Letteratura scientifica selezionata sul tema "Biogas digesters"

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Articoli di riviste sul tema "Biogas digesters"

1

Phuong, Nguyen Le. "STUDY ON CO-FERMENTATION OF COW DUNG AND GIANT DIRT IN SEMI-CONTINUOUS ANAEROBIC DIGESTER". Vietnam Journal of Science and Technology 54, n. 2A (19 marzo 2018): 287. http://dx.doi.org/10.15625/2525-2518/54/2a/11943.

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Abstract (sommario):
Study on co-fermentation of cow dung (CD) and giant dirt (GD - Pistia stratiotes L.) in semi-continuous anaerobic digester aims to test biogas quantity and quality by time. Three mixing rates counted based on ODM of each material were chosen: 100 %CD, 50 %CD + 50 %GD, and 100 %GD. The experiments were set up in laboratory conditions with two types of digesters: one-stage digesters and two-stage digesters (triplicate for each treatment). After 80 days, the biogas produced from the one-stage digesters was not significantly different to the two-stage digesters with similar input material. The highest production of biogas came from digesters of 100 %GD - 235.8 L for the one-stage and 240.3 L for the two-stages. The medium production came from digesters of 50 %CD + 50 %GD - 127.8 L for the one-stage and 118.4 L for the two-stages. After one month, the percentage of CH4 was high enough for burning and almost giant dirt was digested that limited of a blockage inside the digesters. The results showed that co-fermentation of GD and CD is an alternative for livestock raising households to produce biogas for energy purpose.
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Pradip B. Acharya, Pradip, e Prateek Shilpkar. "Solanum tuberosum Supplementation for Biogas Production". Current World Environment 10, n. 1 (30 aprile 2015): 285–87. http://dx.doi.org/10.12944/cwe.10.1.35.

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Production of biogas using animal dung is well documented. Nutritional supplement enhances microbial activity and ultimately results in increase biogas production. Solanum tuberosum (potato) is a vegetable crop grown in most parts of world. It is a rich source of carbohydrate starch and many minerals. Present experiment was conducted in 5L capacity glass digester bottles filled with mixture of buffalo dung and water at 5.3% total solids. A total of six sets were prepared, three as control and three as test. Control sets were fed daily with buffalo dung water mixture throughout the period of experimentation, i.e. 80 days, whereas in test, from 51st day onward digesters were filled with mixture of dung and boiled potato with water. Feed was added daily in the amount of 120mL upto 80 days from beginning. On first day 12 mL fresh digested biogas slurry from running biogas plant was also added in all the digesters as inoculum. From 41th day onward biogas production was recorded by water displacement method and compared. Results reveal that in test digesters addition of potato shows an immediate and long lasting effect and increases biogas production between 90.48 and 192.86% higher than control sets.
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Wang, Yan, e Shan Shan Zhang. "The Investigation Based on Heating with Biomass Energy for Biogas Digesters Winter Gas Production Technology in Cold Regions". Advanced Materials Research 1008-1009 (agosto 2014): 107–10. http://dx.doi.org/10.4028/www.scientific.net/amr.1008-1009.107.

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The average temperature is low in cold regions; therefore, under natural conditions, the gas production is more unlikely to be successful. When temperature drops below 6 °C in the biogas digester, it stops producing gas. By aiming household biogas digesters as subjects, from the test materials, experimental methods, experimental test results and economic analysis, this experiment studied the feasibility of heating with biomass energy for biogas digester to accomplish the digesters gas production in winter in in cold regions.
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Li, Qian, Jingjing Wang, Xiaoyang Wang e Yubin Wang. "The Impact of Training on Beef Cattle Farmers’ Installation of Biogas Digesters". Energies 15, n. 9 (21 aprile 2022): 3039. http://dx.doi.org/10.3390/en15093039.

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Anaerobic digestion is one of the leading ways to manage livestock manure for energy production and move towards the target of carbon neutrality in the agricultural sector. Based on field survey data from China, a binary probit model and the propensity score matching method are employed to empirically examine the impact of agricultural training on livestock farmers’ installation of biogas digesters to manage livestock manure. The survey results show that beef cattle farmers in our study area are reluctant to install biogas digesters and the actual installation ratio of farmers is much lower than that that is willing to install. On the contrary, the beef cattle farmers are enthusiastic to participate in training (e.g., policy-oriented, technology-oriented, and field-based) related to sustainable farming practices. Regression results suggest that training can effectively promote the installation of biogas digesters, and with the increase of training intensity, the probability to install biogas digesters increases. We further find three other factors that affect farmers’ installation of biogas digesters: the education level of a farmer, which is one of the most important factors positively affecting the installation of biogas digesters; longer farming experience of a farmer, which can significantly promote biogas digester installation; and the farther away a farm is from town/urban centers, which means the more likely it is that the farmer will install biogas digesters. Policy implications are discussed.
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Syed Sabeer Ali, S. N., R. Omar, H. Che Man, A. I. Md Idris e H. A. Tajuddin. "Foaming Tendency in Anaerobic Digestion of Wastewater Inoculated with Anaerobic Sludge and Cow Manure: Effect of Protein Concentration". IOP Conference Series: Materials Science and Engineering 1257, n. 1 (1 ottobre 2022): 012043. http://dx.doi.org/10.1088/1757-899x/1257/1/012043.

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Abstract Foaming has impacted the digestion process causing severe process failures. The basis of foaming is often unclear due to multiple foaming compounds in a single system. This study aims to elucidate the effect of protein concentration on foaming in anaerobic sludge and cow manure (CM) digesters inoculated with synthetic wastewater as a substrate. Gelatine was used to alter the protein concentration in the digesters. The foaming tendency, biogas production, protein, and chemical oxygen demand (COD) removal were measured to comprehend the findings. The results show that the foaming tendency increased with protein concentration in anaerobic sludge digesters. It also had the highest biogas production. There was no evident process inhibition observed in the anaerobic sludge digester, even at higher protein and COD concentrations. For CM digester, the foaming tendency and biogas production increased to 9 g/L; however, the biogas production decreased with increased substrate protein concentration, indicating process inhibition. The results indicate that the biogas production, foaming tendency, COD and protein removal increased steadily for both digesters. However, the trend decreased for CM digester at increased protein concentrations. This study also concluded that protein creates foaming when inoculated with anaerobic sludge and CM even at low substrate protein concentration.
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Shang, Y., B. R. Johnson e R. Sieger. "Application of the IWA Anaerobic Digestion Model (ADM1) for simulating full-scale anaerobic sewage sludge digestion". Water Science and Technology 52, n. 1-2 (1 luglio 2005): 487–92. http://dx.doi.org/10.2166/wst.2005.0557.

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A steady-state implementation of the IWA Anaerobic Digestion Model No. 1 (ADM1) has been applied to the anaerobic digesters in two wastewater treatment plants. The two plants have a wastewater treatment capacity of 76,000 and 820,000 m3/day, respectively, with approximately 12 and 205 dry metric tons sludge fed to digesters per day. The main purpose of this study is to compare the ADM1 model results with full-scale anaerobic digestion performance. For both plants, the prediction of the steady-state ADM1 implementation using the suggested physico-chemical and biochemical parameter values was able to reflect the results from the actual digester operations to a reasonable degree of accuracy on all parameters. The predicted total solids (TS) and volatile solids (VS) concentration in the digested biosolids, as well as the digester volatile solids destruction (VSD), biogas production and biogas yield are within 10% of the actual digester data. This study demonstrated that the ADM1 is a powerful tool for predicting the steady-state behaviour of anaerobic digesters treating sewage sludges. In addition, it showed that the use of a whole wastewater treatment plant simulator for fractionating the digester influent into the ADM1 input parameters was successful.
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Kamarád, Luděk, Stefan Pohn, Günther Bochmann e Michael Harasek. "Determination of mixing quality in biogas plant digesters using tracer tests and computational fluid dynamics". Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 61, n. 5 (2013): 1269–78. http://dx.doi.org/10.11118/actaun201361051269.

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The total electricity demand of investigated biogas plants (BGP) makes up 7–8 % of the total electricity produced. Nearly 40 % of this energy is consumed just for mixing in digesters and the energy demand for mixing in some biogas plants can be even higher. Therefore, optimal mixing in anaerobic digesters is a basic condition for efficient plant operation and biogas production. The use of problematic substrates (e.g. grass silage or other fibrous substrates), installation of unsuitable mixing systems or inconvenient mixing intervals may lead to mixing problems. Knowledge about mixing in biogas digesters is still insufficient, so the objective of this study was to fill the information gaps in the literature by determining the minimal retention time of substrates fed into anaerobic digesters and to describe substrate distribution and washing out rates from investigated digesters. Two full-scale biogas plant digesters (2000 m3 and 1500 m3) using different mixing systems and substrates were investigated. To characterize the substrate distribution, lithium hydroxide monohydrate solutions were used for tracer tests at concentrations of 47.1 mg Li+ / kg TS and 46.6 mg Li+ / kg TS in digester. The tracer concentration in the digester effluents was measured during two hydraulic retention times and compared. Although the tracer was detected in the digester effluent at nearly the same time in both cases, the tracer tests showed very different distribution curves. The tracer concentration in effluent B grew much slower than in effluent A and no significant short circuiting streams were detected. Although the data calculated by computational fluid dynamics methods (CFD) showed a very good agreement with the full scale results, full comparison was not possible.
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A, Adewumi, Lasisi K. H, Akinmusere O. K, Ojo A. O e Babatola J. O. "COMPARATIVE STUDY OF ELECTROLYSIS-ENHANCED ANAEROBIC DIGESTION OF THREE SOLUBLE SOLID WASTES FOR BIOGAS PRODUCTION". INDONESIAN JOURNAL OF URBAN AND ENVIRONMENTAL TECHNOLOGY 4, n. 1 (11 ottobre 2020): 11. http://dx.doi.org/10.25105/urbanenvirotech.v4i1.8004.

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<p><strong>Aim</strong>: A comparative study of biogas production from three soluble solid wastes was conducted under anaerobic conditions by subjecting each waste to both conventional and electrolyzed digesters. <strong>Methodology and Results</strong>: Varying weight of each of the waste was mixed thoroughly with water and fed into five digesters. Three of these digesters were electrolytically-enhanced while the other two were not. The digestion of each of the wastes was monitored for 40 days at an ambient temperature ranging from 24 to 35oC. In all the digesters, biogas production started on the day 2, and attained maximum value on day 14 to17. Biogas production ended on the day 34 and 35 in digester 1a, 1b, 2a and 2b with production ending earliest in digester 3 containing wastewater on day 19. The highest biogas was produced in digester 2b containing electrolyzed digester loaded with poultry droppings) with a cumulative volume percentage of 91.41 as compared to its conventional state with a cumulative volume percentage of 85.19 and both states of the cow dung waste with cumulative volume percentages of 77.26 and 71.64 respectively. The least production occurred in digester 3 with a cumulative volume percentage of 4.59. <strong>Conclusion, significance and impact study</strong>: It is therefore concluded that poultry droppings has the greatest potentials for the generation of biogas as compared to cow dung in conventional and electrolyzed state and wastewater.</p>
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Harrison, Ogala, e Ige Ayodeji Rapheal. "Biogas production from blends of fonio husk and donkey dung via anaerobic digestion for sustainable development". International Journal of Advanced Chemistry 9, n. 1 (25 dicembre 2020): 1. http://dx.doi.org/10.14419/ijac.v9i1.31254.

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There is growing public concern over potential impact on environmental quality caused by animal wastes. Anaerobic digestion, a biological conversion process can be used to obtain energy from biologicall wastes. This study explored the production of biogas from co-digestion of fonio hus and donkey dung using anaerobic biological conversion. The digesters were labeled as; digester A –Fonio husk only, digester B - donkey dung only, digester C – Fonio husk (300g) and Donkey Dung (200g), digester D – Fonio husk (200g) and donkey dung (300g). Proximate analysis of the substrates before and after digestion were determined such as total solids (TS), volatile solid, carbon content, nitrogen content, ash content, etc., and pH before and after digestion process. The biogas produced during this period was collected by water displacement method and subsequently measured. The results showed that Fonio husk in bio-digesters A and B gave a cumulative average biogas volume of 4972 ml and 5222 ml (week 3) while pig dung in bio-digesters C and D gave a cumulative average biogas volume of 5564 ml and 5978 respectively (week 3) within three weeks of fermentation. The digester is capable of producing 0.007m at average working temperature of 320C. Digester D produces higher volume of biogas as a result of improved nutrient provide by donkey dung as shown in the results obtained from the proximate analysis and has the best neutral pH, there was a reduction in the startup time.
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Loughrin, John, Stacy Antle, Karamat Sistani e Nanh Lovanh. "In Situ Acoustic Treatment of Anaerobic Digesters to Improve Biogas Yields". Environments 7, n. 2 (8 febbraio 2020): 11. http://dx.doi.org/10.3390/environments7020011.

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Sound has the potential to increase biogas yields and enhance wastewater degradation in anaerobic digesters. To assess this potential, two pilot-scale digestion systems were operated, with one exposed to sound at less than 10 kHz and with one acting as a control. Sounds used were sine waves, broadband noise, and orchestral compositions. Weekly biogas production from sound-treated digesters was 18,900 L, more than twice that of the control digester. The sound-treated digesters were primarily exposed to orchestral compositions, because this made cavitational events easier to identify and because harmonic and amplitude shifts in music seem to induce more cavitation. Background recordings from the sound-treated digester were louder and had more cavitational events than those of the control digester, which we ascribe to enhanced microbial growth and the resulting accelerated sludge breakdown. Acoustic cavitation, vibrational energy imparted to wastewater and sludge, and mixing due to a release of bubbles from the sludge may all act in concert to accelerate wastewater degradation and boost biogas production.
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Tesi sul tema "Biogas digesters"

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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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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Abstract (sommario):
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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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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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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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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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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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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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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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 e 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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Libri sul tema "Biogas digesters"

1

Hayworth, James M. Methane digesters and biogas recovery. New York: Nova Science Publishers, 2011.

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2

Liebrand, Carolyn. Cooperative approaches for implementation of dairy manure digesters. Washington, D.C: USDA, Rural Development, 2009.

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3

Liebrand, Carolyn. Cooperative approaches for implementation of dairy manure digesters. Washington, D.C: USDA, Rural Development, 2009.

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4

Liebrand, Carolyn. Cooperative approaches for implementation of dairy manure digesters. Washington, D.C: USDA, Rural Development, 2009.

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5

Liebrand, Carolyn. Cooperative approaches for implementation of dairy manure digesters. Washington, D.C: USDA, Rural Development, 2009.

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6

California Energy Commission. Public Interest Energy Research. Dairy power production program : dairy methane digester system program evaluation report: PIER consultant report. [Sacramento, Calif.]: California Energy Commission, 2009.

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7

California Energy Commission. Public Interest Energy Research. Centralized dairy digester with power generation: PIER final project report. [Sacramento, Calif.]: California Energy Commission, 2009.

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8

Nakagawa, Charles H. Chinese biogas digester: A potential model for small-scale, rural applications : a manual for construction and operation. Washington, D.C: Peace Corps Information Collection and Exchange, 1985.

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9

Nakagawa, Charles H. Chinese biogas digester: A potential model for small-scale, rural applications : a manual for construction and operation. Washington, D.C: Peace Corps Information Collection and Exchange, 1985.

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10

California Energy Commission. Public Interest Energy Research. Commerce energy biogas/PV mini-grid renewable sources program: Monitoring, reporting, and verification protocol for the Inland Empire Utility [sic] Agency anaerobic digester : PIER final project report. [Sacramento, Calif.]: California Energy Commission, 2009.

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Capitoli di libri sul tema "Biogas digesters"

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Deng, Liangwei, Yi Liu e Wenguo Wang. "Rural Household Digesters". In Biogas Technology, 31–67. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4940-3_2.

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Deng, Liangwei, Yi Liu e Wenguo Wang. "Construction Materials and Structures of Digesters". In Biogas Technology, 157–99. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-4940-3_5.

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Abbasi, Tasneem, S. M. Tauseef e S. A. Abbasi. "Low-Rate and High-Rate Anaerobic Reactors/Digesters/Fermenters". In Biogas Energy, 35–39. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-1040-9_4.

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Abbasi, Tasneem, S. M. Tauseef e S. A. Abbasi. "Biogas Capture from Wastewaters: The High-Rate Anaerobic Digesters". In Biogas Energy, 63–104. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-1040-9_6.

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Balsari, P., P. Bonfanti, E. Bozza e F. Sangiorgi. "Simplified Anaerobic Digesters for Animal Waste". In Biogas Technology, Transfer and Diffusion, 306–16. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4313-1_37.

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Frettlôh, G. "Ferrocement Gasholder for Two 60 M3 Digesters". In Biogas Technology, Transfer and Diffusion, 302–5. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4313-1_36.

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Sow, S. "Cookinations: Mechanisms to Decouple Wood Production and Food Preparation in Sub-Urban Areas". In Sustainable Energy Access for Communities, 139–46. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-68410-5_13.

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AbstractIn Senegal, the share of households that cook using primarily biomass fuels accounts for over 70%. Although the use of these fuels is more frequent in rural areas, there are still households in sub-urban areas that rely on charcoal. Beyond the promotion of subsidized LPG, domestic biogas and improved cookstoves are tested in some rural and sub-urban areas of the country. The results of the experiences compiled in this chapter show that these mechanisms are effective in decoupling biomass use and food preparation in sub-urban areas. Improved cookstoves can contribute to reducing biomass use by up to 45%. Domestic biogas digesters can replace biomass fuels for cooking in rural communities.
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Leonzio, Grazia. "Biogas Produced from Different Feedstocks in Anaerobic Digesters". In Nanotechnology in Oil and Gas Industries, 291–338. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-60630-9_10.

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Rudakiya, Darshan M., e Madhuri Narra. "Microbial Community Dynamics in Anaerobic Digesters for Biogas Production". In Microbial Rejuvenation of Polluted Environment, 143–59. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-15-7459-7_7.

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Abdel-Samie, Mohiy Eldin, e Mohammed Nabil Mahmoud. "The Assessment of Cellulolytic Activities in Anaerobic Digesters by the “Textiles Coupon Technique”". In Biogas Technology, Transfer and Diffusion, 474–79. Dordrecht: Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4313-1_56.

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Atti di convegni sul tema "Biogas digesters"

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DAPKIENĖ, Midona, Laima ČESONIENĖ e Tomas PILIPAUSKAS,. "COMPARISON OF OPERATION OF KAUNAS AND KLAIPĖDA WWTPS DIGESTERS". In Rural Development 2015. Aleksandras Stulginskis University, 2015. http://dx.doi.org/10.15544/rd.2015.042.

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The article provides comparison of operation of digesters for 2014, installed in wastewater treatment plants (WWTP) of two Lithuanian cities Kaunas and Klaipėda. It was established that the temperature and decomposition degree of organic materials had impact on biogas discharge in digesters of both wastewater treatment plants. Increase of these technological parameters resulted in increase of biogas output. Actual output of biogas of Kaunas wastewater treatment plant digester was by 5.8 % less than theoretical output, in Klaipėda WWTP anaerobic reactor – by 4.2 %. After comparison of biogas discharge generated from 1 m3 of sludge in Kaunas and Klaipėda WWTPs it was established that the efficiency of Klaipėda WWTP digester exceeded the efficiency of Kaunas WWTP reactor by 7 %.
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Carl S Hansen e Conly L Hansen. "Inexpensive biogas Conditioning for small Digesters". In International Symposium on Air Quality and Manure Management for Agriculture Conference Proceedings, 13-16 September 2010, Dallas, Texas. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2010. http://dx.doi.org/10.13031/2013.32678.

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Chavero, Jorge, Duff Harrold e Timothy Marbach. "Equilibrium and Kinetics Analysis of NOx Reduction From Biogas Combustion". In ASME 2011 Power Conference collocated with JSME ICOPE 2011. ASMEDC, 2011. http://dx.doi.org/10.1115/power2011-55313.

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The undeveloped potential generation capacity of landfills, wastewater digesters and food digesters is estimated at 600 MW in California and 3,000 MW in the United States. California’s 2000 dairies have the potential to produce an estimated 40 million cubic feet of biogas per day, representing a potential generation capacity of about 140 MW. One of the most significant challenges facing the combustion of digester biogas is high NOx emissions. Sulfur in the biogas poisons post-combustion catalysts, rendering them ineffective for reducing NOx emissions. To address this challenge, an integrated pollution capture and microwave system has been developed to reduce NOx emissions from biogas engines. The feasibility of reburning the captured NOx was assessed and the effect of various operating parameters, including temperature, pressure, and reactant composition were determined using chemical equilibrium and kinetic modeling.
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Zemke, Peter E., Byard D. Wood e Christopher R. Rohleder. "Effect of Solids Removal From Dairy Manure Feedstock on Biogas Production in Anaerobic Digesters". In ASME 2010 4th International Conference on Energy Sustainability. ASMEDC, 2010. http://dx.doi.org/10.1115/es2010-90235.

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Many modern anaerobic digesters in developed countries consist of a digestion process in which solids are reduced to biogas, followed by mechanical separation that removes the majority of the remaining solids from the effluent. Experience has shown that such systems are often plagued with plugging due to excessive solids in the digester influent. Moreover, the mechanical separation equipment is prematurely degraded due to the elevated temperatures and corrosive compounds in the digester effluent. Reversing the order of separation and digestion offers a proven method of eliminating these problems, but at the expense of lower biogas production. The work presented in this paper quantifies this difference in biogas production by comparing the biogas yields of dairy wastewater feedstocks with and without prior mechanical solids separation through a 0.75-mm screen. Laboratory-scale batch digesters were operated up to 40 days at 35–40 °C and monitored for mass of volatile solids consumed and biogas production. Although the initially separated influent contained only half as much volatile solids, the ultimate biogas yield was only 25% less than that obtained with non-separated influent, demonstrating some tradeoff between higher energy production and system reliability.
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Kifle G. Gebremedhin e S. Inglis. "Biogas Production Model for Plug-Flow Anaerobic Digesters". In 2006 Portland, Oregon, July 9-12, 2006. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2006. http://dx.doi.org/10.13031/2013.21157.

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Hala I Chaoui e Tom Richard. "Effect of mixing frequency on biogas yield in anaerobic digesters". In 2008 Providence, Rhode Island, June 29 - July 2, 2008. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2008. http://dx.doi.org/10.13031/2013.25327.

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Dieudonne, Dukuzumuremyi, e Hisato Shima. "Effectiveness of applying IoT to improve biogas digesters in Rwanda". In 2018 IEEE International Conference on Applied System Innovation (ICASI). IEEE, 2018. http://dx.doi.org/10.1109/icasi.2018.8394279.

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Bettocchi, R., M. Pinelli, P. R. Spina, M. Venturini, M. Cadorin, G. Cenci e M. Morini. "Energetic and Economic Analyses of Integrated Biogas-Fed Energy Systems". In ASME Turbo Expo 2008: Power for Land, Sea, and Air. ASMEDC, 2008. http://dx.doi.org/10.1115/gt2008-50044.

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The process which includes production, collection, carriage and transformation of biomass into renewable fuels and then into energy (both electrical and thermal) involves a large number of decisions to select the most efficient plant layout. In order to identify the optimal solutions, models which simulate the whole process represent a useful and practical tool. In this paper, the energetic and economic analysis of the entire process from biomass to energy production is presented. Among the different transformation processes, the thermophilic batch anaerobic digestion is considered in this paper. A sensitivity analysis on system profitability is carried out with respect to the mass of biomass, number of batch digesters and retention time of the biomass inside each digester. Moreover, two different types of biomass (ensiled corn and organic fraction of municipal solid wastes) and two different energy systems (Micro Gas Turbine and Internal Combustion Engine) are considered.
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Gupta, Ankit. "Design of Solar Assisted Community Biogas Plant". In ASME 2009 3rd International Conference on Energy Sustainability collocated with the Heat Transfer and InterPACK09 Conferences. ASMEDC, 2009. http://dx.doi.org/10.1115/es2009-90112.

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This study aims at providing a solution to the difficulty in the production of biogas in cold weather conditions especially during winters and in hilly regions where the temperature remains low throughout the year. As is well known biogas can be produced by anaerobic fermentation of organic materials with the help of bacteria [1]. Meynell [2] pointed out that the production of biogas becomes insignificant when the slurry temperature is less than 15°C. Such situations are usually faced in northern India, where the ambient temperature and, hence, the slurry temperature, in the winters drops below 15°C and hence improper digestion of slurry leads to poor biogas yield. This problem can be overcome by making the biogas plant solar assisted. The heat requirements of the digesters generally consist of three parts; (i) heat required for raising the temperature of incoming slurry for digestion; (ii) for compensating heat losses through the boundaries of the digester and (iii) for compensating losses that might occur in the piping between the heat source and the digester [3]. The required heat is provided from the collector which absorbs solar radiation and converts it into heat which is absorbed by a heat transfer fluid passing through the collector [4]. In this work, a biogas plant for a specified capacity has been designed. Based on the biogas plant dimensions and the average ambient conditions for a specified location, the rate of loss of energy was determined. A solar collector system has been designed to supply sufficient energy to maintain the slurry temperature of 35° C.
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Binxin Wu, Eric L. Bibeau e Kifle G. Gebremedhin. "Three-Dimensional Numerical Simulation Model of Biogas Production for Anaerobic Digesters". In 2006 Portland, Oregon, July 9-12, 2006. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2006. http://dx.doi.org/10.13031/2013.20924.

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Rapporti di organizzazioni sul tema "Biogas digesters"

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Asvapathanagul, Pitiporn, Leanne Deocampo e Nicholas Banuelos. Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation. Mineta Transportation Institute, luglio 2022. http://dx.doi.org/10.31979/mti.2021.2141.

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In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H2) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H2 generates triple the amount of energy compared to hydrocarbon fuels. H2 can be synthesized from several technologies, but currently only 1% of H2 production is generated from biomass. Biological H2 production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H2 production from anaerobic digesters by increasing H2 forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H2 content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H2 gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H2 recovery due to H2 being taken up by other bacteria for methane (CH4) formation. Our experiment was operated under the most optimal condition for CH4 formation as suggested by wastewater operational manuals. Therefore, CH4-forming bacteria possessed more advantages than other microbial populations, including H2-forming groups, and rapidly utilized H2 prior to methane synthesis. This study demonstrates H2 energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.
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Asvapathanagul, Pitiporn, Leanne Deocampo e Nicholas Banuelos. Biological Hydrogen Gas Production from Food Waste as a Sustainable Fuel for Future Transportation. Mineta Transportation Institute, luglio 2022. http://dx.doi.org/10.31979/mti.2022.2141.

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Abstract (sommario):
In the global search for the right alternative energy sources for a more sustainable future, hydrogen production has stood out as a strong contender. Hydrogen gas (H2) is well-known as one of the cleanest and most sustainable energy sources, one that mainly yields only water vapor as a byproduct. Additionally, H2 generates triple the amount of energy compared to hydrocarbon fuels. H2 can be synthesized from several technologies, but currently only 1% of H2 production is generated from biomass. Biological H2 production generated from anaerobic digestion is a fraction of the 1%. This study aims to enhance biological H2 production from anaerobic digesters by increasing H2 forming microbial abundance using batch experiments. Carbon substrate availability and conversion in the anaerobic processes were achieved by chemical oxygen demand and volatile fatty acids analysis. The capability of the matrix to neutralize acids in the reactors was assessed using alkalinity assay, and ammonium toxicity was monitored by ammonium measurements. H2 content was also investigated throughout the study. The study's results demonstrate two critical outcomes, (i) food waste as substrate yielded the highest H2 gas fraction in biogas compared to other substrates fed (primary sludge, waste activated sludge and mixed sludge with or without food waste), and (ii) under normal operating condition of anaerobic digesters, increasing hydrogen forming bacterial populations, including Clostridium spp., Lactococcus spp. and Lactobacillus spp. did not prolong biological H2 recovery due to H2 being taken up by other bacteria for methane (CH4) formation. Our experiment was operated under the most optimal condition for CH4 formation as suggested by wastewater operational manuals. Therefore, CH4-forming bacteria possessed more advantages than other microbial populations, including H2-forming groups, and rapidly utilized H2 prior to methane synthesis. This study demonstrates H2 energy renewed from food waste anaerobic digestion systems delivers opportunities to maximize California’s cap-and-trade program through zero carbon fuel production and utilization.
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Pullammanappallil, Pratap, Haim Kalman e Jennifer Curtis. Investigation of particulate flow behavior in a continuous, high solids, leach-bed biogasification system. United States Department of Agriculture, gennaio 2015. http://dx.doi.org/10.32747/2015.7600038.bard.

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Recent concerns regarding global warming and energy security have accelerated research and developmental efforts to produce biofuels from agricultural and forestry residues, and energy crops. Anaerobic digestion is a promising process for producing biogas-biofuel from biomass feedstocks. However, there is a need for new reactor designs and operating considerations to process fibrous biomass feedstocks. In this research project, the multiphase flow behavior of biomass particles was investigated. The objective was accomplished through both simulation and experimentation. The simulations included both particle-level and bulk flow simulations. Successful computational fluid dynamics (CFD) simulation of multiphase flow in the digester is dependent on the accuracy of constitutive models which describe (1) the particle phase stress due to particle interactions, (2) the particle phase dissipation due to inelastic interactions between particles and (3) the drag force between the fibres and the digester fluid. Discrete Element Method (DEM) simulations of Homogeneous Cooling Systems (HCS) were used to develop a particle phase dissipation rate model for non-spherical particle systems that was incorporated in a two-fluid CFDmultiphase flow model framework. Two types of frictionless, elongated particle models were compared in the HCS simulations: glued-sphere and true cylinder. A new model for drag for elongated fibres was developed which depends on Reynolds number, solids fraction, and fibre aspect ratio. Schulze shear test results could be used to calibrate particle-particle friction for DEM simulations. Several experimental measurements were taken for biomass particles like olive pulp, orange peels, wheat straw, semolina, and wheat grains. Using a compression tester, the breakage force, breakage energy, yield force, elastic stiffness and Young’s modulus were measured. Measurements were made in a shear tester to determine unconfined yield stress, major principal stress, effective angle of internal friction and internal friction angle. A liquid fludized bed system was used to determine critical velocity of fluidization for these materials. Transport measurements for pneumatic conveying were also assessed. Anaerobic digestion experiments were conducted using orange peel waste, olive pulp and wheat straw. Orange peel waste and olive pulp could be anaerobically digested to produce high methane yields. Wheat straw was not digestible. In a packed bed reactor, anaerobic digestion was not initiated above bulk densities of 100 kg/m³ for peel waste and 75 kg/m³ for olive pulp. Interestingly, after the digestion has been initiated and balanced methanogenesis established, the decomposing biomass could be packed to higher densities and successfully digested. These observations provided useful insights for high throughput reactor designs. Another outcome from this project was the development of low cost devices to measure methane content of biogas for off-line (US$37), field (US$50), and online (US$107) applications.
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