O presente estudo teve por finalidade testar a hipótese de que o uso de uma taxa de recirculação variável do lixiviado de um reator tratando a fração orgânica dos resíduos sólidos urbanos domésticos, em um sistema em batelada híbrido, seria capaz de acelerar a degradação deste substrato em comparação com um sistema idêntico, porém que operasse com taxa de recirculação constante. Dois conjuntos de reatores foram operados, um com taxa de recirculação constante (sistema controle) e o outro com taxa de recirculação variável (sistema experimental). Os reatores foram mantidos em sala climatizada, com temperatura mantida em 35 ºC '+ OU -' 1 ºC. Cada conjunto era composto de um reator de sólidos, preenchido com o resíduo a ser digerido misturado a lixiviado de aterro sanitário, e um filtro anaeróbio, destinado a tratar o lixiviado que saía do primeiro. O substrato utilizado foi a fração orgânica dos resíduos sólidos urbanos domésticos padronizada (FORSUDp). Diversas variáveis foram medidas para o acompanhamento do processo: DQO de amostras filtradas e não filtradas, alcalinidade total, alcalinidade a ácidos voláteis, série de sólidos, nitrogênio total Kjeldahl e amoniacal, fósforo total, ácidos voláteis e composição do biogás por cromatografia gasosa. Também se acompanhou o desenvolvimento da microbiota anaeróbia por microscopia óptica de contraste de fase e fluorescência. A microscopia eletrônica de varredura indicou desenvolvimento de biofilme no meio suporte dos filtros anaeróbios. Concluiu-se que a taxa de recirculação variável consegue acelerar o processo, além de alterar de forma significativa o comportamento dos reatores e a forma de interação entre os mesmos / The objective of this study was to test the following hypothesis: varying the leachate recirculation rate in a hybrid batch reactor would make it possible to shorten the time required for the digestion of MSW, in comparison to a similar system operating with constant recirculation rate. Two sets of reactors were operated, one with constant recirculation rate (control system) and the other with varying rate (experimental system). The reactors were kept in a room which internal temperature was controlled. The temperature was kept at 35 ºC '+ OU -' 1ºC. Each set of reactors was composed of a solids reactor, filled with solid wastes and inoculated with landfill leachate, and an anaerobic filter, that should treat the leachate form the first one. The substract used was the standardized organic fraction of the municipal solid wastes (FORSUDp). Several parameters were measured for process monitoring: COD (in filtered and not filtered samples), total alkalinity, volatile acids alkalinity, solids, Kjeldahl nitrogen, ammonium nitrogen, total phosphorus, volatile acids by gas chromatography and biogas composition. The development of the anaerobic microorganisms was observed with phase-contrast and fluorescence microscopy. Scanning electron microscopy of the packed bed media showed biofilm development. It was concluded that the varying leachate recirculation rate proved to be able to enhance the degradation process. Besides, this operational strategy entirely changed the behaviour and interaction of the reactors

Made available in DSpace on 2017-05-12T14:47:04Z (GMT). No. of bitstreams: 1 Higor _Lorin.pdf: 2499051 bytes, checksum: 378cc421aa2a83bfde499d6cf499588c (MD5) Previous issue date: 2014-08-15 / The increasing demand for animal protein is directly related to the confinement of animals and its premises, such as the management of the waste system. Considering that the result of stabilization processes, that is, the organic fertilizer produced, is to be used again in the production cycle, evaluating its agronomic quality becomes important information when choosing the process to be used. The objective of this work was to submit beef cattle waste, raised in feedlot, to the processes of composting, vermicomposting, static piles and anaerobic digestion, showing the stabilization and the potential of each product generated by each process. Composting and vermicomposting are more efficient at mineralization, stabilization and maturity of waste manure. The compost and vermicompost offer larger fraction of available P and K, satisfactory levels of humification and high CTC. The static process is less efficient in mineralization, stabilization and maturity wastes. The disposition of this process in the open provides the greatest loss of nutrients. The anaerobic digestion appears as the most efficient process for the preservation of macronutrients (N and K), and generates a liquid fertilizer with low CEC and high fertilizing potential, with a predominance of inorganic N in the ammonium form, readily available to plants. / A demanda crescente por proteína de origem animal está diretamente relacionada ao sistema de confinamento dos animais e suas premissas, como o manejo dos dejetos. Considerando que o resultado dos processos de estabilização, ou seja, o adubo orgânico produzido, é o produto a ser novamente utilizado no ciclo produtivo, avaliar sua qualidade agronômica, passa a ser uma informação importante na escolha do processo a ser utilizado. Objetivou-se submeter os resíduos da bovinocultura de corte, criados em sistema de confinamento, aos processos de compostagem, vermicompostagem, leiras estáticas e biodigestão anaeróbia, evidenciando a estabilização e as potencialidades de cada produto gerado pelos processos. A compostagem e a vermicompostagem são mais eficientes na mineralização, na estabilização e na maturação dos dejetos. O composto e o vermicomposto oferecem maiores frações disponíveis de P lábil e K lábil, níveis satisfatórios de humificação e alta CTC. O processo estático é o menos eficiente na mineralização, na estabilização e na maturação dos dejetos. A disposição deste processo a céu aberto propicia as maiores perdas de nutrientes. A biodigestão anaeróbia apresenta-se como o processo de estabilização mais eficiente na conservação de macronutrientes (N e K) e gera um adubo líquido com baixa CTC e de alto potencial fertilizante, com predominância de N inorgânico, em forma de amônio, prontamente disponível aos vegetais

Made available in DSpace on 2017-05-12T14:47:38Z (GMT). No. of bitstreams: 1 Carla Limberger _Lopes (Tese revisada) 2016.pdf: 2793834 bytes, checksum: bd8e57da9e9986df4f212107c57ca249 (MD5) Previous issue date: 2016-02-17 / The aim of this study was to evaluate a combined anaerobic-aerobic upflow fixed-bed reactor with recirculation of the liquid phase for the removal of nitrogen and organic matter from poultry slaughterhouse wastewater. The reactor was made of an acrylic tube of internal diameter of 93 mm and the length of 1000 mm with a useful volume of 5.6 L being 3.5 L corresponding to the anaerobic compartments and 2.1 L to the aerobic one. The bed for immobilization of the biomass was formed by expanded clay and polyurethane foam. For discussing the results, this study was divided into three articles. In the first article, was evaluated the reactor performance with respect to the elimination of nitrogen (≈65 mg.NT.L-1) and organic matter (≈600 mg.DQO.L-1) due to the recirculation rate (R = 0.5, 1 and 2) and the hydraulic retention time (HRT) of 11 h (6.8 h in anaerobic condition and 4.2 h in aerobic condition) over the time. The best operating condition was obtained at the recirculating rate of 2. In this condition, the total nitrogen removal was 65% with the effluent concentration of 6 mg.NH4+.L-1 e 12 mg.NO3-.L-1. For all condition, the organic matter removal was greater than to 95% with the effluent concentration of approximately 20 mg.COD.L-1. Thus, the increasing of the recirculation rate influenced positively in the reactor performance. In the second article, the hydraulic detention time was evaluated (HDT) at 14 h, 11 h and 8 h with the recirculation rate (R) of 0.5 (Step I), R = 1 (Step II) and R 2 = (Step III). The affluent average concentrations were 65 mg.NT.L-1, 580 mg.COD.L-1, 77 mg L-1 of total alkalinity and pH of 6.4. The samples were collected inlet and output of each compartment along the reactor height. In the Step I, the nitrification efficiencies were 76%, 70% and 41% respectively for 14 h, 8 h and 11 h, showing the effect of HRT. In all steps, the alkalinity has been regarded as the limiting factor of the process and its deficit was 10 to 30%. It was attributed to this factor the low efficiency of total nitrogen removal of about 45%. Throughout the experiment the removal efficiency of organic matter in terms of chemical oxygen demand (COD) was over 90% and made to fit the first order kinetic model for degradation of the substrate. In the third article, was evaluated the hydrodynamic behavior of this system, through stimulus response tests using eosin Y dye as tracer. It has been evaluated the hydraulic retention time of 8 h with three recirculation rates, of .0.5, 1 and 2 times. Under these conditions, the removal of organic matter was greater than 90% and nitrogen conversion was favored by applying lower loads of (0.18 Kg.N.m-3.d-1). It was found that the hydrodynamic evaluation showed the continuous-stirred reactors behavior with 2 to 2.5 reactors in series (N-CSTR). / O objetivo desse trabalho foi avaliar um reator combinado anaeróbio-aeróbio de leito fixo e fluxo ascendente com recirculação da fase líquida, para a remoção de nitrogênio e matéria orgânica proveniente de água residuária de abatedouro de aves. O reator foi confeccionado em um tubo de acrílico de diâmetro interno de 93 mm e comprimento de 1000 mm, com volume útil de 5,6 L, sendo 3,5 L correspondentes aos compartimentos anaeróbios e 2,1 L correspondentes ao compartimento aeróbio. O leito para a imobilização da biomassa foi formado por argila expandida e espuma de poliuretano. A apresentação desse trabalho foi dividida em três artigos. No primeiro artigo, avaliou-se o desempenho do reator em relação à remoção de nitrogênio (≈65 mg.N.L-1) e de matéria orgânica (≈600 mg.DQO.L-1) em função da taxa de recirculação (R=0,5; 1 e 2) e do tempo de detenção hidráulica (TDH) de 11 horas (6,8 horas na condição anaeróbia e 4,2 horas na condição aeróbia), ao longo do tempo. A melhor condição operacional foi obtida com taxa de recirculação de 2. Nessa condição, a eficiência de remoção de nitrogênio total foi de 65% com concentrações efluentes de 6 mg.NH4+.L-1 e 12 mg.NO3-.L-1. Para todas as condições testadas, a eficiência de remoção de matéria orgânica apresentou-se superior a 95%, com concentração efluente de aproximadamente 20 mg.DQO.L-1. Assim, o aumento da taxa de recirculação influenciou positivamente no desempenho do reator. No segundo artigo, avaliaram-se os tempos de detenção hidráulica (TDH) de 14 horas, 11 horas e 8 horas com taxa de recirculação (R) de 0,5 (Ensaio I), R=1 (Ensaio II) e R=2 (Ensaio III). As concentrações médias afluentes foram 65 mg.NT.L-1, 580 mg.DQO.L-1, 77 mg.L-1 de alcalinidade total e pH de 6,4. As amostras foram coletadas na entrada e saída de cada compartimento, ao longo da altura do reator. Na Etapa I, e as eficiências de nitrificação foram de 76%, 70% e 41%, respectivamente para 14 horas, 11 horas e 8 horas, evidenciando o efeito do TDH. Em todas as etapas, a alcalinidade foi considerada o fator limitante do processo e o seu déficit variou de 10% a 30%. Atribuiu-se a esse fator a baixa eficiência na eliminação de nitrogênio total de aproximadamente 45%. Durante todo o experimento, a eficiência de remoção de matéria orgânica em termos de demanda química de oxigênio (DQO) foi superior a 90% e apresentou ajuste ao modelo cinético de primeira ordem para a degradação do substrato. No terceiro artigo, avaliou-se o comportamento hidrodinâmico desse sistema, a partir de ensaios de estímulo resposta utilizando o traçador Eosina Y. Avaliou-se o tempo de detenção hidráulica de 8 horas com as três taxas de recirculação, de 0,5, 1 e 2 vezes. Nessas condições, a remoção de matéria orgânica foi superior a 90% e a conversão de nitrogênio foi beneficiada com a aplicação de cargas menores (0,18 Kg.N.m-3.d-1). Na avaliação hidrodinâmica verificou-se que o reator apresentou comportamento de reator de mistura completa com 2 a 2,5 reatores em série (N-CSTR).

O objetivo deste trabalho foi avaliar a possibilidade de acelerar o processo de digestão anaeróbia da fração orgânica de resíduos sólidos urbanos domésticos em sistemas de duas fases, com taxas crescentes de recirculação de lixiviado, variando a taxa de recirculação de lixiviado em função da concentração de ácidos voláteis. Para tanto, foram operados dois sistemas de reatores, cada um composto por um reator de sólidos, que continha o resíduo sólido a ser tratado e um filtro anaeróbio de fluxo ascendente, que tratava o lixiviado do primeiro, antes que esse lixiviado fosse recirculado ao reator de sólidos. Um dos sistemas teve sua taxa de recirculação aumentada a intervalos constantes, enquanto que no outro o momento do aumento da taxa foi função da concentração de ácido propiônico no sistema. O trabalho teve ainda dois objetivos secundários: avaliar a validade de comparar os resultados dos dois sistemas, operados em paralelo, em função das características dos resíduos sólidos e dos procedimentos adotados para coleta e preparação do substrato e para o carregamento dos reatores; e avaliou-se a possibilidade de utilizar filtros anaeróbios para recuperar reatores acidificados. Durante o desenvolvimento do experimento, foram monitorados os seguintes parâmetros: DQO (não filtrada e filtrada), pH, alcalinidade, série de sólidos, nitrogênio total Kjeldahl, nitrogênio amoniacal, ácidos voláteis e composição do biogás. Foram realizados ainda exames qualitativos da microbiota que se desenvolveu nos reatores, através de microscopia óptica de fluorescência e contraste de fase. Os resultados obtidos permitiram concluir que: a) os procedimentos testados para o carregamento dos reatores de sólidos permitiram a comparação de resultados entre os sistemas; b) os filtros foram capazes de recuperar reatores acidificados; e c) a utilização da concentração de ácido propiônico para determinar o momento da variação da taxa de recirculação permitiu acelerar o processo, embora de forma restrita, para a escala de reatores utilizada. / The purpose of this dissertation was to evaluate the possibility of accelerating the process of anaerobic digestion of the organic fraction of domestic municipal solid waste, in two-stage systems, with increasing leachate recirculation rate, through the use of volatile acids as determining parameter of the moment in which the rate must be varied. To do so, two systems of reactors were operated, each being composed by a solids reactor, which contained the solid waste intended to be treated, and an upflow anaerobic filter, which treated the leachate of the first reactor, before recirculation. One of the systems had its recirculation rate increased at constant spells of time, while, in the other system, the moment of the increase in the recirculation rate was a function of the concentration of propionic acid in the system. This study had yet two secondary purposes: evaluating the validity of comparing the results from the two systems of reactors, operated in parallel, in view of the characteristics of solid waste and the adopted procedures for collecting and preparing the substrate, as well as for the loading of reactors; and evaluating the possibility of using anaerobic filters to recover acidified reactors. The following parameters were measured during the process: COD (filtered and non-filtered), pH, alkalinity, solids, Kjeldahl nitrogen, ammonium nitrogen, volatile acids and biogas composition. The development of microorganisms in the reactors was observed qualitatively, using optical microscopy. It was possible to reach the following conclusions: a) the tested procedures allow the comparison of results between the systems; b) the filters are capable of recovering acidified reactors; and c) the employment of the concentration of propionic acid to determine the moment of increase of leachate recirculation rate is capable of accelerating the process, though in a restricted way, for the scale of reactors used.

A digestão anaeróbia é uma alternativa para o tratamento de resíduos com altas concentrações de matéria orgânica. Por meio dos processos anaeróbios é possível a produção de biogás, fonte de energia renovável e ambientalmente amigável. Elevadas concentrações de lipídios, todavia, apesar de representarem elevado potencial metanogênico, interferem negativamente nos sistemas de tratamento, podendo inibir a atividade microbiana e, consequentemente, a produção de metano. O presente projeto avaliou o efeito da adição de bagaço de cana-de-açúcar no processo de biodigestão anaeróbia de elevadas concentrações de gorduras advindas de efluentes de laticínio. Para tanto foi utilizado bagaço de cana-de-açúcar in natura e pré-tratadas pelos seguintes métodos: organossolve, hidrotérmico, explosão à vapor e ácido diluído. O uso desse material lignocelulósico teve o objetivo de controlar a inibição causada pelos produtos da hidrólise dos lipídios por meio de sua adsorção e, consequentemente, diminuição das concentrações de tais compostos no meio. Outra hipótese era que o bagaço de cana-de-açúcar pudessem agir como co-substrato no processo de biodigestão anaeróbia. Inicialmente realizaram-se ensaios de biodegradabilidade anaeróbia com concentrações crescentes de gordura, que resultaram em relação entre substrato e microrganismo 0,06, 0,1, 0,2, 0,4 e 0,6 g DQO/gSTV. O ensaio com concentração em que foi verificada a inibição severa (0,4 gDQO/gSTV) do processo foi repetido com adição das fibras tratadas e não tratadas. Aos dados de produção acumulada de metano ajustou-se modelo de Gompertz, e parâmetros cinéticos foram inferidos. O bagaço de cana-de-açúcar mostrou potencial como adsorvente de gordura, pois as produções metanogênicas foram superiores à condição inibida sem adição desse material. A adição de fibras pré-tratadas por método organossolve resultou nas maiores produções de metano. / Anaerobic digestion is an alternative for treating waste with high concentrations of organic matter. Through anaerobic processes biogas production is possible, which represents environmentally friendly renewable energy source. High lipid concentrations, however, although having high methanogenic potential, may negatively interfere with the treatment systems causing microbial activity inhibition and, consequently, depleting the production of methane. This project evaluated the effect of addition of cellulosic fibers in the anaerobic digestion process of high concentrations of fatty residues from dairy effluents. Therefore, sugarcane bagasse fibers were used in natura and pretreated by the following methods: organosolve, hydrothermal, steam explosion and dilute acid. The use of the fibers had the objective to control the inhibition caused by the products of the hydrolysis of lipids through adsorption and thus decrease the concentrations of such compounds in the medium. We also had the hypothesis that the cellulosic fibers could act as co-substrate in the anaerobic digestion process. Initially, anaerobic biodegradability tests were set with increasing concentrations of fatty residue, which resulted in relation entity substrate and microorganism of 0.057; 0.12; 0.24; 0.37 and 0.57 g COD / gSTV. The assay in which severe inhibition was verified (0.37 g COD/gSTV) was repeated with addition of treated and untreated fibers. The sugarcane bagasse showed potential as adsorbent because the methanogenic yields in the presence of the fibers were higher than the inhibited condition, without addition of that material. The addition of pretreated fibers by organosolv method resulted in higher methane production.

Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-07-28T12:07:38Z No. of bitstreams: 1 Jamile Machado Hallam_.pdf: 1161483 bytes, checksum: 328ee4f618bd889a5e3570f303cdb9de (MD5) / Made available in DSpace on 2016-07-28T12:07:38Z (GMT). No. of bitstreams: 1 Jamile Machado Hallam_.pdf: 1161483 bytes, checksum: 328ee4f618bd889a5e3570f303cdb9de (MD5) Previous issue date: 2016-02-26 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / PROSUP - Programa de Suporte à Pós-Gradução de Instituições de Ensino Particulares / O aproveitamento energético obtido pela digestão anaeróbia é uma alternativa viável para o tratamento de resíduos alimentares, no entanto requer um estrito controle operacional. A escolha da melhor condição de partida pelo cálculo da relação substrato/inóculo (S/I) em termos de Sólidos voláteis (SV) pode facilitar estabilização do processo, resultando em elevada produtividade de biogás e teor de metano. Este estudo testou 5 diferentes relações de S/I em regime de batelada a 35oC, visando a estabilidade do processo e otimização da produção de biogás com alto teor de metano. Foi utilizado como substrato o resíduo coletado no restaurante universitário da Unisinos, e o como inóculo o lodo anaeróbio do reator UASB tratando esgoto doméstico da estação de tratamento de esgotos da mesma universidade. Os parâmetros monitorados foram pH, volume de biogás, teor de metano, alcalinidade e ácidos graxos voláteis. Todas as bateladas mantiveram-se dentro da faixa de pH recomendada pela literatura, entre 6,5 e 7,5, com exceção à batelada 5, que utilizou uma relação 1:1 S/I e onde o pH decaiu para 5,0. A produção de biogás em todas as condições estudadas teve sua máxima produção até o terceiro dia de inoculação e foi influenciada pela relação S/I aplicada, pois o aumento da quantidade de SV do substrato aumentou o rendimento e o teor de metano, com exceção da condição 1:1, onde houve a acidificação do sistema. O rendimento de biogás das condições 1:5, 1:4, 1:3, 1:2, 1:1 foram respectivamente 0,69, 0,75, 0,67, 0,89 e 0,18 L/g SV do substrato utilizado, e os teores médios de metano em cada batelada foram 69, 67, 65, 74 58%. Concluiu-se então, que a melhor relação substrato/inóculo para partida do processo foi 1:2, para a qual obteve-se 0,89 L de biogás/g SV do substrato com um teor de metano de 74%, mantendo uma relação AGV/ALC abaixo de 0,5, demonstrando a estabilidade do processo. / The energy recovery acquired through the anaerobic digestion is a viable alternative for treating food waste, though it requires an operational strict control. The choice of the best start up condition athwart the substratum /inoculum (S/I) ratios in terms of volatile solids (VS) may facilitate the process stabilization, resulting in increased production of biogas and methane content. The present study tested 5 different ratios of S/I in batch system at 35ºC, aiming the process stability and the optimization in the raised methane level biogas production. As the substrate, the residue collected at the university restaurant of Unisinos was used, and as inoculum the UASB reactor anaerobic sludge from the sewage wastewater treatment plant at the same university. The monitored parameters were pH, biogas amount, methane content, alkalinity and volatile fatty acids. All of the batches kept within the pH levels recommended by literature, between 6.5 and 7.5, exception to batch 5, which employed a relation of 1:1 substrate/inoculum and in which the pH level declined to 5.0. The biogas production in all of the studied conditions had its utmost production until the third day of inoculation and it was influenced by the S/I ration applied, since the increase of the substratum VS amount raised the yield and the methane content, exception to the condition 1:1 where there was an acidification of the system, and it was considered that the capacity of the commutation of substratum in methane was extrapolated. The biogas yields of the conditions 1:5, 1:4, 1:3, 1:2, 1:1 were, respectively, 0.69, 0.75, 0.67, 0.89 and 0.18 L/g VS of the substratum employed, and the average methane content in each batch were 69, 67, 65, 74 58%. The study shows that the best relation S/I to the process start-up was 1:2, to which it was obtained 0.89 L of biogas/g SV of the substratum with a methane content of 74% keeping the relation AGV/ALC under 0.5, demonstrating stability in the process.

<p>Energimyndigheten har från Regeringen blivit tilldelad 100 miljoner kronor att fördela som investeringsstöd för att främja en effektiv och utökad produktion, distribution samt användning av förnybara gaser såsom biogas. Myndigheten har samtidigt fått i uppdrag att utveckla en sektorsövergripande biogasstrategi och föreslå åtgärder som på kort och lång sikt kan bidra till ökad användning av biogas. Denna strategi ska också tjäna som ett underlag för fördelning av olika former av stöd inom sektorn.</p><p>Syftet med detta examensarbete är att sammanställa information som kan bidra som underlag vid upprättandet av den sektorsövergripande biogasstrategin. Ett annat syfte är att bidra med underlag för Energimyndighetens bedömning av var ett investeringsstöd kan ge störst effekt för den fortsatta utvecklingen inom biogasområdet. Detta stöd avser den senaste, ovan nämnda, utlysning som Energimyndigheten gjort inom området. Examensrapporten innehåller bland annat en sammanställning av gjorda insatser inom forskningsområdet biogas de senaste åren, finansierat av framför allt Energimyndigheten, men även en inblick i vilka biogassatsningar som är gjorda av andra nationella aktörer. Ett antal personer från bland annat branschorganisationer har intervjuats för att ta del av deras syn på den framtida biogasmarknaden, vilka satsningar som bör göras och vilka hinder som har störst inverkan. Organisationerna är valda utifrån kriteriet att de ska representera olika delar av biogasbranschen och att olika synvinklar därigenom ska framkomma. Rapporten innehåller slutsatser som dragits av tidigare biogassatsningar hos Energimyndigheten och identifiering av biogasområden där det föreligger stort behov av framtida satsningar för utökad produktion, distribution och användning. </p><p>Ett område som i detta examensarbete har identifierats ha stort behov av framtida biogassatsningar är bland annat framtagande av alternativa rötningssubstrat, eftersom mängden tillgängligt substrat nuläget inte är tillräcklig. Detta utgör idag en begränsning för biogasproduktionen. Det bör även satsas mer på förbehandling av substrat innan rötning, vilket ökar gasproduktionen och förbättrar substratutnyttjandet i större utsträckning. Mer satsningar behövs också kring hur biogasprocessens slutprodukt, rötresten, kan bli en mer attraktiv produkt så att återcirkulering av växtnäring kan ske i större grad genom rötrestspridning på åkermark. Detta är av stor vikt eftersom en ökad volym rötningssubstrat ger upphov till större mängd rötrester som ska hanteras. Andra områden som är i behov av framtida stöd är utveckling av befintliga anläggningar för att öka och effektivisera produktionen. För att optimera processerna bör framför allt mer medel satsas på kunskapsuppbyggnad och spridning av den vetenskap som finns tillgänglig. Att länka samman universitet, högskolor och naturbruksgymnasium med anläggningar i drift kan vara det mest effektiva sättet att nå ut med relevant information och kunskap. Ur ett samhällsekonomiskt perspektiv bör mer medel läggas på att öka gödselrötning då detta minskar metanläckage.</p> / <p>Swedish Energy Agency has been allocated SEK 100 million from the government to distribute as investment grant to promote efficient and expanded production, distribution and use of renewable gases such as biogas. The Agency has also been given the task to develop a multidisciplinary strategy for biogas and propose measures which can contribute to increased use of biogas in the short and long term. This strategy will also serve as a basis for the allocation of various forms of support in the biogas sector. </p><p>The purpose of this study is to compile information which can be used as input for the establishment of the multidisciplinary strategy for biogas. Another purpose is to provide information to support the Swedish Energy Agency in the assessment of which areas an investment grant will have the greatest impact for the future development of biogas. This grant refers to the latest call of Swedish Energy Agency in the sector. This report includes a summary of what areas grants have been given for research of biogas in recent years, mainly financed by the Swedish Energy Agency, but also an insight into efforts made by other national operators. A number of people from professional biogas organizations have been interviewed to share their views on the future biogas market. Which efforts should be made and the main obstacles to be overcome are other questions discussed. The report contains conclusions from the experience of previous support from the Swedish Energy Agency as well as identification of areas in which there is great need for future efforts in order to expand the production, distribution and use of biogas.</p><p>Some areas which have been identified in this thesis for need of future efforts in the biogas sector is for example the development of alternative substrates for anaerobic digestion, because the amount of available substrate is at present not sufficient. This is currently a limitation for the biogas production. There is also a need to further develop the pre-treatment of the substrate before digestion, in order to increase the gas production and improve substrate utilization to a greater extent. More focus are also needed on how the end product from the biogas process, the digestion residues, can become a more attractive product to the recycling of plant nutrients by use as a bio fertilizer on farmland. This is of great importance because larger volume of digestion will result in greater volume of digestion residues to be managed. Other areas in need of future investments are the development of existing facilities to increase and optimize the production. In order to optimize the production processes, more resources should be devoted to capacity building and dissemination of the available knowledge. Linking universities and colleges together with operating biogas plants could be the most effective way to reach out with relevant information and knowledge. From a socioeconomic perspective more resources should be spent on increasing the volume of manure digestion then it is today, which also will result in reduced methane leaks.</p>

The transport sector is seen as particularly problematic when concerns about climate change and dependency on fossil energy are discussed. Because of this, bioenergy is strongly promoted for use in the transport sector, both on a European level and nationally in Sweden. Even though bioenergy is considered one of the key solutions, it is generally agreed that both supply- and demand-side measures will be needed to achieve a change to a more sustainable transport system. One of the reasons for this is the limited availability of biomass, especially agricultural feedstocks competing with food or feed production. Woody biomass, however more abundant, is also exposed to tough competition from other sectors. In this thesis, the role of biogas as a vehicle fuel in a future sustainable transport system is discussed together with the prerequisites needed to realise such a transport system. Biogas is a biofuel that could be produced in several different ways: by anaerobic digestion, which is a first-generation production route, by gasification, which is a second-generation process, and by catalytic reduction of carbon dioxide, a third-generation technology. The main focus in this thesis is on biogas produced by anaerobic digestion and the results show that there is a significant potential for an increase compared to today’s production. Biogas from anaerobic digestion, however, will only be able to cover a minor part of the demand in the Swedish transport sector. Considering biogas of the second and third generations, the potential for production is more uncertain in a mid-term future, mainly due to competition for feedstock, the possibility to produce other fuels by these processes, and the present immaturity of the technology. The limited potential for replacing fossil vehicle fuels, either by biogas or other renewable fuels, clearly shows the need for demand-side measures in the transport system as well. This thesis shows the importance of technical and non-technical means to decrease the demand for transport and to make the transport as efficient as possible. The results show that both energy-efficient vehicles and behavioural and infrastructural changes will be required. Policies and economic incentives set by governments and decision-making bodies have a prominent role to play, in order to bring about a shift to a more sustainable transport system, however, measures taken on individual level will also have a great impact to contribute to a more sustainable transport system. / <p>QC 20121116</p>

The biological sludge formed in the pulp and paper wastewater treatment constitutes a costlyproblem to dispose off due to poor dewaterability. It is often incinerated or used as soilconditioner improvement. By using anaerobic digestion of the biological sludge, thedewaterability can be increased. Thanks to the formation of biogas, the sludge volume isdecreased and energy can be recovered as methane. By pre-treating the sludge, the biogasproduction can be increased, making the anaerobic digestion more economically feasible. Eleven samples of biological sludges from six Swedish pulp and paper mills, chosen torepresent different types and sizes of mills available in Sweden, were pre-treated with alkali(NaOH, pH12), heat (80˚C, 1 hr) and electroporation (2000 pulses, 10 kV/cm). Initialmethane production rate and methane potential of all sludges and pre-treatments weredetermined using batch experiment. A combination of two sludges (from the same mill) pretreatedwith alkali and heat was further investigated in a semi-continuous digester experiment. The batch experiments showed that alkali pre-treatment had the greatest positive effect onmethane production. Heat treatment performed second best, whereas electroporation had no orlittle effect. Overall, pre-treatments increased the initial methane production rate, but withinsignificant effects on the methane potential. Heat pre-treatment showed no difference inbiogas production compared to the control in the semi-continuous digester experiment. Alkalitreatment was shown to inhibit biogas production and cause high accumulation of acetate. Itcould not be concluded whether it was an effect from hydroxide or sodium ion addition.Further analysis of the NaOH impact on floc structure, toxicity and bioavailability issuggested to determine the suitability of alkali-treated sludge for anaerobic digestion. / Bioslam, som bildas vid vattenreningen på pappers- och massabruk, utgör en kostnad attomhänderta på grund av avvattningssvårigheter. Kvittblivning sker oftast genom förbränningeller användning som jordförbättringsmedel. Genom rötning kan slammet bli merlättavvattnat och tack vare att det bildas biogas minskar slamvolymen samtidigt som energikan utvinnas från metanet. Produktionen av biogas kan ökas genom att förbehandla slammetinnan rötning, vilket skulle innebära ekonomiska fördelar. Denna studie har undersökt effekten av förbehandling för elva bioslam från sex svenskapappers- och massabruk, valda att representera olika typer och storlekar på svenska bruk.Behandlingen gjordes med alkali (NaOH, pH12), värme (80˚C, 1 h) och elektroporering(2000 pulser, 10 kV/cm). Effekten av förbehandling på initial metanproduktionshastighet ochmetanpotential undersöktes med hjälp av satsvis utrötning (batch) av alla slam. Enkombination av två slam från samma burk utvärderades i ett semi-kontinuerligt rötningsförsökefter förbehandling med värme och alkali. Resultatet från utrötningsförsöket visade att den alkaliska förbehandlingen hade störst positivinverkan på metanproduktionen. Värmebehandlingen presterade näst bäst, medanelektroporeringen visade sig ha liten eller ingen effekt. Generellt sett ökade den initialametanproduktionshastigheten till följd av förbehandling, medan metanpotentialen förblevoförändrad. Värmebehandling gav ingen effekt på biogasproduktionen i det semikontinuerligarötningsförsöket jämfört med kontroll, medan alkalisk förbehandling inhiberadebiogasproduktionen och orsakade höga koncentrationer av ackumulerat acetat. Det kunde inteavgöras huruvida det var natrium- eller hydroxidjoner, som orsakade inhiberingen. För attkunna utvärdera möjligheten att röta slam, som förbehandlats med NaOH, rekommenderasvidare analys av dess påverkan på flockstruktur, toxicitet och biotillgänglighet.

This study was carried out to evaluate the potential of high-rate anaerobic digestion of high-solids organic fraction of municipal solid waste (OFMSW) for the production of organic acids and alcohols in leaching bed reactors (LBRs). For this purpose, two different experimental set-ups, namely Set-1 and Set-2, were operated. In the Set-1, only OFMSW without paper was studied in two identical LBRs, whereas, four identical LBRs, fed with OFMSW with paper and cow manure in different proportions, were operated in the Set-2. In this study, 50-60% of hydrolysis efficiency was achieved in the LBRs of Set-1, whereas this value was decreased to 20-25% in the LBRs of Set-2 / which was resulted from OFMSW containing cellulose and less volume of water addition in the Set-2. The mass of total volatile fatty acids (tVFA) production was found as 7000-9000 mg at the end of 80 days in the LBRs of Set-1, fed with OFMSW without paper, whereas it was 3000 mg at the end of 40 days in the LBR of Set-2, containing only OFMSW with paper. It was also observed that cow manure addition increased the amount of tVFA production in the LBR of Set-2. In conclusion, LBRs were found as alternative reactors for the degradation of OFMSW compared to completely stirred tank reactors (CSTRs) in terms of rapid hydrolysis and acidification, which can result in high hydrolysis yield and tVFA production.