfractured and fractured cores. Fractured cores included two types of fracture systems creating two shape models on the core. Also, runs were made with different salinity levels for the injected water, 0 ppm, 60,000 ppm, and 200,000 ppm. Finally, based on the experimental results, a 2-D numerical simulation model was constructed and validated. The simulation model was then extended to conduct sensitivity studies on different parameters such as permeability variations in the core, WAG ratio and slug size, and SWAG ratio. The results of this study indicate that injecting water with CO2 either simultaneously or in alternating cycles increases the oil recovery by at least 10 percent and reduces the CO2 requirements by 50 percent. The salinity of the injected water has shown a detrimental effect on oil recovery only during WAG and SWAG injections. Lowering injected water salinity, which increases the CO2 solubility in water, increases oil recovery by up to 18 percent. Unfractured cores resulted in higher recovery than all fractured ones. CGI in fractured cores resulted in very poor recovery but WAG and SWAG injections improved the oil recovery by at least 25 percent over CGI. This is because of the better conformance provided by the injected water, which decreased CO2 cycling through the fracture. CO2 injection in layered permeability arrangements showed significant decrease in oil recovery (up to 40 percent) compared to the homogenous case. For all injection modes during the layered permeability arrangements, the best oil recovery was obtained when the flow barrier is in the middle of the core. When the permeability was arranged in sequence, each injection mode showed different preference to the permeability arrangements. The WAG ratio study in the homogenous case showed that a 1:2 ratio had the highest oil recovery, but the optimum ratio was 1:1 based on the amount of injected CO2. In contrast, layered permeability arrangements showed different WAG ratio preference depending on the location of the flow barrier.
8

Analyse de cointégration longitudinale de l'impact de la croissance de la population sur les émissions de dioxyde de carbone.

Koffi, Klodji Thomas January 2014 (has links)
Ce mémoire analyse une existence éventuelle d'une relation de long terme entre le dioxyde de carbone et la croissance de la population. Pour ce faire, on s'est intéressé à 81 pays répartis en quatre groupes selon leur niveau de produit intérieur brut par tête sur une période allant de 1980 à 2010. À l'aide du modèle STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology), on trouve qu'il existe une relation de long terme entre l'émission de dioxyde de carbone et la croissance de la population pour l'ensemble des quatre groupes de pays étudiés. Toutefois, l'amplitude de cette relation caractérisée par l'élasticité de long terme dioxyde de carbone-population varie d'un groupe de pays à un autre. Pour les pays à revenu faible, elle est de 1.3; ce qui signifie que l'accroissement de 1% de leur population entraine une augmentation de 1.3% de leur taux d'émission de CO2. Pour ce qui est des pays de l'OCDE, elle est égale à 1 bien que certaines études trouvent des valeurs inférieures mais assez proche de 1.
9

The carbon dynamics of a prairie pothole wetland

Hartwig, Leah Carolyn Metanczuk 18 June 2008 (has links)
Wetlands are very valuable ecosystems as they play an integral role in wildlife habitat, water management and greenhouse gas exchange. The exchange of carbon dioxide between prairie wetlands and the atmosphere is poorly understood. The purpose of this study was to identify rates and trends in the growing season carbon dioxide flux from the riparian and open-water zone of a prairie pothole wetland. In addition to providing core open water and riparian zone CO2 flux measurements, relationships between variations in CO2 flux and characteristics of the wetland���s biological, biochemical and hydrometeorological state were assessed. The CO2 effluxes from the pond during the summer of 2006 were approximately four times greater than in 2005, but were much lower in the early fall. Algal chlorophyll-a concentrations were greater in 2005 than 2006 for all three algal assemblages. The mean chlorophyll-a concentrations in 2005 for epiphyton, phytoplankton and metaphyton were 2.75 �� 0.62 g m-2, 87 �� 24 �� L-1, and 318 �� 187 g m-2 respectively. In 2006 mean concentrations for the same assemblages were 0.008 �� 0.001 g m-2, 8 �� 2 �� L-1, and 27 g m-2 respectively. The amount of DOC in the open water in August of 2005 (140 mg DOC L-1) was 70 times greater than in July of 2005 (2 mg DOC L-1). DOC ranged from 30 to 52 mg DOC L-1 in 2006. Although highly productive, the pond proper appeared to be a source of DOC which is concurrent with literature from littoral zone and shallow inland waters. Soil respiration increased upslope from the wetland to the cropped upland in 2005. Net ecosystem exchange was greater in the cattail ring surrounding wetland than the grass and sedge zone beyond the cattails. The riparian vegetation may have been water stressed in late-July (at the climax of the dry period) when net ecosystem exchange decreased. Diurnal net ecosystem exchange in the riparian zone indicates uptake during the day and emissions at night. From this data it appears that the riparian zone may have acted as a CO2 sink in June, July and August and a source in April. / October 2008
10

Reduction of CO2 Emissions from Cement Plants

Gante Caruso, Hernane 13 May 2007 (has links)
Reduction of CO2 Emissions from Cement Plants Governments around the world have been pressured by society to discuss environmental issues, and global warming is one of the most controversial debates. The Kyoto Protocol is an agreement made under the United Nations Framework Convention on Climate Change (UNFCCC). Under Kyoto protocol some countries committed to reduce their Greenhouse Gas (GHG) emissions. The Intergovernmental Panel on Climate Change (IPCC) has predicted global rise in temperature and carbon dioxide is a major greenhouse gas responsible for global warming. The cement industry contributes approximately five per cent of the total CO2 emitted worldwide. Currently Canada sustains a very aggressive objective to reduce GHG emissions to support the Kyoto Protocol. It is clear that international affairs and global polices will affect different sectors and even though cement production and distribution is constrained by location and natural resource availability, the major cement producers around the globe will be required to meet more stringent environmental regulations. Kyoto presents a ‘cap and trade’ mechanism that requires countries to reduce, on average, 5.2 per cent below their 1990 baseline. This reduction must take place between 2008 and 2012. Although these caps are country specific, most countries are requiring industries to have particular objectives for reduction. This can be seen especially in European countries. The credit trade opportunity increases the possibility for an economical justification of new and environmentally friendly solution for GHG emissions abatement. St Marys Plant, located in St Marys, Ontario, was used as a case study to evaluate the results of various modifications on cement plants operation that can impact on the plant CO2 emissions. An economic model which objective is to highlight the best selection strategy to reduce CO2 emissions with the least cost was developed using St Marys Plant data as part of this thesis. St Marys Plant achieved a significant result of 23.6 per cent reduction in CO2 emissions per tonne of cement produced. The results were achieved mainly by applying a progressive approach prioritising project implementation effort and feasibility. St Marys main steps were 1) implementation of a more robust maintenance system, 2) plant optimization and Kiln expert system; 3) alternative fuels and 4) major equipment modifications.

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