<p>Because of increasing environmental demands, especially on dealing with products end of life phase, product manufacturers and designers must consider the future disposal of their products. For conventional materials like steel and aluminium well-functioning recycling methods exists. This is not the case for structures of polymer composites, which are used more extensively, especially for structures like vehicles and vessels. Several techniques do exist but they are not yet commercially available. The current disposal methods of polymer composites are landfill and incineration.</p><p>Polymer composites are materials, which consist of several materials like fibre, matrix, and additives. In the form of sandwich constructions also foam core material is added. This circumstance complicates the waste treatment of composite materials. In this thesis a model for assessing possible future waste treatment techniques for polymer composites including sandwich structures is presented. The model is meant to be used as an aid for preparing future disposal for end of life products for planning waste treatment and for facilitating communication in contacts with waste receivers.</p><p>Recommendations for waste treatment have been formed for a number of polymer composites. These recommendations are based on the analysis of costs and environmental effects and they compare different scenarios for mechanical material recycling and energy recovery by waste incineration. The result of this study points out material recycling as the preferable method for the main part of the studied materials. But this recommendation is strongly dependent on type of virgin material replaced by the recycled material. Energy recovery can also be considered if the polymer composite waste replaces coal, which is non renewable. Though incineration will always result in a cost for the waste producer.</p><p>In the recommendations mentioned above no information concerning implementation of the different waste disposal techniques is included. Therefore, in this study a model for assessing possible waste disposal techniques for polymer composites is presented. The model is based on internal factors, which are related to the waste and to the processes. To implement the model relevant waste properties must be identified in order to fulfil the conditions set by the required processes involved.</p><p>A case study was carried out using the proposed model for assessing different waste disposal techniques for the hull of the Visby Class Corvette in the Royal Swedish Navy. Six different techniques were studied for the hull structure. Since almost all the important waste properties were known and the waste was assessed to be treatable all the included techniques except one are shown to be usable in the future.</p><p>Many investigations have pointed out material recycling as the best alternative considering environmental effects. This is also valid for polymer composite materials. Since recycling polymer composites is a complicated process, especially recycling thermoset composite it is important to aquire comprehensive information about the constituents of these materials.</p>

In the European Union 500 million tonnes of waste are either incinerated without energy recovery,or deposited in landfills, which could have been recycled instead. The European Union initiated theCircular Economy Package in order to decrease the amount of waste being generated, lost inlandfills, and to increase the recycling and usage of recycled material. However, the CircularEconomy Package did not contain any targets focusing on energy recovery, and only mentionedenergy recovery as having a role in decreasing the amount of waste deposited in landfills. TheCircular Economy Package was in the end of 2014 withdrawn but will come back with moreambitious targets. In Sweden energy recovery is treating more than 50% of the municipal waste andwould then be affected by the targets of the Circular Economy Package when it comes back.This thesis focuses on Linköping and Norrköping to identify the what role energy recovery have inthese municipalities, both present and future, as well as asking the questions of how waste is valuedas a resource.The results were that both municipalities thought that it was important to have separate sorting ofmunicipal waste, to separate organic waste from the rest, in order to use it in material recycling andthe rest in energy recovery. In both municipalities the energy recovery had the role of treating themunicipal waste which was found to be not recyclable, as well as to deliver heat and electricity. Allof the organisations were identified to have a high environmental value on waste, but the economicvalue of waste were low or negative. The municipalities also knew little of the Circular EconomyPackage, but were aware of it, while the energy companies knew a little more of it, but still littlecompared to their national interest organisations Avfall Sverige and Svensk Fjärrvärme. All of theorganisations had identified similar challenges such as increased focus on recycling, minimisationof waste, but also a focus on decreasing amount of hazardous substances in products in order todecrease the amount of waste which needed to be deposited in landfills.

Wastewater contains many valuable constituents, including phosphorus, nitrogen and more energy than what is required to treat it. This, combined with increasingly more stringent effluent requirements and the desire for water reuse, creates a demand for a system capable of both nutrient and energy recovery. The main objective was to develop a new wastewater treatment process configuration capable of maximizing energy recovery while enhancing biological phosphorus removal. Three pilot membrane bioreactors were operated at SRTs ranging from 2 days to 8 days to evaluate membrane fouling, treatment performance, sludge production and sludge settleability. The results showed high organics removal and near complete nitrification at all SRTs. Membrane fouling was highest at lower SRTs. The collected data were then used to calibrate a series of model configurations. The best configuration consisted of two sludge systems in series, with a short SRT anaerobic-aerobic first stage and an extended SRT pre-anoxic second stage. / Canadian Water Network

The shortage of clean water has become a significant global problem, and capacitive deionization (CDI) is a technology that can be used to help relieve the problem. A Ćuk converter system that can recover energy from CDI cells is described. This converter transfers energy between two CDI cells when a cell is in its desorption period, allowing energy that would otherwise be lost to be recovered and improving overall system efficiency. In order to control the states of the MOSFET switches in the converter, a self boost charge pump is used. In this way, the microcontroller can control system duty cycle and optimize energy efficiency. A design method of reducing ripple losses caused by passive elements is presented. Several sensor circuits and their design methods that can minimize power losses are shown. The influence of initial voltage drop and voltage ramp time is also examined. This Ćuk converter system is tested using a dummy cell and a real CDI cell. The converter system shows promising performance experimentally.

The purpose of this study was to investigate the efforts to reduce food waste in local primary schools in two municipalities in northern Sweden, as well as to highlight any similarities and differences. Food waste is a major problem around the world, globally an estimated 1.3 billion tonnes of food are thrown away each year. With a growing population and the environmental impact that is already provides significant consequences, it is not healthy that food that could be eaten are thrown away. Sweden alone are throwing away 1.2 million tonnes of food each year, and school kitchen alone contributes with approximately 40 000 tonnes. To answer the purpose of this study, electronic questionnaires were sent out to the principals for a total of 78 schools. The result of this study shows that 67 % of the schools participating in this study, has received directives from the municipality on how to work to reduce food waste in primary school. But even those who have not received directives from the municipality still perform activities when 12 out of thirteen schools in municipality A and all eight schools in municipality B stated that they actively working to reduce food waste. Even though the measures taken within schools were to some extent similar, the directives from the municipalities differed between schools, also within the same municipality. As consequence, participating schools worked differently with their students on this topic.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O Ãleo de fritura à um resÃduo amplamente produzido em todo o mundo. No entanto, somente alguns paÃses mais desenvolvidos possuem polÃticas de descarte ambiental correto desse resÃduo, o que o torna um poluente em potencial em naÃÃes menos esclarecidas em relaÃÃo à questÃo ambiental. Portanto, este trabalho tem como objetivo principal apresentar uma tecnologia de produÃÃo de biodiesel a partir de Ãleo de fritura como forma de aproveitamento energÃtico, aliado a uma forma ambientalmente correta de destinaÃÃo final para esse resÃduo. O trabalho se inicia com uma revisÃo bibliogrÃfica bÃsica do estado da arte da produÃÃo de biodiesel. Em seguida, apresenta-se a proposiÃÃo de um processo quÃmico para a produÃÃo de biodiesel a partir de Ãleo de fritura e por fim, tem-se uma discussÃo da tecnologia, na forma como ela foi inserida no ambiente computacional utilizado para sua elaboraÃÃo. AlÃm da apresentaÃÃo da tecnologia propriamente dita, uma avaliaÃÃo ambiental do processo à feita para mensurar a capacidade do processo de produÃÃo de biodiesel proposto de diminuir o impacto causado pelo Ãleo de fritura no ambiente. / Waste cooking oil is a residue widely produced around the world. However, only a few developed countries have policies of environmental correct disposal of this waste, which makes it a potential pollutant in less enlightened nations about the environmental issues. Therefore, this work aims to present a technology for producing biodiesel from waste cooking oil as a form of energy recovery, combined with an environmentally correct disposal for this waste. The work begins with a basic review of the state of the art in biodiesel production. Then, it presents a proposition of a chemical process to produce biodiesel from waste cooking oil and finally has a discussion of the technology the way it was inserted in the computing environment used for its elaboration. Besides the presentation of the technology itself, an environmental assessment of the process is performed to measure the ability of the proposed biodiesel production process to reduce the impact caused by the waste cooking oil in the environment.

La production d'acier fait partie des productions mondiales les plus consommatrices d'énergie. L'état de l'art montre que les brames, après la coulée continue, sont refroidies à l'air libre de 900 °C à la température ambiante. Durant ce processus 540 MJ/tonne d'acier sont perdues. Cette thèse a permis de définir une méthode et un équipement aptes à extraire de l'énergie à haute valeur exergétique lors du refroidissement.Deux voies de récupérations sont présentées. La première voie est via un cycle thermodynamique direct. Le cycle choisi pour cette voie est le cycle de Hirn avec resurchauffe ayant un rendement global de 30 % produisant 10 MW de puissance électrique. La deuxième voie est via un système indirect utilisant le SYLTHERM 800 comme fluide caloporteur entre la brame et un cycle ORC, fonctionnant avec du R-245fa et avec un rendement globale de 17,6 %. Dans les deux configurations, les transferts thermiques choisis sont la conduction et le rayonnementUn banc d'essais, dimensionné utilisant la technique de similitude, a permis d'étudier les transferts thermiques intervenant dans l'équipement de récupération. La variation de la résistance de contact à l'interface brame-sole est étudiée en fonction de la température ainsi que le comportement thermique de l'échangeur de conduction. L'étude thermodynamique ainsi que l'étude thermique ont permis d'effectuer un pré-dimensionnement de l'équipement de récupération pour les deux configurations étudiées.Un modèle numérique utilisant la méthode des réseaux de composants est élaboré. Ce modèle est capable de reproduire les mêmes phénomènes physiques que ceux intervenant dans l'équipement de récupération / Steel production industry is one of the most energy consuming sectors. The state-of-the-art indicates that steel slabs leaving the continuous casting process are cooled without energy recovery by radiating to the atmosphere and convection. Not only a large amount of energy is wasted but this type of cooling is time consuming. During the cooling process of steel slabs from an initial temperature of approximately 900°C to outdoor air temperature, 580 MJ per ton of steel are wasted. This study has defined a method and an equipment capable of extracting the energy at high exergy value during cooling.The energy could be recovered using two different systems. The first is a direct thermodynamic generation cycle. The selected direct cycle is the Hirn cycle with intermediate reheating having an overall efficiency of 30 % and producing about 10 MW electric power. The second is an indirect system using SYLTHERM 800 as an intermediate heat transfer fluid between the metal slabs and an organic Rankine cycle using R-245fa as a working fluid with 17.6 % efficiency and producing about 6 MW. In both systems the dominant heat transfers to recover heat are conduction for the floor heat exchanger and radiation for the ceiling heat exchanger.A test bench was mounted, using a similitude technique, to study heat transfers. The variation of the thermal contact resistance as a function of the contact temperature is studied as well as the thermal behaviour of the conduction heat exchanger. The thermodynamic and the thermal studies led to a preliminary design of the recovery equipment.A numerical model is developed using the component interaction network. This model can reproduce the same physical phenomena taking place in the recovery equipment.

The Master Thesis outlines planning and valuation of solid waste incinerator with energy recovery. The focus of due diligence, made before valuation, is on the assessment of the input data in regard to current and future market situation. The beginning of the thesis explains the valuation process with methods used later on. The two subsequent parts describe respectively current market situation and define data for valuation process made in Excel sheet attached. Before concluding the outcomes are compared with other possibilities with changes in financing structure.

Diploma thesis deals with the use of residual energy in the exhaust gas through turbine generators. It is a turbine connected to a generator of electricity, which is inserted into the exhaust pipe. The aim of this thesis is to discover how much power turbine generator in the application produces and assess its applicability in practice.

The implementation of an energy recovery system for retreiving otherways wasted energy is an effective method for reducing the overall energy consumption of a mobile machine. In a fork lift, there are two subsystems that can be effectively modified for recovering energy. These are the driveline and the lift/lower function of the mast. This study focuses on the latter by studying a recovery system whose main component is a hydraulic transformer consisting of a hydraulic motor, a variable displacement pump and an induction motor. Since the flow rate/pressure - ratio can be modified, the utilization of the hydraulic transformer enables downsizing of the accumulator volume. However, the decrease of the gas volume leads to an increase in the compression ratio of the accumulator, which in terms leads to higher gas temperatures after charging and consequently to higher thermal losses during holding phase. In order to reduce these losses, a thermally regenerative unit was implemented to the gas volume of an accumulator to reduce the temperature build up during charging. In this study, the effect of improving the thermal characteristics of the accumulator to the efficiency of the whole energy recovery system is investigated by means of measurements.