• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 82
  • 39
  • 10
  • 8
  • 6
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 172
  • 172
  • 58
  • 29
  • 28
  • 16
  • 16
  • 16
  • 15
  • 15
  • 15
  • 14
  • 14
  • 14
  • 13
  • 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

To What Extent Has Progress Been Made by the International Maritime Organization (IMO) In Reducing CO2 Emissions from Global Shipping?

Bayley-Craig, Lisa 04 May 2020 (has links)
90% of global trade is transported by cargo ships, with fossil fuel being the dominant energy source used. As global trade increases, shipping will be in greater demand resulting in increased emissions of carbon dioxide and other pollutants negatively impacting the environment and human health. Carbon dioxide (CO2), our area of interest, is the number one contributing gas to global warming. We, therefore, examine the role of the International Maritime Organization (IMO) in reducing CO2 emissions from shipping, and determine the progress made so far. Our research reveals that progress in this area is on a slow trajectory. The current IMO regulations focus solely on energy efficiency measures that do not appear to be as successful as envisioned in reducing CO2 emissions. In addition, the concept of decarbonization of the sector, which would lead to zero emissions, is delayed. With this in mind, we provide recommendations regarding future IMO actions.
2

An analysis of the performance of certification schemes in the hotel sector in terms of CO2 emissions reduction

Houlihan-Wiberg, Aoif January 2010 (has links)
In assessing the impact of global tourism on climate change, emissions from transport receive the most attention although emissions associated with accommodation account for more than 20% of the total. A plethora of hotel certification schemes have been established worldwide that assess various environmental performance indicators, among them energy use. However, none explicitly quantify CO2 emissions, and in many, energy is poorly accounted for, or other non-energy related factors are weighted so that the overall impact of energy use (and hence CO2 emission) is weak. The main thrust of the research is to ascertain the effect of certification on CO2 emissions. The research questions whether the certification schemes are robust and rigorous and whether the results are credible. First, four widely used certification schemes are compared Nordic Swan (Scandinavia), Green Globe (Worldwide), EU Flower (European) and Green Hospitality Award (Ireland). The key issues are identified such as performance and process related criteria, use of benchmarks, and the weighting of different categories. A comparison is made with LEED-EB, a well-established environmental certification scheme, not dedicated to the hotel sector. Secondly, the way in which emissions from electricity, including so-called green electricity and carbon offsetting, are accounted for is examined since it is found that in obtaining certification, this often plays an important part. Actual annual energy use data is desperately needed as feedback to designers, managers and owners in order to give confidence that certification schemes have true validity. Results are presented from large multi-hotel data samples and for detailed results from the quality, illustrative in-depth studies which provided invaluable insight into the technical realities of a multitude of causes and effects which can often be masked in large data samples. An analysis was carried out for four In-depth studies located in Sweden (Nordic Swan), Maldives (Green Globe), Malta (EU Flower) and Ireland (Green Hospitality Award). Global CO2 emissions were compared and calculated from the delivered electricity and fuels consumption data from seventy selected certified hotels worldwide. No corrections were made in the calculations for climate, quality of services, existence of services etc. The performance indicator used is kgCO2 per guest night. The analyses shows no clear pattern. CO2 emissions show a wide variance in performance for 8 hotels certified under different schemes, as well as for 28 hotels certified under the same scheme. In some cases emissions reduced after certification in others no change. Certified hotels do not necessarily have lower emissions than uncertified hotels and a comparison of before – and after – certification shows no significant improvement prior to certification. Most dramatically emissions from certified hotels widely vary by a factor of 7. Although it is arguable a number of corrections should be made to account for different climates, the research highlights that hotels with high CO2 emissions are being awarded certification and it questions what message‘certification’ gives to guests and other stakeholders. At worst it appears ‘business as usual’ can achieve certification with no obvious improvement in performance. The overall conclusion is that existing certification schemes do not properly account for CO2 emissions and do not produce more energy efficient (or less CO2 intensive) buildings. Hotel accommodation was found to be more CO2 intensive than domestic emissions. The findings also uncovered inconsistencies in current methods of certification and indicate a vital need for improved methods. The results also challenge prevailing aesthetic stereotypes of sustainable hotels. The author concludes a simple CO2 accounting method is needed as the first step of a diagnostic process leading to a solution i.e. reduced emissions, to the problem i.e. high energy consumption and/or emissions, thus reducing the environmental impact (in terms of emissions reduction) of the hotel. This method of accounting can be adopted universally by using a Regional, European (O.475 kgCO2/kWh) or Universal (0.55 kgCO2/kWh) conversion factor. In relation to the proper calculation of energy and CO2 emission, sub-metering is a key factor, and with current technological developments, realistic and affordable. Furthermore, apart from certification itself, an essential quality with any monitoring system is that the user can obtain results easily and understandably, in order to get feedback from their actions. This could be facilitated by incorporating sub-metering as part of the building environmental management system software. This ensures that the certification activity is not simply a benchmark, but is also part of a diagnostic and educational process, which will continue to drive emissions down. Only then should it be ethically justified to use as a marketing tool providing diagnostic support in existing buildings, and design and operational guidance for new designs.
3

Analysis of future scenarios for electric vehicle adoption in sweden : A case study

Rossbach, Katharina January 2015 (has links)
Transportation is one of the areas where Sweden could not yet manage to reduce the CO2 emissions. One solution that has been suggested to reduce the CO2 emissions in this sector is through the mass adoption of electric vehicles (EVs). However, mass EV adoption brings complications with it. Drivers behavior is a critical aspect since people often charge their car at home after work. This could negatively affect the evening load peak and thus cause a high impact on the electricity system. A survey was sent out to current private EV owners in Sweden, to learn about their charging schedules, driving patterns and battery capacity. 226 of 403 replied to the survey which gave a survey reply rate of 56 %. The goal of this work was to estimate the future adoption of EVs, based on the current trends and national targets in order to develop different scenarios. With the scenarios in mind, the projected consumption of EVs for different periods of the day, the magnitude and time of the peak load as well as the overall consumption and CO2 reduction per year were calculated. Three scenarios were analyzed with 96 000, 650 000 and 1 000 000 electric vehicles where 25 % are defined to be running entirely on electricity in the middle and high penetration scenario since even plug-in hybrid electric vehicles, PHEV where included. The scenarios are estimated as the possible situation in 2030 and a simulation is done in MATLAB for summer and winter cases as well as weekdays and weekends. Results showed that the charging pattern of the EV drivers would cause a peak load at around 20.00 where the peak load from the overall household consumptions also takes place. The highest consumption takes place during the weekend cases but there were no significant difference between summer and winter. For example the peak consumption of the EVs was 150 MWh during winter and weekends at 20.00. The annual consumption of the EVs would be 238 GWh, 342 GWh and 616 GWh for the low, middle and high penetration scenario. By analyzing the current installed power of renewable energy sources in Sweden, it was found that the demand for EVs could be met by renewables entirely today. It was also found that using EVs instead of conventional fossil fueled cars can save up to 264 Mton CO2 for the low penetration scenario, 447 Mton for the middle penetration scenario and 688 Mton for the high penetration scenario. Different assumptions could have caused deviation from the actual result and it was found during the implementation of the simulation that the survey questions could be improved for future surveys. It was concluded that mass adoption of EVs is possible in terms of electricity production and installed power. However, increase in the evening peak led to the conclusion that balancing of the grid is necessary for example through Vehicle-to-grid (V2G), controlled charging or energy storage. Keywords: MATLAB, electricity consumption, EV, CO2 emissions, simulation, 2030, Scenario, penetration level
4

Energy and cost analysis of household electricity efficiency improvements in a rental apartment building

Panigrahi, Manaswita January 2012 (has links)
In this thesis potential for (final and primary) energy and CO2 emission reductions and cost effectiveness of replacing existing household electric appliances and light bulbs with most popular or most energy efficient appliances in a multifamily apartment building in Växjö city is studied. The results showed that there is significant potential to reduce electricity demand and thereby to reduce primary energy use and CO2 emissions. The greatest potential lies with replacing existing incandescent bulbs with LED bulbs, while the lowest savings seem to be with replacement of microwave ovens. Assuming that reduced electricity demand reduces electricity generation in coal-based steam turbine (CST) technology, annually about 63 MWh of primary energy and 25 ton CO2 emissions could be reduced from the investigated building if the existing refrigerator/freezer, stove/oven, microwave oven, televisions and light bulbs are replaced with the most energy efficient alternatives available in the market today. Also, the results from ‚discounted payback period‛ and ‚cost of conserved energy‛ analyses also showed that it is cost-effective to install the most energy efficient appliances. This study for a single building is based on limited number of interviews, selected appliance types, and number of assumptions about marginal electricity production systems. To generalize the results more such studies in different conditions with measurement of actual energy use of all the household appliances should be conducted, which would help to fully understand the potential of primary energy savings and CO2 emission reductions in Swedish apartment buildings.
5

Potenziale der Beschaffung von Ökostrom in Kommunen

Günther, Edeltraud, Klauke, Ines 17 January 2008 (has links) (PDF)
Die Energieerzeugung aus fossilen Brennstoffen trägt weltweit erheblich zum Treibhauseffekt bei. So entfielen 2005 24 % der gesamten CO2-Emissionen in der Europäischen Union auf die Stromerzeugung aus Kohle [1]. Recherchen im Rahmen eines Forschungsvorhabens an der Professur für Betriebliche Umweltökonomie der TU Dresden ergaben, dass öffentliche Gebietskörperschaften einen Anteil von ca. 7,8 % am Stromverbrauch in Deutschland haben. Bisher berücksichtigen jedoch nur wenige Kommunen die CO2-Emissionen als Entscheidungskriterium bei der Ausschreibung von Strom. Damit wird deutlich, welches Potenzial in der Ausschreibung von Strom liegen kann. Hierbei stellt sich allerdings nicht nur die Frage, welche Herausforderungen öffentliche Ausschreibungen mit sich bringen, sondern auch wie diese Möglichkeiten den Markt aus der Sicht des Nachfragers eingrenzen, d. h. ob überhaupt ein entsprechendes Angebot am Markt verfügbar ist. / Energy supplies on the basis of fossil fuels contribute significantly to the global greenhouse effect. In 2005, for example, 24 % of the total CO2 emissions in the EU were attributable to coal-fired power generation. The work of a research project at TU Dresden revealed that public administrative bodies account for approx. 7.8 % of electricity consumption in Germany. To date, however, only few communities have made CO2 emissions a decision criterion in their electricity procurement. It is thus clear, just how much potential lies in the procurement process for electricity. At the same time, however, consideration must be given not only to the challenges arising from the appraisal of public procurement, but also to how these options limit the market scope from the point of view of the community, i.e. whether corresponding offers are actually available on the market.
6

A method for calculating the carbon footprint at Volvo Logistics Corporation

Trönnberg Lundin, André, Strömberg Jonzon, Sofie January 2012 (has links)
This thesis handles the need for Volvo Logistics (VLC) to calculate their total carbon footprint of purchased transportations, i.e. the total carbon dioxide emissions by all vehicles employed by VLC to transport the goods of their customers. The purpose of the thesis is therefore to determine a method with which VLC can calculate the total carbon footprint. To be able to decide upon one method that can fulfil the purpose, the authors searched for various methods, both in the academia and within the transportation sector, with which the emissions can be determined. Simultaneously the available input at VLC was studied to determine what type of method would be best suited to the current state of the company. After gathering several methods and determine what input was available and what was not available at VLC, an analysis of the found methods was done. First matching them with the available input to see which were usable as is, and then a more thorough Analytical Hierarchical Process analysis using three main-criterions; credibility, comparability, and simplicity, each with several sub-criterions. The weighting of these criterions was done in a workshop together with VLC employees, particularly the Environmental Manager and an Environmental Analyst, but also with two employees at the Global Logistics Development department at VLC. Using the weighting and the author’s comparisons of the methods within each of the criterions it was possible to obtain the methods with which further analysis should be done. After further analysis was conducted, considering VLC’s situation and possible development, the final methods was decided upon, one for each mode of transport; air, rail, road, and sea. These had to be adapted to better suit VLC and the input that was available; the distances, the weight, and the transport mode, factors which are incorporated in the methods recommended by the authors. The adaptation was then done using expertise at VLC to be able to determine what input VLC could affect as to be able to work towards lowering the total carbon footprint once it was calculated the first time. This also led to a revaluation of the method for sea transportation, forcing a change from the previously chosen one to a more suited method. This meant that three of the four modes; air, road, and sea, was covered by the NTM method, while rail used the Green Cargo method. While adapting the methods; to make them ready to use for VLC, certain changes required to obtain all the input needed was encountered and forwarded to the environmental department, letting them include it in the annual supplier survey. The thesis was concluded by four sets of instructions to be used to calculate the carbon footprint, one two tiered set for each mode of transportation. The instructions are presented in a step by step fashion of how to perform the calculations. The first part; First time usage, depicts those changes needed before the calculations can be attempted, the second part; Annual usage, cover those steps which has to be gone through every time the total carbon footprint for a period is to be calculated.
7

Improving estimates of CO2 emissions under REDD+ in the Colombian Amazon : better understanding for climate change mitigation

Navarrete Encinales, Diego Alejandro January 2016 (has links)
Land-cover change is the second most important source of anthropogenic greenhouse gases (GHG) emissions, generating around 7-14% of the total carbon dioxide (CO2) emissions around the world. More than one million km2 of tropical forests were lost during the period 2000-2012 around the world, from which forests-to-pasture conversion was the most common land-use change in key regions such as the Amazon. Strategies to mitigate climate change by reducing deforestation and forest degradation (e.g. REDD+) require country- or region-specific information on carbon (C) stocks in forests and their dynamics with land-cover change, in order to develop accurate Forest Reference Emission Levels (FRELs) to be submitted to the UNFCCC as benchmarks for assessing the performance of countries participating in REDD+ activities. Nevertheless, FREL development is incipient and their elaboration is mostly based on highly uncertain Tier 1 information from IPCC. In this research I present the first region-specific Tier 3 information and emission factors on soil, dead wood and below-ground biomass C pools and their dynamics during 20 years of forest-to-pasture conversion under different management practices in the Colombian Amazon. Based on these region-specific Tier 3 emission factors on C stocks in forests and their change after pasture establishment, I report for the first time the net CO2 emissions from forest-to-pasture conversion in the Colombian Amazon. The results also demonstrate that Tier 3 region-specific information is 70% higher and is substantially more accurate than estimates based on using IPCC Tier 1 information, which emphasizes the urgency for countries implementing REDD+ to develop improved data and methodologies. The information reported here will contribute to strengthening the REDD+ National Strategy of Colombia, by supplying accurate data and models that can be included within the next Colombian FREL.
8

Design and optimization of energy systems with effective carbon control

Gharaie, Mona January 2013 (has links)
Environmental concerns about the effect of greenhouse gases have led governments to regulate industrial CO2 emissions, including through emissions caps, trading and penalties, thus creating economic incentives to reduce CO2 emissions. This research focuses on strategies to reduce CO2 emissions from energy systems in the context of the process industries. In the process industries, energy systems consume fuel to generate steam and power for site process units. Improving energy efficiency can reduce costs of energy generation and use, as well as CO2 emissions. This research develops an integrated design and optimisation methodology for energy systems, allowing effective capture and control of carbon dioxide emissions. The first focus of this study is to develop a systematic approach to evaluate combinatorial strategies for reducing CO2 emissions, based on a techno-economic analysis. A conceptual design procedure with hierarchical decision-making is introduced to combine CO2 emissions reduction strategies, accounting for interactions between site components, including the heat exchanger network and utility system. CO2 emissions reduction options considered in development of this procedure include process integration techniques for improving the energy efficiency of the site and fuel switching. The proposed approach considers trade-offs between the economy of energy retrofit and CO2 emissions penalties. Opportunity for reducing the CO2 penalty is included in the economic evaluation of the combined emissions reduction strategies. A mathematical model for simultaneous optimization of emissions reduction strategies is developed. In addition to emissions reduction strategies, options for trading CO2 allowances are considered in the model. The proposed mathematical method applies Mixed Integer Non Linear Programming (MINLP) optimization, which employs a superstructure of the strategies for CO2 reduction. The proposed mathematical model relates the selected options to their operating and capital costs and to their associated CO2 emissions, allowing the optimizer to search for the optimal combination of emissions reduction strategies. While the reduction in CO2 emissions through process integration techniques is based on the existing configuration of a site and the associated structural limitations, integration of Carbon Capture and Storage (CCS) technologies can provide greater mitigation of CO2 emissions from a site. However, important challenges of implementing CCS in the process industries are the energetic and economic impact of the CCS plant on the integrated site. In the second part of this study, these energy-economic issues are explored. The CCS technologies addressed in this thesis include post- and pre-combustion CO2 capture techniques. Simulation of each capture technique is carried out in process simulation software to characterize the energy performance of the CO2 capture plant. Sensitivity analyses are carried out for key parameters of the CO2 capture plant. The relationship between these key parameters and the energy balance of the capture plant is represented using a simple energy performance model for the CO2 capture plant. This model allows the integration of the CO2 capture plant with the site utility system to be explored. Interactions between the utility system and CO2 capture plant are considered. The site utility system, together with the CO2 capture plant, is optimized for minimum operating cost. The proposed procedures are illustrated by application to a case study of a medium-scale oil refinery. The results illustrate that to reduce CO2 emissions, heat integration, utility system optimization and fuel switching provide more cost-effective solutions than integrating CCS technologies. The mathematical model allows more cost-effective solutions to be identified than using sequential, conceptual methods, but the value of the conceptual method for developing insights is also illustrated. The results demonstrate that, depending on the potential of the site for increasing heat recovery and the type of fuel used on site, solutions that combine energy efficiency and fuel switching can provide up to 40% reduction in site CO2 emissions. Integrating a post-combustion CO2 capture plant with the site utility system can provide up to 90 mol% pure CO2 for sequestration; however, the high capital cost of the capture plant reduces the economic performance of the integrated site. The high heat demand of post-combustion CO2 capture for solvent regeneration increases the fuel consumption of the site and its utility system, which in turn reduces the recovery of CO2. The results reveal that pre-combustion CO2 capture can provide opportunities for heat and power generation to improve the techno-economic performance of the overall integrated site.
9

Bureaucrats’ Willingness-to-Pay for CO2 Emission Reduction Programs

Melo, Nelson January 2021 (has links)
Aiming at exploring the issue of duality of the Swedish government system and the possible influence of a detached public administration, a study of bureaucrats’ characteristics, potential preferences and consequent willingness to pay (WTP) for certain policies was needed. This research attempts therefore at investigating how acceptance of CO2 emissions reduction programs among public agents is influenced by factors such as the cost of the program, concerns with air quality, impacts on biodiversity, improvements in the fuelling stations infrastructure, the use of electricity as fuel and individual characteristics such as gender. Subsequently what impact these predictors have on bureaucrats from different public agencies’ WTP for the same programs. For the estimates, binary probit regressions were performed. The results revealed significance of the attributes for the decision over accepting one of the scenarios, particularly the additional information of a budget constraint. However, it was possible to conclude that WTP did not vary significantly among agencies.
10

Production of blue ammonia as a clean fuel in Qatar

Al-Shamari, M., Khodary, A., Han, D.S., Mujtaba, Iqbal M., Rahmanian, Nejat 03 June 2023 (has links)
Yes / The production of blue ammonia is considered an alternative fuel to reduce CO2 emissions in the ecosystem. Qatar aims to construct the world's largest blue ammonia plant, with an annual capacity of 1.2 million tons (MT), in the first quarter of 2026. Blue ammonia is produced by combining nitrogen with "blue" hydrogen from natural gas feedstocks, with carbon dioxide captured and stored safely. Blue Ammonia can be transported by conventional ships and utilized in power stations to produce low-carbon electricity and potential future applications in decarbonized industries. The new plant will be located in Mesaieed Industrial City (MIC) and operated by QAFCO as part of its integrated facilities. QAFCO is already a significant ammonia and urea producer worldwide, with an annual production capacity of 3.8 million MT of ammonia and 5.6 million MT of urea per annum. Furthermore, QAFCO is the largest producer of urea and ammonia at a single facility worldwide. Qatar Energy Renewable Solutions (QERS) will develop and manage integrated carbon capture and storage facilities to capture and sequester 1.5 MT of CO2 per year for the blue ammonia plant. QERS will also provide more than 35 MW of renewable electricity to the Ammonia-7 facility from its upcoming PV Solar Power Plant in MIC. This project is a step towards reducing the carbon intensity of energy products and is a crucial pillar of Qatar’s sustainability and energy transition strategy to align with Qatar’s 2030 National Vision.

Page generated in 0.0961 seconds