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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

[en] ORGANIC SOLID WASTE TREATMENT: ANAEROBIC DIGESTION ANALYSIS OF THE POTENTIAL BIOGAS YIELD FROM TANGERINE PEEL / [pt] TRATAMENTO DE RESÍDUOS SÓLIDOS ORGÂNICOS: ANÁLISE DO POTENCIAL DE GERAÇÃO DE BIOGÁS PROVENIENTE DA DIGESTÃO ANAERÓBIA DA CASCA DE TANGERINA

RAFAEL VIEIRA DE CARVALHO 30 December 2020 (has links)
[pt] Em um cenário onde a geração de resíduos ao redor do mundo cresce cada vez mais, técnicas de tratamento de resíduos são fundamentais para garantir menores emissões de gases de efeito estufa ao meio ambiente. Esta pesquisa apresenta uma análise realizada com cascas de dois tipos distintos de tangerina, com a finalidade de estudar o potencial de geração de biogás das mesmas através da realização de um ensaio BMP (Biochemical Methane Potential). A digestão anaeróbia de resíduos orgânicos corresponde a um tratamento biológico que apresenta uma solução com produtos valiosos, como o biogás, no combate ao aumento de emissões poluidoras, já que o mesmo pode ser utilizado como energia térmica, elétrica ou combustível em detrimento aos combustíveis fósseis. Dessa forma, esta pesquisa também realiza um estudo acerca do processo de fabricação de sucos naturais por parte de pequenos e grandes produtores e de como os mesmos podem utilizar as cascas dos restos da produção dos sucos para a geração de biogás como fonte de energia limpa. Os resultados encontrados apresentam para a casca da tangerina Ponkan um potencial de geração de biogás de 615,38 NmL/gSV e, para a casca da tangerina Montenegrina, o valor encontrado foi de 565,84 NmL/gSV. Os resultados obtidos sugerem um potencial de geração de biogás positivo para o substrato analisado, a tangerina, quando comparados aos demais resultados de outras frutas encontradas na literatura. / [en] The constant increase in global warming that occurred after the middle of the twentieth century and intensified by anthropogenic actions based on the emission of greenhouse gases such as methane, is a reality that worries not only for the harmful damages to the environment and the quality of life of human beings, but also for the preservation of future generations (Silva and Paula, 2009). In the mid-1980s, with the Brundtland conference, the concept for sustainable development emerged which is defined as meeting the needs of the present without compromising future generations (BRUNDLAND, 1987). In order to avoid excessive damage to the existence of human beings, recent studies by the Intergovernmental Panel on Climate Change (IPCC, 2018) examined the need to limit global warming to 1.5 Celsius instead of 2 Celsius, as previously predicted by the Paris Climate Agreement signed in 2015. According to the study, the absence of measures to be taken at present may generate extremely harmful damage to the environment, human beings, fauna, and flora of the planet. Limiting global warming to 1.5 Celsius involves large reductions in the emission of methane (CH4) and carbon dioxide (CO2). Thus, a strong demand in the bioenergy sector is necessary, highlighting the importance of using appropriate management measures which contribute to minimizing the problem, as is the case with the use of anaerobic digestion as a treatment for organic solid waste. The growing increase in the world population and the accelerated urbanization process of cities have resulted in the generation of excessive amounts of solid urban waste (Roth & Garcias, 2008), which, if poorly managed, contribute not only to the increase in damage caused to environment, but also inflict several problems in the social and economic aspect of modern society, thus aggravating the problem.
2

Estimativa da geração de biogás no aterro Sanitário metropolitano de João Pessoa através Do teste BMP

Silva, Gardênia Azevedo 14 December 2012 (has links)
Made available in DSpace on 2015-05-14T12:09:31Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4535021 bytes, checksum: 6a466a19576e3fff542d984d0c14fecd (MD5) Previous issue date: 2012-12-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The study of biological conversion for energy purposes in landfills of municipal solid waste is a major breakthrough to the society and it is considered having an extremely environmental and economic importance. Given this ostentation a study was conducted in the João Pessoa's metropolitan landfill , in order to estimate the production of biogas and its main component, methane. There is no an official protocol of the Biochemical Methane Potential Test (BMP) for the prediction of gas generated for this reason literature searches were conducted and a methodology was adapted based on the characterization and monitoring of the main factors involved in the degradation process. The steps of the study were as following: waste's gravimetric characterization, physicochemical characterization and acclimatization of inoculum and the BMP test, which includes the inoculation of the reaction ways , the monitoring of the biogas' volume produced, the quantitative and qualitative control of the generation of gases comprising the biogas and consequently the estimate of the generation of biogas in the landfill. The results has showed that the gravimetric characterization of the municipal solid waste, which used the French method MODECOM brought data definitions more precise, giving reliability to the composition of the waste. The proposed methodology for the BMP test was effective in obtaining the results, as it has produced a volume of accumulated biogas 282.66 NL.kg-1MS in 90 days in the biodegradable waste, consistent with the literature, providing a favorable production of biogas in the João Pessoa's metropolitan landfill. As it was considered an excellent experimental tool for determining the potential for the biogas generation in MSW, the BMP test enables the preparation for the official procedure. / O estudo da conversão biológica com fins energéticos em aterros de resíduos sólidos urbanos representa um grande avanço para a sociedade, sendo considerada de extrema importância ambiental e econômica. Diante dessa ostentação foi realizado um estudo no aterro sanitário metropolitano de João Pessoa, visando estimar a produção de biogás e do seu principal componente, o metano. Por não existir um protocolo oficial do Teste do Potencial Bioquímico de Metano (Teste BMP) para a previsão dos gases gerados, foram realizadas pesquisas bibliográficas e adaptada uma metodologia fundamentada nas caracterizações e monitoramentos dos principais fatores envolvidos no processo de degradação. As etapas do trabalho foram as seguintes: caracterização gravimétrica dos resíduos, caracterização físico-química e aclimatação do inóculo e o Teste BMP, o qual inclui a inoculação dos meios de reação, o monitoramento do volume de biogás produzido, o controle quantitativo e qualitativo da geração dos gases que compõem o biogás e consequentemente a estimativa de geração do biogás no aterro. Os resultados mostraram que a caracterização gravimétrica dos resíduos sólidos urbanos, a qual utilizou o método francês MODECOM, trouxe definições de dados mais precisos, dando confiabilidade à composição dos resíduos. A metodologia proposta para o teste BMP mostrou-se eficiente na obtenção dos resultados, pois produziu no resíduo biodegradável um volume acumulado de biogás de 282,66 NL.kg-1MS em 90 dias, condizente com a bibliografia, possibilitando uma produção favorável de biogás no aterro sanitário metropolitano de João Pessoa. Por ter sido considerado uma excelente ferramenta experimental para determinação do potencial de geração de biogás nos RSU, o teste BMP, viabiliza a elaboração para um procedimento oficial.
3

Etude du potentiel de valorisation énergétique ou matière de composés organiques extraits de lixiviats de déchets ménagers / Energetic valorization and soil enrichment with organic compounds extracted from a landfill leachate

Baccot, Camille 16 December 2016 (has links)
Les contraintes techniques et économiques induites par la gestion des lixiviats de déchets ménagers et assimilés (LDMA) pourraient être minimisées en considérant le LDMA non plus comme un déchet mais comme un « co-produit » partiellement valorisable. Parmi la diversité des constituants des LDMA, la matière organique dissoute (MOD) présente 2 intérêts majeurs : une forte charge et des processus de transformations comparables à ceux de la matière organique naturelle (MON). Ce travail de thèse s’attache donc à extraire cette MOD des LDMA selon son caractère hydrophobe et à identifier des axes de valorisation. Seules les fractions de type hydrophobe (HPO*) et transphilique (TPH*), de par leurs caractéristiques et leur réactivité, ont été considérées dans cette étude et 2 voies de valorisation ont été testées : une valorisation énergétique et une valorisation matière par amendement sur un sol en déficit de carbone organique (Corg).La caractérisation des fractions de MOD anthropiques et leur comparaison à des fractions de MON a confirmé l’intérêt majeur de leur valorisation. En effet, elles sont (i) physiquement et chimiquement comparables à la MON, (ii) quantifiables à des concentrations jusqu’à plus de 1000 fois supérieures à la MON permettant ainsi un potentiel d’extraction conséquent en comparaison aux matrices environnementales telles que les eaux de surface, et (iii) plus facilement biodégradables que la MON, tout en ne présentant aucun caractère phytotoxique avéré.Un test BMP optimisé et adapté au LDMA a été développé via un plan d’expérience, puis utilisé pour mettre en évidence l’impact du caractère hydrophobe de la MOD du LDMA sur la digestion anaérobie, et notamment la production de méthane. Selon les résultats obtenus, les molécules organiques de type transphilique favorisent la production de biogaz. De plus, la fraction hydrophile, faiblement aromatique, diminue la teneur en méthane du biogaz, contrairement à la fraction hydrophobe.Enfin, l’amendement de fractions organiques extraites de LDMA présente un réel intérêt dans le cas d’un sol initialement pauvre en Corg. La fraction HPO* permet un apport de Corg plus important comparé à la fraction TPH*, tandis que les composés transphiliques favorisent l’activité biologique du sol.Ce travail de thèse a ainsi mis en évidence l’intérêt d’extraire les fractions hydrophobe (HPO*) et transphilique (TPH*) de la MOD de LDMA afin de les engager dans des processus de valorisation énergétique et agronomique. / The management of municipal solid waste leachates (MSWL) is technically and economically restrictive. It thus should be interesting to consider this effluent no more as a waste but rather as a partially valorizable “co-product”. The dissolved organic matter (DOM) is one of the major components of MSWL and presents a twofold interest: a high load and comparable processes of transformation to those of natural organic matter (NOM).This study thus aimed at extracting the DOM from MWSL according to its hydrophobic character and identifying ways of valorization. Only hydrophobic (HPO*) and transphilic (TPH*) fractions were considered because of their characteristics and reactivity. Two different ways of valorization were investigated: energetic valorization and enrichment of a soil with low content in organic carbon (Corg).The characterization of HPO* and TPH* fractions and their comparison with fractions of NOM confirmed their high valorizable potential. Indeed, they are physically and chemically comparable to NOM, they can be quantified at concentrations up to 1000 times higher than NOM (high extraction potential when compared to environmental matrices such as surface water), and they are more easily biodegradable than NOM without any phytotoxic character.An optimized BMP test was first developed by using an experimental design to adapt the experimental conditions to the digestion of MSWL. It was then applied in different conditions to highlight the impact of the hydrophobic character of the DOM of MSWL on the anaerobic digestion, and mainly on methane production. According to the results, the transphilic-like organic molecules improve the biogas production. Besides, the hydrophilic-like compounds with low aromatic character decrease the methane content of the produced biogas contrary to the hydrophobic fraction.Finally, organic fractions extracted from MSWL were relevant to enrich soil with low content in organic carbon. The HPO* fraction better improves the Corg content when compared to the TPH* fraction whereas transphilic-like molecules enhances the soil biological activity.With the results of this research study, the HPO* and TPH* fractions extracted from a MSWL can thus be considered both to produce biogas and particularly methane and to be amended on soils. Their extraction can thus be economically viable and their treatment no more highly costly.
4

Optimering av driftstemperatur vid mesofil rötning av slam : - funktionskontroll vid Uppsalas reningsverk / Optimizing operational temperature in mesophilic digestion of sewage sludge : – a study at Uppsala wastewater treatment plant

Andersson, Johanna January 2019 (has links)
För att minska klimatpåverkan är energisnåla processer och användning av fossilfria bränslen viktigt. Vid stabilisering av avloppsslam vid reningsverk är en vanlig metod rötning som förutom att ta hand om slammet även producerar biogas, ett fossilfritt bränsle med låga växthusgasutsläpp. Processer som drivs inom det mesofila temperaturområdet har visat sig vara stabila och ger en jämn gasproduktion. Det mesofila området sträcker sig mellan 25–40°C men de flesta processer drivs mellan 35–40°C. Den här studien undersöker möjligheten att sänka temperaturen inom det mesofila området för att få en lägre energiförbrukning och en energisnålare process. Då det är viktigt att biogasproduktionen inte försämras av en sänkt temperatur har skillnad i utrötningsgrad, metanpotential och utrötningstid undersökts vid tre olika temperaturer (32, 34,5 samt 37,5°C) via satsvisa utrötningsförsök. Utöver påverkan på biogasproduktionen har en energibalansberäkning utförts för rötkamrarna vid Uppsala reningsverk. Detta ger ett mått på hur stora vinster i värmeenergi en sänkt temperatur kan leda till. En betydande kostnad vid reningsverk är avvattningen av slam och det är därför viktigt att den inte riskerar att försämras om temperaturen sänks. Ett filtreringsförsök som mäter CST (Capillary Suction Time) ger ett mått på slammets avvattningsegenskaper och har därför utförts vid tre olika temperaturer. Resultaten visade ingen försämring i biogasproduktion vid en sänkning till 34,5°C och en minskning i metanpotential med 11 % vid en sänkning till 32°C. Nedbrytningshastigheten försämrades inte vid en sänkt temperatur. Vinster i form av lägre värmeförbrukning uppgick till 14 % vid sänkning till 34,5°C och 27 % vid sänkning till 32°C. Avvattningsförsöket visade ingen försämrad avvattning vid lägre temperaturer. Den här studien visar att det finns en möjlighet att sänka temperaturen i rötkammaren vid reningsverket i Uppsala och på så sätt sänka energiförbrukningen. För att bekräfta resultaten bör även kontinuerliga försök utföras men denna studie visar att det är möjligt att få en lyckad nedbrytning även i lägre mesofila temperaturer. Resultatet öppnar upp för fortsatta undersökningar om temperaturförändringar inom det mesofila området och kan leda till en optimering av rötningsprocessen och möjlighet att få en effektiv och energisnål produktion av biogas. / Energy efficient processes and the use of fossil free fuels play an important role in order to reduce the impact of climate change. Anaerobic digestion is a common way for stabilizing sewage sludge at wastewater treatment plants (WWTP). One of the benefits with anaerobic digestion is that it also produces biogas, a fossil free fuel with low greenhouse gas emissions. An operational temperature within the mesophilic range has proven to give a stable process with an unfluctuating production of gas. The mesophilic temperature range between 25-40°C but most processes are operated between 35-40°C. This study investigates the opportunity to lower the temperature within the mesophilic range in order to reduce energy consumption. It is important to maintain the production of biogas with a lower temperature. Therefore, the reduction in VS-content (VS-volatile solids), methane yield and time for degradation was determined by a BMP-experiment (BMP-Biochemical Methane Potential) in three different temperatures (32, 34.5 and 37.5°C). In order to quantify the reduction in heat consumption with lower operational temperatures the change in heat balance for a full-scale WWTP in Uppsala was calculated. A major part of the operational cost is dewatering of sludge and it is therefore important that it does not deteriorate with a lower temperature. The effect on the dewaterability at different temperatures was examined by a filterability test measuring CST (capillary suction time). The results from the study showed no significant difference in methane yield between 37.5°C and 34.5°C. The methane yield at 32°C was 11 % lower compared to 37.5°C but the degradation kinetic was not affected by a temperature change. The reduction in heat consumption was 14 % when the temperature was reduced to 34.5°C and 27 % when it was reduced to 32°C. The filterability test did not show a deterioration with lower temperatures. The study showed that it is possible to reduce the operational temperature for anaerobic digestion at the WWTP in Uppsala in order to reduce the energy consumption. To confirm these results a continuously experiment should be done, but this study shows that it is possible to get a successful degradation in a lower mesophilic temperature. This leads the way for further investigations within the mesophilic range and could lead to optimizing anaerobic digestion and the opportunity to get an energy efficient production of biogas.
5

Co-méthanisation des déchets fermiers et alimentaires : expérimentation et modélisation / Anaerobic co-digestion of farm and food washes : modeling and experimentation

Rakotoniaina, Volana Astérie 17 August 2012 (has links)
Les deux principaux objectifs de cette thèse sont de développer les aspects théoriques et expérimentaux sur la co-méthanisation des déchets fermiers et alimentaires. Les objectifs de nos études portent sur l'élimination du maximum de déchets mis en ISDND, la réduction des pollutions des milieux naturels (eau, sol, air) par les effluents d'élevage, les boues de STEP et sur la mise en disposition d'une source énergétique renouvelable via le biogaz obtenu. Premièrement, nous avons effectué des expérimentations sur la co-méthanisation des effluents liquides, lisier de porc, boues de STEP, et de la vinasse et le mélange de ces effluents d'élevage avec les déjections solides des animaux (fumier, fientes) et des biodéchets (restes de repas). Ces expérimentations avaient pour but de suivre l'évolution du milieu réactionnel en fonction du composant du mélange ainsi co-digéré. Deuxièmement des tests des potentiels méthane et biogaz issus de mélange associant plusieurs types de déchets organiques sous différents états physiques (liquide, semi liquide, pâteux, solide) ont été effectués. La problématique qui se posait étant de savoir parmi les déchets à mélanger, quelle proportion de chaque mono-substrat donnera le meilleur potentiel méthanogène et s'il était possible de mettre en avant des effets synergétiques entre déchets. Nous avons fait appel à un outil statistique, le plan de mélange pour définir les mélanges à tester. Pour un mélange à 3 composants (fumier de vache, lisier de porc, restes de repas), le nombre d'expériences optimum à réaliser a été de 13. La réalisation du plan de mélange, c'est à dire la campagne expérimentale sur les co-méthanisations des 13 mélanges proposés nous a permis d'observer que le potentiel méthane d'un mélange dépend tout premièrement de sa texture (état physique) à l'entrée du processus. Un mélange contenant un maximum en proportion en co-produits liquides (lisier de porc) associé avec le maximum de déchets riches en substrats solubles (restes de repas) nous a donné les meilleurs potentiels méthane et biogaz. Cette observation a été confirmée par le taux de conversion de la matière sèche (MS) en matière volatile (MV) du mélange. Compte tenu du taux de MS, MV et le ratio MV/MS d'un mélange, ainsi que les interactions entre les composants du mélange, une loi permettant de prédire le potentiel biogaz d'un mélange doit considérer ces facteurs. Cette loi doit tenir compte de l'effet positif (synergisme) et l'effet négatif (antagonisme) entre les composants du mélange. Cette loi a été définie dans le but de prédire le potentiel méthane des mélanges constitués de fumier de vache, lisier de porc et restes de repas et se situant à l'intérieur du domaine expérimental défini par les limites sur les proportions minimale et maximale de chaque composant du mélange. Toutefois, cette loi définie n'est applicable qu'aux mélanges d'association de fumier de vache, de lisier de porc et des restes de repas. Cette loi a été définie pour estimer le BMP des mélanges, et ne permet pas de suivre le procédé de la méthanisation. Aussi, pour prédire le volume de biogaz (méthane) journalier ou cumulé de la cométhanisation. / The two main objectives of this thesis are to develop theoretical and experimental aspects of the anaerobic co-digestion of farm wastes associated with food. Our general studies have for objectives the elimination as much as possible the maximum of organic waste into non-hazardous landfills, reduce pollution of natural environments (water, soil, air) by the effluent livestock, sewage sludge, and dispose of energy via the produced biogas.Firstly, we carried out experiments on the anaerobic co-digestion of the liquid effluents association (pig slurry, sewage sludge, vinasse effluents) and the mixture of animal slurries, manures, and food waste. The aim of these experiments was to follow the evolution of the reactor behavior according to the component of the co-digested mixture.Secondly, BMP tests of mixture of association several types of organic waste under different physical condition (liquid, semi liquid, pasty, solid) were carried out. We have been tried to know, which proportion of each mono-substrate will give the best BMP among waste to mix? We used a statistical tool, the mixture design to define the mixtures to be tested. For a mixture with 3 components (cow dung, pig slurry, food waste), the optimum number of experiments to realize was 13.The realization of the mixture design, i.e. the experiment series on the anaerobic co-digestion of the 13 proposed mixtures enabled us to observe that the BMP of a mixture firstly depends on its texture (physical state) at the entry of the process. A mixture containing a maximum in proportion in liquid substrate (pig slurry) associated with food waste gave us the best biogas and methane potential. This observation was confirmed by the conversion rate of dry matter to volatile solid (VS) of the mixture. These results were proven by the activity (synergism, antagonism) of mixtures components influencing to BMP tests.The empiric law defined to predict the BMP of a mixture must to account the rate of VS/DM of a mixture, and the interactions between components of the mixture. This law must also include the positive effect (synergism) and negative (antagonism) between components of the mixture. This law has been defined in order to predict the potential methane mixtures of cow dung, pig slurry and food wastes and being within the experimental domain defined by the limits on minimum and maximum proportions of each component of the mixture. However, this definite law is applicable only to the mixtures of cow dung, pig slurry and food waste. The definite law is limited for prediction of mixtures BMP. However, this empiric law can not be used to follow reactor process. Model with three stages (hydrolysis of soluble substrate, acidogenic production stage and methanogenic stage) was used to predict daily and cumulative of biogas and methane production of anaerobic digestion of farm waste associated with vegetable waste. This model must be adapted with substrate type used and experimentations conditions (batch and mesophilic conditions). An adjustment of the model equations describing hydrolysis polymers stage was necessary in order to take into account of the concentration of polymers in particulate forms contained in complex substrates such as manure, slurry, and vegetable food waste. This adapted model was called model of Coupling. Indeed, a calibration of the most influential parameters of the model of Coupling, on the output must be carried out in order to validate the model.Daily and cumulative predictions of biogas and methane production of anaerobic digestion of farm waste associated with food waste were obtained by using adapted dynamical model. Model parameters values depend on the substrate type using in experimentation processes. Moreover, parameters values must be verified, needing further work.

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