• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 111
  • 10
  • 9
  • 9
  • 6
  • 1
  • 1
  • Tagged with
  • 204
  • 204
  • 85
  • 66
  • 49
  • 47
  • 46
  • 44
  • 40
  • 27
  • 22
  • 21
  • 20
  • 19
  • 19
  • 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.
131

Transmedia education on carbon capture and storage technology : The case of the CO2 degrees challenge

Kanco, David January 2021 (has links)
The master’s thesis addresses the transmedia education strategies applied in the CO2 degrees challenge, a project by the Global Carbon Capture and Storage Institute (GCCSI), dedicated to educating students about the low-carbon technology carbon capture and storage (CCS). Based on the literature review, the thesis theoretically discusses the public perception of low-carbon technology and carbon capture and storage in connection to transmedia storytelling and education. The thesis is structured upon a qualitative approach and conducts a detailed study of a selected single case. In addition, expert interviews are used to support the in-depth analysis of the case study with the use of the transmedia design analytical and operational model by Gambarato et al. (2020). The analysis provides insights into how this technical process was presented to the educators and students and identifies challenges and opportunities of the transmedia education project in the realm of low-carbon technologies. The results of the study show that the CO2 degrees challenge offered a significant contribution to the knowledge dissemination about the CCS technology among students, helped them to understand current problems, and to discuss real-time solutions. The results also point to the challenge of communicating a scientific and engineering topic with the audience outside of the technological and engineering industry, the complicated structure of the project, and difficulties connected with possible financial interests of the private companies supporting and funding the educational material and the project itself.
132

The Effect of Soot Models in Oxy-Coal Combustion Simulations

Brinkerhoff, Kamron Groves 16 March 2022 (has links)
Soot in coal combustion simulations is often ignored due to its computational complexity, despite significant effects on flame temperature and radiation. In this research, a 40 kW oxy-coal combustion system is modeled using Large Eddy Simulations (LES) and a semi-empirical monodisperse coal soot model. Simulation results are compared to experimental measurements of temperature, species concentrations, and soot concentration. Cases where soot is modeled are compared with cases where soot is neglected to determine the accuracy benefits of modeling soot. The simulations were able to replicate experimental results within an acceptable level of error. Including soot in the simulations did not consistently increase accuracy for the simulation setup and modeling assumptions used in this research.
133

Möjligheterna att implementera bio-CCS och CCS på Högdalenverket : En fallstudie över fyra olika koldioxidavskiljningsteknologier och deras kompatibilitet på Högdalenverket med avseende på tekniska, ekonomiska, miljömässiga och energirelaterade aspekter. / The possibilities to implement bio-CCS and CCS at Högdalenverket : A case study about four different carbon capture technologies and their compatibility at Högdalenverket with regards to technical, economical, environmental and energy related aspects

Nilsson, Emma, Östlund, Evelina January 2021 (has links)
Increased carbon dioxide in the atmosphere has raised the attention to Carbon Capture and Storage (CCS). Stockholm Exergi is a company conducting research on CCS and bio-CCS, a form of CCS where biogenic CO2 is captured. This master thesis analyzed the possibilities to implement CCS and bio-CCS at Högdalenverket, one of Stockholm Exergi’s combined heat and power plant with waste incineration. The aim was to investigate advantages and disadvantages with different carbon capture technologies (CC technologies) considering technical, economical, and energy related aspects. Industrial and household waste are incinerated in four boilers at Högdalenverket. Two cases were analyzed, one case with all boilers connected to the CC technology and one case with the boiler with the highest degree of CO2 emission connected. The CC technologies taken into consideration were amine technology, Hot Potassium Carbonates (HPC), Compact Carbon Capture (3C), and Svante. Amine technology and HPC use chemical absorption in static columns. The Amine technology is the most investigated and used one. It uses temperature swing absorption with amines as absorbent. HPC uses pressure swing absorption with potassium carbonate as absorbent. The remaining two are new process intensified technologies. 3C uses rotating packed beds and absorbs CO2 chemically using, most commonly, amines. Svante also uses a rotating technique by chemically adsorbing CO2 with nanomaterial as the solid adsorbent. All CC technologies need steam to regenerate CO2. The steam was assumed to be extracted from the existing steam network at Högdalenverket with a pressure and temperature of 36 bar and 400 degrees. The method used in the study was mainly literature review with peer reviewed articles regarding CCS as base. It was of importance to analyze how the flue gases could affect the CC technologies since the waste has an inhomogeneous composition. The flue gas composition was compiled using external and internal measurements from 2019 and 2020. Furthermore, energy and power calculations were performed to investigate how the heat and electricity delivery would be affected if the different CC technologies were implemented. Moreover, economic calculations regarding the cost for heat and electricity were carried out. Two interviews were also conducted, one with a CCS consultant company and one with internal staff at Högdalenverket. According to the literature review, O2, SO2, and NO2 appeared to be the pollutants causing highest risk of solvent degradation in the flue gases. The high O2 content at Högdalenverket could cause oxidative degradation, especially in amine technology. The SO2 and NO2 content in the flue gases was mainly low and would therefore not significantly affect the technologies. Peeks with high content did however occur and amines, especially within the amine technology, could form toxic and cancerogenic nitrosamines with NO2 which should not be released to the atmosphere. The flue gas composition proved not to be the limiting factor for implementation of CC technology on all incinerators. However, it is costly and complex to handle the variations in flue gas flow which can occur when all boilers are used. The technologies showed high need of heat and electricity which would result in significant reductions in delivery from Högdalenverket. The need of heat and electricity would in turn lead to high operating costs. The Amine technology showed the greatest influence on the heat delivery due to the significant steam requirement to regenerate CO2. HPC showed extreme influence on the delivery of electricity due to the flue gas compression needed in pressure swing processes. Both technologies consist of high columns with significant degree of land use which would be difficult to implement within the limited area at Högdalenverket. As a result of these aspects, HPC and Amine technology are not considered to be suitable technologies to implement at Högdalenverket. However, the master thesis presented measures for energy saving that should be considered before excluding the technologies. One energy saving measure is to find the optimal heat recovery, for example by pinch-analysis. Moreover, composition, concentration, and flowrate of the absorbent can be analyzed. In addition, higher columns are associated with lower need of energy. Finally, modifications of the capture process can be investigated, and one example is to split the flow of the absorbent into two streams into the columns. 3C and Svante are compact technologies that require less land and have potential to fit at more locations at Högdalenverket. The compact design also leads to 50 percent less investments costs compared to the other two technologies. Moreover, these technologies are presented as more resistant against degradation of sorbents, and both requires less energy to regenerate CO2. These technologies are therefore more suitable for implementation at Högdalenverket. A drawback is that they are not yet commercially developed, they are only located at 6-7 at the TRL-scale. TRL stands for Technology Readiness Level and implies how developed the technology is. The scale ranges from one to nine where nine means that the technology is commercially developed. Today, there are no economic incentives for the biogenic part of the CO2 emissions. However, there are investigations ongoing to create a market and economic incentives for the bio-genic part, one of the suggestions is reversed auctions. It is important to investigate methods to reduce the technologies need of heat and electricity, e.g., by finding other ways to extract steam instead of using steam with high exergy. Reducing the need of energy is important in the view of cost reduction, but also to avoid potential transfer of emissions to fossil CO2 generating production. The losses of heat and electricity generation that occur when implementing a CC technology need to be replaced. This replacement could end up being production from fossil fuels if no other options are available. Another aspect that needs to be considered is the suitability of using amines to a greater extent since it could cause serious environmental and health issues.
134

Assessment of Forest Cover Change on Carbon Capture in the Youngstown Metropolitan Area

Nkopio, Jeniffer Simpano 05 May 2022 (has links)
No description available.
135

Capture those opinions! A synthesis analysis of the types of public attitudes measured in waste-to-energy and carbon capture and storage acceptance research

Balla, Patricia January 2023 (has links)
Waste-to-Energy incineration (WtE), coupled with Carbon Capture and Storage (CCS), especially Bioenergy with Carbon Capture and Storage (BECCS), suggest a way to simultaneously retrieve energy from the otherwise disposed waste and reduce CO2 emissions. Independent of one another, WtE, CCS, and BECCS are implemented in a few regions of the world, but their joint diffusion is uncommon in comparison. Regardless of how the future of their combined implementation unfolds, social acceptance is almost certainly expected to play a role in their diffusion. This thesis categorically identified overlaps and contrasts between factors that have been subjects of investigation in public acceptance research on WtE and CCS/BECCS’s social acceptance using Huijts et al’s (2012) energy technology acceptance framework. To allocate peer-reviewed international literature from the two fields for analysis, a systematic literature review was conducted. The results revealed that WtE and CCS/BECCS studies most commonly measured the public’s wide array of emotional experiences regarding the respective technologies and addressed their knowledge and experience with the technologies to the smallest degree. Energy technology projects are bound to attract emotionally charged responses, thus the commonality to address affect makes probing for emotional responses possible. Whereas knowledge can be difficult to measure due to its subjectivity. Factors that were commonly measured in one field but not in the other included public perceptions of fairness, trust, and climate change. The findings provided a comprehensive overview of factors to take into consideration when collecting public opinions on a WtE incineration facility that is coupled with CCS technology.
136

A Theoretical Study of Carriers in Polymeric Facilitated Transport Membranes for Post-combustion Carbon Capture

Deng, Xuepeng January 2021 (has links)
No description available.
137

The Reduction of CO<sub>2</sub> Emissions Via CO<sub>2</sub> Capture and Solid Oxide Fuel Cells

Fisher, James C., II 01 September 2009 (has links)
No description available.
138

Energy Process Enabled by Cryogenic Carbon Capture

Jensen, Mark 01 February 2015 (has links) (PDF)
Global climate change concerns help shape current environmental regulations, which increasingly seek to reduce or capture CO2 emissions. Methods for capturing CO2 emissions from energy processes have been the focus of numerous studies to provide support for those seeking to reduce the environmental impact of their processes. This research has (1) simulated a baseline case of energy-storing cryogenic carbon capture for implementation on a 550 MWe coal fired power plant, (2) presented a novel cryogenic carbon capture process for removing CO2 from natural gas down to arbitrary levels, (3) presented a natural gas liquefaction process that has the ability to be highly CO2 tolerant, and (4) developed theoretical models and their experimental validation of CO2 capture predictions for all aforementioned processes.
139

Bio-enhanced silicate weathering : Coupled to sequestration of CO2

Westholm, Marcus January 2022 (has links)
Weathering of silicate minerals has long been a known source of natural CO2 sequestration, that could be increased in the presence of microorganisms. Bio-enhanced weathering of silicate minerals could increase the sequestration of CO2 from the atmosphere.   The aim of this project was to evaluate the potential for a new Neutral emission technology (NET), using four different organisms, Aspergillus Niger, Knufia Petricola, Bacillus Subtilis and Cupriavidus Metallidurans and their potential to increase olivine weathering (dunite). Straw, manure and digestate was used as carbon sources. In total 9 biotic - and 9 abioitc reactors were made, containing a mixture of dunite and one of the three carbon sources. In total 250 mL of water was added to each reactor per week, for 6 weeks, and collected at the end of the week for analysis. Geochemical analyses of the leachate were performed, including pH, conductivity, alkalinity, total organic carbon (TOC), total inorganic carbon (TIC), cations, anions and three organic acids: citrate, acetate, and oxalate. Scanning emission microscope (SEM) was used to monitor potential differences pre- and post-treatment.   Straw reactors produced the most growth, both on the carbon source and the dunite grains. Likely due to the increased labile organic carbon concentrations. The total inorganic carbon and alkalinity demonstrated that inoculation of the reactors promoted weathering for all carbon sources, most significantly for the straw reactors. This observation was evidenced by etch pits in the SEM images and higher TIC, alkalinity, and magnesium values. Microbially enhanced silicate weathering has demonstrated it could be used for the development of NETs for the sequestration of atmospheric carbon. / BAM!
140

Development of Zeolitic Imidazolate Frameworks for Enhancing Post-combustion Co2 Capture

Lee, Dustin 01 September 2020 (has links) (PDF)
Post-combustion CO2 capture is a promising approach for complementing other strategies to mitigate climate change. Liquid absorption is currently used to capture CO2 from post-combustion flue gases. However, the high energy cost required to regenerate the liquid absorbents is a major drawback for this process. As a result, solid sorbents have been investigated extensively in recent years as alternative media to capture CO2 from flue gases. For example, metal organic frameworks (MOFs) are nanoporous materials that have high surface areas, large pore volumes, and flexible designs. A large number of MOFs, however, suffer from 1) low CO2 adsorption capacity at low pressure, which is the typical condition for flue gases, 2) degradation upon exposure to water present in flue gases, and 3) low selectivity of CO2 when present in a mixture of gases. Zeolitic Imidazolate Frameworks (ZIFs) are heavily investigated MOFs for CO2 sorption applications because they have better selectivity for CO2 compared to other MOFs and are resistant to degradation in water due to their hydrophobic nature. However, ZIFs (e.g., ZIF-8) investigated for CO2 sorption applications are typically produced using toxic solvents and their CO2 sorption capacity is drastically lower than other types of MOFs. Post-synthesis modifications with amine functional groups have been known to increase CO2 sorption capacity and selectivity within nanoporous materials. For ZIFs, previous research showed that sufficient loading with linear polyethyleneimine increased their CO2 sorption capacity. Therefore, the objectives of this research were to a) investigate the CO2 sorption capacity of ZIF-8 synthesized by solvothermal methods that use more eco-friendly solvents (e.g., methanol and water) and b) introduce post-synthetic modifications to ZIF-8 using branched polyethyleneimine (bPEI) to enhance its sorption capacity. A custom quartz crystal microbalance (QCM) system was assembled and used to measure the CO2 sorption capacity of unmodified and bPEI-modified ZIF-8 sorbent. The tests were conducted at 0.3 - 1 bar. The results showed that the unmodified ZIF-8 synthesized in methanol (ZIF-8-MeOH) had comparable crystal structure, thermal stability, surface area, and chemical properties to that of literature (Ta et.al 2018). ZIF-8-MeOH had a surface area of 1300 m2/g and a CO2 sorption capacity of 0.85 mmol CO2/g ZIF-8 @ 1 bar. This surface area and sorption capacity are comparable to those of ZIF-8 made in dimethylformamide (DMF). Therefore, ZIF-8-MeOH proved to be a worthy candidate MOF for replacing the ZIF-8 made in DMF for CO2 capture research. Water-based ZIF-8 was also synthesized in this study; however, its CO2 sorption capacity was not tested because it exhibited a significantly lower surface area (732 m2/g) compared to that of ZIF-8-MeOH. Modification of the ZIF-8-MeOH with bPEI resulted in a decrease in its CO2 sorption capacity. This undesired outcome is likely a result of insufficient bPEI load (mass attached), on ZIF-8-MeOH (~ 10% w/w) combined with the surface area lost (~ 770 m2/g) due to bPEI blocking some of the ZIF-8-MeOH pores. Therefore, the bPEI load attained in this study was not enough to compensate for the loss of surface area of the modified ZIF-8 and thus, the CO2 sorption capacity decreased. Future investigations should enhance the post-synthetic modification by increasing the loading of amine functional groups onto the eco-friendlier ZIF-8-MeOH used in this study.

Page generated in 0.0581 seconds