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1

Kidby, David W. "Biogas hydrogen as an indicator of digester instability in anaerobic sewage sludge digesters." Thesis, University of Essex, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280473.

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2

Tumwesige, Vianney. "Adaptation of small scale biogas digesters in sub-Saharan Africa." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=234015.

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While facing increasing challenges in Sub-Saharan Africa (SSA) of climate change, population growth and deforestation, over 700 million people rely on biomass fuels to meet their basic cooking and heating needs. Increasing use of biomass fuels has resulted in negative impacts on the environment through land degradation and deforestation. To overcome problems associated with using biomass fuels, some households in SSA have adopted biogas as an alternative cooking fuel. Use of biogas production technology has led to the development of a number of different biogas appliances. However, these appliances often have low efficiencies; locally made appliances that are affordable and of high quality are needed to support uptake of biogas. In households in Uganda and Cameroon where biogas digesters were installed there was a 52 % reduction in wood fuel consumption, reducing carbon loss by 0.52 (±0.08) t y-1 and deforestation by 0.06 (±0.01) ha y-1 for each household. Water demand was increased by 88 (±25) %, increasing water collection time by 46 (± 13) min d-1. Complete conversion to biogas resulted in a 24 hour mean exposure in households of 18 µg m-3 for fine particulate matter and 0.5 ppm carbon monoxide. However, partial fuel switch resulted in 173 µg m-3 for fine particulate matter which was likely to continue to harm the health of those exposed. Continued use of biogas digesters can reduce the use of wood fuel, but it increases the water demand, which may result in an increase in overall household labor. A new innovation, the slurry separation technology was installed on digesters to reduce labor and water requirements. This significantly reduced (p < 0.05) the volume of water required from 150 (± 25) dm3 d-1 to 30 (±8) dm3 d-1) and household labor from 34 (± 5) min d-1 to 17 (± 3) min d-1.
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3

Hall, Stephen. "Optimisation of biogas production from percolating packed bed anaerobic digesters." Thesis, University of South Wales, 1986. https://pure.southwales.ac.uk/en/studentthesis/optimisation-of-biogas-production-from-percolating-packed-bed-anaerobic-digesters(6825c6bf-4ee7-439e-832a-28aa8b7cd4d3).html.

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Percolating packed bed digesters were operated successfully in a batch mode using a wheat straw - dairy manure substrate of between 21 and 27% total solids. The vessels used had a nominal 10 1 volume and were constructed of perspex. Temperatures of 25-35°C were used, recirculation rates of 0-15 litres.hr-1 (the digesters having a diameter of 0.18 metres thus corresponding to superficial flow rates of between O and 0.382 l/m2 /hr), solid : liquid ratios of 1:1 to 4:1 and bed heights of 0.26 to 2.05 metres. The optima found were a temperature of 35°C, recirculation rate of 3 litres.hr1-, a solid: liquid ratio of 2:1 and a bed height of 1.5 metres. Experiments were conducted for periods of up to 70 days, though operation beyond a 40 day period was found to produce little extra biogas. The performance compared favourably with other high solids waste digesters with gas yields of 0.305 m 3 /kg VS added and solids losses of 47% volatile solids and 64% cellulose being obtained over a 40 day period. No major problems of inhibition or blocking occurred. Linking of digesters in series via their recirculation systems was found to be advantageous. Gas yields were found to be increased by approximately 18% and solids losses increased by approximately 20% when the waste was treated in this semicontinuous manner. These increases were found to be a result of the rapid transfer of well-adapted bacteria to the fresh digester. Lag phase in the fresh digester was reduced by three days and potentially inhibitory levels of volatile fatty acids were not present. Concentrations of up to around 5000 ppm VFAs were found during the start-up of batch digesters causing some inhibition of gas production. During semi-continuous operation however concentrations of around 2000 ppm were developed when fresh digesters were linked in, no inhibition occurred and in fact this concentration proved stimulatory to gas production. Experimentation into the optimum retention time of a maximum of three digesters in series was conducted, with retention times of 90, 60 and 30 days being considered. A 30 day retention period was found to depress gas production due to unstable conditions when fresh digesters were added by up to 32% compared with Batch Operation. Gas production was increased at both 60 and 90 day retention times by amounts similar to those previously stated. A retention time of 60 days was found to be optimum as little extra gas was produced after this time, with volatile solids losses being increased by only 9.3% by operating for a further 30 days. Colonisation of the solid substrate was shown to be rapid, by the use of adenosine 51 triphosphate analysis, gas production rate and electron microscope analysis. In addition a dynamic bacterial population appeared to be present in the solid phase with the rates of growth and attachment being approximately equal to the rates of decay and detachment. When digesters were operating in their steady phase, methanogens were present in the liquor at concentrations of between 10 6 - 10 7 /ml and non-methanogens at between 10 7 - 108 /ml showing a large population of bacteria to be present for the inoculation of fresh digesters.
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4

Castano, Juan Mauricio. "Anaerobic Digestion of Low Rate Digesters in Temperate Climates." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1345220853.

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5

Langley, Kyle Anthony. "Potential benefits and experienced challenges of small household biogas-digesters for rural households." Thesis, Rhodes University, 2016. http://hdl.handle.net/10962/d1021268.

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Access to renewable energy supplies is a critical foundation for sustainable development and poverty alleviation. Anaerobic biogas-digesters also referred to as bio-digesters, have been identified as one of the leading technologies with regards to assisting in improving energy access for remote rural areas that still remain dependent upon biomass usage. This thesis assesses the potential feasibility of bio-digesters for rural households in South Africa by focusing on the experiences of a remote and rural community in Eastern Cape. A standardised survey was used to capture household details and energy use patterns of households with 180 interviews being conducted. Field observations were also conducted on the five bio-digesters installed in the community over a three month period. Despite the predominance of electrification in the community, households were heavily reliant upon biomass in the form of fuelwood and cattle dung to supplement their energy needs. Households supplemented their energy usage with alternative energy sources such as LPG gas and paraffin, especially during periods when electricity was unavailable or deemed too expensive. Initial knowledge of bio-digester technology in the community was non-existent, however with the installation of bio-digesters within the targeted villages, social learning was observed. Despite low temperatures bio-digesters continued to function throughout the study period, though malfunctions did occur and gas production did not reach optimal levels. Primary challenges encountered were the lack of financial subsidies for wide-spread adoption; the limited technical capacity of the community to conduct repairs and minimal gas production due to a build-up of ligneous materials within the gas chamber of the bio-digesters. Bio-digesters were found to provide significant benefits for households and further studies into maximising their effectiveness for rural South African households are recommended.
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6

Nguyen, Vo Chau Ngan. "Small-scale anaerobic digesters in Vietnam - development and challenges." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-88525.

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Small-scale anaerobic digesters, known as biogas plants, were applied as an optimal livestock waste treatment as well as biogas supply for cooking and lighting demand for small-scale farmers in Vietnam. Although the biogas technology was introduced for nearly 30 years, the number of the constructed biogas plants is still limited. The current development of biogas plants is far below the real demand on livestock waste treatment that has increased significantly. This paper gives a comprehensive overview on the biogas plant development in Vietnam and attempts to address the challenges and discuss appropriate solutions for the further biogas development
Mô hình lên men yếm khí quy mô nhỏ (được biết với tên hầm ủ khí sinh học) đã được ứng dụng hiệu quả trong xử lý chất thải chăn nuôi cũng như cung cấp nguồn nhiên liệu phục vụ nhu cầu nấu ăn và thắp sáng cho các hộ chăn nuôi nhỏ ở Việt Nam. Mặc dù đã hiện diện gần 30 năm, nhưng số lượng hầm ủ khí sinh học vẫn còn hạn chế. Sự gia tăng số lượng hầm ủ khí sinh học chưa theo kịp với nhu cầu về xử lý chất thải chăn nuôi đang ngày càng gia tăng. Bài báo trình bày các chặng đường phát triển của hầm ủ khí sinh học tại Việt Nam, ghi nhận các thách thức trong việc nhân rộng hầm ủ khí sinh học trong thực tế và thảo luận một số giải pháp để phát triển công nghệ khí sinh học
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7

Moreira, Andrà Pimentel. "Controle de vazÃo de biogÃs com baixa pressÃo para produÃÃo descentralizada de eletricidade." Universidade Federal do CearÃ, 2011. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=6732.

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Banco do Nordeste do Brasil
A presente dissertaÃÃo propÃe a implementaÃÃo de um sistema de aquisiÃÃo de dados, controle e monitoramento de uma planta de geraÃÃo de energia elÃtrica acionada por biogÃs. Foi realizado o estudo experimental das estratÃgias de modelagem, identificaÃÃo e controle aplicado ao controle de vazÃo da planta de biogÃs do LaboratÃrio de Energias Alternativas - LEA da Universidade Federal do Cearà - UFC. Foi utilizado e testado para o controle de vazÃo de biogÃs o controlador PI paralelo, alÃm de realizar a comparaÃÃo com o controle existente (controle centrÃfugo) do conjunto motor/gerador. Para vericar a resposta do gerador movido a biogÃs, foi inserido uma carga correspondente a 60% da potÃncia nominal. O sistema proposto reduziu a intervenÃÃo humana no ajuste de vazÃo da vÃlvula de expansÃo. Os resultados demonstraram que o tempo de resposta para estabilidade apÃs a introduÃÃo do contolador PI ao controlador original permitiu a reduÃÃo do tempo de resposta para estabilidade em no mÃnimo 20% mostrando uma resposta satisfatÃria e boa estabilidade para a transiÃÃo da gasolina para o biogÃs, com amplitude de 10 Hz e 8 segundos para estabilizaÃÃo do sistema sem carga. A aÃÃo foi considerada viÃvel para automatizar o processo de partida do conjunto motor/gerador.
The present dissertation proposes the implementation of a data acquisition system, control and monitoring of a electricity generation plant powered by biogas. The experimental study of the modelling strategies, identication and control was done applied to ow control of the biogas plant of the Renewable Energy Laboratory - LEA at the Federal University of Cearà - UFC. To control the biogas ow a parallel PI controller was used and tested, and the controller was used to perform the comparison with the existing control (centrifugal control) of the gen-set. To check the response of the gen-set powered by biogas, a load corresponding of 60% of the nominal power was used. The proposed system reduced the human intervention in ow setting of the expansion valve. The results showed that the stability response time after the introduction of the PI controller to the original controller allowed the reduction of the response time for at least 20% showing a satisfactory response and a stability for the transition from gasoline to biogas, with 10 Hz amplitude and 8 seconds for the system stabilization with load. This action was considered feasible to automate the process of starting up of the gen-set.
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8

Sauve, Terrence. "Enhancement of Biogas Production Using Co-Substrates In Anaerobic Digesters for Medium Size Dairy Farms." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28635.

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The use of co-substrates can significantly enhance biogas production from manure while helping to treat and dispose of high carbon organic wastes from the food processing industry and municipalities. This thesis will focus on the experimental setup and results collected at the University of Guelph -- Campus d'Alfred from a series of Biochemical Methane Potential assays and six 30 L semi-continuous anaerobic digesters operating under mesophilic conditions. The co-substrates investigated during the study include: corn silage, canola meal, whey, glycerine and dissolved air floatation sludge. The use of liquid dairy manure proved to be beneficial for the anaerobic digestion process by supplementing necessary buffering capacity, nitrogen, micro and macro elements for the co-digestion of high carbon organic wastes. Biochemical Methane Potential assays of the co-substrates increased the biogas yield from 5 to 250%. When these co-substrates were elaborated in semi-continuous pilot digesters, volumetric biogas production increased two to three-folds in relation to liquid dairy manure.
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9

Sindall, Rebecca Clare. "Increasing the efficiency of anaerobic waste digesters by optimising flow patterns to enhance biogas production." Thesis, University of Birmingham, 2015. http://etheses.bham.ac.uk//id/eprint/5636/.

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Anaerobic digestion is used to stabilise sewage sludge and produce biogas. Whilst the need to mix digesters is well-recognised, the level of mixing required and its effects on biogas production are not clear. Here, the effects of mixing speed in mechanically-mixed lab-scale digesters on biogas production are considered. For the first time, positron emission particle tracking was used to visualise flow patterns in lab-scale digesters at different mixing speeds. Computational fluid dynamics models were then built to identify the turbulence characteristics. Four lab-scale digesters were run for four months at different mixing speeds and key indicators of digester stability and microbiological population were recorded alongside gas production. Increased mixing speed leads to higher levels of turbulence and in these digesters, increasing the mixing speed reduces the stability of the methane generation process and accordingly has a detrimental effect on the gas production. Similarly, the abundance of methanogenic communities was adversely affected by increasing mixing speeds. However, the unmixed digester produced less biogas than the digester mixed at a low speed, due to uncontrolled digestion. As such, for these digesters, minimal mixing represents the ideal scenario. By considering the velocity gradient in the digester as a surrogate for turbulence, a threshold of 6 8 s-1 was identified. Below this threshold, increased mixing was beneficial but increasing mixing above the threshold was detrimental to digester stability and gas production.
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Tukana, Andrew, University of Western Sydney, of Science Technology and Environment College, and School of Environment and Agriculture. "A study of biogas digesters as an animal waste management tool on livestock farming systems in Fiji." THESIS_CSTE_EAG_Tukana_A.xml, 2005. http://handle.uws.edu.au:8081/1959.7/632.

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Ever since 1976, livestock farmers in Fiji have been intrigued about biogas digesters as an animal waste management measure, but the concept has never evolved into one that is sustainable. Renewed interest came in 1997 after a better Chinese Modified Dome (CMD) design was established, with this came government funding, however by 2002, some failure was also observed. This study set out to investigate the reasons why biogas digesters have never been established as a sustainable concept, its effectiveness as an animal waste management tool and what changes if any, can be made to try and influence the further development of the concept in Fiji. In order to achieve the objectives, which were simply obtaining the answers to the questions presented above, several different approaches had to be followed. This study was the first on biogas digesters in Fiji and it was unique in the sense that the major component dealt with the social aspects of farmers in relation to their biogas digesters. Basically the study was carried out in two parts - desktop studies and field studies. Desktop studies were done to better understand the situation while the field studies included semi-structured interviews with the farmers as well as the collection of biophysical data. Twelve outcomes are presented in chapter 7 of this paper. Two in particular are the improvement of construction and maintenance, which can only come about through training. The research questions are also answered in chapter 7, with recommendations put forward on possible directions to take in terms of trying to influence the development of the concept in Fiji
Master of Science (Hons)
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11

Tukana, Andrew. "A study of biogas digesters as an animal waste management tool on livestock farming systems in Fiji." Thesis, View thesis, 2005. http://handle.uws.edu.au:8081/1959.7/632.

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Ever since 1976, livestock farmers in Fiji have been intrigued about biogas digesters as an animal waste management measure, but the concept has never evolved into one that is sustainable. Renewed interest came in 1997 after a better Chinese Modified Dome (CMD) design was established, with this came government funding, however by 2002, some failure was also observed. This study set out to investigate the reasons why biogas digesters have never been established as a sustainable concept, its effectiveness as an animal waste management tool and what changes if any, can be made to try and influence the further development of the concept in Fiji. In order to achieve the objectives, which were simply obtaining the answers to the questions presented above, several different approaches had to be followed. This study was the first on biogas digesters in Fiji and it was unique in the sense that the major component dealt with the social aspects of farmers in relation to their biogas digesters. Basically the study was carried out in two parts - desktop studies and field studies. Desktop studies were done to better understand the situation while the field studies included semi-structured interviews with the farmers as well as the collection of biophysical data. Twelve outcomes are presented in chapter 7 of this paper. Two in particular are the improvement of construction and maintenance, which can only come about through training. The research questions are also answered in chapter 7, with recommendations put forward on possible directions to take in terms of trying to influence the development of the concept in Fiji
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12

Tukana, Andrew. "A Study of biogas digesters as an animal waste management tool on livestock farming systems in Fiji /." View thesis, 2005. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20060502.151953/index.html.

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Thesis (M. Sc.) (Hons) -- University of Western Sydney, 2005.
" A thesis presented to the School of Environment and Agriculture, University of Western Sydney, in fulfilment of the requirements for the degree of Master of Science (Honours)." Includes bibliography : leaves 165 -175, and appendices.
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Dhital, Avinash. "Opportunities for small-scale anaerobic digesters for hotels and restaurants in Kathmandu, Nepal." Thesis, KTH, Energiteknik, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-244406.

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About 83% of total energy consumed in Nepal comes directly from the solid fuels. The import of Liquified Petroleum Gas (LPG) is also growing at an exponential rate. The hospitality subsector (hotels and restaurants), one of the key economic subsectors in the country, consumes most of the energy within the commercial sector primarily for cooking purposes. The bio-waste generated from growing hospitality subsector and other sectors in Kathmandu is poorly managed. Similarly, on the other hand, Nepal has an extensive knowledge and experience of manure based anaerobic household biogas systems mainly in rural areas. Based upon this situation, the thesis investigates the opportunities for anaerobic biogas production for cooking at hotels and restaurants by utilizing their own organic waste. Currently available biogas technologies, important parameters affecting the biogas yield, policy and financial supports and case studies of various stakeholders employing the biogas technologies in the hotels and restaurants in Nepal were considered. The most applicable technology for the purpose was then chosen. The organic waste sampling study from randomly selected 4-star hotel (Yatri Spa and Suites), tourist standard hotel (Hotel Bliss International) and restaurant (Fren’s Kitchen) in Thamel, the tourist zone of Kathmandu was conducted. Similarly, various data especially focusing on the current cooking energy need, demand, supply, cost, organic waste management of the hotels and the restaurant was collected through questionnaires and series of interviews. The average amount of daily organic waste and organic waste fraction for Yatri, Bliss and Fren’s was found to be 61.3 kg and 63.0%, 18.4 kg and 82.7%, and 16.3 kg and 81.8% respectively. Similarly, the variations in weekly organic wastes and waste generated per guest was also determined. Based upon the amount and characteristics of organic waste from the sampling survey, the theoretical biogas potential of the organic waste at digester output rate of 0.27 kWh/kg/day for JUAS digesters, the technology selected for the biogas conversion, was found to be 18.4 kWh/day, 5.5 kWh/day and 4.9 kWh/day equivalent to 4.9%, 3.0% and 5.4 % of the current daily energy need for Yatri, Bliss and Fren’s respectively. Similarly, the economic implications of the small-scale biogas technology if employed in the hotels and the restaurant was scoped out. It was found that the recommended Polyvinyl Chloride (PVC) based 3000 l sized JUAS bio-digesters had positive Net Present Value (NPV), Internal Rate of Return (IRR) and payback time of around 5 years on average for all the eateries under study. The monthly life cycle cost of the integrated LPG-JUAS system is found be cheaper for all eateries as compared to the current LPG system. Levelized Cost of Energy (LCoE) of the JUAS digesters is calculated to be competitive as compared to energy from other renewables in the country. There is, however, need to improve the digester conditions to get higher biogas yields. For the wider adoption of the digesters across urban sectors, the subsidies amount should also be increased together with information dissemination regarding biogas uses and its potential among the stakeholders.
Omkring 83% av den totala energiförbrukningen i Nepal kommer direkt från det fasta bränslet. Importen av flytande petroleumgas (LPG) växer också i exponentiell takt. Underhållningsbranschen (hotell och restauranger), en av de viktigaste ekonomiska delområdena i landet, förbrukar mest energi inom kommersiell sektor, främst för matlagning. Det biologiska avfallet som genereras av växande underhållsbranschen och andra sektorer i Katmandu är dåligt förvaltad. På samma sätt har Nepal en omfattande kunskap och erfarenhet av gödselbaserade anaeroba hushållsbiogasystem, huvudsakligen i landsbygdsområden. Baserat på denna situation undersöker man avhandlingen möjligheterna till anaerob biogasproduktion för att laga mat på hotell och restauranger genom att använda eget organiskt avfall. För närvarande finns biogasteknik, viktiga parametrar som påverkar biogasutbytet, politiska och finansiella stöd och fallstudier av olika intressenter som använder biogasteknik i hotell och restauranger i Nepal. Den mest tillämpliga tekniken för ändamålet valdes sedan. Undersökning av organiska avfallsprov från slumpmässigt utvalt 4-stjärnigt hotell (Yatri Spa and Suites), turisthotell (Hotel Bliss International) och restaurang (Fren's Kitchen) i Thamel, utförs turistområdet Katmandu. På samma sätt samlades olika data som speciellt fokuserade på dagens energibehov, efterfrågan, tillgång, kostnad, organisk avfallshantering av hotellen och restaurangen genom enkäter och intervjuer. Den genomsnittliga mängden dagligt organiskt avfall och organiskt avfallsfraktion för Yatri, Bliss och Fren var visat sig 61,3 kg respektive 63,0%, 18,4 kg respektive 82,7% respektive 16,3 kg respektive 81,8%. På samma sätt bestämdes också variationerna i organiskt avfall per vecka och avfall som genererades per gäst. Baserat på mängden och egenskaperna hos organiskt avfall från provtagningsundersökningen befanns den teoretiska biogaspotentialen hos det organiska avfallet vid kokareutgångshastigheten på 0,27 kWh / kg / dag för JUAS-kokare, den teknik som valts för biogasomvandling, befunnits vara 18,4 kWh / dag, 5,5 kWh / dag och 4,9 kWh / dag motsvarande 4,9%, 3,0% och 5,4% av dagens energibehov för Yatri, Bliss och Fren. På samma sätt scenkades de ekonomiska konsekvenserna av den småskaliga biogastekniken om de anställdes i hotell och restaurangen. Det visade sig att de rekommenderade polyvinylkloridbaserade (PVC) -baserade JUAS-bioförstörare av polyvinylklorid med jämna mellanrum hade positivt nettoförsäkringsvärde (NPV), interna avkastningsräntor och återbetalningstid på cirka 5 år i genomsnitt för alla restauranger som studerades. Den månatliga livscykelkostnaden för det integrerade LPG-JUAS-systemet befinner sig vara billigare för alla matställen jämfört med det aktuella LPG-systemet. Nivånad kostnad för energi (LCoE) hos JUAS-kokare beräknas vara konkurrenskraftig jämfört med energi från andra förnybara energikällor i landet. Det är dock nödvändigt att förbättra kokareförhållandena för att få högre biogasutbyten. För det bredare godkännandet av kokare i städerna bör bidragsbeloppet också ökas tillsammans med informationsspridning avseende biogasanvändning och dess potential bland intressenterna.För det bredare godkännandet av kokare i städerna bör bidragsbeloppet också ökas tillsammans med informationsspridning avseende biogasanvändning och dess potential bland intressenterna.
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Dobrzanska, Dorota A. "Using bio-adhesive and bio-inert surfaces to maximize biogas production and influence microbial growth in anaerobic digesters." Thesis, University of Warwick, 2014. http://wrap.warwick.ac.uk/66487/.

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The optimisation of biogas digesters is crucial for further development of sustainable energy sources. In this research, an integrative approach was taken to understanding how this problem can be addressed including: seeking a better understanding of protein – surface interactions on the molecular level; larger scale experiments to screen the best materials for use in laboratory scale anaerobic digesters to influence microbial growth and biofilm development as well as analysis of farm-scale data using the ADM1 multiparameter model. The laboratory-scale experiments were undertaken to develop surfaces suitable for studying microbial immobilization. This work, currently using tertiary amines, amine oxides and comparator oligoethylene glycol studies the adsorption of two classic model proteins: lysozyme and fibrinogen using quartz crystal microbalance methods and represents important steps for selecting and exploring surface – protein interactions. The data showed that tertiary amine oxides are more resistant to nonspecific protein adsorption than the corresponding tertiary amines. Heat modified polyurethane foam was used to explore biofilm and planktonic phase microbial populations in a fixed film biogas reactor. After four weeks the foam was analysed by ‘next generation’ 454-sequencing to identify the influence of the supporting materials on microbial population residing in anaerobic digesters. The results revealed that Spirochaetes, Methanobacterium and Methanocorpusculum associated themselves with heat modified polyurethane foams. Finally, data from a farm-scale anaerobic digester (volatile fatty acid concentration, temperature and pH) have been gathered and entered into the ADM1 model, developed by the mathematical modelling group from Lund University, to mimic the behaviour of a laboratory scale 1.5 l reactor and identify improved conditions for methanogens stability. The combination of approaches described above will allow the identification of which parameters will enhance the operation of anaerobic digesters and has identified surfaces that promote adhesion of particular Bacteria and Archaea in order to increase biogas production.
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Wilhelmsson, Ella. "Investigations of the Effects of Lowering the Temperature in Full Scale Mesophilic Biogas Digesters at a Wastewater Treatment Plant." Thesis, Linköpings universitet, Tema Miljöförändring, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-167059.

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This thesis has investigated the effects of running the two full scale biogas digesters at Slottshagen wastewater treatment plant at 34 °C compared to 37 °C, in terms of process stability, biogas production and energy savings with the aim of saving energy and money by not heating the digesters as much. The main objective was to investigate whether it is at all possible to operate the biogas process at 34 °C or if the process becomes inhibited or otherwise unstable. If the process could be operated at 34 °C it might mean savings of both energy and money, provided that there is still a sufficient production of biogas.The experiment lasted for three months and investigated the short-term effects of the reduction of temperature. The process was monitored closely, and samples from the reactors were collected and analysed twice a week to ensure the stability of the biogas process. Several parameters were monitored online, the biogas production and methane content amongst others. Other parameters were calculated, such as the degree of degradation and specific methane production. This was done to ensure process stability and a sufficient production of biogas. The energy balance was calculated to evaluate if energy was saved by lowering the temperature in the digesters.The results show that the biogas process does remain stable at 34 °C while still producing a satisfactory amount of biogas during the short time of the experiment. Calculations show that both energy and money has been saved during the experiment. However, the system is largely dependent on seasonal variations, therefore further studies over a longer time period would be desirable. During the course of the thesis it has also become evident that the biogas process at Slottshagen is irregular in several aspects, and that it would be beneficial to even the process out, especially with regards to the hydraulic retention time. Making the process more even would enable further improvements to be made and simplify interpretations and comparisons of processstability data.
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16

Rowse, Laurel Erika. "Design of Small Scale Anaerobic Digesters for Application in Rural Developing Countries." Scholar Commons, 2011. http://scholarcommons.usf.edu/etd/3324.

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The high incidence of upper respiratory diseases, contamination of waterways due to pathogens and nutrients from human and animal wastes, unsustainable deforestation, gender disparities in burden of disease due to unequal exposure to indoor air pollutants, and carbon black emissions from the burning of solid fuels are interrelated problems in many developing countries. Small scale anaerobic digestion provides a means of alleviating these problems by treating livestock waste onsite to produce biogas (methane and carbon dioxide) in rural areas in developing countries. Fuel can then be used for cooking, lighting, and heating. Methane fuel is an alternative to traditional three-stone fires, improved cook stoves, and liquid petroleum gas. However, there is a lack of information available on design methods for these systems. The goal of this research was to develop a design tool that could be used for anaerobic digester sizing based on livestock waste availability. An Excel spreadsheet model was developed for sizing the bioreactor and the gas container based upon recommended values from a literature review. Needed monitoring parameters for operation of an anaerobic digester in the field were identified and standard methods of analysis were recommended. Sample preservation techniques were detailed. Guidelines for pathogen reduction in thermophilic anaerobic digestion were identified. Further study of pathogen reduction in low temperature reactors currently in use in developing countries was recommended. Three digester designs included in the Excel spreadsheet model were: the polyethylene tubular digester, the floating drum digester, and the fixed dome digester. The design tool may be requested from Dr. Sarina Ergas, sergas(at)usf.edu. An organic loading rate of 1.0 kg VS/(m3*d) was chosen for use in the design tool based upon a review of the literature. A semi-empirical kinetic model was developed for defining the SRT based on the temperature inputted by the user. Three case studies, based upon livestock waste availability in a rural community in the Dominican Republic, were analyzed using the sizing design tool. The case studies were conducted on three scales: one household, six households, and a village of 48 households. The specific biogas production rates were, for Case Studies one through three, respectively, 0.0076, 0.0069, and 0.010 m3 biogas/kg Volatile Solids reduced. Additional future work included: characterization of human feces and guinea pig manure, laboratory and field testing of the Excel spreadsheet design tool, and promotion of anaerobic digesters by development workers, non-governmental organizations, and governments.
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17

Stoddard, Isak. "Communal Polyethylene Biogas Systems : Experiences from on-farm research in rural West Java." Thesis, Uppsala University, Global Energy Systems, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-131203.

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In Lembang, a farming community on western Java, family-sized, plug-flow, polyethylene biogas systems fed with cow dung, are being used as an integrated solution to issues related to energy, agriculture and waste management. Through simple, on-farm research and observation, a number of key problems have been addressed and improvements made to the design. Due to the large supply of cow dung in the area, and the potential to spread the benefits of the technology beyond the homes of dairy farmers, the feasibility of developing a communal, polyethylene biogas system for several households, has been investigated. Experiments on small model-digesters were combined with observations of full-scale biogas systems in use. Measurement equipment and techniques were constructed and developed, in order to measure biogas production and other relevant process parameters. Results indicate that a communal system can be an appropriate choice, but only under a certain set of circumstances.

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18

Rehman, Zia-ur [Verfasser], Roland [Gutachter] Span, and Mandy [Gutachter] Gerber. "Process stability in biogas digesters : influencing parameters control using carbonate addition / Zia-ur Rehman ; Gutachter: Roland Span, Mandy Gerber ; Fakultät für Maschinenbau." Bochum : Ruhr-Universität Bochum, 2019. http://d-nb.info/1182682308/34.

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19

Rockenbach, Felipe Luis. "VIABILIDADE ECONÔMICA DA PRODUÇÃO DE BIOGÁS EM GRANJAS DE SUÍNOS, POR MEIO DA ANÁLISE DE SÉRIES TEMPORAIS." Universidade Federal de Santa Maria, 2014. http://repositorio.ufsm.br/handle/1/8320.

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This study aims to gather, analyze, and interpret the potential and economic feasibility of sequestering carbon dioxide and/or generating renewable energy from the processing of pig manure, via time series analysis, using the Box and Jenkins (1970) models for future prediction. Swine production systems generate large amounts of waste which are highly polluting and impact the environment, principally greenhouse gases. When treated, these gases produce methane gas and in turn biogas, which when removed correctly is converted into electricity and carbon credits, leaving behind a high quality biofertilizer. This scenario of carbon dioxide sequestration was only possible after the adoption of the Kyoto Protocol, which provides for the Clean Development Mechanism (CDM) and the sale of Certified Emission Reductions (CER); electrical energy was affected by Regulatory Resolution 482/ 2012 of the National Electric Energy Agency (ANEEL). Data were was gathered with the support of the Municipal Association of Swine Producers of Toledo (AMST) and the BRF Company. This study demonstrates that it is feasible to use biogas and that the payback period follows a production scale with equipment operating 10 hours or more daily. Consequently, the payback period will be between 70 and 80 months, with production of electrical energy and/or in conjunction with the production of carbon credits. The study also shows that the production volume is feasible and should accommodate a minimum number of pigs. In addition, prediction models are important tools since they anticipate the behavior of the series under study, providing support so that investments can be made, reducing risks to the both the swine producer (in the area of finances) and to the farm, as well as allowing for another source of income. By reducing production costs, autonomy is guaranteed in ensuring an uninterrupted supply of electricity, which is needed for swine operations which become more and more dependent on technology.
O presente estudo visa reunir, analisar e interpretar o potencial e a viabilidade econômica do sequestro de gás carbônico e/ou a geração de energia renovável proveniente do tratamento de dejetos suínos, por meio da análise de séries temporais, com utilização dos modelos de previsão Box e Jenkins (1970). Como os sistemas de produção de suínos geram grande quantidade de dejetos altamente poluentes e impactantes no meio ambiente, principalmente os gases de efeito estufa, estes, ao serem tratados, produzirão o gás metano e dentro deste o biogás que, ao ser eliminado corretamente é convertido em energia elétrica e em créditos de carbono, restando na propriedade um biofertilizante de alta qualidade. Cenário do sequestro de gás carbônico que só foi possível após a aprovação do Protocolo de Quioto que prevê o Mecanismo de Desenvolvimento Limpo (MDL), a comercialização dos Certificados de Emissões Reduzidas (CER) e, no âmbito da energia elétrica, pela Resolução Regulamentadora 482/2012 da Agência Nacional de Energia Elétrica (ANEEL). Para o levantamento dessas informações, contou-se com o apoio da Associação Municipal dos Suinocultores de Toledo (AMST) e da Empresa BRF. Esta pesquisa demonstra que é viável a utilização do biogás e que o período de retorno obedece a uma escala de produção com um funcionamento diário dos equipamentos de 10 horas ou mais. Dessa forma, o período do retorno do investimento será entre 70 a 80 meses, com a produção de energia elétrica e/ou em conjunto com a produção de créditos de carbono. Mostra também que o volume de produção é viável, desde que aloje um número mínimo de suínos. Além disso, o uso de modelos de previsão é importante ferramenta, pois antecipam o comportamento da série em estudo, fornecendo ao produtor subsídios para que o investimento seja feito reduzindo o risco ao suinocultor, tanto nos aspectos financeiros, pois a granja terá mais uma fonte de renda, quanto na redução dos custos de produção, já que terá autonomia no fornecimento de energia elétrica ininterruptamente, o que é necessário nos sistemas de criação cada vez mais tecnificados.
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20

Aires, Airon Magno. "Biodigestão anaeróbia da cama de frangos de corte com ou sem separação das frações sólida e líquida /." Jaboticabal : [s.n.], 2009. http://hdl.handle.net/11449/96593.

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Orientador: Jorge de Lucas Júnior
Banca: Mônica Sarolli Silva de Mendonça Costa
Banca: Roberto Alves de Oliveira
Resumo: Objetivou-se avaliar o efeito da reutilização das camas de quatro lotes de frango de corte, sobre a produção de biogás, sendo estas submetidas ou não à diluição e separação de sólidos e líquidos em biodigestores operados em batelada e contínuo. No Capítulo 1 é apresentado o problema, a justificativa do estudo juntamente com os objetivos gerais do projeto. O Capítulo 2 teve como objetivo avaliar as diluições de cama de frango e as concentrações de Sólidos Totais (ST). As camas de casca de amendoim foram diluídas em água e separadas em peneira de malha de 3 mm, nas seguintes proporções: 2:1; 4:1 até 14:1. Assim foi escolhida a diluição 4:1 (a qual se obteve 3,01 % de ST) para realizar os ensaios. Os Capítulo 3 e 4 avaliaram as camas de quatro lotes de frango de corte com diluição 4:1, submetidas ou não à separação de sólidos, em biodigestores batelada e contínuo respectivamente. O tratamento não peneirado obteve maiores produções de biogás em relação ao tratamento peneirado (Capítulo 3), ao passo que no Capítulo 4 os resultados se inverteram. Em ambos os os ensaios experimentais, ocorreram aumento da concentração de minerais em massa. O objetivo do Capítulo 5 foi avaliar o processo de compostagem da cama de frango, após diluição e separação de sólidos. O ensaio foi conduzido por um período de 90 dias, utilizando-se a cama de frango de corte de 4º reutilização. Foram utilizados para montagem da leira 348,94 kg de cama de frango/MN. A cama retida na peneira se mostrou favorável ao processo de compostagem, apresentando uma relação C:N de 12:1, o que influenciou na redução de 25 % dos ST ao final do enleiramento.
Abstract: This study aimed to evaluate the effect of reuse of litters of four batches of broilers on the production of biogas. The litters were submitted or not the dilution and separation of solids and liquids in batch and continuous systems of anaerobic digestion (AD). In Chapter 1 is presented the problem, the justification of the study together with the general objectives of the project. Chapter 2 was to evaluate the dilutions of broiler litter and the concentrations of Total Solids (TS) for AD. The litter of peanut hulls was diluted in water and separated in a mesh sieve of 3 mm, as follows: 2:1, 4:1 to 14:1. The highest values of TS were found in the lower dilutions, was chosen as the dilution 4:1 (which returned 3.01% in TS) to perform the tests for AD. In Chapter 3 and 4 were intended to assess the DA of the litters of four batches of broiler with 4:1 dilution, or not submitted to the separation of solids in batch and continuous systems, respectively. The treatment not sieved obtained higher production of biogas in the treatment sieved (Chapter 3), while Chapter 4 the results are reversed. In both chapters were reductions of mineral mass (kg) after AD. The purpose of Chapter 5 was to evaluate the process of composting of broiler litter, after dilution and separation of solids. The test was conducted in a period of 90 days, using the litter of broilers from 4 reuses. Were used for assembling a pile 348.94 kilograms of broiler litter / MN. The litter retained on the sieve was favorable to the process of composting, giving a C:N of 12:1, which influenced the reduction of 25% of the end of piling ST.
Mestre
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21

Barichello, Rodrigo. "O USO DE BIODIGESTORES EM PEQUENAS E MÉDIAS PROPRIEDADES RURAIS COM ÊNFASE NA AGREGAÇÃO DE VALOR: UM ESTUDO DE CASO DA REGIÃO NOROESTE DO RIO GRANDE DO SUL." Universidade Federal de Santa Maria, 2010. http://repositorio.ufsm.br/handle/1/8169.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
From the duration of the Kyoto Protocol, there has been a renewed interest in technology of bio-digesters. As they allow a reduction in the emission of greenhouse gases compared to other waste treatment methods, their deployment can permit the marketing of carbon credits, resulting in money. The present study aims to analyze the process of dissemination of this technology in Santa Rosa, situated in the northwestern of Rio Grande do Sul state, especially powered by private companies. The profile properties that have these installed equipment, in addition to an examination of possible difficulties encountered by land owners, towards the deployment and use of this technology, with the contribution of biodigesters, on the energy issue and mitigation of environmental pollution in these areas. Through a revision of the existing literature and application of questionnaires some information about the installation of bio-digesters were taken, noticing if they contribute as alternatives in order to add value to the breeding properties and as viable alternative to the solution of environmental problems involved in the process. This study revealed that 33.33% of installed equipment is disabled. The work also presents a case study of isolated electric power generation using biogas as a fuel in an internal combustion engine of Otto cycle, in conjunction with CDM project, installed in a midsize property of pig breeding. The generation plant consists of a stationary Otto cycle engine, adapted to operate with biogas, coupled to an electric generator nominal 30 kVA three-phase. Through the study of the economic and financial feasibility, it was concluded that the application for generating electricity is viable and the overall efficiency of the system is satisfactory. Through another point of view, it presents a second case study, on the insertion of a property in a project of clean development mechanism (CDM) in pig production.
A partir da vigência do Protocolo de Kyoto, houve um interesse renovado pela tecnologia dos biodigestores. Como eles permitem uma redução na emissão de gases do efeito estufa, em relação a outros métodos de tratamento de dejetos, a sua implantação pode permitir a comercialização de créditos de carbono, resultando em valores monetários. O presente trabalho tem como objetivo analisar o processo de disseminação desta tecnologia na microrregião de Santa Rosa, situada na mesorregião do Noroeste Riograndense, impulsionada, especialmente, por empresas privadas. Estudou-se o perfil das propriedades que possuem estes equipamentos instalados, além de uma análise das possíveis dificuldades encontradas pelos proprietários rurais, no sentido de implantação e utilização dessa tecnologia, verificando-se a contribuição dos biodigestores, referente à questão energética e minimização da poluição do meio ambiente nessas áreas. Através da revisão da literatura existente e aplicação de questionários, foram levantadas diversas informações acerca da instalação de biodigestores, observando se contribuem como alternativa de agregação de valor às propriedades criadoras e como alternativa viável para a solução dos problemas ambientais envolvidos no processo. O presente estudo revelou que 33,33% dos equipamentos instalados encontram-se desativados. O trabalho também apresenta um caso prático de geração de energia elétrica isolada, utilizando biogás como combustível em um motor à combustão interna do Ciclo Otto, em conjunto com projeto de MDL, instalado em uma propriedade de médio porte, para criação de suínos. A planta de geração consiste de um motor estacionário de Ciclo Otto, adaptado para operar com biogás, acoplado a um gerador elétrico trifásico de 30 kVA nominal. Através do estudo da análise de viabilidade econômico-financeira, concluiu-se que a aplicação para a geração de energia elétrica é viável e a eficiência global do sistema é satisfatória. Numa outra visão, apresenta-se um segundo caso prático, na inserção de uma propriedade em um projeto de mecanismo de desenvolvimento Limpo (MDL) na suinocultura.
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22

Aires, Airon Magno [UNESP]. "Biodigestão anaeróbia da cama de frangos de corte com ou sem separação das frações sólida e líquida." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/96593.

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Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-20Bitstream added on 2014-06-13T20:08:42Z : No. of bitstreams: 1 aires_am_me_jabo.pdf: 8042698 bytes, checksum: cee6205ffc3aed9386f08ebaca4e0466 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Objetivou-se avaliar o efeito da reutilização das camas de quatro lotes de frango de corte, sobre a produção de biogás, sendo estas submetidas ou não à diluição e separação de sólidos e líquidos em biodigestores operados em batelada e contínuo. No Capítulo 1 é apresentado o problema, a justificativa do estudo juntamente com os objetivos gerais do projeto. O Capítulo 2 teve como objetivo avaliar as diluições de cama de frango e as concentrações de Sólidos Totais (ST). As camas de casca de amendoim foram diluídas em água e separadas em peneira de malha de 3 mm, nas seguintes proporções: 2:1; 4:1 até 14:1. Assim foi escolhida a diluição 4:1 (a qual se obteve 3,01 % de ST) para realizar os ensaios. Os Capítulo 3 e 4 avaliaram as camas de quatro lotes de frango de corte com diluição 4:1, submetidas ou não à separação de sólidos, em biodigestores batelada e contínuo respectivamente. O tratamento não peneirado obteve maiores produções de biogás em relação ao tratamento peneirado (Capítulo 3), ao passo que no Capítulo 4 os resultados se inverteram. Em ambos os os ensaios experimentais, ocorreram aumento da concentração de minerais em massa. O objetivo do Capítulo 5 foi avaliar o processo de compostagem da cama de frango, após diluição e separação de sólidos. O ensaio foi conduzido por um período de 90 dias, utilizando-se a cama de frango de corte de 4º reutilização. Foram utilizados para montagem da leira 348,94 kg de cama de frango/MN. A cama retida na peneira se mostrou favorável ao processo de compostagem, apresentando uma relação C:N de 12:1, o que influenciou na redução de 25 % dos ST ao final do enleiramento.
This study aimed to evaluate the effect of reuse of litters of four batches of broilers on the production of biogas. The litters were submitted or not the dilution and separation of solids and liquids in batch and continuous systems of anaerobic digestion (AD). In Chapter 1 is presented the problem, the justification of the study together with the general objectives of the project. Chapter 2 was to evaluate the dilutions of broiler litter and the concentrations of Total Solids (TS) for AD. The litter of peanut hulls was diluted in water and separated in a mesh sieve of 3 mm, as follows: 2:1, 4:1 to 14:1. The highest values of TS were found in the lower dilutions, was chosen as the dilution 4:1 (which returned 3.01% in TS) to perform the tests for AD. In Chapter 3 and 4 were intended to assess the DA of the litters of four batches of broiler with 4:1 dilution, or not submitted to the separation of solids in batch and continuous systems, respectively. The treatment not sieved obtained higher production of biogas in the treatment sieved (Chapter 3), while Chapter 4 the results are reversed. In both chapters were reductions of mineral mass (kg) after AD. The purpose of Chapter 5 was to evaluate the process of composting of broiler litter, after dilution and separation of solids. The test was conducted in a period of 90 days, using the litter of broilers from 4 reuses. Were used for assembling a pile 348.94 kilograms of broiler litter / MN. The litter retained on the sieve was favorable to the process of composting, giving a C:N of 12:1, which influenced the reduction of 25% of the end of piling ST.
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23

Racz, Tiffany A. "Anaerobic Digestion of Wastewater-Grown Algae Biomass With Optimized Biogas Yields and Nutrient Solubilzation." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/2245.

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Whole-cell algae biomass grown on nutrient-rich wastewater can be anaerobically digested to produce renewable heat and power, and to solubilize nutrients to grow additional algae biomass in a biorefinery system. In this study, algae biomass was grown on clarified primary wastewater in 33-m2 ponds at a 4-day residence time with sedimentation harvesting of the biomass. Lab digesters were used to test biogas yields and nutrient solubilization from the anaerobic digestion of algal biomass with and without mixing and with sonication as a pretreatment. Additionally, algae were fed to unheated and unmixed 1135-L pilot digesters to determine the effects of seasonal temperatures and organic loading rates on biogas yields and nutrient solubilization. Finally a scalability experiment was conducted to determine how well lab digesters replicated the nutrient solubilization and biogas yields of pilot digesters when they were operated at the same average daily temperature, and organic load. Overall, the tested conditions included mixing, temperature, feed pretreatment by sonication, scale, and organic loading. It was determined that unmixed, 20˚C digesters fed an average variable organic loading of 0.12 g VS/L-day had the highest yield of 0.3 L CH4/g VS fed. Compared to similarly operated digesters (30˚C, constant organic load 0.25 g VS/L-day) sonicated feed increased the mass yield of methane by 18% (0.28 L CH4/g VSintroduced), and mixing increased the mass yield of methane by 4% (0.25 L CH4/g VS). For the same digesters, sonicated feed increased the average nitrogen and phosphorus solubilization 10% and 11% with 36% N and 28% particulate P remaining, respectively. Eliminating mixing increased the average nitrogen and phosphorus solubilization by 13% and 27%, with 40% and 31% remaining as particulates, respectively. The pilot digesters produced an overall average mass yield of 0.19 L CH4/g VS, with a summer average of 0.46 L CH4/g VS and a winter average of 0.15 L CH4/g VS. For the pilot digesters, the average amount of remaining particulate nitrogen and phosphorus was 36% and 39%, respectively, with an average of 57% volatile solids destruction. Finally for the scale experiment, the pilot digesters exhibited mass and volumetric yields of 47% and 28% (0.19 L CH4/g VS; 0.011 L CH4/L-d) greater than the lab digesters. Additionally, the pilot digesters had 2% greater nitrogen solubilization and 29% less phosphorus solubilization with 23% N and 15% P, than the lab digesters. Based on these results, for a low organic load (0.01 – 0.65 g VS/L-day), it is recommended that digesters be unmixed and heated which, and have a longer winter residence time. In addition to benefiting methane yield and nutrient solubilization, these digester operating conditions would allow increased supply of nutrients to ponds during the most productive months when nutrients are being consumed at faster rates in the algae ponds.
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24

Carvalho, Eraldo Henriques de. "Disposição de resíduos gerados nas estações de tratamento de água em estações de tratamento de esgoto com decantação primária." Universidade de São Paulo, 2000. http://www.teses.usp.br/teses/disponiveis/18/18138/tde-13072018-091220/.

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No presente trabalho foram realizados estudos para verificar as interferências do lançamento de resíduos de Estações de Tratamento de Água nas Estações de Tratamento de Esgoto com decantação primária. A ETA estudada utilizava cloreto férrico como coagulante primário e possuía decantadores com descarga de fundo diária. As interferências nos decantadores primários da ETE foram simuladas por meio de testes de sedimentação e nos digestores de lodo, por meio de testes de tratabilidade anaeróbia. Testes e análises complementares também foram realizados para verificar eventuais interferências no tratamento biológico da fase líquida do esgoto e no tratamento físico da fase sólida do esgoto. Os resultados indicaram aumento na eficiência de sedimentação em conseqüência do aumento da quantidade e concentração do resíduo de ETA introduzido no esgoto. Obteve-se, por exemplo, um incremento de até 50% na remoção de sólidos suspensos e turbidez, 40% na de DQO e fosfatos e 30% na de nitrogênio. No entanto, obteve-se um maior volume de lodo primário, embora de menos concentrado. De acordo com os resultados dos testes de tratabilidade anaeróbia, os resíduos da ETA não foram tóxicos ao processo. Com relação ao tratamento biológico da fase líquida do esgoto e ao tratamento físico do lodo, não foram verificadas interferências significativas no desempenho dos mesmos, embora recomenda-se o desenvolvimento de pesquisas mais específicas, especialmente sobre o processo de adensamento. Pode-se concluir que resíduos similares aos gerados na ETA estudada poderão ser dispostos em ETEs com decantação primária, sem interferências prejudiciais no seu desempenho.
In the present work simulations studies were conducted to verify the impact of Water Treatment Plants (WTP) residuals on the performance of Wastewater Treatment Plants (WWTP). The WTP under investigation used ferric chloride as primary coagulant, was type Complete Cicle with sedimentation tanks with daily bottom discharge. The interferences in the primary sedimentation tanks were simulated using sedimentation tests, while the sludge digesters were simulated using anaerobic treatability tests. Complementary tests and analysis also were realized to verify eventual interferences in the wastewater biological treatment and in the physical treatment of the sludge. The results indicated an increment in the sedimentation eficiency caused by increasing the WTP residuals dose added into the wastewater. As WTP residuals was added at up to 225 mg dry weight solids per liter of wasterwater, the removal of solids, COD, phosphate and nitrogen, for example, increased in 50%. However, the primary tanks settled sludge volume increased considerably. According to the anaerobic treatability tests results, the WWP residuals had not toxical effects on the process, interfering positively on the methane production. Concerning the wastewater biological treatment and sludge physical treatment, no significant impacts on their performance were observed. Therefore, it can be concluded that conventional WWTP can receive similar WTP residuals as those of the WTP here studied without any negative impacts on their performance.
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Dornack, Christina. "Biogas production from organic waste and biomass - fundamentals and current situation." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99414.

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The use of renewable waste for bioenergy production is in discussion because of the concurrence to the food or animal feed. The treatment of organic waste is necessary in order to keep clean the environment. The combination of those proposals, the waste utilization and the production of renewable energy can be combined with several techniques. In Vietnam the energy demand will increase rapidly in the next years, because a lot of people do not have access to electricity. The development of power sources is limited mainly to large central power plants using hydropower and traditional fossil fuels. So in the country there exists a considerable potential for sustainable energy sources like biomass and residues. The biogas potential is large due to the high livestock population. There are more than 30 million animals in farms, mostly pigs, cattle, and water buffalo. There is a high potential for biogas utilization. Biogas production is economic in small and in big plants, so household biogas digesters are one opportunity for production of renewable energy in small villages or cities with a high livestock population. The advantage of anaerobic treatment of organic waste is the work in closed loops. The treatment of organic waste and the utilization of digested sludge from wastewater treatment plants are samples for the circulation of materials after use. The remaining materials can be used in the natural circulation process, because the nutrients such as nitrogen, phosphorous and carbon, and also trace elements remain in the digested matter. In biogas plants a huge variety of substrates can be used. The adaption of biogas technology to the special conditions of the substrates, the increase of the prices for energy, the aim to replace fossil energies with renewable energies will be forced in the next years
Việc sử dụng chất thải có thể tái tạo được để sản xuất năng lượng sinh học là vấn đề còn đang được thảo luận vì sự cạnh tranh với thức ăn hoặc thức ăn cho động vật. Việc xử lý các chất thải hữu cơ là cần thiết để giữ sạch môi trường. Sự kết hợp của các đề xuất đó, tận dụng các chất thải và sản xuất năng lượng tái tạo có thể có thể được kết hợp với một số kỹ thuật. Ở Việt Nam, nhu cầu năng lượng sẽ tăng lên nhanh chóng trong những năm tiếp theo, bởi vì rất nhiều người vẫn chưa có điện sử dụng. Sự phát triển của các nguồn năng lượng chỉ giới hạn chủ yếu là các nhà máy điện lớn trung tâm sử dụng thủy điện và các nhiên liệu hóa thạch truyền thống. Vì vậy, trong nước tồn tại tiềm năng đáng kể cho các nguồn năng lượng bền vững như sinh khối và những nguồn khác. Tiềm năng khí sinh học lớn do quần thể động vật nuôi rất lớn. Có hơn 30 triệu động vật trong trang trại, chủ yếu là lợn, bò, trâu nước. Tiềm năng sử dụng khí sinh học rất cao. Sản xuất khí sinh học rất có hiệu quả kinh tế trong các nhà máy nhỏ và lớn, do đó, các thiết bị phản ứng tạo khí sinh học ở các hộ gia đình là một cơ hội để sản xuất năng lượng tái tạo trong các thành phố hay làng mạc nhỏ với số lượng lớn các gia súc được chăn nuôi. Ưu điểm của việc xử lý kỵ khí các chất thải hữu cơ là làm việc trong vòng khép kín. Việc xử lý các chất thải hữu cơ và sử dụng bùn phân hủy từ các nhà máy xử lý nước thải là các ví dụ cho việc tuần hoàn các vật chất sau khi sử dụng. Các vật chất còn lại có thể được sử dụng trong quá trình tuần hoàn tự nhiên, vì các chất dinh dưỡng như phốt pho, nitơ và carbon, và cả các nguyên tố vi lượng vẫn tồn tại trong nguyên liệu đã phân hủy. Trong các nhà máy khí sinh học, rất nhiều loại chất nền có thể được sử dụng. Sự cải tiến công nghệ sản xuất khí sinh học theo các điều kiện đặc biệt của các chất nền, sự gia tăng của giá năng lượng, mục đích thay thế nguồn năng lượng hóa thạch bằng năng lượng tái tạo sẽ là bắt buộc trong những năm tới
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26

Laperrière, Wendy. "Évaluation des limites d'un digesteur biogaz pour une utilisation flexible dans un réseau local de production d'énergie." Thesis, Montpellier, 2017. http://www.theses.fr/2017MONTT068/document.

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Avec l’augmentation de la part des énergies renouvelables intermittentes (solaire et éolien) dans les mix énergétiques, des problèmes dans la stabilité de la fourniture d’électricité peuvent se présenter. La solution pour compenser ces fluctuations réside dans la production flexible de biogaz. Le biogaz peut en effet être stocké puis utilisé en période de demande; sa production doit donc être assurée de manière flexible, contrairement à ce qui est fait actuellement sur la majorité des digesteurs. L’objectif de la thèse était d’étudier et de déterminer les limites de digesteurs biogaz en fonctionnement flexible. Trois réacteurs de 15L, alimentés avec trois mélanges différents de deux substrats solides, ont été alimentés pendant 550 jours en fonctionnement flexible. Il a été démontré au cours de cette thèse que le fonctionnement flexible avec des surcharges organiques ponctuelles n’avait aucune incidence négative à long terme sur la production de méthane. La flexibilité instantanée a été définie comme la marge entre le maximum de production sur un réacteur et sa production de base. Elle a été fortement influencée par la charge de base du réacteur et par les cinétiques de dégradation des substrats utilisés en surcharge, mais très peu par l’intensité des surcharges appliquées. L’utilisation de substrats rapidement dégradables en surcharge a permis d’atteindre un maximum de production de 1 à 1,2 LCH4/Lréacteur.j dans les premières 24 heures, même sur des réacteurs alimentés de base avec du fumier, conduisant à des flexibilités allant de +92 à +150%. Ce plafond dépend de la vitesse d’hydrolyse des substrats et il peut être relevé en utilisant des composés plus simples à dégrader en surcharge (type glycérol). Un mode opératoire prêt à être validé sur des installations pilote a été défini ; il précise la démarche à suivre pour la détermination du maximum de production et le niveau de la charge de base à adopter, pour une flexibilisation optimale de la production de méthane sur les CSTR. Un modèle simple, basé sur deux vitesses de dégradation, a également été développé et proposé pour simuler un fonctionnement flexible sur un réacteur
With the increasing share of intermittent renewable energies in the electricity mix, some stability problems are expected in the grid. The solution consists in using biogas as buffer energy. Biogas can be stored, then used on-demand. As the storage is limited, biogas production should be flexible. The aim of this thesis was to study and determine the limits of anaerobic reactors in a flexible operation. Three 15L reactors, fed with three different mixtures of two solid substrates, were fed for 550 days in flexible operation. It was demonstrated in this thesis that flexible operation with one-off overloads had no negative impact on methane production on long-term. The flexibility was defined as the margin between the maximum production on a reactor and its baseload production. It was strongly influenced by the baseload of the reactor and the substrates used in overloads, but not by the intensity of the overloads applied. The use of readily degradable substrates in overloads allowed a maximum production of 1 to 1.2 LCH4/Lreactor.d to be achieved in the first 24 hours, even in reactors fed mainly with manure, leading to flexibility ranging from +92 to + 150%. This ceiling depends on the rate of hydrolysis of the substrates. It can be increased by using compounds that are of a simpler structure (glycerol for example). An operational strategy ready to be validated on pilot plants has been defined; it specifies the approach for the determination of the maximum production and the level of the baseload to be adopted, for an optimal flexibilization of the methane production on CSTRs. A simple model, based on two degradation rates, has also been developed to simulate flexible operation of anaerobic reactors
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27

Tramoni, Félicien. "Analyse du traitement et de la gestion durable des boues d’épuration en Corse. Proposition de solutions énergétiques alternatives, axées sur la méthanisation des boues avec production d’énergies, aux méthodes appliquées en Corse. Utilisation de l’outil d’aide multicritère à la décision dans le cadre du surclassement de ces nouveaux procédés." Thesis, Corte, 2015. http://www.theses.fr/2015CORT0019.

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La qualité des boues est directement liée à la qualité des étapes de traitement présentes au sein d’une station d’épuration. En termes de traitement et d’élimination des boues, nous observons de la part des acteurs locaux, une volonté d’abandon définitif et durable de la filière « dépôt en centre de stockage », étant donnée une règlementation et des plans régionaux (notamment le PREDIS de Corse), toujours plus exigeant en termes de valorisations des déchets industriels et spéciaux. Nous observons également un abandon progressif et programmé des pratiques relatives à l’épandage. En effet, l’épandage des boues d’épuration fait l’objet d’une vaste controverse qui met en avant les risques sanitaires et environnementaux qu’elle engendrerait sur les sols agricoles. Au sein de notre région, cette pratique est réalisée de manière non règlementaire. En Corse, les acteurs locaux semblent avoir optés pour la solution du compostage en vue de valoriser la production de boues d’épuration. En effet, près des 2/3 du tonnage annuel en MS de boues sont actuellement valorisés via cette filière. Le processus de compostage équivaut à une fermentation aérobie, faisant intervenir une multitude de micro-organismes. Cette filière de compostage, au même titre que l’épandage, a connu une forte expansion de son activité mais semble avoir des failles et des limites : problèmes de mauvaises odeurs ; règlementation de plus en plus exigeante ; et enfin surproduction de compost invendable aux vues de la demande. Une autre solution pourrait présenter des atouts supérieurs : la méthanisation avec production d’électricité et de chaleur par cogénération. Cette production d’énergies passe obligatoirement par la valorisation du biogaz produit par ce système. En effet, le biogaz est un mélange contenant principalement du méthane (50 à 70%) et du dioxyde de carbone Du fait d’une forte concentration en méthane, le biogaz est un bon fournisseur d’énergie (1m3 de biogaz a un pouvoir calorifique de 6 kWh soit l’équivalent de 0,6 l de fuel). Pour produire de l’électricité, le processus de méthanisation doit être couplé à un moteur à cogénération ou à plusieurs microturbines. EDF a alors l’obligation de racheter l’électricité produite à un prix se situant entre 11 et 14 centimes d’euros/kwh., Après 15 ans, le rachat du kwh produit se fait aux taux proposés par EDF. En Corse, seulement une station d’épuration est équipée d’un digesteur couplé en série à cinq microturbines, produisant de la chaleur et de l’électricité par cogénération : La station de traitement des eaux usées de Campo Dell’Oro à Ajaccio. Ce procédé de valorisation énergétique pourrait être amélioré via le remplacement à terme, des microtubines par un moteur à cogénération. Une AMCDP a notamment permis de surclasser cette technologie vis-à-vis des microturbines, beaucoup moins efficaces en termes de rendement mais aussi de fonctionnement. L’équipement des stations d’épuration de plus fortes capacités en Corse, de digesteurs associés à un moteur à cogénération pourrait être une solution durable à la problématique de la valorisation énergétique des boues
Sludge quality is directly related to the quality of of these processing steps present in a water treatment plant. In terms of treatment and disposal of sludge, we observe on the part of local actors, a willingness to permanent and lasting abandonment of the sector 'deposit in storage centre'', given a regional plans and regulations (including the PREDIS Corsica), increasingly demanding in terms of valuations of industrial and special waste. We also observe a gradual and planned abandonment of practices for spreading. Indeed, the spreading of sewage sludge is the subject of widespread controversy which highlights the health and environmental risks it would lead to agricultural soils. In our region, this practice is not carried out regulatory manner. In Corsica, the local actors seem to have opted for the solution of compost to enhance the production of sewage sludge. Nearly 2/3 of the annual tonnage MS sludge is currently valued via this pathway. The composting process is equivalent to an aerobic fermentation involving a multitude of microorganisms. This composting stream, as well as spreading, experienced strong expansion of its business but seems to have flaws and limitations: problems with odors; regulatory increasingly demanding; and finally overproduction unsaleable compost to the views of the application.Another solution could present higher advantages: anaerobic digestion with production of electricity and heat from cogeneration. . This energy production go through the biogas produced by this system. Indeed, the biogas is a mixture containing mostly methane (50 – 70 %) and carbon dioxide. Due to a high concentration of methane, biogas is a good energy supplier (1m3 biogas has a calorific value 6 kWh equivalent to 0.6 liters of fuel). To generate electricity, the anaerobic digestion process must be coupled to an engine cogeneration or several microturbines. EDF has the obligation to purchase electricity at a price ranging between 11 and 14 euro cents/kwh. After 15 years, the redemption of the kwh produced is done at the rate offered by EDF.In Corsica, only a treatment plant is equipped with a digester coupled in series to five microturbines, producing heat and electricity cogeneration: The wastewater treatment plant at Campo Dell'Oro /Ajaccio. This energy recovery process could be improved with an eventual replacement of the microtubines by a cogeneration engine. An AMCDP allowed to outperform this technology towards microturbines, much less efficient in terms of performance.The equipment of the highest capacity treatment plants in Corsica, digesters associated with a cogeneration engine could be a lasting solution to the problem of energy recovery of sewage sludge
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28

Stephenson, Robert John. "A comparison of retained biomass anaerobic digester designs." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26740.

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The principles behind anaerobic digestion are fairly well understood, but the limits of application of each digester design are not known. Because there are significant differences in the properties of the many wastewaters requiring treatment optimal anaerobic digester performance requires the matching of feed characteristics to a digester design and mode of operation. No consensus has yet emerged on digester design, operating conditions or feed/digester match-ups. In this study, three bench scale retained biomass anaerobic digester designs were examined for their response to a sequence of varied hydraulic retention times (HRTs) and influent wastewater concentrations. The digester designs studied were the upflow anaerobic filter, the upflow anaerobic expanded bed and the upflow anaerobic sludge bed. The wastewater was screened and diluted dairy cow manure obtained from the UBC dairy barn. The parameters monitored included the total and soluble chemical oxygen demand (TCOD and SCOD), volatile and suspended solids (VS and SS), total volatile fatty acids (VFAs), total Kjeldahl and ammonia nitrogen (TKN and NH₃-N), pH, biogas production, and the methane (CH₄) and carbon dioxide (C0₂) content of the biogas. Wastewater treatment efficiencies, measured in terms of TCOD, SCOD, VS, and TVFA removals, and methane productivity and methane yield for each of the digester designs were examined for the range of the operating conditions. The anaerobic filter digester effected a mean TCOD removal efficiency of 47% ± 14% at a mean 4.0 day HRT, 51% ± 9% at a mean 2.3 day HRT and 35% ± 11% at a mean 1.3 day HRT. The expanded bed digester effected a mean TCOD removal of 45% ± 15% at a mean 4.3 day HRT, 38% ± 12% at a mean 2.5 day HRT and 28% ± 9% at a mean 1.3 day HRT. The sludge bed digester effected a mean TCOD removal of 53% ± 9% at a mean 3.8 day HRT, 45% ± 12% at a mean 2.2 day HRT and 32% ± 10% at a mean 1.2 day HRT. For all three digesters, the difference in the treatment efficiency over the range of HRTs tested, from 5 to 1.25 days was not in proportion to the change in HRT. Methane productivity, measured against either the removal or addition of substrate in terms of TCOD, SCOD, VS and TVFA, demonstrated considerable variability. Methane production increased with both substrate addition and substrate removal. Methane yield increased with increasing HRT. The sludge bed digester generally exhibited the greatest but most variable methane yields. It produced 0.095 L CH₄/g VS added at a mean 3.8 day HRT and 0.037 L CH₄/g VS added at a mean 1.2 day HRT. The anaerobic filter delivered the greatest methane yield at the intermediate HRT, 0.044 L CH₄/g VS added at a mean 2.3 day HRT. The expanded bed demonstrated low methane yields over the range of feed strengths and HRTs tested. Biogas composition averaged 62.1% methane and 17.1% carbon dioxide for the anaerobic filter, 43.6% methane and 5.3% carbon dioxide for the expanded bed. and 61.1% methane and 18.9% carbon dioxide for the sludge bed.
Applied Science, Faculty of
Graduate
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29

Tcha-Thom, Maglwa. "Recherche d'une filière durable pour la méthanisation des déchets de fruits et d'abattoirs du Togo : Evaluation du potentiel agronomique des digestats sur les sols de la région de la Kara." Thesis, Limoges, 2019. http://www.theses.fr/2019LIMO0061/document.

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La digestion anaérobie, procédé d’énergie renouvelable, constitue un atout indéniable de récupération des flux matière et énergie des déchets en réponse aux enjeux du développement durable. Ainsi, la présente étude a pour objectif de contribuer à la compréhension des mécanismes qui gouvernent l’environnement réactionnel de digestion en anaérobie et les effets des digestats sur la matrice bio-physico-chimique des sols à vocation agricole. Le développement des tests de lixiviation en réacteurs contrôlés aérobie et anaérobie, les modes de mobilisation du contenu organo-minéral des substrats et la valorisation du biogaz pour l’équarrissage des bêtes ont été réalisés. Les verrous techniques et physico-chimiques entachant la digestion anaérobie des déchets d’ananas ont été levés et optimisés grâce à des co-substrats notamment les bouses de vache et les cendres. Les digestats ont été apportés sur des sols agricoles, des sols des zones de forêts et des milieux sans matière organique ni argiles et ont permis de déceler les limites d’utilisation des digestats et les interactions avec les fractions organiques et minérales du sol. Cette étude montre ainsi, l’importance de développer la filière de méthanisation pour une élimination durable des déchets organiques
Anaerobic digestion, a renewal energy process, constitutes an undeniable asset of material and energy flows recovering in response to sustainable development issues. Thus, the aim of this current study was to contribute to the understanding of mechanisms that govern the reactive environment of anaerobic digestion and the effects of digestates on the biophysico- chemical matrix of agricultural soils sector. The running of leaching tests in aerobic and anaerobic controlled reactors, organo-mineral mobilizations patterns of the substrates and the valorization of biogas in slaughtered animals knackering have been realized. The physicochemical and technical locks tarnishing the pineapple wastes anaerobic digestion have been lifted and optimized through the co-substrates including cattle manure and ashes. The digestates have been brought on agricultural soils, forests areas soils and medium free of organic matter and clays and allowed to detect the limits of digestates uses and the interactions with organic and mineral fractions of soils. This study, thus show, the importance to develop the anaerobic digestion sector for a sustainable removal of organic wastes
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30

Moazedian, Amitis. "Energy Extraction from Horse Manure Biogas plant vs. Heating Plant : A Case Study in Wången." Thesis, Mittuniversitetet, Institutionen för teknik och hållbar utveckling, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-19192.

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Wången is a trotting school located in Alsen region in Mid Sweden. Currently they keep almost 105 horses in their premises, which produce 2 400 m3 of stall waste per year.  Stall waste has always been a concern for those who keep animals, and though composting has been a viable solution to this problem for quite some time, it is no longer the only solution. Stall waste can be converted to energy and there are different techniques and approaches to do so.  In this study the writer compares the viability of two possible techniques (Biogas and heating plant) by collecting data from two existing biogas and heating plant providers for Wången trotting school. The results show that with almost same amount of investment on the reactors, a heating plant can meet 85% of Wången heating demand while Biogas plant could only meet 10 % of Wången’s heating consumption. On the other hand, as a result of nitrogen bound compound existence in horse manure, burning stall waste in the heating plant showed a more acidifying potential compared to the biogas plant.
Investigation for Wången trotting school
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31

Freitas, Andrew Daniel Sanchez. "Method Development for the Synthesis of Anaerobic Digester Biogas with the Laboratory Environment." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/51388.

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Biogas, a gaseous mixture produced during decomposition of organic matter, is a renewable, easily generated and common byproduct of anaerobic digestion at wastewater treatment plants (WWTP), landfills and agricultural operations. There is growing interest in researching and utilizing the energy potential associated with its combustion. Siloxanes, a family of volatile organic silicon compounds, pose large impediments to biogas usage due to the formation and precipitation of silicon dioxide within combustion devices. Removal of siloxanes prior to combustion is therefore a growing endeavor. Research was performed to synthesize a representative gas stream produced from anaerobic digesters within WWTP. Methane, carbon dioxide and hydrogen sulfide were combined with humidity and gaseous siloxane in levels characteristically seen exiting anaerobic digesters. A methanol impinger train was utilized to sample the biogas composite. Gas chromatography-mass spectrometry (GC-MS) was used to determine gas-phase siloxane concentrations in the gas stream effluent for the purposes of confirming the generation of a consistent and reproducible biogas stream.
Master of Science
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32

Silva, Ireneu Pereira de Miranda. "Sistemas de agitação para digestores anaeróbios." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/1711.

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Mestrado em Engenharia e Gestão Industrial
A Digestão anaeróbia envolve o processo da agitação de digestores que permite, por um lado, aumentar a probabilidade do contacto entre o substrato e os microrganismos que o degradam e por outro, facilita a libertação do biogás produzido, produto de determinadas reacções que ocorrem durante o complexo processo da digestão (fase metanogénica). Pretende-se com este trabalho encontrar um sistema de agitação de digestores, que por um lado cumpra os requisitos de qualidade funcionais inerentes à sua função, e que por outro lado seja o mais económico possível. Partiu-se de um caso real com digestores pré definidos, procuraram-se no mercado várias alternativas, analisaram-se as vantagens e desvantagens de cada uma delas e por fim decidiu-se qual delas seria a mais adequada para o caso em estudo. ABSTRACT: The anaerobic digestion involves the process digesters mixing that increases the probability of the contact between the substrate and the microorganisms and improves the release of biogas. The main goal of this work is to find a system of digesters mixing to satisfy the functional quality requirements and to be economical. This study is based on real case with defined digesters, comparing with some alternatives available in the market. The advantages and disadvantages of each one of them were analyzed in order to choose the more adequate system.
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Mukumba, Patrick. "Modelling of the performance of a batch biogas digester fed with selected types of substrates." Thesis, University of Fort Hare, 2013. http://hdl.handle.net/10353/d1016197.

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The increasing population and the rapid economic growth in South Africa have led to higher consumption of food resulting in the generation of large amounts of waste. In addition, South Africa has plenty of biomass from cattle, donkeys, horses, goats, pigs, chicken and sheep. However, anaerobic digestion could be an alternative solution for the utilization of these kinds of waste due to its environmental and economic benefits. Therefore, the main focus of the research was design, construct a field batch biogas digester, monitor its performance when fed with co-substrates and model the methane yield for an optimized mixing ratio.
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34

Bercelli, Lorenzo. "Modellizzazione di un digestore anaerobico per la produzione di biogas da rifuti zootecnici." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2021. http://amslaurea.unibo.it/22933/.

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Il digestore anaerobico è una vasca contenente materiale organico in decomposizione (substrato). Selezionando le popolazioni batteriche che operano questa decomposizione, si può ottenere una digestione del substrato che produca una miscela di metano e anidride carbonica (biogas) come materiale di scarto. Il substrato digerito a seguito della permanenza nel digestore (digestato), povero di attività biologica ma ricco di micronutrienti, può infine essere smaltito facilmente, per esempio spargendolo sul suolo come fertilizzante. Le popolazioni batteriche agenti si sviluppano dunque in un equilibrio simbiotico e dinamico, generando un processo chimico complesso e resiliente. I due vantaggi apportati dal digestore sono la produzione di biogas e la trasformazione di materiale organico in decomposizione in digestato. La decomposizione di materiale organico è infatti un processo potenzialmente pericoloso, fonte di cattivi odori, agenti patogeni e emissioni di metano, un gas con un potente effetto serra, nell’atmosfera. Attraverso la decomposizione controllata nel digestore anaerobico otteniamo invece un digestato già largamente decomposto e dunque privo di carica patogena, quasi inodore e con un potenziale metanogeno già largamente speso In questo lavoro ci occuperemo nello specifico di un digestore costruito da Schmack Biogas Srl.(https://www.schmack-biogas.it/) e di proprietà di Inewa Srl.(https://www.inewa.it/), annesso ad un allevamento di vacche da latte, di proprietà dell'azienda agricola famiglia Montagnini di San Pietro in Casale. Questo digestore trasforma i liquami provenienti dalla stalla e gli scarti agricoli della coltivazione di foraggio in digestato e biogas. Obbiettivo del lavoro è ottenere una migliore comprensione del funzionamento del digestore attraverso la modellizzazione dei processi fisico-chimici coinvolti nella digestione batterica e validare il modello scelto applicandolo ad un digestore industriale.
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35

Moço, Eunice Alexandra dos Santos. "Projeto de uma unidade produtora de biogás." Master's thesis, Instituto Politécnico de Tomar, 2012. http://hdl.handle.net/10400.26/5847.

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Começa-se a acreditar que a sociedade poderá colapsar, caso não se resolvam alguns problemas de foro estrutural e de comportamento, em particular os problemas associados à sustentabilidade, ou falta dela, dos recursos energéticos. Num momento em que Portugal se encontra numa crise económica profunda, as alternativas que possam reduzir a nossa dependência de combustíveis fósseis são cada vez mais determinantes para o nosso futuro. É verdade que as fontes de energia renovável estão a ganhar grande relevo, particularmente em Portugal. Mas, as bioenergias estão ainda em segundo plano, face à energia hídrica, solar e eólica. Entre as bioenergias, uma das formas com elevado potencial, mas ainda pouco aproveitado é o biogás. O biogás é principalmente obtido de resíduos (agropecuários, aterros sanitários, estações de tratamento de águas residuais): a transformação desses resíduos através de digestão anaeróbia, representa uma forma atrativa de os valorizar, e simultaneamente reduzir os impactos ambientais gerados pelo despejo direto desses resíduos na natureza. Neste projecto avaliou-se a possibilidade de implementar uma unidade de produção de biogás, e da sua conversão em electricidade, a partir das lamas residuais do saneamento da região de Cantanhade, nos casos em que estas não são convertidas em biogás nas próprias ETAR da região. Procederam-se aos balanços de massa e de energia, e ao dimensionamento dos equipamentos principais, apesar de forma simplificada, para uma capacidade de digestão de 600 toneladas por ano. Determinou-se que seria possível produzir cerca de 1200 MWh de energia anualmente. Porém, verificou.se que a capacidade é demasiado pequena para viabilizar economicamente a instalação. Mas aumentando a capacidade para cerca do dobro, a instalação já poderia ser viável num horizonte de 20 anos.
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36

Khan, MD Ershad Ullah. "Feasibility Analysis of Biogas Based Polygeneration for Rural Development in Bangladesh." Licentiate thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-145207.

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Around three-quarters of Bangladeshis (total population 164 million) live in rural areas: only 25% of these households have access to grid electricity with non-reliable supply despite the country’s successful rural electrification program, kerosene is the predominant source for lighting, and woody biomass is virtually the only option available for cooking. Aside from this energy service challenges the rural population also struggles with unsafe drinking water in terms of widespread arsenic contamination of well water. Access to electricity, clean cooking gas, and safe drinking water services are genuine needs of the rural poor and are essential to improving welfare. These needs can be addressed individually or using an integrated approach. Anaerobic digesters are now a proven technology and remain economically promising in the rural setting, where connection to the public electric and gas grids are not available/either not cost effective or feasible, and where energy and water scarcity are severe. As the technologies continue to improve, and as energy and safe water becomes scarce and fossil fuel energy prices rise, renewable energy based services and technological integration becomes more viable techno-economically. In these circumstances, the integration of biogas digester with power generation and water purification unit is an innovative concept that could be applied in remote areas of Bangladesh.   This work presents a new concept for integrated polygeneration and analyzes the techno-economic performance of the scheme for meeting the demand of electricity, cooking energy and safe drinking water of 30 households in a rural village of Bangladesh. This study considers a holistic approach towards tackling both of these issues via integrated renewable energy-based polygeneration employed at the community level. The polygeneration unit under consideration provides electricity via cow dung-fed digester, which in turn is coupled to a gas engine. Excess digester gas is employed for cooking, while waste heat from the process drives a membrane distillation unit for water purification. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester; internal combustion engine; and air-gap membrane distillation. The technical features, energy consumption, and potential of renewable energy use in driving the main integrated processes are reviewed and analyzed in this thesis. This study also examines one approach by investigating the application of suitable membrane technologies, specifically air gap membrane distillation (AGMD), as a promising method for small-scale, low cost deployment.    Experimental results show that the tested AGMD prototype is capable of achieving high separation efficiency, as all product water samples showed arsenic levels below accepted limits. Mass flows and energy balance, life cycle cost (levelized cost) of producing electricity, cooking gas and safe drinking water as well as the payback period of such a polygeneration system were studied. The results indicate that this polygeneration system is much more competitive and promising than other available technologies when attempting to solve the energy and arsenic-related problems in Bangladesh. One of the main encouraging issues of this integrated system is the levelized cost of the three major services: cooking gas (0.015 USD/kWh), electricity (0.042 USD/kWh–an orders of magnitude lower than comparable photovoltaic or wind systems) and safe drinking water (0.003 USD/liter). Additionally, the payback period is between 2.6 to 4 years.

QC 20150516

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Gajardo, Alarcón Ninoska Loreto. "Estudio de la producción de biogás en función de la temperatura en un biodigestor tipo chino." Tesis, Universidad de Chile, 2013. http://www.repositorio.uchile.cl/handle/2250/114944.

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Memoria para optar al título profesional de Ingeniera en Recursos Naturales Renovables
La temperatura es un parámetro importante para el desarrollo de la digestión anaeróbica, que es la base de la producción de biogás; puede limitar sectores para aplicar la tecnología, regular la eficiencia, ayudar en la eliminación de patógenos, afectar el tiempo de retención de la materia e incrementar la producción de biogás. Este trabajo se desarrolló para evaluar la dinámica de producción de biogás en función del régimen térmico, estableciendo la relación entre las temperaturas que afectan a un biodigestor tipo chino y proponer zonas en Chile que posean mayor aptitud para aplicar esta tecnología. El biodigestor utilizado con capacidad de 10 m3, se alimentó tres veces por semana con una mezcla de relación 3:1 agua/estiércol (v/v). Se realizaron monitoreos en dos periodos, febrero a julio (2011) y enero a agosto (2012); en este último se instalaron sensores de registro continuo (temperatura y humedad) y se realizaron análisis de la composición del biogás generado cada semana. En el primer periodo se aplicaron correlaciones lineales a las variables, obteniendo que la temperatura del aire afectó en mayor proporción a la temperatura de descarga, estanque y la del biodigestor. Para el segundo periodo se analizaron las tendencias de las variables, se aplicaron análisis de anomalías para series de tiempo, promedios móviles y ajustes funcionales de las variables más relevantes en el estudio. De los resultados se obtuvo, que la temperatura interna del biodigestor mantuvo una temperatura promedio de 22°C y la temperatura media del suelo se ajustó mejor a la temperatura media máxima del aire. Los análisis de composición fluctuaron de 55 a 85% de CH4 (metano) y de 16 a 35% de CO2 (dióxido de carbono). La zonificación se realizó aplicando el “índice térmico” propuesto en un estudio previo, pero esta vez con información térmica actualizada para todo el país; obteniendo que a partir de la región de Los Lagos y a lo largo de la cordillera de Los Andes, no es apta la aplicación de esta tecnología. Así es posible afirmar que estos biodigestores favorecen la estabilidad térmica interna y que Chile posee un importante potencial para su implementación.
Temperature is an important parameter for the development of anaerobic digestion, base of biogas production. Limit sectors to apply technology, regulate efficiency, assist in the elimination of pathogens, affect the retention time and increase the biogas production. This work was developed to assess, the dynamics of biogas production based on the thermal regime, linking between temperatures affecting a chinese digester and propose areas in Chile that have greater ability to apply this technology. A digester with 10 m3 of capacity was fed three times a week with a 3:1 mixture of water/manure. Monitorings were applied in two periods, february to july (2011) and january to august (2012); installing continuously recording sensors and analyzes compositional of biogas generated weekly. In the first period were applied linear correlations to the variables, it was found that the air temperature affects mainly the discharge, the pond and the digester temperature. In the second period was performed trend analysis, anomalies, moving averages and functional adjustements, it was found that temperature inside of digester was 22°C average and the soil average temperature is more similar with the air average temperature. In the analysis of composition, methane ranged from 55 to 85% and 16 to 35% of carbon dioxide. The zoning was performed by “thermal index”, it was found that since the region of Los Lagos and Andes mountain, range is not suitable the application of this technology. So it can be said that these digesters favor internal thermal stability and that Chile has significant potential for implementation.
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Vathsava, Rajoli Sree. "Retrofitting analysis on first generation ethanol production." Thesis, Högskolan i Borås, Akademin för textil, teknik och ekonomi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-372.

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First generation bioethanol generated from feedstocks is a sustainable alternative to fossil fuels, and the demand for fuel ethanol has promoted studies on the use of the grain as feedstock. This thesis describes various process designs and the economic feasibility for producing the main product ethanol and other by-products such as Biogas and DDGS (Distillers Dried Grains with Solubles) from the grain. The techno-economic analysis was performed by the data provided by Agroetanol industry, located in Norrköping, Sweden. The key target of this simulation work was to evaluate the influence of several process designs and the main production factors on the ethanol production process, in terms of energy efficiency, ethanol production cost and plant profitability. The main aim of this work was to simulate the current industrial process and to develop novel alternative retrofits by integrating new technologies and for investigating the effects on the plant profitability. In the base case, the cost sensitivity analysis was carried out on the grain buying price, ethanol and DDGS selling price. Along with the cost sensitivity analysis, the capacity sensitivity analysis was performed on the base case model to check the influence of different capacities on the plant profitability. While coming to the study of developing alternative retrofits, the three retrofits were developed on the base case process and they are as following: Retrofit 1) modifying the distillation and dehydration section of the base case retrofit (current process in Agroetanol), Retrofit 2) checking the impact of ethanol concentration on technical and economic aspects of the plant and Retrofit 3) installing the biogas digester.The modelling effort resulted in developing the base case model with an ethanol production rate of 41,985 ton/ year. The capital cost of the base case process was calculated to be at 68.85 million USD and the aspen economic analyzer calculated the product value of the ethanol and DDGS as 0.87 USD/litre and 0.37 USD/kg, respectively. Through cost sensitivity analysis results, it is identified that the ethanol selling price and the grain buying price have significant effects on the plant economy and it is confirmed that they are the main factors playing on the plant profitability in the base case model.The results of the alternative retrofits clearly demonstrate the importance of higher ethanol tolerant strains in ethanol production, which showed a less payback period compared to the base case. The payback periods of all the cases are showing the following patterns from the least to the highest: Retrofit 2 (17%) > Base case > Retrofit 3 > Retrofit 2 (4%) > Retrofit 1.Further retrofitting analysis results also suggested that using the stillage for biogas production will help in reducing the energy costs of the plant. The energy consumption of all the retrofits in ascending manner is as follows: Retrofit 3 > Retrofit 2 (17%) > Base case > Retrofit 1 > Retrofit 2 (4%). The energy usage result comparison of all the cases shows that, in third retrofit the overall energy consumption is decreased by 40% than the base case model.
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39

Jeyanayagam, Samuel S. "Engineering analysis of a Chinese-type anaerobic digester." Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49800.

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40

Agustini, Caroline B., Costa M. Da, M. Gutterres, and A. C. C. Pena. "Monitoring of biogas production from tannery solid wastes at-line in a laboratory-scale anaerobic digester - 163." Verein für Gerberei-Chemie und -Technik e. V, 2019. https://slub.qucosa.de/id/qucosa%3A34307.

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Content: The understanding of how chemical, physical and environmental parameters work during anaerobic digestion production and waste treatment is an important step in improving the efficiency and process stability. This study provides the evolution of the biogas production and the efficiency of the treatment of the anaerobic digestion of solid wastes of tanneries at-line monitored in batch laboratory-scale bioreactors. Leather shavings and sludge from wastewater treatment plants substrates were considered in the study. The findings suggest that AD of the tannery solid waste can be separated into three phases: a long lag phase, a log phase with a low metabolic rate and the final phase where all the shavings were metabolized. Take-Away: The AD of the tannery solid waste can be separated into three phases: a long lag phase, a log phase with a low metabolic rate and the final phase where all the shavings were metabolized
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41

Rempel, Neuri. "Biodigestão anaeróbica da fração orgânica de resíduos sólidos urbanos consorciado com glicerina." Universidade do Vale do Rio dos Sinos, 2014. http://www.repositorio.jesuita.org.br/handle/UNISINOS/3373.

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CNPQ – Conselho Nacional de Desenvolvimento Científico e Tecnológico
FINEP - Financiadora de Estudos e Projetos
Ministério da Ciência, Tecnologia e Inovação
O aproveitamento energético da fração biodegradável dos Resíduos Sólidos Urbanos (RSU) na forma de biogás, é uma das alternativas para minimizar os impactos sociais e ambientais causados pela disposição destes resíduos. A digestão anaeróbia sob condições controladas, objetivando o máximo de rendimento de biogás é uma alternativa promissora, principalmente quando for conduzida com o acréscimo de outros resíduos orgânicos de elevado potencial para geração de biogás, como a glicerina. A glicerina é um subproduto da produção de biodiesel e possui percentual de carbono acima de 90%, tornando-se um excelente cosubstrato para digestão anaeróbia. Esta pesquisa avaliou a geração de biogás em escala piloto, utilizando a fração orgânica do RSU pós-esteira de triagem da cidade de São Leopoldo/RS, com incremento de glicerina em relação à massa de resíduo adicionada no digestor. Utilizou-se um reator de 50L com agitação intermitente e temperatura controlada (~35ºC). O incremento de glicerina possibilitou aumento de até 30% no volume de biogás gerado, além de antecipar em até 10 dias a produção máxima de biogás, quando comparado com o processo somente com os RSU. O decréscimo gradativo do pH, a elevada relação C:N no materialdigerido e adição de NaOHpara o controle do pH, indicam que o percentual de glicerina adicionado, nas condições desse estudo pode ter sido elevado, necessitando maiores investigações para chegar no volume adequado.Os resultados observados indicam a necessidade de se determinar o percentual ótimo de glicerina a ser utilizado, o que não foi possível nesse estudo. Agitação intermitente, manutenção do pH próximo de 7,5 e Tempo Retenção de Sólidos máximo de 25 dias, foram os principais parâmetros observados para a otimização na geração do biogás, nas condições desse estudo. O volume médio de biogás produzidofoi de 44m3/ton. de RSU, com valores mínimos e máximos de 30 m3/ton.e 60 m3/ton. de RSU, respectivamente.
The energetic use of the biodegradable fraction of Municipal Solid Waste (MSW) in the form of biogas is one of the alternatives to minimize the social and environmental impacts caused by the disposal of this waste. Anaerobic digestion under controlled conditions, aiming the maximum yield of biogas, is promising alternative, especially when conducted with the addition of others organic wastes with high potential for biogas generation, such as glycerin. Glycerin is a subproduct of biodiesel production and carbon percentage above 90%, making it an excellent co-substrate for anaerobic digestion. This research evaluated the generation of biogas in pilot scale, using the organic fraction of the MSW post-treadmill screening of São Leopoldo/RS, with the increase of glycerin on the mass of residue added to the digester. A 50L reactor with intermittent agitation and controlled temperature (~35°C) has been used. The increase of glycerin made possible the raise up to 30% in the volume of generated biogas, besides anticipate within 10 days maximum biogas production compared to the process only with MSW. The gradual decrease in pH, the high C:N ratio in digested material and the addition of NaOH to control the pH, indicate that the percentage of glycerin added, under the conditions of this study may have been high, requiring further investigation to reach proper volume. The results indicate the necessity to determine the optimal percentage of glycerin to be used, which was not possible in this study. Intermittent agitation, maintaining the pH close to 7.5 and Maximum Solids Retention Time of 25 days, were the main parameters observed to optimize the generation of biogas, in the conditions of this study. The mean volume of biogas produced was 44m3/ton of MSW with minimum and maximum values of 30 m3/ton and 60 m3/ton MSW, respectively.
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Ek, Anders. "Ultrasonic treatment of sewage sludge in order to increase biogas yields." Thesis, Linköping University, Department of Water and Environmental Studies, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4581.

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Biogas, a mixture of methane and carbon dioxide, is produced in the anaerobic digestion of sewage sludge. After anaerobic digestion, the digested sludge is often allowed to degas for one or two days. This gas is seldom utilised, but if the degassing could be accelerated, utilisation would be easier. Ultrasound can be used as a pretreatment method for waste activated sludge. It has a disintegrating effect on the sludge and causes lysis of bacteria in the sludge. It also speeds up the hydrolysis; the limiting step of anaerobic digestion of waste activated sludge. Ultrasound can be used to degas waterbased liquids. Ultrasonic degassing of sewage sludge has not been examined previously. The present study aims to investigate the effect of ultrasound on waste activated sludge as well as the potential of ultrasound to speed up the degassing of digested sludge. A semi-continuous, lab-scale digestion experiment was performed with four reactors: two receiving untreated sludge and two receiving treated sludge. The effect of the sonicator was 420 W and the treatment time was 6 min, which corresponds to an energy input of 8.4 kWh/m3. Total solids (TS) of the waste activated sludge was ~3.5 %. The ultrasonic treatment caused an increase in gas production of 13 %. There was no difference in methane content. The concentration of filterable chemical oxygen demand (fCOD) increased 375 %, or from 2.8 % to 11 % of total COD. In terms of energy loss/gain the increase in gas production resulted in a loss of 2.7 kWh/m3, i.e. more energy is needed to treat the sludge than the potential energy of the increased gas production. However, if the sludge is thickened to a TS >5 %, a net energy gain should be reached. The effect of ultrasound on the degassing of digested sludge was examined in three barrels. The degassing was measured with and without circulation as well as with ultrasonic treatment. The digested sludge had a gas emission rate of 115 L/(m3 day). No direct burst of gas occurred due to ultrasonic treatment. Over two days more gas was emitted from the barrel equipped with ultrasound, probably due to an induced post-digestion. Thus, ultrasonic pretreatment of waste activated sludge increases the biogas yield. It is inconclusive, whether ultrasonic treatment of digested sludge effects the degassing or not.

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43

Fukayama, Ellen Hatsumi [UNESP]. "Características quantitativas e qualitativas da cama de frango sob diferentes reutilizações: efeitos na produção de biogás e biofertilizante." Universidade Estadual Paulista (UNESP), 2008. http://hdl.handle.net/11449/104913.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Objetivou-se avaliar o efeito da reutilização de cama de quatro lotes de criações de frangos de corte sobre a produção de cama de frango, a produção de biogás e a utilização do biofertilizante para adubação de milho. No capítulo sobre produção de cama foram avaliados quatro reutilizações de cama de frangos de corte criados em um galpão comercial dividido em 12 boxes pertencente à Empresa Rei Frango em São Carlos - SP - Brasil. Para caracterização da produção de cama foi avaliado a quantidade de cama produzida na matéria seca (MS) e o coeficiente de resíduo (Cr), ou seja, a quantidade de resíduo por kg de peso vivo das aves. Na caracterização qualitativa, foram analisados os teores de macro, micronutrientes e metais na casca de amendoim e cama de frango. Com o acréscimo de casca de amendoim nova mais o aumento de excretas do lote anterior, houve aumento (P<0,05) na produção de cama (MS). Assim, o Cr aumentou de acordo com a reutilização da cama. Porém, quando se avalia o Cr acumulado, ou seja, a quantidade de resíduo por kg de peso vivo acumulado das aves dos lotes criados, não houve diferença (P>0,05). De forma geral, foi observado que, com a reutilização da cama houve aumento (P<0,05) na concentração de nutrientes na cama. Conclui-se que com a reutilização de cama é possível igualar ou diminuir os custos com a aquisição de nova cama, aumentar a quantidade de nutrientes na cama para ser utilizada como biofertilizante na agricultura e estabilizar ou diminuir o impacto ambiental com a produção de cama por ave produzida. No capítulo sobre biodigestão anaeróbia de cama de frangos, para cada lote de aves conduzidos foram realizadas duas avaliações de biodigestão anaeróbia, sendo 4 ensaios (camas de 1 a 4º reutilização) avaliados de 2 formas: as 4 camas foram avaliadas em diferentes épocas do ano e também avaliadas na mesma época...
The objective was to evaluate the effect of reuse of litter of four broiler breeding cycle on the broiler litter’ production, the biogas’ production and use of organic fertilizer for fertilization of maize. In the chapter on production of litter were evaluated four reuses of litter of broiler chickens reared in a commercial shed divided in 12 boxes belonging to Rei Frango Company in São Carlos - São Paulo - Brazil. To characterize the production of litter was assessed the amount of litter produced in dry matter (DM) and the coefficient of waste (CW), or the amount of waste per kg of live birds. In qualitative characteristics, were analyzed the levels of macro, micro and metals in the shell of peanuts and broiler litter. With the addition of new peanut shell, plus the increase of manure of the previous batch, there was an increase (P<0.05) in the production of litter (dry matter - DM). Thus, the increased CW according to the reuse of litter. But when assessing the cumulative CW, or the amount of waste per kilogram of body weight of accumulated lots of birds created, there was no difference (P>0.05). Overall, it was observed that with the reuse of the litter there was an increase (P<0.05) in the concentration of nutrients in litter. It follows that with the reuse of litter can be equal or lower cost for the purchase of new litter, increase the amount of nutrients in litter to be used as organic fertilizer in agriculture and keep or reduce the environmental impact to the production of litter by produced per bird. In the chapter on anaerobic digester with litter of broiler, for each batch of birds conducted two evaluations were made of anaerobic digester, and 4 trials (litters from 1 to 4 reuse) evaluated in 2 ways: the 4 litters were evaluated at different times of the year and also evaluated in the same season, totaling 8 tests. 24 digesters were used in batch, distributed... (Complete abstract click electronic access below)
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44

Santos, Cristiano Vieira dos. "Análise da potencialidade da casca do amendoim como resíduo gerador de biogás na agricultura familiar /." Tupã, 2020. http://hdl.handle.net/11449/192843.

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Orientador: Ana Elisa Bressan Smith Lourenzani
Resumo: Diante da constante busca pelo avanço na melhoria da matriz energética global, as energias renováveis assumem papel de suma importância para atender os Objetivos de Desenvolvimento Sustentável (ODS). O município de Herculândia, no oeste do estado de São Paulo, possui como principal atividade econômica a produção e processamento do amendoim. Durante esse processo é gerada uma grande quantidade de cascas, resíduo com potencial gerador de energia. Nesse contexto, o problema de pesquisa consiste na seguinte questão: qual o potencial de produção de biogás a partir da casca de amendoim? Partindo dessa questão, o objetivo principal dessa pesquisa é analisar a potencialidade e sustentabilidade da utilização da casca de amendoim como resíduo para a geração de biogás pela agricultura familiar do município de Herculândia – SP. Para tal, foi construído um protótipo de biodigestor com o intuito de avaliar o volume de biogás produzido por meio do processo de biodigestão da casca de amendoim. A análise dos resultados possibilitou avaliar o potencial da produção de biogás a partir desse resíduo, assim como quantificar o volume de biofertilizante gerado. A avaliação da sustentabilidade desse processo foi feita por meio da aplicação da contabilidade emergética. Os resíduos da casca de amendoim produziram 22,3 m³ de biogás por hectare, o que corresponde a uma energia gerada de 31, 84 kWh/mês. Assim, verificou-se que a biodigestão da casca do amendoim consiste em uma alternativa para o aproveita... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
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45

Mažrimas, Jonas. "Technologinių rodiklių įtaka Kauno nuotekų valyklos metantanko veikimo efektyvumui." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2012. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2012~D_20120530_124508-96080.

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Darbo tikslas – nustatyti technologinių rodiklių įtaką Kauno nuotekų valyklos metantanko efektyvumui. Darbo uždaviniai: nustatyti išsiskyrusių biodujų debito priklausomybę nuo temperatūros, organinės medžiagos suirimo laipsnio, palyginti teorinį ir faktinį pagaminamų biodujų kiekį. Tyrimo objektai: Kauno miesto nuotekų valykloje dumblo pūdymui periodiškai naudojami du metantankai. Tyrimo metodika: buvo stebimi pagrindiniai rodikliai, įtakojantys biodujų išeigą metantanke: pirminio dumblo debitas, perteklinio dumblo debitas, temperatūra ir organinės medžiagos suskilimo laipsnis. Apskaičiuotas organinės medžiagos kiekis dumble, nustatytas teorinis biodujų kiekis. Apdoroti 75 dienų tyrimų duomenys. Tyrimo rezultatai: biodujų debitas tiesiogiai proporcingas organinės medžiagos kiekiui, esančiam pirminio ir perteklinio dumblo mišinyje. Dumblas pastoviai susidaro pirminiuose ir antriniuose sėsdintuvuose, todėl negalima reguliuoti tiekiamo dumblo debito į metantanką, nes tai gali sutrikdyti nuotekų valymo proceso eigą. Vidutiniškai per dieną į Kauno miesto nuotekų valyklos metantanką tiekiama 432,5 m3 dumblo. Organinės medžiagos kiekis dumble priklauso nuo nuotekų, atitekančių į valyklą, sudėties. Kauno miesto nuotekų valyklos metantankas dirba mezofiliniu režimu. Pagal tyrimų duomenis metantanko darbo temperatūra svyruoja tarp 32,7 – 35,4 °C. Dėl šio temperatūrinio intervalo išsiskiriančių biodujų debitas yra netolygus. Išsiskyrusių biodujų debitas kinta nuo 4600 m3/d iki 9400 m3/d... [toliau žr. visą tekstą]
The object of the research: the two anaerobic digesters that are used for the sludge digestion in Kaunas wastewater treatment plant. The aim of the research: to determine the influence of the technological indicators on the performance efficiency of the anaerobic digester in Kaunas wastewater treatment plant. The objectives of the research: to estimate the dependence of the amount of biogas on the temperature and the degree of biolysis; to compare theoretical and actual amount of the biogas produced. Research methods: the main indicators, influencing biogas emission from the anaerobic digester, such as: primary sludge discharge, surplus sludge discharge, temperature, and the degree of biolysis, were observed. The amount of the organic material in the sludge was evaluated, theoretical amount of biogas was determined from the chart. Research data acquired in 75 days was processed. The results of the research: biogas discharge is directly proportional to the amount of organic material in the compound of primary and surplus sludge. Sludge is constantly forming in the primary and secondary sludge separators, therefore the sludge discharge added to the anaerobic digester cannot be controlled, as this could disorganize the process of wastewater treatment. On the average, 432,5 m3 of sludge are added to the anaerobic digester in Kaunas wastewater treatment plant. The amount of the organic material in the sludge depends on the composition of the sewage that the treatment plant is... [to full text]
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46

Fukayama, Ellen Hatsumi. "Características quantitativas e qualitativas da cama de frango sob diferentes reutilizações : efeitos na produção de biogás e biofertilizante /." Jaboticabal : [s.n.], 2008. http://hdl.handle.net/11449/104913.

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Orientador: Jorge de Lucas Junior
Banca: Roberto Alves de Oliveira
Banca: Júlio Cesar Pascale Palhares
Banca: Nilva Kazue Sakomura
Banca: Mônica Sarolli Silva de Mendonça Costa
Resumo: Objetivou-se avaliar o efeito da reutilização de cama de quatro lotes de criações de frangos de corte sobre a produção de cama de frango, a produção de biogás e a utilização do biofertilizante para adubação de milho. No capítulo sobre produção de cama foram avaliados quatro reutilizações de cama de frangos de corte criados em um galpão comercial dividido em 12 boxes pertencente à Empresa Rei Frango em São Carlos - SP - Brasil. Para caracterização da produção de cama foi avaliado a quantidade de cama produzida na matéria seca (MS) e o coeficiente de resíduo (Cr), ou seja, a quantidade de resíduo por kg de peso vivo das aves. Na caracterização qualitativa, foram analisados os teores de macro, micronutrientes e metais na casca de amendoim e cama de frango. Com o acréscimo de casca de amendoim nova mais o aumento de excretas do lote anterior, houve aumento (P<0,05) na produção de cama (MS). Assim, o Cr aumentou de acordo com a reutilização da cama. Porém, quando se avalia o Cr acumulado, ou seja, a quantidade de resíduo por kg de peso vivo acumulado das aves dos lotes criados, não houve diferença (P>0,05). De forma geral, foi observado que, com a reutilização da cama houve aumento (P<0,05) na concentração de nutrientes na cama. Conclui-se que com a reutilização de cama é possível igualar ou diminuir os custos com a aquisição de nova cama, aumentar a quantidade de nutrientes na cama para ser utilizada como biofertilizante na agricultura e estabilizar ou diminuir o impacto ambiental com a produção de cama por ave produzida. No capítulo sobre biodigestão anaeróbia de cama de frangos, para cada lote de aves conduzidos foram realizadas duas avaliações de biodigestão anaeróbia, sendo 4 ensaios (camas de 1 a 4º reutilização) avaliados de 2 formas: as 4 camas foram avaliadas em diferentes épocas do ano e também avaliadas na mesma época... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The objective was to evaluate the effect of reuse of litter of four broiler breeding cycle on the broiler litter' production, the biogas' production and use of organic fertilizer for fertilization of maize. In the chapter on production of litter were evaluated four reuses of litter of broiler chickens reared in a commercial shed divided in 12 boxes belonging to Rei Frango Company in São Carlos - São Paulo - Brazil. To characterize the production of litter was assessed the amount of litter produced in dry matter (DM) and the coefficient of waste (CW), or the amount of waste per kg of live birds. In qualitative characteristics, were analyzed the levels of macro, micro and metals in the shell of peanuts and broiler litter. With the addition of new peanut shell, plus the increase of manure of the previous batch, there was an increase (P<0.05) in the production of litter (dry matter - DM). Thus, the increased CW according to the reuse of litter. But when assessing the cumulative CW, or the amount of waste per kilogram of body weight of accumulated lots of birds created, there was no difference (P>0.05). Overall, it was observed that with the reuse of the litter there was an increase (P<0.05) in the concentration of nutrients in litter. It follows that with the reuse of litter can be equal or lower cost for the purchase of new litter, increase the amount of nutrients in litter to be used as organic fertilizer in agriculture and keep or reduce the environmental impact to the production of litter by produced per bird. In the chapter on anaerobic digester with litter of broiler, for each batch of birds conducted two evaluations were made of anaerobic digester, and 4 trials (litters from 1 to 4 reuse) evaluated in 2 ways: the 4 litters were evaluated at different times of the year and also evaluated in the same season, totaling 8 tests. 24 digesters were used in batch, distributed... (Complete abstract click electronic access below)
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47

Bradáč, Antonín. "Návrh optimálního promíchávání velkokapacitních vyhnívacích nádrží." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2017. http://www.nusl.cz/ntk/nusl-318823.

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The aim of this diploma thesis is an optimal method of mixing of the digester with consideration to the uniform mixing of the whole volume, ensuring the quality process conditions for the anaerobic fermentation and the maximum yield and quality of the produced biogas. First chapters describe the basic design parameters, general calculations and the principles for design of individual types of mixers, supplemented by practical examples of mixing large capacity tanks. The work introduces the problem of sludge formation at the sewage treatment plant with an emphasis on sludge treatment and the processes which take place inside the fermenter. Various types of design of anaerobic sludge stabilization digester were introduced. Also ways of their operation, which are necessary for the quality of the fermentation, were presented. In the next chapters, various ways of mixing high-capacity digester tanks and experience from the operation of selected treatment plants were described. According to the theoretical research part of this thesis, several types of mixing equipment was designed for the experimental digestion tank built at the Institute of Process Engineering which is used for research work with mixers. Measurement of the selected pneumatic mixing method was performed on the experimental tank and the findings were evaluated.
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48

Pérez, Medel Javier Andrés. "Estudio y Diseño de un Biodigestor para Aplicación en Pequeños Ganaderos y Lecheros." Tesis, Universidad de Chile, 2010. http://www.repositorio.uchile.cl/handle/2250/103926.

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Esta memoria se motiva en la necesidad energética de los pequeños ganaderos y lecheros de la zona sur de Chile y en la débil situación de diversificación de la matriz energética del país, es por esto que se propone un Biodigestor como solución viable a esta necesidad. Un Biodigestor es un equipo que produce gas metano (CH4), a partir de la descomposición de restos orgánicos, particularmente heces animales (vacunos, porcinos, etc.). Aquí se propone el diseño en términos de ingeniería básica, de un Biodigestor adecuado para las necesidades introducidas. La metodología comienza con una serie de análisis elementales que caracterizan el usuario medio del equipo, la demanda esperada, la cinética de los procesos bio-químicos presentes, las consideraciones de geometría y espacio utilizado, para concluir con los parámetros de diseño del Biodigestor y el posterior diseño. Los recursos utilizados comprendieron un apoyo bibliográfico independiente con entidades públicas relacionadas al área económicamente involucrada como el INDAP, INE o Ministerio de Economía. Se abordó un proyecto de instalación de biodigestión anaeróbica a nivel básico, utilizando un criterio económico que permite que la inversión del proyecto sea recuperada en 3 [años] y se realizó el diseño básico del estanque de biodigestión con sus componentes principales. El resultado de esta memoria es un equipo de biodigestión anaeróbica que procesa 59 [m3/mes] de purines de Bovino y produce 4,1 [m3/H] promedio de biogás. Se contempló la incorporación de un equipo generador eléctrico que es alimentado por un caudal compatible de biogás y que permite que la energía eléctrica sea aprovechable.
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49

Sekar, Samantha. "The Effects of Biochar and Anaerobic Digester Effluent on Soil Quality and Crop Growth in Karnataka, India." The Ohio State University, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=osu1343750717.

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50

Steil, Lara [UNESP]. "Avaliação do uso de inóculos na biodigestão anaeróbia de resíduos de aves de postura, frangos de corte e suínos." Universidade Estadual Paulista (UNESP), 2001. http://hdl.handle.net/11449/88047.

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Made available in DSpace on 2014-06-11T19:23:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2001-09-27Bitstream added on 2014-06-13T19:08:56Z : No. of bitstreams: 1 steil_l_me_araiq.pdf: 799428 bytes, checksum: ea2cd9b8adbc44bdd76ac6b53c7d3a09 (MD5)
Investigou-se a influência da utilização de inóculos sobre a digestão anaeróbia de resíduos de aves de postura, frangos de corte e suínos em biodigestores modelo batelada com volume útil de 60 L operados à temperatura ambiente, por meio da caracterização do potencial e distribuição da produção de biogás ao longo do tempo, o estudo da redução de sólidos, a análise das características dos efluentes quanto à concentração de ácidos graxos voláteis e por meio da determinação do número mais provável (NMP) de coliformes fecais e totais nos afluentes e efluentes. Avaliou-se também a atividade metanogênica nos biodigestores com 10 % de inóculo. Foram testadas três concentrações de inóculo: 0, 10 e 15 %. Os resultados mostraram que os resíduos de aves de postura, frangos de corte e suínos são bons substratos para o processo de digestão anaeróbia, apresentando potenciais médios que variaram de 0,3828 a 0,4403 m3, de 0,3495 a 0, 3915 m3, e de 0,1949 a 0,4466 m3 de biogás por kg de ST adicionados, respectivamente para resíduos de aves de postura, frangos de corte e suínos. Com base em todos os parâmetros estudados, as concentrações de inóculo que promoveram melhores resultados foram 10 % para resíduos de aves de postura e frangos de corte, e 15 % para resíduos de suínos. O tratamento anaeróbio revelou-se eficiente na remoção de coliformes totais e fecais independente da concentração de inóculo, alcançando porcentagens médias de redução de NMP que variaram de 99,71 % de 1,09 x 102 a 100 %. A atividade metanogênica específica foi mais elevada nas amostras provenientes dos biodigestores operados com resíduos de aves de postura (0,0340 mmol CH4 g-1 SV h-1), seguida pelos resíduos de frangos de corte (0,0188 mmol CH4 g-1 SV h-1) e suínos (0,0029 mmol CH4 g-1 SV h-1). Estes resultados parecem estar mais associados aos teores...
This study was carried out in 60 L volume batch digesters at ambient temperature and investigated the inoculums concentration effects on anaerobic digestion of laying hens, poultry and piggery wastes through evaluation of potential and distribution of biogas production along the time, solids removal, analyze of volatile fatty acids efluent concentration and by monitoring the most probable number (MNP) of total and faecal coliforms in the inffluents and effluents. Specific methanogenic activity (SMA) into the 10 % inoculum digesters was also measured. Three inoculum concentrations (0, 10 and 15 %) were tested. Results showed that laying hens, poultry litter and piggery wastes are good substrats to anaerobic digestion. The potential biogas production varied from 0.03828 to 0.4403 m3, 0.3495 to 0.3915 m3 and 0.1949 to 0.4466 m3 of biogas kg-1 of total solids added, respectively for laying hens, poultry and piggery wastes. The best results for inoculum concentration were 10 % for laying hens and poultry wastes, and 15 % for piggery wastes. Anaerobic digestion was efficient for reduction of the most probable mean number of total and faecal coliforms. Reduction of MNP mean varied from 99.71 of 1,09 x 102 to 100 %. SMA test showed the best activity was from laying hens wastes (0,03400 mmol CH4 g-1 SV h-1), followed by poultry wastes (0,01877 mmol CH4 g-1 SV h- 1) and by piggery wastes (0,00293 mmol CH4 g-1 SV h-1). Results of SMA test appear to be most affected by volatile solids content of the samples than the best ability of the microrganisms to convert substrate. The best organic load rate for activity test were 0,25 g DQO g-1 SV.
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