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Industrial Ecology and Development of Production Systems : Analysis of the CO2 Footprint of CementFeiz, Roozbeh January 2014 (has links)
This research is an attempt to create a comprehensive assessment framework for identifying and assessing potential improvement options of cement production systems. From an environmental systems analysis perspective, this study provides both an empirical account and a methodological approach for quantifying the CO2 footprint of a cement production system. An attributional Life Cycle Assessment (LCA) is performed to analyze the CO2 footprint of several products of a cement production system in Germany which consists of three dierent plants. Based on the results of the LCA study, six key performance indicators are dened as the basis for a simplied LCA model. This model is used to quantify the CO2 footprint of dierent versions of the cement production system. In order to identify potential improvement options, a framework for Multi-Criteria Assessment (MCA) is developed. The search and classication guideline of this framework is based on the concepts of Cleaner Production, Industrial Ecology, and Industrial Symbiosis. It allows systematic identication and classication of potential improvement options. In addition, it can be used for feasibility and applicability evaluation of dierent options. This MCA is applied both on a generic level, reecting the future landscape of the industry, and on a production organization level re ecting the most applicable possibilities for change. Based on this assessment a few appropriate futureoriented scenarios for the studied cement production system are constructed. The simplied LCA model is used to quantify the CO2 footprint of the production system for each scenario. By integrating Life Cycle Assessment and Multi-Criteria Assessment approaches, this study provides a comprehensive assessment method for identifying suitable industrial developments and quantifying the CO2 footprint improvements that might be achieved by their implementation. The results of this study emphasis, although by utilizing alternative fuels and more ecient production facility, it is possible to improve the CO2 footprint of clinker, radical improvements can be achieved on the portfolio level. Compared to Portland cement, very high reduction of CO2 footprint can be achieved if clinker is replaced with low carbon alternatives, such as Granulated Blast Furnace Slag (GBFS) which are the by-products of other industrial production. Benchmarking a cement production system by its portfolio product is therefore a more reasonable approach, compared to focusing on the performance of its clinker production. This study showed that Industrial Symbiosis, that is, over the fence initiatives for material and energy exchanges and collaboration with nontraditional partners, are relevant to cement industry. However, the contingent nature of these strategies should always be noted, because the mere exercise of such activities may not lead to a more resource ecient production system. Therefore, in search for potential improvements, it is important to keep the search horizon as wide as possible, however, assess the potential improvements in each particular case. The comprehensive framework developed and applied in this research is an attempt in this direction.
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Análise multicriterial das preferências de gestores e das decisões nas operações logísticas de uma empresa do setor químicoForneck, Marcelo 30 September 2008 (has links)
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Previous issue date: 30 / Nenhuma / No contexto de organizações humanas, o processo de avaliação de desempenho tem merecido a atenção de praticantes e pesquisadores, pois, pela avaliação de desempenho, a empresa pode identificar diferenciais que as ajudem a serem mais competitivas. Para tanto, o rápido
desenvolvimento de produtos, integração de informações, tecnologias de comunicação avançadas, customização de produtos e coordenação de redes de suprimentos, vêm forçando as empresas à tomada de decisões mais rápidas. O uso de métodos qualitativos de apoio à decisão pode contribuir para reduzir riscos e gerenciar incertezas nesta tomada de decisão mais rápida. O objetivo deste trabalho foi apresentar um estudo de caso no qual foi desenvolvido e testado um método de análise das preferências dos gestores de operações logísticas empresariais internas. O resultado da
aplicação do método foi comparado com o resultado de algumas decisões tomadas na empresa. A metodologia de pesquisa contou com um grupo focado, formado pelos gestores da logística in / The context of human organizations, researchers and professionals has considered a lot the process of performance evaluation, once it provides to the company to identify differentials which can help them to be more competitive. Therefore, the fast development of products, information integration, advanced communication technologies, customization of products and coordination of supply nets, is forcing the companies to take faster decisions. The use of qualitative method of support to the decision, may contribute to reduce risks and manage uncertainties in this faster decision taking. The objective of the present work was to present a case study in which was developed and tested an analysis method of the preferences of the internal entrepreneurial logistic operations managers. The result of the method’s application was compared to the result of some decisions taken in the company. The research methodology reckoned with a focus group formed by the company’s internal logistic managers, involving the supply, prod
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Um modelo computacional baseado em análise de decisão multicritério para priorização na alocação de recursos: uma aplicação ao caso das comunidades ribeirinhas da cidade de Coari-AMMagalhães, Elionai de Souza 04 March 2016 (has links)
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Previous issue date: 2016-03-04 / IFAM - Instituto Federal de Educação, Ciência e Tecnologia do Amazonas / A responsabilidade de tomar decisões em si não é fácil, e quando está relacionada à gestão de recursos na área pública é uma tarefa ainda mais difícil, pois está ligada a um alto nível de complexidade. Neste trabalho, é apresentado um modelo computacional baseado em análise de decisão multicritério para a priorização da alocação de recursos financeiros para as comunidades ribeirinhas da região de Coari, Amazonas. Com o surgimento da Pesquisa Operacional, foi possível o desenvolvimento de métodos que auxiliam os tomadores de decisão no que se refere à avaliação e escolha em ambientes que envolvem multicritérios. É o caso da gestão pública, cuja decisão sobre a alocação de recursos passa pela análise de diversos critérios. As técnicas de decisão multicritério, aliadas às novas tecnologias de informação e comunicação, possibilitam novas formas de conhecimento e maior qualidade em diversos serviços. O emprego destas tecnologias no desenvolvimento de ferramentas de auxílio à decisão para a alocação de recursos é de grande utilidade, tendo em vista a automação no processo de análise e rapidez na obtenção dos resultados, possibilitando agilidade na tomada de decisão. Neste trabalho, é desenvolvido um modelo computacional baseado na técnica de Auxílio à Decisão Multicritério para ajudar na alocação de recursos públicos em comunidades ribeirinhas do Amazonas. O modelo emprega a técnica TOPSIS de análise multicritério com o intuito de obter um ranking das comunidades, para assim indicar aquela com maior grau de prioridade para receber a alocação de recursos públicos. Os experimentos foram realizados assumindo um conjunto de seis critérios empregados na ordenação de oito regiões de comunidades ribeirinhas. No estudo realizado, a lista de priorização indicou a região de comunidades do Baixo Solimões como a prioritária para a alocação de recursos públicos e a robustez da priorização obtida na aplicação efetuada foi avaliada através da realização de uma análise de sensibilidade. / The responsibility of making decisions itself is not easy, and when it is related to the management of resources in the public sector is an even more difficult task, because it is linked to a high level of complexity. In this paper, we present a computational model based on multi-criteria decision analysis to prioritize the allocation of financial resources to the coastal communities of Coari region of Amazonas. With the emergence of Operational Research, development methods was possible that assist decision makers with regard to the evaluation and choice in environments that involve advanced. This is the case of public administration, whose decision on the allocation of resources involves the analysis of various criteria. The techniques of multi-criteria decision, combined with the new technologies of information and communication, enable new forms of knowledge and higher quality in different services. The use of these technologies in the development of the decision support tools for the allocation of resources is useful in view of automation in the process of analysis and speed in obtaining results, enabling agility in decision making. In this work, we developed a computational model based on the technique of Aid to Decision Multicriteria to assist in the allocation of public resources in riverine communities of Amazonas. The model uses the TOPSIS technique of multi-criteria analysis in order to obtain a ranking of the communities, so as to indicate that more priority to receive the allocation of public resources. The experiments were performed assuming a set of six criteria used in the ordination of eight regions of riverside communities. In the study, the list of priority indicated the region of the Lower Solimões communities as a priority for the allocation of public resources and the robustness of the obtained priority in the application made was assessed by performing a sensitivity analysis.
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Proposition d'un outil d'aide à la décision multicritère sous incertitudes à base de colonies de fourmis : une approche intégrée appliquée à la gestion des risques dans les projets d'ingénierie système. / A proposition of a multi-criteria decision making tool under uncertainty based on ant colony algorithm : an integrated approach applied to risk management in systems engineering projects.Lachhab, Majda 07 December 2018 (has links)
Dans cette thèse nous proposons un outil d’aide à la décision multicritère qui permet aux décideurs de sélectionner un scénario optimal dans un graphe de projet qui contient toutes les alternatives de choix de conception et de réalisation d’un nouveau système, tout en tenant compte des risques inhérents aux choix réalisés. Le modèle du graphe est construit en considérant toutes les décisions collaboratives des différents acteurs impliqués dans le projet. Cet outil d’aide à la décision est basé principalement sur les techniques de l’optimisation combinatoire. En effet, nous avons choisi de travailler avec la métaheuristique ACO (algorithme d’optimisation par colonies de fourmis) vu sa capacité à fournir des solutions optimales dans un temps raisonnable. Les objectifs à minimiser sont le coût global du projet, sa durée totale de réalisation et l’incertitude sur ces critères (coût, durée). La modélisation des incertitudes a été abordée suivant deux approches différentes. La première approche consiste à modéliser l’incertitude en utilisant des intervalles simples et en la considérant comme un objectif à part entière à optimiser avec le coût et la durée. Quant à la deuxième approche, elle permet de modéliser l’incertitude sur les objectifs du projet (coût, durée) sous formes de distributions de probabilités. L’outil d’optimisation proposé dans la thèse fait partie d’un processus intégré et plus global qui se base sur les standards industriels (processus d’ingénierie système et de management de projet) qui sont largement connus et utilisés dans les entreprises. Ainsi, le travail développé dans cette thèse constitue un vrai guide pour les industriels dans leurs processus de conception et de réalisation des systèmes complexes innovants dans le domaine d’ingénierie système. / In this thesis, we propose a multi-criteria decision making tool that allows decision-makers to select an optimal scenario in a project graph that includes all the alternative choices of a new system’s conception and realization, while taking into account the risks inherent to these choices. The model of the graph is constructed by considering all the collaborative decisions of the different actors involved in the project. This decision making tool is based mainly on the techniques of combinatorial optimization. Indeed, we have decided to work with the metaheuristic ACO (Ant Colony Optimization algorithm) for its ability to provide optimal solutions in a reasonable amount of time. The objectives to be minimized are the total cost of the project, its global duration and the uncertainties about these criteria (cost, duration). The uncertainties modeling is performed according to two different approaches. The first approach consists in using single intervals to model the uncertainty and it is considered as a third objective to optimize besides cost and duration. As for the second approach, the uncertainty about project objectives (cost, duration) is performed by using probabilities distributions. The optimization tool proposed in this thesis is a part of an integrated and more global process, based on industrial standards (the systems engineering process and the project management one) that are widely known and used in companies. Thus, the work developed in this thesis is a real guide for companies in their process of design and realization of innovative complex systems in the systems engineering field.
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Optimisation multicritères et applications aux systèmes multi-processeurs embarqués / Multi-Criteria Optimization and its Application to Multi-Processor Embedded SystemsLegriel, Julien 04 October 2011 (has links)
Dans cette thèse nous développons de nouvelles techniques pour résoudre les problèmes d'optimisation multi-critère. Ces problèmes se posent naturellement dans de nombreux domaines d'application (sinon tous) où les choix sont évalués selon différents critères conflictuels (coûts et performance par exemple). Contrairement au cas de l'optimisation classique, de tels problèmes n'admettent pas en général un optimum unique mais un ensemble de solutions incomparables, aussi connu comme le front de Pareto, qui représente les meilleurs compromis possibles entre les objectifs conflictuels. La contribution majeure de la thèse est le développement d'algorithmes pour trouver ou approximer ces solutions de Pareto pour les problèmes combinatoires difficiles. Plusieurs problèmes de ce type se posent naturellement lors du processus de placement et d'ordonnancement d'une application logicielle sur une architecture multi-coeur comme P2012, qui est actuellement développé par STMicroelectronics. / In this thesis we develop new techniques for solving multi-criteria optimization problems. Such problems arise naturally in many (if not all) application domains where choices are evaluated according to two or more conflicting criteria such as price vs. performance. Unlike ordinary optimization, such problems typically do not admit a unique optimum but a set of incomparable solutions, also known as the Pareto Front, which represent the best possible trade-offs between the conflicting goals. The major contribution of the thesis is the development of algorithms for finding or approximating these Pareto solutions for hard combinatorial problems that arise naturally in the process of mapping and scheduling application software on multi-core architectures such as P2012 which is currently being developed by ST Microelectronics.
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Análise da localização de plataformas logísticas: aplicação ao caso do ETSP - Entreposto Terminal São Paulo - da CEAGESP. / Facility location problems of logistics plataforms: the case of the ETSP (Entreposto Terminal de São Paulo).Romero, Bianca de Cássia 26 April 2006 (has links)
O presente trabalho aborda o problema de localização de plataformas logísticas. Buscaram-se métodos de auxílio à tomada de decisão com enfoque multicritério. A essência da tomada de decisão multicritério é a escolha da melhor alternativa, a partir de um conjunto de alternativas competitivas que são avaliadas sob critérios conflitantes. Entre os métodos estudados, o Método de Análise Hierárquica (AHP), proposto inicialmente por Saaty (1971), foi selecionado como ferramenta de apoio à tomada de decisão. Ele permite considerar simultaneamente atributos quantitativos e qualitativos e, também, incorporar a experiência e a preferência dos tomadores de decisão. Foram ainda levantados os fatores determinantes para escolha de alternativas de localização para plataformas logísticas. O caso do ETSP (Entreposto Terminal São Paulo) da CEAGESP (Companhia de Entrepostos e Armazéns Gerais de São Paulo) foi objeto da aplicação do método selecionado. A análise do problema de localização do Entreposto da CEAGESP está restrita à Região Metropolitana de São Paulo. O software Expert Choice foi utilizado para a aplicação do AHP ao caso do CEAGESP. Após a discussão dos resultados, conclusões e recomendações são apresentadas. / This work deals with the facility location problems of logistics platforms, considering multi-criteria approaches for decision making. The essence of multi-criteria decision making is the choice of the best alternative, from a set of competitive alternatives, which are evaluated under conflicting criteria. Among the multi-criteria methods researched in the bibliography, the Analytic Hierarchy Process (AHP), initially proposed by Saaty (1971), has been chosen and successfully applied to the case in consideration. This method allows to consider quantitative and qualitative measurable criteria and, also, to incorporate the experience and preference of the decision makers. Determinant factors for the choice of location alternatives for logistic platforms have been considered. The case of the ETSP (Entreposto Terminal São Paulo) of the CEAGESP (Companhia de Entrepostos e Armazéns Gerais de São Paulo) was object of application of the selected method. The Expert Choice software was used for the AHP application to the CEAGESP case. After discussion of the results, conclusions and recommendations from the application are presented.
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Proposta de modelo para priorização de investimentos em infraestrutura de transporte de cargas: abordagem multicritério para problemas de fluxos em rede. / A proposed model for prioritizing investments in freight transport infrastructure: multi-criteria approach for network flow problems.Kazan, Samir 23 September 2013 (has links)
A relevância da infraestrutura de transporte para incrementos em produtividade, induzindo ao desenvolvimento socioeconômico de determinada região é amplamente reconhecida. O Brasil, no entanto, apresenta sérias deficiências em relação à sua infraestrutura de transporte, oriundas de seu desenvolvimento histórico e da redução de níveis de investimentos públicos no setor nas últimas décadas. Estas deficiências traduzem-se em grande concentração no modal rodoviário para o transporte de cargas, menos eficiente do que os modais ferroviário e hidroviário, resultando em reduzida competitividade das organizações nacionais. Neste contexto, objetivou-se no presente trabalho a proposição de um modelo para avaliação e seleção de investimentos em infraestrutura de transporte de cargas, considerando-se seu caráter multidimensional. Para isso, foi proposta metodologia integrando os conceitos de análise de decisão multicritério e de programação matemática, representados pela teoria de utilidade multiatributo (Multi-Attribute Utility Theory - MAUT) e por problema de otimização de fluxos em rede (Minimum Cost Network Flow Problem - MCNFP), respectivamente. No desenvolvimento do modelo foram contemplados critérios de avaliação referentes às dimensões de análise financeira, operacional e ambiental. Posteriormente, foi considerada a aplicação de versões do modelo proposto com diferentes números de períodos de análise em caso ilustrativo, representativo da rede de transporte disponível e planejada da região Norte do Brasil. A aplicação das diversas versões do modelo proposto, de forma geral, apresentou resultados compatíveis com as teorias relacionadas à avaliação deste problema de decisão, incluindo indução à multimodalidade. Algumas versões do modelo apresentaram violações em algumas de suas restrições. Estes resultados adversos não foram plenamente eliminados, devido a limitações das ferramentas adotadas para aplicação. No entanto, foi possível a correção manual destas violações, resultando em soluções viáveis que, apesar de não serem consideradas ótimas, são mais completas do que soluções obtidas por meio de metodologias unidimensionais de análise. Por fim, foram apresentadas recomendações para condução de trabalhos futuros visando eliminação dos resultados adversos do modelo proposto e complementação de sua análise. / The role of transport infrastructure in productivity increases leading to regional social-economic development is widely recognized. Brazil, however, has serious deficiencies in its transport infrastructure, rooted in the country\'s historical development and in the recent decades\' reduction of public investment in the sector. These deficiencies can be observed in Brazil\'s strong focus on roads for cargo transportation, which besides being less efficient than rail and waterways, results in reduced competitiveness of national enterprises. In this context, the aim of this work was to propose a model for evaluating and selecting investments in freight\'s transportation infrastructure, considering its multidimensional character. It was proposed a methodology integrating the concepts of multi-criteria decision analysis and mathematical programming, represented by the Multi-Attribute Utility Theory (MAUT) along with the Minimum Cost Network Flow Problem (MCNFP). The developed model included financial, operational and environmental analysis evaluation criteria. Subsequently, this study applied the proposed model into a case study of the transportation network, available and planned, of the Northern region of Brazil. Overall, the application of various versions of the proposed model yielded results consistent with related evaluation and decision making theories, including induction of multimodality. Some versions of the model presented some violations of its restrictions. These adverse results were not fully eliminated due to the limitations of the application tools utilized. It was possible, however, to manually correct these violations and obtain viable solutions that, while cannot be considered optimal, are more complete than those obtained by single dimension analysis. Finally, recommendations were made for future studies aiming at eliminating the proposed model\'s adverse outcomes, and complementing its analysis.
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Дефинисање и оцена критеријума утицаја саобраћајне приступачности на развој приградских насеља / Definisanje i ocena kriterijuma uticaja saobraćajne pristupačnosti na razvoj prigradskih naselja / Defining and Assessment of Criteria for Traffic Accessibility Impact onDevelopment of Suburb AreasStanković Milan 19 March 2019 (has links)
<p>Основни циљ рада јесте дефинисање и квантификација критеријума који имају<br />највећи утицај на саобраћајну приступачност приградских насеља. Овај модел<br />односи се на саобраћајну приступачност приградских насеља у којима<br />функционише систем јавног градског превоза и представља квалитативни<br />приступ истраживању. Истраживање је показало да мрежа линија јавног градског<br />превоза (ЈГП), мрежа приступних путева у насељу, време путовања и ред вожње,<br />имају највећи значај у описивању и генерисању новог модела. Као резултат<br />истраживања у овом раду, очекује се да ће примена модела омогућити развој и<br />одрживост приградских насеља, социјалну равноправност и укључивање<br />становника (посебно млађе популације) у друштвене активности, а све у циљу<br />квалитетнијег живота људи.</p> / <p>Osnovni cilj rada jeste definisanje i kvantifikacija kriterijuma koji imaju<br />najveći uticaj na saobraćajnu pristupačnost prigradskih naselja. Ovaj model<br />odnosi se na saobraćajnu pristupačnost prigradskih naselja u kojima<br />funkcioniše sistem javnog gradskog prevoza i predstavlja kvalitativni<br />pristup istraživanju. Istraživanje je pokazalo da mreža linija javnog gradskog<br />prevoza (JGP), mreža pristupnih puteva u naselju, vreme putovanja i red vožnje,<br />imaju najveći značaj u opisivanju i generisanju novog modela. Kao rezultat<br />istraživanja u ovom radu, očekuje se da će primena modela omogućiti razvoj i<br />održivost prigradskih naselja, socijalnu ravnopravnost i uključivanje<br />stanovnika (posebno mlađe populacije) u društvene aktivnosti, a sve u cilju<br />kvalitetnijeg života ljudi.</p> / <p>The main aims of the paper are to define and quantify the criteria which have the<br />greatest influence on traffic accessibility of suburban areas. This model refers to traffic<br />accessibility of suburban areas, where the system of urban public transport is<br />operational and represents a qualitative approach to research.The research has shown<br />that the factors such as a network of public transport (PT) lines, the network of<br />accessible roads in a settlement, travel time and the timetable have the greatest<br />importance in description and generation of a new model. Based on the results of<br />research presented in this paper, it is expected that the application of this model will<br />enable development and sustainability of suburban areas, as well as greater social<br />equality and involvement of dwellers (especially young generation) in social activities,<br />in view of achieving better quality of life among people.</p>
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Life cycle sustainability assessment of shale gas in the UKCooper, Jasmin January 2017 (has links)
This research assesses the impacts of developing shale gas in the UK, with the focus of determining whether or not it is possible to develop it sustainably and how it could affect the electricity and gas mix. There is much uncertainty on the impacts of developing shale gas in the UK, as the country is currently in the early stages of exploration drilling and the majority of studies which have been carried out to analyse the effects of shale gas development have been US specific. To address these questions, the environmental, economic and social sustainability have been assessed and the results integrated to evaluate the overall sustainability. The impacts of shale gas electricity have been assessed so that it can be compared with other electricity generation technologies (coal, nuclear, renewables etc.), to ascertain its impacts on the UK electricity mix. Life cycle assessment is used to evaluate the environmental sustainability of shale gas electricity (and other options), while life cycle costing and social sustainability assessment have been used to evaluate the economic and social sustainability. Multi-criteria decision analysis has been used to combine the results of three to evaluate the overall sustainability. The incorporation of shale gas into the UK electricity mix is modelled in two future scenarios for the year 2030. The scenarios compare different levels of shale gas penetration: low and high. The results show that shale gas will have little effect on improving the environmental sustainability and energy security of the UKâs electricity mix, but could help ease energy prices. In comparison with other options, shale gas is not a sustainable option, as it has higher environmental impacts than the non-fossil fuels and conventional gas and liquefied natural gas: 460 g CO2-Eq. is emitted from the shale gas electricity life cycle, while conventional gas emits 420 g CO2-Eq. and wind 12 g CO2-Eq. The power plant and drilling fluid are the main impact hot spots in the life cycle, while hydraulic fracturing contributes a small amount (5%). In addition to this, there are a number of social barriers which need to be addressed, notably: traffic volume and congestion could increase by up to 31%, public support is low and wastewater produced from hydraulic fracturing could put strain on wastewater treatment facilities. However, the results indicate that shale gas is economically viable, as the cost of electricity is cheaper than solar photovoltaic, biomass and hydroelectricity (9.59 p/kWh vs 16.90, 11.90 and 14.40 p/kWh, respectively). The results of this thesis show that there is a trade-off in the impacts, but because of its poor environmental and social ratings shale gas is not the best option for UK electricity. The results also identify areas for improvement which should be targeted, as well as policy recommendations for best practice and regulation if shale gas were to be developed in the UK.
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Analyse du traitement et de la gestion durable des boues d’épuration en Corse. Proposition de solutions énergétiques alternatives, axées sur la méthanisation des boues avec production d’énergies, aux méthodes appliquées en Corse. Utilisation de l’outil d’aide multicritère à la décision dans le cadre du surclassement de ces nouveaux procédés / Analysis of treatment and management of sewage sludge in Corsica. Proposal for alternative energy solutions, focusing on methanisation of sludge with production of Energies, to methods applied in Corsica.Use of the multicriteria decision support tool in the context of the upgrade of these new processes.Tramoni, Félicien 15 December 2015 (has links)
La qualité des boues est directement liée à la qualité des étapes de traitement présentes au sein d’une station d’épuration. En termes de traitement et d’élimination des boues, nous observons de la part des acteurs locaux, une volonté d’abandon définitif et durable de la filière « dépôt en centre de stockage », étant donnée une règlementation et des plans régionaux (notamment le PREDIS de Corse), toujours plus exigeant en termes de valorisations des déchets industriels et spéciaux. Nous observons également un abandon progressif et programmé des pratiques relatives à l’épandage. En effet, l’épandage des boues d’épuration fait l’objet d’une vaste controverse qui met en avant les risques sanitaires et environnementaux qu’elle engendrerait sur les sols agricoles. Au sein de notre région, cette pratique est réalisée de manière non règlementaire. En Corse, les acteurs locaux semblent avoir optés pour la solution du compostage en vue de valoriser la production de boues d’épuration. En effet, près des 2/3 du tonnage annuel en MS de boues sont actuellement valorisés via cette filière. Le processus de compostage équivaut à une fermentation aérobie, faisant intervenir une multitude de micro-organismes. Cette filière de compostage, au même titre que l’épandage, a connu une forte expansion de son activité mais semble avoir des failles et des limites : problèmes de mauvaises odeurs ; règlementation de plus en plus exigeante ; et enfin surproduction de compost invendable aux vues de la demande. Une autre solution pourrait présenter des atouts supérieurs : la méthanisation avec production d’électricité et de chaleur par cogénération. Cette production d’énergies passe obligatoirement par la valorisation du biogaz produit par ce système. En effet, le biogaz est un mélange contenant principalement du méthane (50 à 70%) et du dioxyde de carbone Du fait d’une forte concentration en méthane, le biogaz est un bon fournisseur d’énergie (1m3 de biogaz a un pouvoir calorifique de 6 kWh soit l’équivalent de 0,6 l de fuel). Pour produire de l’électricité, le processus de méthanisation doit être couplé à un moteur à cogénération ou à plusieurs microturbines. EDF a alors l’obligation de racheter l’électricité produite à un prix se situant entre 11 et 14 centimes d’euros/kwh., Après 15 ans, le rachat du kwh produit se fait aux taux proposés par EDF. En Corse, seulement une station d’épuration est équipée d’un digesteur couplé en série à cinq microturbines, produisant de la chaleur et de l’électricité par cogénération : La station de traitement des eaux usées de Campo Dell’Oro à Ajaccio. Ce procédé de valorisation énergétique pourrait être amélioré via le remplacement à terme, des microtubines par un moteur à cogénération. Une AMCDP a notamment permis de surclasser cette technologie vis-à-vis des microturbines, beaucoup moins efficaces en termes de rendement mais aussi de fonctionnement. L’équipement des stations d’épuration de plus fortes capacités en Corse, de digesteurs associés à un moteur à cogénération pourrait être une solution durable à la problématique de la valorisation énergétique des boues. / Sludge quality is directly related to the quality of of these processing steps present in a water treatment plant. In terms of treatment and disposal of sludge, we observe on the part of local actors, a willingness to permanent and lasting abandonment of the sector 'deposit in storage centre'', given a regional plans and regulations (including the PREDIS Corsica), increasingly demanding in terms of valuations of industrial and special waste. We also observe a gradual and planned abandonment of practices for spreading. Indeed, the spreading of sewage sludge is the subject of widespread controversy which highlights the health and environmental risks it would lead to agricultural soils. In our region, this practice is not carried out regulatory manner. In Corsica, the local actors seem to have opted for the solution of compost to enhance the production of sewage sludge. Nearly 2/3 of the annual tonnage MS sludge is currently valued via this pathway. The composting process is equivalent to an aerobic fermentation involving a multitude of microorganisms. This composting stream, as well as spreading, experienced strong expansion of its business but seems to have flaws and limitations: problems with odors; regulatory increasingly demanding; and finally overproduction unsaleable compost to the views of the application.Another solution could present higher advantages: anaerobic digestion with production of electricity and heat from cogeneration. . This energy production go through the biogas produced by this system. Indeed, the biogas is a mixture containing mostly methane (50 – 70 %) and carbon dioxide. Due to a high concentration of methane, biogas is a good energy supplier (1m3 biogas has a calorific value 6 kWh equivalent to 0.6 liters of fuel). To generate electricity, the anaerobic digestion process must be coupled to an engine cogeneration or several microturbines. EDF has the obligation to purchase electricity at a price ranging between 11 and 14 euro cents/kwh. After 15 years, the redemption of the kwh produced is done at the rate offered by EDF.In Corsica, only a treatment plant is equipped with a digester coupled in series to five microturbines, producing heat and electricity cogeneration: The wastewater treatment plant at Campo Dell'Oro /Ajaccio. This energy recovery process could be improved with an eventual replacement of the microtubines by a cogeneration engine. An AMCDP allowed to outperform this technology towards microturbines, much less efficient in terms of performance.The equipment of the highest capacity treatment plants in Corsica, digesters associated with a cogeneration engine could be a lasting solution to the problem of energy recovery of sewage sludge.
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