Anaerobic digestion is a key energy and resource recovery technology. This work investigated potential organic waste resources to co-digest with household food waste (HFW) to stabilise the process and future-proof feedstock availability. This included novel feedstock macroalgae (seaweed) waste (SW). Hydrothermal (autoclave) pretreatment was also investigated to optimise energy recovery from HFW and SW. Preliminary experiments investigated the behaviour of HFW co-digested with either a green waste (GW) or paper waste (PW), using a batch-test laboratory scale and systematic approach with a revised waste mixture preparation method. Following preliminary trials, the co-digestion of HFW/SW was investigated using an air-dried SW mixture. Batch experiments to determine the biomethane potential (BMP) at different ratios of HFW to SW were set up. Co-digesting HFW and SW at ratio 90:10 (d.w.) achieved a BMP similar to HFW alone (252±13 and 251±1 cm3 g-1 VS, respectively), and a peak methane yield for HFW:SW (90:10) at day 12 of 69±3% compared to a peak methane yield for HFW at day 19 of 70±3%. Addition of SW optimised the C/N ratio, increased concentrations of essential micronutrients and produced an overall increase in reaction kinetics. Concentrations of SW ≥25%, associated with high sulphur levels, reduced final methane productivity. Analysis of the macroalgae strains L. digitata, U. lactuca and F. serratus from the SW mixture was carried out to compare mono-digestion and co-digestion with HFW at a 90:10 ratio and the effect of autoclave pretreatment at 136°C. Co-digestion had a positive impact on methane yields for U. lactuca and F. serratus, whilst autoclave pretreatment had no significant impact on the SW strains When results were modelled for a 320 m3 anaerobic digester treating 8m3 feed per day the theoretical energy balance showed that optimal energy production from pretreated HFW at 8.09 GJ/day respectively could be achieved. To verify the suitability of using macroalgae, known to readily uptake polycyclic aromatic hydrocarbons (PAH), toxicity tests were used to determine the impact of phenanthrene sorbed by U. lactuca on the AD process. Despite U. lactuca’s ability to biosorb phenanthrene in under 2 hours, no impact on the AD process was observed. Overall, results of this study demonstrated that co-digestion of HFW and SW, at batch laboratory scale, provide a viable and sustainable waste revalorisation solution. In addition, low temperature autoclave pretreatment increased methane production (p=0.002) from the AD of HFW.

The rapid development in renewable generation technologies and flexible distribution networks requires current infrastructure to be modified and developed to adapt high penetration levels of distributed generation. Existing distribution networks were not initially designed and anticipated to accommodate generators on large scale. Short circuit studies ensure the effectiveness of protection equipment settings and coordination is maintained in case of short circuit, despite any additional distributed generation is connected to the distribution network. This research aims to study and compare the different network fault situations for wind energy systems with induction generators, photovoltaic energy systems, and diesel generators connected to distribution networks. The simulation study will be conducted on the existing IEEE case study systems including 13 bus and 30 bus distribution test systems, using ETAP software. Short circuit analysis will be performed twice to include the ANSI/IEEE and the IEC methods for short circuit currents calculation. Simulated results showed that the wind energy systems have significant impact on the short circuit currents, whereas the photovoltaic energy systems are found to have inconsequential effect. The most moderate solution is found to be a distributed generation mix.

In the light of advancing climate change and the anticipated scarcity of affordable fossil fuels, a transition towards more sustainable energy systems is vital to allow for the long-term sustainability of human wellbeing. Energy is a key sustainability issue, at the heart of the complex interactions of socioeconomic and biophysical systems. The overall aim of this study is to contribute to furthering the understanding of these systems interactions. It intends to deliver methodological insights on how to identify and appraise favourable energy futures in a changing and uncertain world. In order to cope with the complexity and uncertainty of future developments and with the plethora of partly contradictory social preferences, a participatory approach was combined with scenario development and the application of an appraisal tool that takes account of the multidimensionality of system interlinkages. In a case study for Austria, favourable renewable energy scenarios were developed in a participatory setting, involving key Austrian energy stakeholders. The scenario development consisted of two stages: first an exploratory stage with stakeholder engagement and second a modelling stage generating forecasting-type scenarios. Accordingly, the scenarios consist of a narrative part, the storyline, and a modelled, quantitative part. The application of Multi-Criteria Analysis (MCA) allowed the integration of multi-dimensional sustainability information (social, environmental, economic, and technological criteria) and the social preferences of the stakeholders into the appraisal of the energy scenarios. In the case study presented, five renewable energy scenarios for Austria for 2020 were compared against 17 sustainability criteria. The study illustrates how the combined use of participatory scenario building techniques and MCA acknowledges and integrates inherent complexity, irreducible uncertainty, multi-dimensionality, and, a multiplicity of legitimate perspectives in the appraisal. The main empirical result of the sustainability appraisal undertaken shows that, contrary to the current energy policy in Austria, a profoundly decentralised energy system (scenario E) and an innovative long-term investment strategy (scenario C) rank highest, whereas the renewable strategy based on biomass (scenario D), which represents the dominant political trajectory in Austria's renewable energy policy, ranks very low. The research demonstrates the integration of biophysical, social, economic, and, technological appraisal criteria, presents and discusses best practice criteria, and, illustrates the challenges and opportunities to incorporate bio-physical aspects into the concept of sociotechnical systems and their transitions in the light of a more sustainable development.

Education has contributed to a society-wide awareness of environmental issues, and we are increasingly confronted with the need for new ways to generate energy, save water and reduce pollution. Thus new forms of work are emerging and government, employers and educators need to know what ‘green’ skills South Africa needs and has. This creates a new demand for ‘green skills’ research. We propose that this new knowledge field – like some other educational fields – requires a transformative approach to research methodology. In conducting reviews of existing research, we found that a transformative approach requires a reframing of key concepts commonly used in researching work and learning; multi-layered, mixed method studies; researching within and across diverse knowledge fields including non-traditional fields; and both newly configured national platforms and new conceptual frameworks to help us integrate coherently across these. Critical realism is presented as a helpful underpinning for such conceptual frameworks, and implications for how universities prepare educational researchers are flagged.

To combat the rising global temperature Sweden have signed the Paris Agreement to limit the release of CO2 and keep the temperature to a minimum increase of 1,5 degrees. A transformation of today’s energy system towards renewable energy is paramount to this endeavour, which in part relies on public acceptance where media plays an important role inshaping public acceptance. This study aims to map acceptance of renewable energy sources and draws on framing theory, which states that the media focuses attention on certain events and gives information meaning, in a sense how something is presented to the audience influences their choices in how to process said information. As this is a qualitative study, 49 articles about bio-, geothermal, solar, water and wind energy from Sweden’s four major newspapers, Aftonbladet, Dagens Nyheter, Expressen and Svenska Dagbladet, have been gathered from the Svenska dagstidningar database and examined through frame analysis. Media framing contributing to public acceptance was bio- and solar energy while water subtracted from it. Wind energy were both contributing and subtracting from acceptance while geothermal lacked articles entirely, prohibiting it from entering public discourse altogether. Meanwhile the biggest deciding factor towards framing acceptance for renewable energy depended largely on the newspaper. / För att bekämpa den stigande globala temperaturen har Sverige undertecknat Parisavtalet föratt begränsa koldioxidutsläppen och hålla temperaturen till en minsta ökning på 1,5 grader. En omvandling av dagens energisystem mot förnybar energi är avgörande för detta mål, vilket delvis bygger på allmänhetens acceptans och som media har en viktig roll i att utforma. Denna studie syftar till att kartlägga acceptans av förnybara energikällor och bygger på Framing Theory, som menar att media fokuserar uppmärksamhet på vissa händelser och ger det mening, hur det presenteras sedan för publiken påverkar deras val. Eftersom det här är en kvalitativ studie har 49 artiklar om bio-, geotermisk-, sol-, vatten- och vindenergi från Sveriges fyra största tidningar, Aftonbladet, Dagens Nyheter, Expressen och Svenska Dagbladet samlats från databasen Svenska dagstidningar, dessa granskas genom Frame Analysis. Media framing som bidrar till allmän acceptans var bio- och solenergi medan vatten inte bidrog. Vindenergi både bidrar till och minskar acceptans medan geotermisk saknad eartiklar helt och hållet, vilket gör att den utelämnas från den offentliga diskursen. Samtidigt berodde den största avgörande faktorn av framing för acceptans av förnybar energi på nyhetstidningen.

The demand for energy continues to grow but concerns over climate change means that conventional fossil fuels will eventually need to be replaced. The solution to the energy crisis will require a combination of both conventional energy sources with CO2 capture and renewable technologies. While many renewable technologies exist, it is not common that CO2 capture is incorporated into the process. Biomass is an ideal feed-stock for bio-energy production as it is CO2 neutral. Many thermochemical conversion technologies exist, but the Alkaline Thermal Treatment (ATT) reaction is particularly interesting because it combines conventional thermochemical conversion with CO2 capture in order to create a process that is potentially CO2 negative. By reacting biomass with a metal hydroxide, high purity H2 can be produced while simultaneously locking the carbon as a stable carbonate, which is a form of Bio-energy with Carbon Capture & Storage (BECCS). The H2 can then be used for applications ranging from Fischer-Tropsch synthesis to PEM fuel cells. Group I & II hydroxides were investigated for their ability to react with cellulose (a biomass model compound) in the ATT reaction scheme. Comparison between both groups indicated that NaOH and Ca(OH)2 were the best hydroxides from groups I & II respectively. However, the amount of H2 produced during the ATT of cellulose with Ca(OH)2 is considerably lower than with NaOH. A 10% Ni/ZrO2 catalyst was then added to increase the yield of H2 from the reaction between cellulose and Ca(OH)2. It was found that at 20% catalyst loading, the amount of H2 produced and the suppressed level of CO2 was similar to the ATT with NaOH. Several other catalytic metals were also investigated and found to have the following H2 production activity: Ni > Pt≈Pd > Co > Fe, Cu. Since Ni was the most active and has a considerably lower cost than noble metals it was chosen for additional studies. The ATT reaction in the presence of Ni has two distinct steps in the formation of H2 from cellulose. The presence of Ca(OH)2 enhances the formation of linear oxygenates from cellulose. These oxygenates are then reformed over the Ni-based catalyst to H2 and CO2, the latter of which is captured by Ca(OH)2 to form CaCO3. If either Ca(OH)2 or Ni was removed from the reaction, the yield H2 fell significantly. Although the reactants and the catalyst are all solid materials, they do not need to be physically mixed. The Ni-based catalyst produced H2 primarily through the reforming of gaseous species and therefore could be placed ex-situ of the cellulose and Ca(OH)2 mixture. However, placing the catalyst away from Ca(OH)2 prevented CO2 capture. In order to remedy this Ca(OH)2 was mixed with the Ni-based catalyst and mixture was placed ex-situ of pure cellulose. This created a process whereby cellulose could be decomposed thermally followed by a single gas-phase Alkaline Thermal Treatment (GATT) reforming step of the pyrolysis vapors to H2 with suppressed CO2.

Orientador: Odivaldo José Seraphim / Banca: Ivo Reis Fontes / Banca: José Ângelo Cagnon / Banca: João Alberto Borges de Araújo / Banca: Frederico Guilherme de Paula Ferreira Ielo / Resumo: A utilização de sistemas energéticos alternativos, nos dias atuais, é uma necessidade de caráter urgente devido aos problemas que o planeta vem enfrentando como o aquecimento global, efeito estufa e a perda da camada de ozônio. A limitação das fontes de energias convencionais é outro problema que terá de ser equacionado para o futuro da humanidade; deve-se considerar que as pessoas estão habitando, cada vez mais, locais afastados e desprovidos de infra-estrutura energética. Aplicando-se tecnologias como as de automação e controle podemos solucionar esse problema; portanto, o trabalho visou a aplicação de um equipamento de uso industrial, o Controlador Lógico Programável, em sistemas de energia renováveis, notadamente o sistema de geração eólica e a geração fotovoltaica, usados para bombeamento de água, objetivando-se um controle automático e mais eficiente nos locais onde haja disponibilidade simultânea dessas fontes, baseados em critério de prioridade pré-estabelecido. Fez-se, também, uma avaliação do potencial hidráulico e energético dos sistemas de energia fotovoltaico e eólico utilizados no sistema automático de bombeamento de água no local de realização do experimento para as condições físicas pré-estabelecidas. Os resultados mostraram que o sistema de controle utilizando o CLP é viável, possui confiabilidade e o programa desenvolvido em linguagem Ladder pode ser adaptado para a utilização com várias fontes de energia disponíveis em um determinado local. 2 O sistema fotovoltaico de bombeamento direto, que utilizou um painel solar policristalino de 70 Watts ligado a uma bomba Shurflo 8000, mostrou-se eficiente com vazões significativas em quase todos os meses. O sistema eólico de bombeamento indireto, utilizando um mini aerogerador de 400 Watts alimentando uma bateria ligada à bomba Shurflo, não demonstrou capacidade energética suficiente para utilização nesse tipo específico de aplicação. / Abstract: The use of alternative energy systems in the current days is an urgent necessity due to the problems that the planet is facing as the heating and loss of ozone layer. The scarcity of conventional energy is another problem that must be solved for the future of humanity. It must be considered that the people are inhabiting places moved away not always with available energy. The application of technologies as automation and control can help us to solve this problem. Therefore, this work aimed at apply an equipment of industrial usage, the Programmable Logical Controller, PLC, in alternative energies systems, as eolic generation and fotovoltaic generation used for water pumping, aiming the automatic control and the efficiency in the places where it has simultaneous availability of these sources, based in criterion of priority that previously established itself between them. It was made a hydraulic and energetic evaluation of the energy system, eolic and fotovoltaic, used in the automatic control system of pumping, in the place of accomplishment of the experiment, according to previously established physical conditions. The results have shown that the control system using the PLC is practicable and has trustworthiness. The program developed can be adapted for the use with several power plants in a specific application place. The fotovoltaic system of pumping, using a polycrystalline of 70 Watts connected to a pump Shurflo 8000, showed to be efficient with significant flows in almost all the months. The eolic system of pumping, using an eolic generator of 400 Watts assembled in place of experiment, did not demonstrate energetic capacity for use in this specific type of application. / Doutor

On planet Earth, fossil fuels are the most important sources of energy. However, these resources are limited and being depleted dramatically throughout last decades. Finding feasible substitutes of these resources is an essential duty for humanity. Fortunately, Mother Nature is providing us a number of good solutions for this crucial threat against our planet. Solar irradiance, wind blowing, oceanic and maritime waves are natural resources of energy that are capable of completely covering the annual consumption of all inhabitants on the Earth. In this research a set of components including “Northern Power NPS 100-24” wind generators, “Kyocera KD 145 SX-UFU” PV arrays, “Gildemeister 10kW-40kWh Cellcube” battery bank and HOMER bi-directional converter system were considered and successfully applied on HOMER tool and Particle Swarm Optimization (PSO) method. The main design goals of the presented hybrid system are to use 100% renewable energy resources in the commercial sector, where all power is produced in the immediate vicinity of the business place, adding strong advertising values to the setup. In order to supply hourly required load for a grocery store   (1000 ) in Malmö city with 115 kW peak load and 2002 kWh/d with maximum 0.1% unmet, the system was optimized to achieve minimum Levelized Cost of Energy (LCOE) and the lowest Net Present Cost (NPC). The HOMER simulation for quantitative analysis, along with a Particle Swarm Optimization (PSO) solution method is proposed and the results are compared. The results show that an optimized hybrid system with 3.12  LCOE, and power production of 28.5% by PV arrays and 71.5% by wind generators, is the best practice for this case study. / De fossila bränslena är idag de viktigaste energikällorna på jorden. Dessa resurser är dock begränsade och har utarmats i en allt högre takt under de senaste decennierna. Att hitta möjliga ersättare för dessa resurser är därför viktigt. Lyckligtvis tillhandahåller naturen ett antal bra lösningar för detta avgörande hot mot vår planet. Solstrålning, vind, havsströmmar och -vågor är naturliga resurser av energi som kan täcka hela den årliga globala förbrukningen. I den här rapporten studeras ett hybridsystem bestående av Northern Power NPS 100-24 vindkraftverk, Kyocera KD 145 SX-UFU solcellerspaneler, Gildemeister 10kW-40kWh Cellcube batteribank och HOMER dubbelriktad växelriktare. Detta modellerades och optimerades dels i mjukvaran HOMER, dels via optimeringsmetoden Particle Swarm Optimaization (PSO). Det övergripande designkravet för det presenterade hybridsystemet är att använda 100% förnyelsebar energi i en kommersiell verksamhet, där all elektricitet produceras i närhet av verksamheten, vilket kan ge tydliga marknadsföringsvärden till installationen. För att kunna möta energibehovet varje timme för en livsmedelsbutik (1000 ) i Malmö med 115 kW toppförbrukning och 2002 kWh/dag, med maximalt 0,1% ej mött behov, optimerades systemet för att uppnå minimal energikostnad (Levelized Cost of Energy, LCOE) och lägsta nettonuvärde (Net Present Cost, NPC). En HOMER-simulering för kvantitativ analys, tillsammans med en PSO-optimering, har genomförts och resultaten har jämförts. Resultaten visar att ett optimerat hybridsystem med LCOE på 3,12 SEK/kWh, där solceller står för 28,5% av kraftproduktionen och vindkraftverk för 71,5%, är den bästa lösningen för denna fallstudie.

The European Union has committed itself to a goal of reaching 20 % share of renewable energy in its total energy consumption by 2020. A corresponding goal is to reach a certain share of renewables in the sector of electricity generation. This paper examines whether the EU is able to reach its goals through its current public policy. First, obstacles preventing renewables from better market integration are identified. Then union soft- and hard-law legislative support of renewable sources of energy is discussed. Last chapter analyses the EU's response to the identified obstacles and its public policy in the field of renewables.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-05-03T13:32:24Z No. of bitstreams: 1 PDF - Ramon Freire da Silva.pdf: 2172249 bytes, checksum: 4d80236030ada8b7da00fcc846672e9b (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-25T19:29:36Z (GMT) No. of bitstreams: 1 PDF - Ramon Freire da Silva.pdf: 2172249 bytes, checksum: 4d80236030ada8b7da00fcc846672e9b (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-07-25T19:32:45Z (GMT) No. of bitstreams: 1 PDF - Ramon Freire da Silva.pdf: 2172249 bytes, checksum: 4d80236030ada8b7da00fcc846672e9b (MD5) / Made available in DSpace on 2016-07-25T19:32:45Z (GMT). No. of bitstreams: 1 PDF - Ramon Freire da Silva.pdf: 2172249 bytes, checksum: 4d80236030ada8b7da00fcc846672e9b (MD5) Previous issue date: 2016-02-18 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Biodiesel is an alternative to renewable fuel production in the national energy matrix comes from oilseeds such as the castor bean and peanuts which are plants grown by farmers in semi-arid northeast. In the paper aimed to optimize via ethyl, basic catalysis using ultrasound system 3 biodiesel synthesis of castor beans and peanuts. Initially we used the designs Box Behnken 2 with 12 factorial points (+1 and -1), to estimate the experimental error were used three central points (0), totaling 15 experiments. They were analyzed three independent variables catalyst concentration, proportion castor beans/peanut, molar ratio alcohol:oil due to the mass yield of biodiesel. We analyzed the effects of the variables and the significance using the Student test and analysis of variance to 95% probability. Aiming to optimize the reaction conditions of synthesis used a second Box Behnken 2 design with 12 factorial points, three central points with three independent variables: catalyst concentration, castor bean/peanut proportion and molar ratio alcohol / oil, adapting the levels under the influence of variables from the previous design. The 3 experimental optimum condition was determined using response surface methodology. The ultrasound system is feasible for biodiesel synthesis castor beans and peanuts, because we used a reaction time and temperature under 60 minutes and 40°C respectively, without compromising the mass yield of biodiesel. The design has set a great experimental conditions: catalyst concentration 1.06%, proportion castor bean/peanut 32.6/67.4 and molar ratio alcohol/oil 22.95:1. In these experimental conditions the maximum theoretical yield calculated was 91,83%. After application of the theoretical conditions was observed a 91,56% yield small difference exists between 0,27% yields. / O biodiesel é uma alternativa para produção de combustível renovável na matriz energética nacional, tem origem em grãos oleaginosos a exemplo da mamona e amendoim que são plantas cultivadas por agricultores familiares no semiárido nordestino. No trabalho, objetivou-se otimizar via etílica, catálise básica, utilizando sistema de ultrassom a síntese de biodiesel de mamona e amendoim. Inicialmente utilizou-se o delineamentos Box Behnken 2 com 12 pontos fatoriais (+1 3 e -1), para estimativa do erro experimental foram utilizados 3 pontos centrais (0), totalizando 15 experimentos. Foram analisadas três variáveis independentes concentração de catalisador, proporção mamona/amendoim, razão álcool/óleo em função do rendimento mássico de biodiesel. Analisou-se os efeitos das variáveis e a significância por meio do teste t-student e análise de variância a 95% de probabilidade. Objetivando-se otimizar as condições reacionais de síntese utilizou-se um segundo delineamento Box Behnken 2 com 12 pontos fatoriais, 3 pontos centrais com três variáveis independentes: concentração de catalisador, proporção mamona/amendoim e razão álcool/óleo, adequando-se os níveis de acordo com a influência das variáveis do 3 delineamento anterior. A condição ótima experimental foi determinada utilizando-se metodologia de superfície de resposta. O sistema de ultrassom é viável para síntese de biodiesel de mamona e amendoim, pois utilizou-se um tempo de reação e temperatura baixos 60 minutos e 40ºC respectivamente, sem comprometer o rendimento mássico do biodiesel. O delineamento estabeleceu como ótimo experimental as condições: concentração de catalisador 1,06%, proporção mamona/amendoim 32,6/67,4 e razão álcool/óleo 22,95:1. Nessas condições experimentais o rendimento máximo teórico calculado foi 91,83%. Após aplicação das condições teóricas observou-se um rendimento 91,56% existindo pequena diferença entre os rendimentos de 0,27%.