The continuous rising of anthropogenic emission into the atmosphere as a consequence of industrial growth is becoming uncontrollable, which causes heating up the atmosphere and changes in global climate. Therefore, CO2 emission becomes a big problem and key issue in environmental concerns. There are several options discussed for reducing the amount of CO2 emitted into the atmosphere. CO2 sequestration is one of these options, which involves the capture of CO2 from hydrocarbon emission sources, e.g. power plants, the injection and storage of CO2 into deep geological formations, e.g. depleted oil reservoirs. The complexity in the structure of geological formations and the processes involved in this method necessitates the use of numerical simulations in revealing the potential problems, determining feasibility, storage capacity, and life span credibility. Field K having 32o API gravity oil in a carbonate formation from southeast Turkey was studied. Field K was put on production in 1982 and produced until 2006, which was very close to its economic lifetime. Thus, it was considered as a candidate for enhanced oil recovery and CO2 sequestration. Reservoir rock and fluid data was first interpreted with available well logging, core and drill stem test data. Monte Carlo simulation was used to evaluate the probable reserve that was 7 million STB, original oil in place (OOIP). The data were then merged into CMG/STARS simulator. History matching study was done with production data to verify the results of the simulator with field data. After obtaining a good match, the different scenarios were realized by using the simulator. From the results of simulation runs, it was realized that CO2 injection can be applied to increase oil recovery, but sequestering of high amount of CO2 was found out to be inappropriate for field K. Therefore, it was decided to focus on oil recovery while CO2 was sequestered within the reservoir. Oil recovery was about 23% of OOIP in 2006 for field K, it reached to 43 % of OOIP by injecting CO2 after defining production and injection scenarios, properly.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20338号 / 工博第4275号 / 新制||工||1662(附属図書館) / 京都大学大学院工学研究科社会基盤工学専攻 / (主査)教授 石田 毅, 教授 林 為人, 准教授 奈良 禎太 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Transitioning from the conventional steel process to a direct hydrogen reduction process in the steel industry is a significant step towards reducing carbon dioxide emissions and achieving greater sustainability. The process involves using hydrogen gas as a reducing agent instead of carbon to remove oxygen from the iron ore. This study aimed to investigate the future capacity of the hydrogen-based steelmaking process in Sweden by 2050 while also examining the pathway for transitioning to hydrogen-based steelmaking in other European countries in comparison to the Swedish case. To achieve this goal, a systematic literature search was conducted using Scopus and Web of Science databases to identify relevant case studies and reviews that focused on green steel solutions and that discussed associated challenges and barriers. A aconsupteal model was designed by simplifying the process into three production steps, hydrogen storage, and hot briquette iron storage to calculate the energy consumption and material requirements for the hydrogen direct process in Sweden. Additionally, a survey providing insights regarding current practices and perspectives was administered to seven companies in Sweden and two in other European countries, namely the Netherlands and Germany. Furthermore, a comparative analysis of the literature review on life cycle assessment was conducted to compare the carbon emissions associated with two different steel production processes: the conventional process using the basic oxygen furnace and the emerging hydrogen-based steel production process.  An analysis of the energy consumption within the hydrogen-based steelmaking process reveals several components, including the electrolyze, direct reduction shaft furnace, electric arc furnace, and briquetted iron and hydrogen storage. The model results showed that electrolyzing alone accounts for 60% of the energy needed in the process. The model showed that hydrogen direct reduction steelmaking needs 3.66 MWH of electricity per ton of liquid steel produced in Sweden.  Only a few of the Swedish companies have adopted innovative approaches while the remaining steel mills primarily rely on scrap-based methods. While they may obtain hydrogen-reduced iron as a raw material in the future, emissions reduction is not their primary focus. These mills contribute to emissions through fuel usage, and efforts are underway to transition from fossil fuels to electricity, bio -based gas, or hydrogen. Hydrogen-based steel production produces significantly lower greenhouse gas emissions than conventional steel productio, by up to 90 percent, depending on the specific process and energy used, as stated in the life cycle analysis reviews.  This thesis shows key factors for the success of hydrogen-based steel production methods; low -emission electricity and flexibility to store hydrogen. All three countries have expressed interest in and invested in hydrogen-based steelmaking. the share of renewable energy produced and consumed in hydrogen-based steel production in Sweden is expected to make up a share of 2.3% of the total renewable energy production in the country, while Germany and the Netherlands are projected to contribute a modest 1.5% and 1.3% respectively. However, the search for ways to lower carbon dioxide emissions is costly in terms of the amount of electricity required. There are practical reasons for the restricted usage of this steelmaking process in Europe, including the availability of steel scrap, electricity demand, and the low likelihood of scrap generation and recycling scrap availability on the EU  market. Because of this, it is challenging to predict capacity and carbon dioxide reduction by 2050.

Understanding the drivers of climate change requires knowledge about the global carbon (C) cycle. Although inland waters play an important role in the C cycle by emitting and burying C, streams and lakes are in general overlooked in bottom-up approached C budgets. In this thesis I estimated emissions of carbon dioxide (CO2) and methane (CH4) from all lakes and streams in a 15 km2 subarctic catchment in northern Sweden, and put it in relation to the total catchment C exchange. I show that high-latitude aquatic systems in general and streams in particular are hotspots for C emission to the atmosphere. Annually, the aquatic systems surveyed in this study emitted about 10.8 ± 4.9 g C m-2 yr-1 (ca. 98 % as CO2) which is more than double the amount of the C laterally exported from the catchment. Although the streams only covered about 4% of the total aquatic area they emitted ca. 95% of the total aquatic C emission. For lake emissions, the ice break-ups were the most important annual events, counting for ca. 45% of the emissions. Overall, streams dominated the aquatic CO2 emission in the catchment while lakes dominated CH4 emission, 96 % and 62 % of the totals, respectively. When summing terrestrial and aquatic C fluxes together it showed that the aquatic emissions alone account for approximately two thirds of the total annual catchment C loss. The consequence of not including inland waters in bottom-up derived C budgets is therefore a risk of overestimating the sink capacity of the subarctic landscape. However, aquatic systems can also act as C sinks, by accumulating C in sediment and thereby storing C over geological time frames. Sediment C burial rates were estimated in six lakes from a chronology based on 210Pb dating of multiple sediment cores. The burial rate ranged between 5 - 25 g C m-2 yr-1, which is of the same magnitude as lake C emissions. I show that the emission:burial ratio is about ten times higher in boreal compared to in subarctic-arctic lakes. These results indicate that the balance between lakes C emission and burial is both directly and indirectly dependent on climate. This process will likely result in a future increase of C emissions from high-latitude lakes, while the C burial capacity of these same lakes sediments weaken.

The present study presents a draft national CCT (Clean Coal Technologies) and CCS (Carbon Capture and Storage) technology roadmap to policy makers. Various technical and non-technical (economic and social) challenges that currently prevent CCT and CCS from being a widely used commercial technology are discussed and the goals for each research pathway are defined. The process of creating the roadmap started with a review and assessment of the existing national and international technology roadmaps which represent a global picture of the state of the art and national and international plans for future on CCT and CCS research development, demonstration and deployment (R&amp / D&amp / D). Following this step, the national situation, capacities and priorities were examined. Finally, R&amp / D&amp / D actions discussed in the existing roadmaps and/or new actions were carefully selected and suggested as a draft Turkish CCT and CCS Roadmap that needs further development and discussion by the input of interdisciplinary national stakeholders. As a conclusion a number of technical and non-technical suggestions are delivered.

Master's Thesis is focused on production of CO2 from fossil fuels combustion and the methods of CO2 emission from fossil fuels combustion reduction, resp. pre-combustion and post-combustion separation of CO2. Recapitulation of world consumption of primary energetic resources and carbon dioxide production as a result of theirs combustion in years 1971 - 2006 was made using a number of information sources. Whilst combustion o fossil fuel is related with production of CO2, calculation of emission rate of CO2 from fossil fuels (natural gas, crude oil and coal) was demonstrated. The Case Study of energy and material balances of gas turbine cycle with synthesis of methane from CO2 and from hydrogen which is produced in water splitting was made, using CHEMCAD software.

Sweden has recently increased its efforts to reach net-zero greenhouse gas emission by 2045.The purpose of this study is to assess the feasibility for Bollnäs municipality to meet itsenvironmental goals through the conversion of its current fleet to a Natural Gas Vehicle basedfleet. A CO2 emission-based comparison has been used to estimate from an environmentalstandpoint the viability of biogas as the main fuel for the Bollnäs municipality fleet. Theresults have shown how a compressed natural gas (CNG) based fleet would lower by morethan five times the estimated CO2 emission of the current fleet. The viability of a biogas fleethas been proven and further results have shown how if the CNG fuel was produced from100% renewable resources the environmental impact would be even lower. The results havealso shown how Electric Vehicles (EV) and Hydrogenated Vegetable Oil (HVO) from 100%renewable resources could be viable environmental alternatives but it requires furtherinvestigation from an infrastructure and economic standpoint. / <p>2021-06-04</p>

Species must interact with air—aqueous interfaces in order to transport between either phase, however organic coated water surfaces are ubiquitous in the environment, and the physical and chemical processes that occur at organic coated aqueous surfaces are often different than those at pure air—water interfaces. Three studies were performed investigating the transport of species across air—aqueous interfaces with organic coatings in an effort to gain further insight into these processes. Gas and solution phase absorption spectroscopy were used to study the effect of octanol coatings on the formation of molecular iodine (I2) by the heterogeneous ozonation of iodide and its partitioning between phases. Compared to uncoated solutions, the presence of octanol monolayers had a minor effect on the total amount of I2 produced, however, it did significantly enhance the gas to solution partitioning of I2. Incoherent broadband cavity-enhanced absorption spectroscopy (IBBC-EAS) was used to measure the gas-phase nitrogen dioxide (NO2) evolved via photolysis of aqueous nitrate solutions either uncoated or containing octanol, octanoic acid and stearic acid monolayers. Both octanol and stearic acid reduced the rate of gaseous NO2 evolution, and octanol also decreased the steady-state amount of gaseous NO2. Alternatively, octanoic acid enhanced the rate of gaseous NO2 evolution. Finally, the loss of aqueous carbon dioxide (CO2) from aqueous solutions saturated with CO2 was measured using a CO2 electrode in the absence and presence of stearic acid monolayers and octanol coatings, and a greenhouse gas analyzer was used to measure the evolution of gaseous CO2 from solutios with octanol monolayers. Enhanced losses of aqueous and evolved gaseous CO2 were observed with organic coated solutions compared to those uncoated. The results of these studies suggest that organic coatings influence the transport of I2, NO2 and CO2 via one, or a combination of: barrier effects, surface tension effects, chemistry effects and aqueous – surface – gas partitioning effects. These results, particularly the enhanced partitioning of these species to octanol coated aqueous surfaces, have important implications for species transport at air—aqueous interfaces, and may provide useful insight for future studies and parameters for atmospheric models of these species.

Species must interact with air—aqueous interfaces in order to transport between either phase, however organic coated water surfaces are ubiquitous in the environment, and the physical and chemical processes that occur at organic coated aqueous surfaces are often different than those at pure air—water interfaces. Three studies were performed investigating the transport of species across air—aqueous interfaces with organic coatings in an effort to gain further insight into these processes. Gas and solution phase absorption spectroscopy were used to study the effect of octanol coatings on the formation of molecular iodine (I2) by the heterogeneous ozonation of iodide and its partitioning between phases. Compared to uncoated solutions, the presence of octanol monolayers had a minor effect on the total amount of I2 produced, however, it did significantly enhance the gas to solution partitioning of I2. Incoherent broadband cavity-enhanced absorption spectroscopy (IBBC-EAS) was used to measure the gas-phase nitrogen dioxide (NO2) evolved via photolysis of aqueous nitrate solutions either uncoated or containing octanol, octanoic acid and stearic acid monolayers. Both octanol and stearic acid reduced the rate of gaseous NO2 evolution, and octanol also decreased the steady-state amount of gaseous NO2. Alternatively, octanoic acid enhanced the rate of gaseous NO2 evolution. Finally, the loss of aqueous carbon dioxide (CO2) from aqueous solutions saturated with CO2 was measured using a CO2 electrode in the absence and presence of stearic acid monolayers and octanol coatings, and a greenhouse gas analyzer was used to measure the evolution of gaseous CO2 from solutios with octanol monolayers. Enhanced losses of aqueous and evolved gaseous CO2 were observed with organic coated solutions compared to those uncoated. The results of these studies suggest that organic coatings influence the transport of I2, NO2 and CO2 via one, or a combination of: barrier effects, surface tension effects, chemistry effects and aqueous – surface – gas partitioning effects. These results, particularly the enhanced partitioning of these species to octanol coated aqueous surfaces, have important implications for species transport at air—aqueous interfaces, and may provide useful insight for future studies and parameters for atmospheric models of these species.

The study focussed on the research question namely: “How will the introduction of new ecological taxes impact the South African agricultural sector?” To answer the question, eight international eco-taxes were selected and further investigated. The nature and history of each eco-tax was examined. The effects or expected effects (where implementation have not yet taken place) of the eco-taxes on the agricultural sectors of the foreign countries, were then considered. The study continued by considering the possible impact on South African agriculture, should these taxes be implemented in South Africa. This was accomplished by extrapolating the foreign effects previously investigated. Mindful of findings, recommendations were then made of what eco-taxes could be implemented which will not impede South African agriculture. It was concluded that the British Climate Change Levy and Climate Change Agreement scheme, Australian Carbon Farming Initiative and Swedish meat consumption tax could be considered for implementation. / Financial Accounting / M. Phil (Accounting Science)