• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 8
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 13
  • 13
  • 7
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Techno-economic assessment of solar technologies and integration strategies for the Canadian housing stock

Nikoofard, Sara 29 August 2012 (has links)
Energy security is probably one of the most challenging issues around the world. Therefore, the focus on methods of decreasing energy consumption and consequently its associated greenhouse gas (GHG) emissions is intensified by policy decision makers. Residential buildings are one of the potential sectors that can reduce its energy consumption in various ways, such as: improving thermal characteristics of the building, using more energy efficient appliances and using renewable energy resources. Among these methods, integration of solar technologies to buildings provides one of the substantial opportunities for reducing energy consumption and the associated GHG emissions in Canada’s residential sector. Therefore, this research work was conducted to assess the impact of solar technologies and solar technology integration strategies on the end-use energy consumption and the associated greenhouse gas (GHG) emissions in Canadian residential sector by using a new state-of-the-art end-use energy and GHG emissions model of the Canadian residential housing stock. The new Canadian residential end-use energy and emissions model that is used in this project incorporates a 17,000 house database developed using the latest data available from the Energuide for Houses database, Statistics Canada housing surveys, and other available housing databases, and utilizes an advanced building energy simulation program as its simulation engine. A new neural network methodology is incorporated into the model to estimate the socio-economic and demographic dependencies of the energy consumption of discretionary end-uses such as appliances, lighting and domestic hot water, while a new approach is used to incorporate occupancy, appliance, lighting and domestic hot water load profiles into the model. A new method is used to calculate the GHG emissions from electricity consumption used in the residential sector based on the actual electrical generation fuel mix and the marginal fuel used in each province as a function of time of the year. Each solar technology is added to the eligible houses to examine the interrelated effects of integrated solar technologies and practices on the housing stock. The objective is to conduct realistic assessments of the cost effectiveness, energy savings and GHG emission reduction benefits of integrated solar technologies for the entire Canadian housing stock (CHS) as well as for different regions, house type, and fuel types. The integrated solar technologies and practices that are assessed include passive solar with added thermal storage and motorized blinds, solar DHW system, and photovoltaic electricity and heat generation systems. This project provides a comprehensive techno-economic and emissions assessment of integrated solar technologies and practices, and will be useful for developing national and regional policies and strategies related with integrating solar energy into the residential sector.
2

A STUDY ON LOW-CARBON SOCIETY DEVELOPMENT IN BANGLADESH / バングラデシュの低炭素社会構築に関する研究

Jilani, Tahsin 24 September 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第17880号 / 工博第3789号 / 新制||工||1579(附属図書館) / 30700 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 松岡 譲, 教授 米田 稔, 准教授 倉田 学児 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
3

Process simulation, integration and optimization of blending of petrodiesel with biodiesel

Wang, Ting 15 May 2009 (has links)
With the increasing stringency on sulfur content in petrodiesel, there is a growing tendency of broader usage of ultra low sulfur diesel (ULSD) with sulfur content of 15 ppm. Refineries around the world should develop cost-effective and sustainable strategies to meet these requirements. The primary objective of this work is to analyze alternatives for producing ULSD. In addition to the conventional approach of revamping existing hydrotreating facilities, the option of blending petrodiesel with biodiesel is investigated. Blending petrodiesel with biodiesel is a potentially attractive option because it is naturally low in sulfur, enhances the lubricity of petrodiesel, and is a sustainable energy resource. In order to investigate alternatives for producing ULSD, several research tasks were undertaken in this work. Firstly, base-case designs of petrodiesel and biodiesel production processes were developed using computer-aided tools ASPEN Plus. The simulations were adjusted until the technical criteria and specifications of petrodiesel and biodiesel production were met. Next, process integration techniques were employed to optimize the synthesized processes. Heat integration for petrodiesel and biodiesel was carried out using algebraic, graphical and optimization methods to maximize the integrated heat exchange and minimize the heating and cooling utilities. Additionally, mass integration was applied to conserve material resources. Cost estimation was carried out for both processes. The capital investments were obtained from ASPEN ICARUS Process Evaluator, while operating costs were calculated based on the updated chemical market prices. The total operating costs before and after process integration were calculated and compared. Next, blending optimization was performed for three blending options with the optimum blend for each option identified. Economic comparison (total annualized cost, breakeven analysis, return on investment, and payback period) of the three options indicated that the blending of ULSD with chemical additives was the most profitable. However, the subsequent life-cycle greenhouse gas (GHG) emission and safety comparisons demonstrated that the blending of ULSD with biodiesel was superior.
4

Mudanças de uso da terra e estimativas de emissões antrópicas de CO2 em bacia hidrográfica / Changes in land use and estimates of anthropogenic CO2 emissions in watershed

Sousa, Jocy Ana Paixão de 11 January 2018 (has links)
Submitted by JOCY ANA PAIXÃO DE SOUSA null (jocy_belem@hotmail.com) on 2018-02-06T16:26:54Z No. of bitstreams: 1 SOUSA, JOCY ANA PAIXÃO DE-DISSERTAÇÃO.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) / Approved for entry into archive by Lucimara Kurokawa Shinoda null (lucimaraks@sorocaba.unesp.br) on 2018-02-07T11:59:59Z (GMT) No. of bitstreams: 1 sousa_jap_me_soro.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) / Made available in DSpace on 2018-02-07T11:59:59Z (GMT). No. of bitstreams: 1 sousa_jap_me_soro.pdf: 4608931 bytes, checksum: 2e5913d39dda79bea7ac97e19d2f5d15 (MD5) Previous issue date: 2018-01-11 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As interferências antrópicas sobre natureza sempre provocaram impactos ambientais. Porém, entre os mais significativos encontram-se as mudanças de uso da terra, nos quais contribuem com as emissões dos gases do efeito estufa. Entre esses principais gases destacam-se o dióxido de carbono, CO2. O estudo apresentou como objetivo estimar as emissões do dióxido de carbono devido as mudanças de uso da terra para a análise do fluxo de carbono em bacia hidrográfica. A área de estudo localiza-se na Bacia Hidrográfica do Rio Una, Ibiúna, São Paulo. Para atingir os objetivos foram realizados o mapeamento de uso do solo e cobertura vegetal, mapeamento pedológico, análise da textura do solo, mapeamento da vegetação pretérita, estoque de carbono sob associação solo-vegetação, matriz de transição e os cálculos das emissões líquidas de CO2. Constatou-se que em relação ao mapeamento do uso do solo e cobertura vegetal, o maior quantitativo foi de floresta e estas predominam no sul da bacia. Ao longo de nove anos houve uma redução de florestas, campo e área alagada e um aumento da área de agricultura, área urbana, pastagem e reflorestamento. Foram encontrados solos do tipo Argissolos e Latossolos, além das texturas argilosa, franco-argilo-arenosa, argilo-arenosa e franco-argilosa. Para a vegetação pretérita constatou-se floresta ombrófila densa montana, floresta estacional decidual e semidecidual. Em relação ao conteúdo de carbono no solo sob a associação solo-vegetação foram definidos valores que variam de 2,59 a 6,33 Kgc/m2. Nas matrizes de transições para os períodos de 2007-2010, 2010-2013 e 2013-2016, observou-se que a floresta convertida para as demais categorias apresentou posição de destaque. As emissões líquidas para todos os períodos mostraram que há mais emissões do que remoções na bacia, com um destaque para o período de 2013 a 2016, em que houve uma maior estimativa de emissões CO2, porém a menor remoção ocorreu no último período. A pesquisa mostrou que a maioria das transições que ocorreram foram em função da mudança de floresta para outras categorias, fator que mais contribuiu para emissões líquidas de CO2, resultante do intenso processo de antropização da bacia. / Anthropogenic interference with nature has always had environmental impacts. However, among the most significant are land use changes, in which they contribute to the emissions of effect gases, especially carbon dioxide, CO2. The objective of the study was to estimate carbon dioxide emissions due to the change in land use for an analysis of the carbon flux in the watershed. The study area is located in the Una Watershed, Ibiúna, São Paulo. To achieve the objectives, the mapping of land use and vegetation cover, pedological mapping, soil texture analysis, mapping of past vegetation, carbon stock under soil-vegetation association, transition matrix, and calculations of net CO2 emissions. It was verified that in relation to the mapping of the land use and vegetal cover, the biggest quantitative one was of forest and these predominate in the south of the basin. During nine years there was a reduction of forests, field and flooded area and an increase of the area of agriculture, urban área, pasture and reforestation. Soils of the type Argisols and Latosols were found, in addition to clay, clay-loam-sandy, clay-sandy and loam-loamy textures. For the past vegetation it was verified dense montane forest, deciduous and semidecidual forest. Regarding the non-singlet carbon content in a soil-vegetation association to define values ranging from 2.59 to 6.33 Kgc / m2. In the transitional matrices for the periods 2007-2010, 2010-2013 and 2013-2016, it was observed that the forest converted to the other categories presented a prominent position. Net emissions for all periods showed that there are more emissions than removals in the basin, with a highlight for the period from 2013 to 2016, where there was a higher estimate of CO2 emissions, but the lowest removal occurred in the last period. The research showed that most of the transitions that occurred were due to the change of forest to other categories, which contributed most to net CO2 emissions, resulting from the intense process of anthropization of the basin.
5

Study on the climate change mitigation potential of a poly-generation system in Bangladesh – a supply chain analysis

Emran, Saad Been January 2014 (has links)
Livestock and poultry are two growing subsectors of global farming economy with an impact on the environment and thus deserving closer attention. While the farms play a major role in providing protein essential for human diets, they are also sources of significant amounts of greenhouse gas (GHG) emissions. Hence, the sectors need to improve their environmental performance and mitigate their negative impacts on climate. To estimate the annual GHG emissions from a dairy and poultry farm, a case study was conducted in the rural area of Bangladesh. The study has considered the supply chains of both farms while estimating the emissions.  The study also estimated the GHG emission reduction potential of a small biogas based polygeneration system aimed at providing energy services in the rural area. LCA (lifecycle assessment) has been used as the main tool while estimating the emissions.
6

Environmental Impact Assessment of aPhotovoltaic Power Station in Stockholm / Miljöutvärdering av en fotovoltaisk solcellsanläggning i Stockholm

Raouz, Khalid January 2017 (has links)
The paper at hand presents the environmental impact analysis of a photovoltaic (PV) power station sited in Stockholm, Sweden, using life cycle assessment (LCA). The LCA considers the primary energy return on investment and global warming potential of the PV-station, including; resource extraction, manufacturing, transportation, operation and maintenance, and decommissioning. Other environmental impact indicators are also presented, such as; the eutrophication, acidification, human toxicity, and ozone depletion potentials. The results show that the most critical phase of the lifecycle is the upgrade from metallurgical to solar grade silicon due to the high consumption of energy. The emissions results are compared to the emissions factors used for calculations in Sweden in accordance with the Swedish Energy agency and the European Commission’s directive for emissions calculations. The results for the other environmental indicators showed inconsistencies compared to existing studies, something that is according to the IEA’s guideline for PV-systems LCA caused by data scarcity and the indicators lacking consensus within the PV LCA-community. The studied PV-station is expected to reach energy neutrality after 2,4 years and offset annual GHG emissions of up to18 ton of CO 2 equivalents. / Studien tillhands presenterar miljöutvärderingen av en fotovoltaisk solcellsanläggning i Stockholm. Detta utfördes med hjälp av livscykelanalysverktyget. Analysen använder energiåterbetalningstiden och den globala uppvärmningspotentialen som indikatorer på anläggningens miljöinverkan. Både återbetalningstiden och den globala uppvärmningspotentialen beräknas för gruvarbetet, transporten, drift och underhåll samt avveckling och bortskaffning av anläggningen. Överföringsförluster beräknas också över anläggningens livscykel. Andra indikatorer som beräknas i denna studie är potentialen för försurning, övergödning, ozonnedbrytning och humantoxicitet. Dessa beräknas endast för modulens tillverkningskedja. Studiens resultat visar att den mest kritiska processen under solcellsanläggningens livscykel är kiselmetallens omvandling till solkisel, detta med avseende på energiförbrukningen och utsläpp av växthusgaser. Anläggningens globala uppvärmningspotential uttrycks i växthusgasutsläpp och jämförs med den nordiska elmixens utsläppsfaktor. Jämförelsen görs enligt dem gällande EU-direktiven. Resultaten för dem andraindikatorerna har visat på väsentliga avvikelser jämfört med tidigare studier. Detta beror enligt det internationella energirådet på databrist och på att dessa indikatorer saknar stöd inomLCA samfundet. Solcellsanläggningen beräknas bli energineutral efter 2,4 år samt eutralisera utsläpp på upp till 18 ton koldioxidekvivalenta per år.
7

Experimental and feasibility study on co-incineration of sewage sludge and municipal solid waste / 下水汚泥と都市ごみとの混焼に関する実験的検討と実現可能性

Chen, Minhsuan 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第23870号 / 工博第4957号 / 新制||工||1774(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高岡 昌輝, 教授 藤原 拓, 准教授 大下 和徹 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
8

Waste-to-Energy in Kutai Kartanegara, Indonesia : A Pre-feasibility study on suitable Waste-to-Energy techniques in the Kutai Kartanegara region

Torstensson, Johan, Gezelius, Jon January 2015 (has links)
The thesis outlined in this report is a pre-feasibility study of the potential to use waste-to-energy technology in the region Kutai Kartanegara, Borneo, Indonesia. The project is a collaboration between the Kutai Kartanegara government, Uppsala University, the Swedish University of Agricultural sciences and the technology consulttancy Sweco. The current waste management system in Kutai Kartanegara consists of landfills in the cities and open burnings and dumping in the lesser developed sub-districts. This is a growing problem both environmentally and logistically. The electrification in the sub-districts is sometimes as low as 17 % and access to electricity is often limited to a couple of hours per day. The current electricity production in the region is mainly from fossil fuels. Data was collected during a two month long field study in Tenggarong, the capital of Kutai Kartanegara. From the collected data, various waste-to-energy systems and collection areas were simulated in Matlab. Results from the simulations show that a system using both a waste incineration and biogas plant would be the best solution for the region. The chosen system is designed to handle a total of 250,000 tons of waste annually, collected from Tenggarong and neighbouring districts. The system will provide between 155 and 200 GWh electricity and between 207 and 314 GWh of excess heat energy annually. Some of this is used in a district heating system with an absorption-cooling machine. The system investment cost is around 42.5 MUSD and it is expected to generate an annual profit of 16 MUSD. The recommended solution will decrease the emissions of CO2-equivalents compared to the current waste system and fossil electricity production with 50%. The results in the study clearly show that there are both economic and environmental potential for waste-to-energy technologies in the region. But the waste management and infrastructure has to be improved to be able to utilize these technologies. By implementing waste-to-energy technologies, the supplied waste can be seen as a resource instead of a problem. This would give incentives for further actions and investments regarding waste management.
9

Livscykelanalys av interiöra golvmaterial / Life cycle analysis of interior floor material

Svärd-Husu, Jennie, Ljungman, Martin January 2020 (has links)
I Sverige används många olika interiöra golvmaterial i offentliga byggnader. Studien har undersökt fyra interiöra golvmaterial, keramik, enomer, massivt furu och linoleum. Dessa material är vanligt förekommande i svenska offentliga miljöer och de jämfördes ur ett livscykelperspektiv. Studien undersökte materialens olika livsskeden, från produktion till slutskede och omfattade materialens totala GHG-utsläpp för en referensbyggnad med en livslängd på 75 år, belägen i Växjö.Denna fallstudie visar att en byggnads klimatpåverkan går att minimera vid val av interiört golvmaterial. Keramik är att rekommendera i fuktkänsliga utrymmen då klimatpåverkan är 38 % minder och linoleum rekommenderas i allmänna utrymmen då klimatpåverkan är 20 % mindre. Det finns ytterligare möjlighet att minimera klimatpåverkan genom att använda trägolv i utrymmen med mindre folk i rörelse. / In Sweden, lots of different interior flooring materials are used in public buildings. This study examines four interior flooring materials, ceramics, mineral based, solid pine floor and linoleum flooring. These materials appear regularly in public buildings in Sweden and are compared to each other in a life cycle assessment perspective. The study examines the materials different life stages from production to its end of life and included the materials GHG-emissions for a reference building with a lifespan of 75 years in Växjö, Sweden.This case study shows that a buildings climate impact can be minimized through choices for interior flooring materials. Ceramics are to recommend in areas sensitive to moisture, do to 38 % less climate effect and linoleum are to recommend more public areas do to 20 % less climate effect. Further possibilities to minimize climate impact is through use of massive pine flooring in areas with low traffic.
10

Techno-economic Feasibility Study of a Biogas Plant for Treating Food Waste Collected from Households in Kartamantul Region, Yogyakarta

Al Naami, Adam January 2017 (has links)
This thesis presents the potential of biogas production using food waste collected from the region of Kartamantul in Yogyakarta, Indonesia. Biogas can be used for cooking and generating electricity. The study compares two different end uses or markets for utilizing the biogas in the region. The daily food waste collected in the region of Kartamantul is 120 tonnes. This corresponds to a daily biogas production of 13 087 m3. Electricity generated from biogas can replace fossil-based coal electricity while cooking biogas can substitute the common fossil fuel liquefied Petroleum Gas (LPG). The price for selling one kWh of electricity to the state owned enterprise PLN is 16.5 USD cents. The price for selling one m3 of biogas for cooking is 38.5 USD cents, which is equivalent to the available price of LPG. The study finds that the avoided emission due to the substitution of fossil-based coal electricity and cooking LPG-gas is around 64 GgCO2-eq per year. Considering the economical results for a life span of 20 years in the first utilization option Biogas for Electricity gives a net present value (NPV) of 2 MUSD while for the utilization option Biogas for Cooking gives a net present value (NPV) of 5.82 MUSD. The breakeven for Biogas for Electricity is 13.8 USD cents per kWhe while for Biogas for Cooking is 25.5 USD cents per m3-biogas. The study concludes that it is feasible to invest in AD plant in the region of Kartamantul where both markets are profitable and environmentally friendly. / Denna avhandling visar potentialen för biogasproduktion med hjälp av matavfall som samlats från regionen Kartamantul i Yogyakarta, Indonesien. Biogas kan användas för matlagning och elproduktion. Studien jämför två olika slutanvändningar eller marknader för att utnyttja biogasen i regionen. Det dagliga matavfallet som samlas i regionen Kartamantul är 120 ton. Detta motsvarar en daglig biogasproduktion på 13 087 m3. Elektricitet som genereras från biogas kan ersätta fossilbaserad koldioxid, medan tillagning av biogas kan ersätta det gemensamma fossila bränslet flytande petroleumgas (LPG). Priset för att sälja en kWh el till det statligt ägda företaget PLN är 16,5 USD cent. Priset för att sälja en m3 biogas för matlagning är 38,5 USD cent, vilket motsvarar det tillgängliga priset på LPG. Studien konstaterar att den undvikna utsläppet på grund av substitutionen av fossilbaserad kolkraft och matlagning av gasol är cirka 64 GgCO2-ekv per år. Med tanke på de ekonomiska resultaten för en livslängd på 20 år i det första utnyttjandegradet ger Biogas for Electricity ett nettopåverkande värde (NPV) på 2 MUSD medan för utnyttjandegraden Biogas for Cooking ger ett nettoförskott (NPV) på 5,82 MUSD. Breakeven för biogas för el är 13,8 USD cent per kWhe medan för Biogas for Cooking är 25,5 USD cent per m3-biogas. Studien drar slutsatsen att det är möjligt att investera i AD-anläggningar i regionen Kartamantul där båda marknaderna är lönsamma och miljövänliga.

Page generated in 0.0755 seconds