Orientador: Jorge de Lucas Junior / Banca: Osmar de Carvalho Bueno / Banca: Tânia Mara Baptista dos Santos / Resumo: Nos últimos anos, verifica-se crescente a produção de resíduos sólidos urbanos associada a um aumento populacional e ao maior consumo de produtos com embalagens que poderiam ser recicladas. Medidas rápidas de valorização e reciclagem devem ser tomadas para que permitam um consumo contínuo de alguma forma racional, diminuindo conseqüentemente, as agressões ambientais. No presente estudo avaliaram-se parâmetros que proporcionem subsídios na tomada de decisões sobre o melhor aproveitamento dos resíduos sólidos urbanos orgânicos, utilizando-se a compostagem ou a biodigestão anaeróbia. O resíduo sólido urbano orgânico (lixo) foi cedido pela empresa CONSTROESTE, localizada no município de São José do Rio Preto-SP, e o experimento foi conduzido no Laboratório de Biodigestão Anaeróbia do Departamento de Engenharia Rural da Faculdade de Ciências Agrárias e Veterinárias - Campus de Jaboticabal da Universidade Estadual Paulista - Unesp. Foram conduzidos ensaios de compostagem e biodigestão anaeróbia, utilizando-se resíduo sólido urbano orgânico coletado no município de São José do Rio Preto - SP, no intuito de avaliar as características químico-minerais, o potencial energético e a interferência da qualidade do resíduo no desenvolvimento dos processos. Avaliaram-se as reduções de sólidos totais e voláteis, produções de biogás e qualidade do biofertilizante durante a biodigestão anaeróbia, que foi conduzida com a utilização ou não de inóculo, e parâmetros como temperatura, umidade, peso, teores de nutrientes, e redução de massa enleirada durante a compostagem e a equivalência energética nos dois processos. Observaram-se reduções de 58,5% nas quantidades de massa seca enleirada e de 40,9% nos teores de carbono orgânico, matéria orgânica compostável e demanda química de oxigênio. Foram verificadas temperaturas acima de 40º C,...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: An increasing production of urban organic wastes is noticed in the last years, associated with the growth of the global population and the increased of resultant consumption. Fast actions of valorization and recycling must be done, in a way that it allows a rational continuous consumption and consequently decreasing environmental aggressions. This work has evaluated some parameters that supply decision making over better use of urban organic wastes through composting or anaerobic digestion processes. The urban organic waste was supplied by Controeste company, in São José do Rio Preto - SP. The experiment was conducted in the Anaerobic Digestion Laboratory - Agricultural Engineering Department - Veterinary and Agricultural Sciences College - Jaboticabal Campus - São Paulo State University - UNESP. Samples of composting and anaerobic digestion were collected done from the wastes in the city of São José do Rio Preto - SP, with the objective of evaluating to the chemical and mineral properties and consequent interference of the residues on the processes. The reductions of total and volatile solids, biogas production and biofertilizer quality werw evaluated during the anaerobic digestion. It was conducted using inoculums or not and parameters such as temperature, humidity, weight, nutrient content and reduction of heap mass during the composting. A reduction the 58.5% in the quantity of heap dry mass, 40.9% in the organic carbon contents, recycling organic material and chemical demand of oxygen was observed. It was registered temperatures above 40ºC in the heaps interior, evidencing the importance of the process of reduction and/or elimination of pathogens.The presence of innocuous in the substrate anticipated the biogas production in the process of anaerobic digestion...(Complete abstract click electronic access below) / Mestre

Då vi lever i en tid med hög konsumtion som innebär en hög produktion av avfall måste vi tänka på hur vi kan möta problem som kan uppstå vid hantering av avfall. I detta arbete ligger fokus framförallt på den organiska fraktionen av avfall och specifikt på matavfall och avloppsslam. I Sverige har slam rötats länge med syfte att minska volymen av slammet, men idag är målet främst biogasproduktion. Att återvinna så långt som möjligt är ett av de mest effektiva sätten att möta dagens miljöproblem med avfall, genom att omvandla oönskad avfall till önskad material och/eller energi. Examensarbetet är genomförd på universitetet i Rio de Janeiro (Brasilien) under handledning av docent Isaac Volschan Jr. och Prof. Dr. Magali Christe Cammarota som en del av forskningsprojektet av Janaína dos Santos Ferreira. Syftet med arbetet var att undersöka ifall och på vilket sätt påverkas biogasproduktionen då olika volymprocentförhållanden av matavfall och avloppsslam tillämpas. Resultaten blev som förväntat, att ju högre andel matavfall desto högre biogasproduktion. Processen blev ostabil när mycket matavfall fanns i blandningen som en följd av överbelastning och det tog längre tid för mikroorganismer att återhämta sig från pH-sjunkningar. Upplägget av försöken skulle ha behövts göras på ett annat sätt så att de olika blandningsförhållanden hade samma mängd VS, eftersom den var nyckelfaktorn. I de här försöken var det därför svårt att jämföra resultaten.

Production of biogas is one of several alternatives to meet sustainable energy solutions and waste management. However, managing the by-product (digestate) can be problematic with its high handling costs. Digestate from wet co-digestion biogas plants contains large volumes of water, causing high transportation costs and low concentration of the valuable nutrients. An alternative to try and reduce the associated costs is by processing the digestate. Processing the digestate for volume reduction allow for more economic and resource efficient ways of handling the product. This master thesis was performed on an initiative from Tekniska verken AB and address digestate handling from Linköping biogas plant, a large co-digestion biogas plant in Sweden. The project aimed to find a feasible, more resource efficient management of their digestate by looking at digestate processing alternatives.The approach systematically evaluated a large number of processing techniques by both literature and communication with TvAB or experts. A selection of techniques were further evaluated were studies in laboratory and a market analysis on digestate provided complementary information, aiding the economical evaluation. Results suggest that processing by centrifuge is a viable, economic option when digestate management is costly and a liquid fraction can be recirculated in the process. It has the potential to significantly reducing digestate management costs. Other processing alternatives may be beneficial if transportation distance can be greatly reduced and/or synergies can be found, but the findings in this project suggest that only treatment with centrifuge is of interest. The results are subject to a number of conditions (such as size of the plant) and assumptions (such as recirculation of a liquid fraction) and therefore need individual adaption to be applicable at any specific plant. Conclusive remarks are that although site specific conditions affect the choice of processing, a project such as this may help reducing the necessary time spent on evaluation. Both research process and results may provide valuable findings for similar evaluations in any industry.

<p>In this bachelor thesis we focus on how to controlling different machines that would be used in the Bio-gas production processes. By useing the Labview program, we can do controlling, detecting, data storing and other jobs all together.</p><p>The whole project is just a blueprint for the following work, as for there are too many components and units that we haven't seen yet. What we have done is to design a program that could be used in reality base on the principle of the whole bio-gas producing processes. Actually we did a quite good job on designing the limited machines that we have in hand, like the Pt-100 unit and the circulation pump are working as well as we had imagined.</p><p>Hopefully, this thesis and the program I designed can give a direction for the following work on the project, and the most important part--temperature checking and controlling can work well in reality as we expected.</p>

Pacific Island Countries (PICs) currently rely heavily on imported, expensive and unsustainable fossil fuels as their primary source for energy production. Establishing an alternative energy source from local resources would therefore have considerable benefits for many Island communities. Coconut copra is high in biodegradable organic carbon and is found growing abundantly in PICs. One alternative use for this local resource would potentially be the conversion of the coconut copra into a valuable and useful energy source through biological processes, such as anaerobic digestion. The purpose of this research was to investigate the biogas generation potential of coconut copra as a carbon source using anaerobic digestion processes. Both batch and continuously stirred reactors (CSTRs) in addition to the environmental and operating variables that affect the production of biogas were investigated in order to optimize methane production and increase the overall conversion efficiencies of organic matter to methane. The results suggest that coconut copra is amenable to anaerobic digestion due to the high theoretical methane yields from the substrate’s high lipid content. However, the optimal organic loading rate (OLR) was limited to within a narrow range of 3.6-6 g VS (2.4 - 4 g VS/L Reactor) for the batch reactors and a maximum of 0.420 L CH4/ g VS was achieved at an OLR of 3.6 g VS. OLRs exceeding 15 g VS resulted in low pH values and negligible methane production due to substrate overloading. High average methane yields of 0.708 L CH4/ g VS•day were also successfully achieved for the CSTRs and increased mixing was observed to have an improved effect on methane production. However, the addition of nitrogen and phosphorus supplements failed to increase biological activity and ultimately resulted in the accumulation of ammonia to concentrations toxic to methanogenic bacteria. The failure of an accelerated CSTR start-up procedure also reinforced the requirement for a gradual and steady acclimated period for anaerobic digestion of this particular substrate.

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Sustainable alternatives to using mined nutrients in agriculture must be found in order to limit environmental impacts such as eutrophication, habitat destruction and greenhouse gas emis-sions. Biogas slurry and urine recycled to hydroponic food production (a type of soilless agri-culture) have the potential of providing inorganic nitrogen and phosphorus, the main essential nutrients required for plant growth. A Life Cycle Inventory Assessment (LCI) methodology has been used to compare the systems of producing artificial fertilizer, biogas slurry and urine based nutrient solutions for the growth of Brassica rapa L. (Chinese cabbage) in the context of a large scale hydroponic vertical farm. Costs and energy requirements have been the basis of the comparison and results show that both biogas slurry and urine are considerably cheaper than the commercial alternative and based on the nutrient content they have the potential of being successful nutrient solutions after dilution and nutrient supplementation. Filtration might also be required in order to remove suspended particles and pathogens.

Vi lever i en värld som konsumerar en allt större mängd energi. Att minska den icke förnyelsebara energianvändningen är en mycket viktig del för ett långsiktigt hållbartsamhälle. Sjöstad är ett av flera reningsverk i Sverige som rötar avloppsslam för att utvinna ett av framtidens bränslen; Biogas. Framställningen av biogas sker genom anaerob nedbrytning, en känslig process som lätt störs av yttre faktorer, som temperatursvängningar och förändringar av substratsammansättning. För att anaerob nedbrytning ska fungera optimalt krävs exakt rätt koncentrationer av näringsämnen i reaktorerna. I detta projekt har en rad olika mikronäringsämnen, som metaller, salter och vitaminer testats för att se om en tillsats av något av dessa kan öka Sjöstads biogasproduktion. Genom ett antal försök vid olika tidpunkter under våren 2013 har ett ämne, magnesiumklorid identifierats som det näringsämne som kan vara det mest begränsande för Sjöstadverket. Resultatet visade att en liten mängd magnesiumklorid, 0,05 mg/l, kan ge en ökad biogasproduktion från rötresten. Labbskaleförsöken visade även en stor produktionsökning från rötresten under våren, vilket kan tyda på att en ökad dagvattenproduktion från snösmältningen för med sig de näringsämnen som reaktorerna behöver.