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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

Waste to Energy (WTE): Conventional and Plasma-assisted Gasification - Experimental and Modeling Studies

Lavaee, Mohammad Saleh 06 November 2014 (has links)
Ever-increasing amounts of industrial and residential wastes and their environmental footprint dictates the need for effective Waste Management practices. Thermal waste processing technologies play an important role in energy recovery from the waste. Conventional and more importantly Plasma-assisted Gasification, an advanced thermal processing technology, have been introduced as promising and environmentally benign ways for energy utilization from biomass and municipal solid waste (MSW). This work aims to study the thermal technologies, which result in production of synthesis gas that is useful for heat and power generation; therefore, conventional and plasma-assisted gasification of biomass/MSW are reviewed. In addition, various economic, environmental and policy-related issues are examined in this study. From the experimental and modeling perspective, this study also reports on the work conducted to characterize the gasification process using a gasification reactor called Gasifier Experimenters Kit (GEK) level IV. Both the syngas quality and quantity have been investigated based on a variety of feedstock, such as wood charcoal, poplar and tamarack wood chips. Moreover, the composition of the gas has been analyzed using a Gas Chromatography (GC) unit and the exact concentrations of carbon monoxide, hydrogen, methane and nitrogen were measured. In this study, a thermochemical model based on the experimental setup (GEK IV) has also been developed in the AspenPlus?? environment, an established simulation tool in chemical engineering and the energy industry. This model is capable of predicting the syngas composition, the energy required for the gasification reactions. A comparative analysis involving the experimental and simulation results is presented in this study.
2

Industrial Buying Behavior in the Waste-to-Energy Market : A Case Study in Germany

Klinkmann, Lars Hendrik January 2016 (has links)
Abstract Waste-to-Energy power generation describes the process of incinerating solid waste. The produced heat is used to drive a power generation unit generating electric energy or for direct district heating. Waste-to-Energy is a viable method to treat solid waste and to produce energy.The Waste-to-Energy power generation market has significantly grown throughout the past decade. This is rather based on an increasingly important waste management issue than on higher demands for energy. Even in light of a growing market, literature concerned with the customers’ buying behavior and customer motives in the process of industrial buying in this segment is very limited. Therefore, this study investigates these aspects in further detail and determines patterns in the Waste-to-Energy market in Germany.This research project solves and fills the problem and knowledge gap concerned with the affecting factors, influences and drivers in industrial buying in Germany. Since this is a very global perspective and exceeds the capacities of this study, more specific aspects such as the buying centers, buying situations or supplier selection criteria are assessed.Pursuing an approach on the philosophical stances of constructivism and interpretivism, this research topic has been approached by conducting phone interviews with representatives from power plant operators and public authorities. These representatives mostly fill positions in purchasing and environmental departments, among others.A number of Waste-to-Energy power plants in Germany have been investigated by interviewing individuals involved in the planning, purchasing and construction process. The information they provided on the topics of the plants’ backgrounds, buying centers, customer motives, buying decision phases and buyer-seller relations have been analyzed in order to draw conclusions and to answer the research questions.It has emerged from this research study that the Waste-to-Energy power plants investigated were built primarily in order to solve waste management issues and not to produce energy. In these cases, power generation is just a byproduct of the waste incineration. Furthermore, it has evolved that constructions of power plants are rolled out as new tasks or modified re-buys, but never as straight re-buys. Additionally, buyers do not only focus on suppliers’ characteristics such as their pricing and their products’ quality, but also on their financial situation and performance, capability to meet deadlines and environmental impacts.
3

Prefeasibility Study for a Waste-to-EnergyApplication in Gauteng Province, South Africa

Subasinghe, Gayan January 2013 (has links)
Waste-to-Energy concept becomes increasingly popular from the perspectives of the waste management and alternative energy. South Africa, which is a country heavily dependent on the fossil fuel, can explore the opportunities of Waste-to-Energy in order to deal with increasing amount of waste generated while reducing what is deposited at non-engineered landfills, thereby increase the renewable energy share. This prefeasibility study attempts to identify Waste-to-Energy potentials in Gauteng provinceso as to develop a Waste-to-Energy facility under the new renewable Independent Power Producer procurement programme of South Africa. The analysis identifies abundant Wasteto-Energy incineration and landfill gas opportunities linked with municipal solid waste in twomunicipalities. The prefeasibility study further evaluates environmental, socio-economic aspects of Waste-to-Energy initiative. The financial viability of a Waste-to-Energy incineration facility with the Feed-in-Tariff proposed by the government of South Africa isalso detailed analysed.
4

Koncepce integrovaných zařízení pro jednotky „waste-to-energy“ / Concepts of an integrated equipment for waste-to-energy units

Petrasová, Zuzana January 2020 (has links)
The diploma thesis deals with design modifications of the investigated industrial „waste-to-energy“ unit and possible deployment of modern integrated equipment instead of existing devices that would reduce economic demands and improve environmental impacts of thermal treatment of gaseous waste in order to increase thermal efficiency. Within the considered modifications, possible modifications of the process according to current technological trends are presented. For all solved devices, investment costs were determined according to the price offers of suppliers in accordance with professional literature, which deals with the economic aspect during the phase of synthesis and selection of the most suitable concept from the investor's point of view. The Venture Profit is used as a measure of the profitability of a given operation to evaluate individual modifications. The output of the thesis is to determine the optimum modification for the process based on the mentioned criteria.
5

Barreiras e facilitadores para o planejamento e implantação de usinas de recuperação de energia de resíduos sólidos urbanos / Barriers and facilitators in the process of planning and building waste to energy plants of municipal solid waste

Grynwald, Sami 08 October 2014 (has links)
Historicamente, o Brasil possui dificuldades para equacionar a questão da disposição dos Resíduos Sólidos Urbanos (RSU) gerados pela população. Durante anos, eles foram depositados em locais inapropriados, gerando uma série de problemas sociais e ambientais. O gerenciamento dos RSU requer ações diversificadas e complexas, devido à quantidade, composição e localização de geração. O principal desafio é encontrar soluções ambientalmente responsáveis, socialmente adequadas e economicamente viáveis. Presentes em diversos países, as Usinas de Recuperação de Energia (URE) produzem energia elétrica por meio de uma fonte renovável, que elimina os efeitos adversos de sua disposição inadequada e reduz o volume dos resíduos destinados aos aterros. Mas, no Brasil, a implantação das URE ainda enfrenta um grande desafio, pois mesmo com a existência de diversos estudos, até hoje não há nenhuma em operação no país. Com base na importância das URE tanto para o equacionamento de questões relativas à disposição final dos RSU quanto como solução conveniente para suprimento de energia elétrica, este trabalho visa entender como a utilização de conceitos e técnicas de gerenciamento de projetos podem favorecer a superação de barreiras e o aproveitamento de facilitadores do processo de planejamento e implantação das URE de RSU. / Historically, Brazil has difficulties disposing of the municipal solid waste (MSW) generated by its population. For years, it was disposed in inadequate places, generating a series of social and environmental problems. Managing the MSW requires diverse and complex actions, depending on the quantity, composition and location. The main challenge is finding environmentally responsible, socially adequate and economically viable solutions. Present in many countries, the waste to energy plants (WTE) are able to produce electricity through a renewable source, which eliminates the adverse effects of its inadequate disposal, as well as reduces the volume of waste destined to landfills. However, in Brazil, the WTE implantation is still a great challenge, even with various studies done, none is operating in the country. Regarding the WTE importance, considering it a solution for the MSW final disposal as well as a convenient alternative for electricity supply, this study aims to understand how concepts and techniques of project management can help overcome barriers and use facilitators in the process of planning and building a WTE of MSW.
6

Estudo comparativo de processos de gaseificação de resíduos sólidos urbanos no Brasil. / Sem título em inglês.

Araújo, Ramires Menezes da Silva 21 June 2016 (has links)
Os resíduos sólidos urbanos (RSU) no Brasil são na grande maioria direcionados para aterros e lixões a céu aberto, onde ocupam grandes áreas, geram transtornos relacionados ao trafego aéreo, emitem gases responsáveis pelo efeito estufa sem o devido reaproveitamento energético. Como alternativa para a minimização do passivo ambiental causado pelos RSUs e potencial reaproveitamento energético propõe-se um estudo comparativo de processos de gaseificação desses resíduos em diferentes meios gaseificantes. A modelagem e simulação dos processos foram feitas aplicando-se o método de minimização da energia livre de Gibbs não estequiométrica. Considerou-se a quantidade de resíduo sólido urbano destinado da sub-região de Campo Limpo - São Paulo - e a sua composição representativa expressa pelo método ultimate-analysis. O processo de gaseificação foi implementado em simulador de processo e o estudo se concentrou nas etapas do processo de gaseificação, investigando-se a ação dos seguintes meios gaseificantes: ar, vapor e mistura ar e vapor. Os principais resultados analisados foram a composição do produto da gaseificação e o potencial energético do produto. / The major destiny of Municipal Solid Waste (MSW) in Brazil is landfill. These sites occupy large areas; most of them are open, being simply disposal areas. This situation causes several problems ranging from greenhouse gases to air traffic jeopardizing. The use of MSW in energy generation addresses these problems, once it is one of most promising solutions to MSW treatment. This work is the study of gasification from the energy potential. It was carried out through minimization of Gibbs energy in a process simulator. The MSW considered was the one from area of Campo Limpo in São Paulo city. Its composition was expressed by ultimate analysis. The use of different gasification agents included air, steam and their mixtures was analyzed. The results were HHV and composition of generated gases.
7

Mineral Solubilization from Municipal Solid Waste Combustion Residues: Implications for Landfill Leachate Collection Systems

Rhea, Lisa R 12 November 2004 (has links)
Leachate collection systems consist of a series of pipes installed beneath the waste at the base of a landfill. The liquid drains toward a central location where it is pumped and then treated, discharged, or recirculated. In some landfills, solid precipitates form in the collection system resulting in clogging and malfunctions of the drainage system. The formation of the precipitates is linked to the chemical and biological stability of the leachate generated within the landfill. To control the formation of precipitates and prevent clogging of leachate collection systems, it is important to understand factors that influence leachate characteristics. Ashes from municipal solid waste (MSW) combustion are either placed in monofills or combined with traditional solid waste, and sludges and biosolids from wastewater and drinking water treatment plants when landfilled. The ashes, depending on the type of combustion process, contain high concentrations of metals and non-biodegradable materials. As the waste degrades, oxygen in the landfill is consumed and the leachate becomes anaerobic. The reducing environment allows for greater solubility of metals. This research tested ashes from three different Waste-to-Energy (WTE) facilities to understand better the role MSW fly ash and MSW bottom ash in the chemical make-up of landfill leachate. Two different types of batch tests were used to analyze the leaching behavior. First, a contact time batch test with a range of different contact times was used to assess the rate at which different elements reach equilibrium. This was followed by a sequential extraction batch test that predicted the total amount of soluble material in the ashes. The chemical characteristics of the leachate produced by the ashes were understood and the leaching behaviors analyzed, dominant chemical factors that influence the formation of precipitates were identified. This data produced a better understanding of the roles of WTE ashes in the production of precipitates in leachate collection systems.
8

Conversion of Biomass to Liquid Hydrocarbon Fuels via Anaerobic Digestion: A Feasibility Study

Naqi, Ahmad 19 March 2018 (has links)
The use of biomass as a potential feedstock for the production of liquid hydrocarbon fuels has been under investigation in the last few decades. This paper discusses a preliminary design and a feasibility study of producing liquid hydrocarbon fuels from biomass through a combined biochemical and thermochemical route. The process involves anaerobic digestion (AD) of the biodegradable portion of the biomass to produce methane rich gas. The methane rich biogas stream is purified by removing contaminants and upgraded to liquid hydrocarbon fuel in a gas to liquid facility (GTL) via thermochemical conversion route. The biogas conversion involves two major steps: tri-reforming step to produce syngas (a mixture of CO and H2), and Fischer-Tropsch Synthesis (FTS) step to convert the syngas to a spectrum of hydrocarbons. Separation and upgrading of the produced hydrocarbon mixture allows production of synthetic transportation fuels. AD is ranked as one of the best waste management options as it allows for: energy recovery, nutrient recovery, and reduction in greenhouse gases emission. A detailed process modeling of the process was carried out using ASPEN Plus process design software package. Data for the process was based on literature on AD combined with laboratory results on the biogas to liquid conversion process. The composition of the final liquid hydrocarbon from the ASPEN model has been compared to the composition of commercial diesel fuel, and results have shown good agreement. As a result, the most current commercial diesel prices were used to evaluate the potential revenue from selling the product in the open market. The total capital investment to construct the plant with a capacity of handling 100,000 ton per year of wet biomass is $16.2 million with a potential of producing 2.60 million gallons of diesel. The base case feedstock is corn stover. The annual operating cost to run the plant is estimated to be $8.81 million. An annual revenue from selling the diesel product is estimated to be $14.6 million taking into account a green energy incentive of $3.00/gallon of diesel sold. The net present worth at the end of the plant life is $8.76 million with a discounted cash flow of return of 26.2%. The breakeven cost of diesel is determined to be $4.34/gallon assuming no tipping fees are charged for handling the waste. Sensitivity analyses results concluded that the profitability of the process is most sensitive to variation in diesel selling price. Based on these results, it can be concluded that the process is profitable only if incentives are provided for renewable fuels due to the current low prices of fossil fuels.
9

The Possibility of Energy Recovery from Waste Material in Arges County, Romania

Nordström, Emma, Enochsson, Evelina January 2009 (has links)
<p></p><h1>Abstract</h1><p>Waste disposal is a global problem contributing to the ongoing climate change by large emissions of greenhouse gases. By using waste material as a resource instead of landfilling, the greenhouse gas emissions from landfills are reduced. Waste material can be used for waste incineration with energy recovery, thus decreasing the greenhouse gas emission from energy utilization by changing from fossil fuels to a partly renewable fuel.</p><p>Arges County in Romania has severe problems with its waste material, mainly sewage sludge and waste from households and industries. As a consequence of the Romanian EU accession in 2007, Arges County is obliged to close its landfills for waste in a near future. A reconstruction of the wastewater treatment plant and an improved management of the sewage sludge residue are necessary in order to comply with EU standards. The requirements from the EU regarding waste disposal together with the existence of a district heating network in the residence city Pitesti, makes it interesting to investigate energy recovery from waste material in Arges County.</p><p>Therefore, the goal of the study is to evaluate the possibility to extract energy from co-incineration of the waste material, sewage sludge and waste generated in Arges County. In order to reach this goal, the composition and quantities of the waste material is investigated. A suitable technology for the waste-to-energy (WTE) plant is proposed, based on the data of the waste material as well as on   established WTE technologies and their costs. It is assumed that the WTE plant will be implemented in 2020 and that all the generated waste will be incinerated. Furthermore, an environmental analysis is carried out, which presents the reductions of greenhouse gas emissions with the proposed WTE plant in comparison with the present system; including the management of waste and sludge and the district heating production, which is based on fossil fuels.</p><p>The result shows that the waste material in Arges County has a calorific value of 7.5 MJ per kg, which is suitable for co-incineration of waste and sludge. The suggested WTE plant has the total power of 130 MW, annually recovering 620 and 330 GWh of heat and electric power respectively. The investment cost of the WTE plant is estimated to 226 million euro with a payback time of 8 years. The environmental analysis shows that the proposed system in comparison with the present system will decrease greenhouse gas emissions by 88 percent.</p><p>A WTE plant appears to be a sound investment in Arges County and would sharply reduce the emissions of greenhouse gases in the county. However, some obstacles exist. Waste management is a new field in Romania and currently there are no WTE plants. Furthermore, the data used in this study concerning the quantity and composition of the waste, is uncertain and further studies are necessary before a WTE plant can be established.</p><p> </p>
10

Differentiating the Methods of Waste Treatment in the Wider Caribbean Region : Introducing a Comprehensive Data-collecting Model to Promote Waste-to-Energy Practices

Corti, Alberto January 2013 (has links)
The Wider Caribbean Region does not have a regional waste management strategy. An integrated approach to waste management throughout the region would benefit many economic sectors, safeguard people’s health and improve environmental quality. Numerous studies, above all a project conducted in 1994 by the World Bank, pointed out that one of the main reasons why such strategy has not been developed yet lies in the scarce availability of data in the waste management sector. Through on field researches and the analysis of institutional reports, the objective of the present study is defining the reasons that led and still underpin such scarcity. Furthermore, the study proposes a new methodology of data collection and improvements to one of the mathematical model that is used to estimate waste quantities in ports. The purpose of the paper is to find an integrated solution to a double challenge: waste abundance and energy scarcity, with focus on ship generated waste management.

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