This research developed novel methodologies to achieve cost effective solutions to overcome many of the difficulties associated with unsteady state material recovery network synthesis. The work focuses on the development of three different methodologies: the first is a hierarchical multi-step methodology developed for the design and scheduling of batch water (material of interest) recycle networks. A new source- double tank-sink arrangement is introduced to overcome the limitation of samecycle assignment by permitting sources to be optimally recycled within the same batch cycle and/or storing and recycling sources to sinks in the following batch cycle. The problem is solved in interconnected stages. First, network targets such as minimum fresh water consumption and minimum waste water discharge are identified ahead of network design. Once design targets have been identified, an iterative procedure is followed to tradeoff fixed and operating cost to achieve a network design which has the minimum total annualized cost (TAC). The second developed methodology is a one-step simultaneous approach to design and schedule cost-effective batch water recycle networks. A new source-tank-sink representation is developed to embed potential configurations of interest for design and scheduling. As a result, water may be assigned from sources to sinks within the same cycle (with or without a storage tank) and in two subsequent cycles using a double tank arrangement. A mathematical formulation is developed to determine the network design and sufficient information on the scheduling of the network with the minimum TAC in one step. The third methodolgy this research developed is a systematic procedure to schedule the operation of an unsteady state material recovery network. The network has a set design and receives a number of feedstocks (sources) that are to be processed into higher value/quality products. The sources may be stored in tanks, mixed, and/or intercepted in separation devices to produce the desired products while maximizing profits and meeting all process constraints. The developed systematic procedure includes mathematical formulations that allow available sources to be stored, mixed, intercepted and determine the optimal scheduling scheme over time period ??with the objective of maximizing total annualized profit of the network.

We dispose of things when they fall out of style, when taste changes, when they break or when we can no longer find a use for them. Sometimes, we sell things when we see value in them. Sometimes we recycle. Sometimes we feed the landfill — the meeting point for materials that have lost their utility. Many of them have the potential to serve their use much longer than having just one life as one object. My degree project investigates what role disassembly plays in the lifespan of a material. Can it support the recovery and subsequent use of matter? Whose responsibility is to take care of an object’s afterlife? By researching the possibilities of exchanging fixed pieces of joinery for detachable ones, my project reinvents the way we attach materials based on forces such as tension, pressure and gravity. Can joinery invite us to disassemble?

Energy recovery by waste incineration has a double function as waste treatment method and supplier of electricity and/or heat, thereby linking the systems of energy and waste management. Both systems are undergoing great changes, mainly due to new regulations. Important regulations within waste management in Sweden are a ban on landfill of combustible waste and organic waste, and a tax on landfill of waste. New waste incineration facilities are being built in order to increase capacity to meet these demands. The aim of this thesis is to investigate impacts on Swedish district heating systems of increased use of waste as a fuel in economic and environmental terms, the latter mainly by assessing emissions of carbon dioxide. Of importance is the influence of various policy instruments. To highlight the connection between the energy and waste management systems and how these influence each other is another goal, as well as the function of district heating systems as user of various waste heat supplies. An important assumption for this thesis is a deregulated European electricity market, where the marginal power production in the short term is coal condensing power and in the long term natural gas based power, that affects the conditions for combined heat and power in district heating systems. The method used is case studies of three Swedish municipalities that utilise waste in their district heating systems. In two papers, the scope is broadened from the energy utility perspective by comparing the energy efficiency of energy recovery and material recovery of various fractions, and the effect of including external costs for CO2 as well as SO2, NOx and particles. The ambition is that the results can be part of the decision making process for energy utilities and for policy makers in the energy sector and waste management. It is economically advantageous to use waste as a fuel in the energy sector and regulations in the waste management sector and high taxes on fossil fuels contribute to profitability. Waste incineration plants are base suppliers of heat because they derive revenue from receiving the waste. Economic conditions for waste incineration are altered with the introduction of a tax on incinerated municipal waste. A conflict may arise between combined heat and power production in district heating systems and waste incineration, since the latter can remove the heat sink for other combined heat and power plants with higher efficiencies. Combined heat and power is the main measure to decrease carbon dioxide emissions in district heating systems on the assumption that locally produced electricity replaces electricity in coal condensing plants. It can be difficult to design policy instruments for waste incineration due to some conflicting goals for waste management and energy systems. Comparing the energy efficiency of material recovery and energy recovery is a way to assess the resource efficiency of waste treatment methods. From that perspective, if there is a district heating system which can utilise the heat, biodegradable waste and cardboard should be energy recovered and plastics and paper material recovered. To put costs on environmental effects, so called external costs, is a way to take these effects into regard in traditional economic calculations, but the method has drawbacks, e.g. the limited range of environmental effects included and uncertainties in the monetary valuation of environmental effects.

In this thesis, we work on adisassembly lot-sizing problem for multiple products with parts commonality,i.e., general product structure. We assume that supply of discarded products is infinite. When a product (or a subassembly) is disassembled, all its immediate child items are obtained,i.e., complete disassembly case.Intermediate and leaf items obtained are demandedbyexternal suppliers or remanufacturers. The maximum possible salesfor each intermediate and leaf item are known.Sales of the intermediate and leaf items are the revenue sources. The discarded products are purchased ata unit purchasing cost. The disassembly operation incurs a fixed and a variable disassembly cost. Due to this cost structure, intermediate and leaf items can be stocked incurring an inventory holding cost. We develop an integer programming formulation to determine the time and quantity of the discarded products to be purchased / thetime and quantity of the discarded products and the intermediateitemsto be disassembled / and the time and quantity of intermediate and leaf items to be soldin order tomaximizethe total profit over a finite planning horizon. We state that ourproblem is NP-hard by refering the study of Kim et. al. (2009). We propose a heuristic solution approach that solves the problem in a reasonable computational time and generates near optimal solutions. The solution approach is based on the idea of sequentially solving a relaxed version of the problem and one-period integer programming models.In a computational study, the performance of the heuristic approach is assessed for a number ofrandomly generated problem instances.The results of the computational study show that the solutions of the heuristic approacharevery close to the optimal and the best feasible solutions obtained within the time limit.

Made available in DSpace on 2014-10-09T12:27:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:54Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:27:58Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:54Z (GMT). No. of bitstreams: 0 / O tratamento de rejeitos de determinados processos industriais vem ganhando importância, seja pelo impacto negativo do simples descarte no meio ambiente, seja pelo valor econômico de materiais e substâncias que podem ser eventualmente recuperados e reciclados. O rápido empobrecimento de reservas minerais primárias e o aumento de demanda de energia são problemas que merecem atenção especial. Neste contexto, a recuperação de metais existentes nos rejeitos de alguns processos de fabricação assume papel de maior importância. A recuperação do molibdênio presente em soluções nitro-sulfúricas, na forma de rejeitos líquidos do processo de fabricação de lâmpadas incandescentes e fluorescentes, não constitui exceção no que diz respeito à importância da reciclagem. Este rejeito, proveniente da dissolução dos mandris de conformação dos filamentos de tungstênio das lâmpadas, apresenta valores que podem ser recuperados e até reciclados no próprio processo. É o caso dos ácidos nítrico e sulfúrico. Já o molibdênio, presente em concentrações em torno de 40 a 90 g.L-1, pode ser recuperado e utilizado na fabricação de aços especiais, pigmentos, lubrificantes, adubo, etc. Neste trabalho foram desenvolvidos dois processos de recuperação deste rejeito. No primeiro, o rejeito é diluído e por cromatografia de troca iônica o molibdênio é recuperado. Os ácidos efluentes são destilados para a retirada da água. No segundo processo, o rejeito passa por uma destilação e ao mesmo tempo o molibdênio é precipitado. Em ambos os processos, os ácidos recuperados podem voltar à fábrica de lâmpadas para a dissolução dos mandris do filamento de tungstênio e o molibdênio encontra outras diferentes aplicações, além de possuir um valor significativo no mercado. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Fiber-based packaging has emerged as an alternative to plastic packaging, driven by concerns regarding environmental impact and excessive usage of plastic. In response to market trends favouring circular packaging solutions, Stora Enso is preparing to introduce Papira, an innovative fiber-based cushioning packaging material, in Europe. However, assessing the practical acceptability of new materials within existing recycling systems is crucial alongside laboratory tests that analyse recyclability. Therefore, the purpose of this study is to examine waste paper recycling practices implemented in Europe and identify factors that should be considered when introducing a new product into the European market to provide insights that will help evaluate the positioning of Papira and provide recommendations accordingly. To accomplish this aim, after creating a conceptual framework, a combination of interviews and desk research, including analysis of academic and grey literature sources, was employed to gather valuable insights and develop a comprehensive understanding. The scope of the study focuses on paper and board waste generated by households including eight countries: Belgium, Finland, France, Germany, Luxembourg, Poland, Sweden, and the Netherlands. One of the key findings of this study is the variation observed in the practices employed within the waste paper recycling system. The implementation of the Extended Producer Responsibility system highlights the prominence of both single and multiple Producer Responsibility Organizations, while the household separate collection system involves the collection of waste through different fractions. Consequently, the fractions collected and the designated mills for separated materials play a crucial role in the mechanical sorting stage, alongside the divergence in manufacturing methods employed by mills during the material recycling phase. This underscores critical considerations that arise during the introduction of new fiber-based products. Notably, the composition and fiber content of a product significantly influence its registration within the system, thereby impacting pricing. Additionally, effective labelling is imperative to provide clear guidance to consumers regarding proper disposal methods. Moreover, the suitability of products for mechanical sorting is contingent upon ensuring that sorting technologies align with the waste composition. Lastly, the study identifies four key aspects that hold significance for recycling processes: printing inks, additives, pulping time, and fiber length. In conclusion, Papira, with its high fiber content and biobased additives, has shown promising environmental qualities. However, at the same time, it requires further recognition by the recycling system and consumers, appropriate classification in accordance with the standards, and testing by sorting facilities and recycling mills to meet industry standards and optimise its integration into the recycling system. This study highlights the importance of encompassing the monitoring of actions under the PPWR proposal, the role of consumer communication, and the imperative of maintaining consistent communication among all stakeholders. / Fiberbaserad förpackning har framträtt som ett alternativ till plastförpackning, drivet av oro överplastens miljöpåverkan och överdriven användning. Som svar på marknadstrender som främjarcirkulära förpackningslösningar förbereder Stora Enso att införa Papira, ett innovativt fiberbaseratdämpningsmaterial för förpackningar, i Europa. Att bedöma den praktiska acceptansen av nya materialinom befintliga återvinningssystem är dock avgörande, tillsammans med laboratorietester somanalyserar återvinningsbarhet. Syftet med denna studie är därför att undersöka återvinningspraxis förpappersåtervinning som tillämpas i Europa och identifiera faktorer som bör beaktas vid introduktionenav en ny produkt på den europeiska marknaden för att ge insikter som hjälper till att utvärderapositioneringen av Papira och ge rekommendationer därefter. För att uppnå detta syfte användes enkombination av intervjuer och skrivbordsforskning, inklusive analys av akademiska och grålitteraturkällor, för att samla värdefull information och utveckla en omfattande förståelse. Studiensomfattning fokuserar på pappers- och kartongavfall som genereras av hushåll i åtta länder: Belgien,Finland, Frankrike, Tyskland, Luxemburg, Polen, Sverige och Nederländerna. En av huvudresultaten av denna studie är den variation som observeras i de metoder som används inomåtervinningssystemet för pappersavfall. Införandet av det utökade producentansvarssystemet belyserbåde enskilda och flera organisationer med producentansvar, medan det separata insamlingssystemetför hushåll innebär insamling av avfall genom olika fraktioner. Följaktligen spelar de insamladefraktionerna och de avsedda fabrikerna för separerade material en avgörande roll i det mekaniskasorteringsskedet, tillsammans med skillnader i tillverkningsmetoder som används av fabrikerna undermaterialets återvinningsfas. Detta betonar viktiga överväganden som uppstår vid introduktionen av nyafiberbaserade produkter. Särskilt sammansättningen och fiberinnehållet i en produkt påverkar avsevärtdess registrering inom systemet, vilket i sin tur påverkar prissättningen. Dessutom är effektiv märkningav avgörande betydelse för att ge tydliga anvisningar till konsumenter om rätt hantering av produkten.Dessutom är lämpligheten hos produkter för mekanisk sortering beroende av att sorteringsteknikernaöverensstämmer med avfallsammansättningen. Slutligen identifierar studien fyra nyckelaspekter somär betydelsefulla för återvinningsprocesser: tryckbläck, tillsatser, pulpingstid och fiberlängd. Avslutningsvis har Papira, med sitt höga fiberinnehåll och biobaserade tillsatser, visat lovandemiljöegenskaper. Samtidigt kräver det ytterligare erkännande av återvinningssystemet ochkonsumenter, lämplig klassificering i enlighet med standarder och tester genom sorteringsanläggningaroch återvinningsverk för att uppfylla branschstandarder och optimera dess integration iåtervinningssystemet. Denna studie belyser vikten av att omfatta övervakningen av åtgärder enligtPPWR-förslaget, rollen för konsumentkommunikation och nödvändigheten av att upprätthålla enkonsekvent kommunikation bland alla intressenter.

Abstract AJ The goal of this thesis is to thoroughly chart the problem of waste management in Czech Republic and the European Union and to outline legal and economic situation in waste treatment and in its alternatives. This thesis deals with different types of landfills, their technical aspects and methods of depositing waste. The thesis also tries to point out material and energetic use of waste before landfilling. Recycling is considered to be important because it decreases the amount of waste stored in landfills. Composting and anaerobic digestion are the other methods of disposal. The thesis also describes the possibilities of usage of the landfill gasses with the help of cogeneration units. The thesis refers to current level of waste landfilling in the Czech Republic and in other countries of the European Union. Key words: waste management, landfilling, landfills, waste sorting, material recovery from waste, recycling, composting, energy recovery from waste, incineration,