Download or read book The Operation and Monitoring of an On farm Anaerobic Digester written by Mark C. Schlueter and published by . This book was released on 1987 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computer Operation and Monitoring for a Dairy Manure Anaerobic Digester written by Scott Andrew Shore and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anaerobic Digesters for Dairy Farms written by and published by . This book was released on 199? with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monitoring the Anaerobic Digestion Process written by Harry Michael Falk and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the anaerobic digestion process, microorganisms produce methane and carbon dioxide from organic substrates, either organic waste or renewable primary products. Being a versatile biofuel, biogas can be combusted in a combined heat and power plant to produce electricity and heat or, after purification, fed directly into the natural gas grid as biomethane. Due to the Renewable Energy Sources Act introduced in 1991 in Germany, this process became economically advantageous and led to a boom of biogas plants being built in Germany. A major problem of operating a biogas plant is to monitor an unstable process over time. Parameters like pH or redox potential do not necessarily suffice to estimate the degree of fermentation. At present, the preferred indication parameter are the concentrations of process intermediates, particularly short chain volatile fatty acids. They can be quantified with different gas or liquid chromatographic methods, which requires in-depth knowledge and expensive hardware and is usually carried out by specialized laboratories. Periodically, the digestate is sampled and sent in for analysis. Knowing the absolute concentrations of the different volatile fatty acids can only give a hint about the current fermentation status, though what would be more meaningful would be elucidating the dynamics of generation and degradation of the respective short chain volatile fatty acids. A new online technique using attenuated total-reflectance Fourier-transformed infrared spectroscopy (ATR-MIR-FTIR) was developed, which allows an online monitoring of the concentrations of the different volatile fatty acids in situ. This can give an insight into the dynamics of the anaerobic digestion process. It was adapted to a laboratory scale one-stage biogas plant fed with typically renewable primary products to simulate an agricultural biogas plant. Chemometric models were developed using spiked samples and samples from a real fermentation for acetic, propionic, iso-butyric, butyric, iso-valeric and valeric acid. The methods were evaluated by monitoring the startup phase of the anaerobic digestion of ground wheat in a 10 l continuous-stirred tank reactor. Sample preparation, recording and analysis of IR-spectra of digestate were fully automated. Predictions of the absolute concentration for acetic and propionic acid were reasonable, the existence of other volatile fatty acids could be detected. The developed anaerobic sensor system is able to determine their concentration dynamics and can thereby help to utilize unused potential in biogas plants. Another ascending problem are the substrates being used for the production of biogas. Renewable primary products are in direct rivalry with the agricultural and food industry. For a sustainable future, other biomass sources have to be made accessible for energy production. In contrast to energy crops, especially waste products can be used for energy generation without any concerns. The biogas potential of potential substrates is estimated with parallel running batch experiments. In the process, the minor gas flow rate of these lab-scale fermentations has to be monitored closely and accurately. Especially for this purpose, an easy to build and maintain automated biogas meter was developed to measure the biogas flow in anaerobic digestion experiments. The flow meter is built upon the open-source Arduino platform, and can therefore be easily enhanced or adapted to other environments. Recordings are sent via ethernet to a MySQL database, making the data widely accessible. By combining nine fermenters into an array, triplicate batch experiments according to VDI 4630 with negative control, positive control and the test substrate are monitored effortlessly. Concluding, this thesis focuses on optimizing the biogas production with the development of novel measurement instrumentation. The already well-established process of industrial digestion of energy crops is made transparent with an advanced online measurement method for the volatile fatty acids. Methane potential of novel biodegradable substrates can be monitored with the affordable low-cost gasUino biogas meter.
Download or read book Anaerobic Digestion of Poultry Manure written by Leonard Eldan Ripley and published by . This book was released on 1988 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inventory of Federal Energy related Environment and Safety Research for FY 1978 Project listings and indexes written by and published by . This book was released on 1979 with total page 740 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy from Biomass written by and published by . This book was released on 1986 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inventory of Federal Energy related Environment and Safety Research for written by and published by . This book was released on 1979 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Biogas Handbook written by Arthur Wellinger and published by Elsevier. This book was released on 2013-02-19 with total page 507 pages. Available in PDF, EPUB and Kindle. Book excerpt: With increasing pressures to utilize wastes effectively and sustainably, biogas production represents one of the most important routes towards reaching renewable energy targets. This comprehensive reference on the development and deployment of biogas supply chains and technology reviews the role of biogas in the energy mix and outlines the range of biomass and waste resources for biogas production. Contributors provide detailed coverage of anaerobic digestion for the production of biogas and review the utilization of biogas for various applications. They consider all aspects in the biogas production chain from the origin of the biomass feedstocks, feedstock selection and preparation, the anaerobic digestion process, biogas plant equipment design and operation, through to utilization of the biogas for energy production and the residue, the digestate, which can be used as a biofertilizer. The book also addresses biogas utilization, and explores environmental impacts and commercial market applications. Table of Contents: Biogas as an energy option: An overview Part 1 Biomass resources, feedstock treatment and biogas production: Biomass resources for biogas production; Analysis and characterisation of biogas feedstocks; Storage and pre-treatment of substrates for biogas production; Fundamental science and engineering of the anaerobic digestion process for biogas production; Optimisation of biogas yields from anaerobic digestion by feedstock type; Anaerobic digestion as a key technology for biomass valorisation: Roles and contribution to the energy balance of biofuel chains Part 2 Plant design, engineering, process optimisation and digestate utilization: Design and engineering of biogas plants; Energy flows in biogas plants: Analysis and implications for plant design; Process control in biogas plants; Methane emissions in biogas production; Biogas digestate quality and utilization; Land application of digestate Part 3 Biogas utilisation: international experience and best practice: Biogas cleaning; Biogas up-grading to biomethane; Biomethane injection into natural gas networks; Generation of heat and power from biogas for stationery applications: Boilers, gas engines and turbines, combined heat and power (CHP) plants and fuel cells; Biomethane for transport applications; Market development and certification schemes for biomethane
Download or read book Inventory of Federal Energy related Environment and Safety Research for FY 1978 written by and published by . This book was released on 1979 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bioenergy Production by Anaerobic Digestion written by Nicholas Korres and published by Routledge. This book was released on 2013-08-29 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in anaerobic digestion (AD), the process of energy production through the production of biogas, has increased rapidly in recent years. Agricultural and other organic waste are important substrates that can be treated by AD. This book is one of the first to provide a broad introduction to anaerobic digestion and its potential to turn agricultural crops or crop residues, animal and other organic waste, into biomethane. The substrates used can include any non-woody materials, including grass and maize silage, seaweeds, municipal and industrial wastes. These are all systematically reviewed in terms of their suitability from a biological, technical and economic perspective. In the past the technical competence and high capital investment required for industrial-scale anaerobic digesters has limited their uptake, but the authors show that recent advances have made smaller-scale systems more viable through a greater understanding of optimising bacterial metabolism and productivity. Broader issues such as life cycle assessment and energy policies to promote AD are also discussed.
Download or read book An Evaluation of the Barriers to Anaerobic Digestion Technology Implementation for Energy Production and Waste Stabilization on Dairy Farms written by Joseph G. Usack and published by . This book was released on 2016 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anaerobic digestion is an established technology used for energy production (as biogas), organic waste stabilization, and nutrient recovery. This technology has been successfully implemented by municipal and industrial wastewater treatment facilities for decades. Dairy farming operations are energy intensive, require considerable nutrient inputs, and generate large quantities of organic residues, which without proper treatment, cause greater environmental damage. Thus, anaerobic digestion seems particularly suited for use on dairy farms, however various barriers exist, which have limited its widespread adoption. The central aim of this thesis was to evaluate these barriers. In the first study, a general methodology was developed explaining how to properly construct, inoculate, operate, and monitor laboratory-scale anaerobic digesters during long-term experiments. The second study focused on improving the design of low-cost, plug-flow anaerobic digester systems deployed in Indonesia, whose tendency to clog discouraged their continued use by village operators. Operational modifications allowing either internal mixing or effluent recycling were shown to reduce the level of solids retained within the digester while maintaining comparable methane yields, which may translate to fewer clogging incidences at scale. In the third study, three substrates: 1) food waste; 2) alkaline hydrolysate; and 3) crude glycerol were individually codigested with dairy manure to identify the substrate-specific qualities that ultimately destabilized the anaerobic digestion process. Food waste co-digestion did not cause any appreciable reduction in process performance. However, alkaline hydrolysate co-digestion was ultimately inhibited by unionized ammonia toxicity. Crude glycerol co-digestion became unstable at higher organic loading rates due to foaming induced by long-chain fatty acid accumulation. In the fourth study, an environmental life-cycle and techno-economic assessment (LCA-TEA) with uncertainty analysis was performed to evaluate the impacts of co-digestion on dairy farms. Co-digestion scenarios involving ten unique co-substrates were evaluated over a range of mixture ratios. While economically favorable, high loading rates reduced the technical performance of the digester and caused proportionally greater environmental emissions on the farm, particularly for co-substrates characterized by high nutrient loads and low organic strength. Gate-fees were the main driver behind economic performance. Revenue associated with electricity production and fertilizer displacement were not sufficient to recoup capital and operational costs, yet their substitution led to significant net reductions in overall environmental impacts. The final study was built on the LCA-TEA model and investigated the feasibility of applying combined cooling, heat, and power (CCHP) production on dairy farms. Particular cooling applications were evaluated, including: 1) conductive cow cooling to mitigate heat stress; and 2) substitution of electricity-driven cooling cycles (e.g., milk chilling/refrigeration). Conductive cooling scenarios led to significant environmental impact reductions in categories associated with milk production, while substitution of electricity-driven cooling cycles contributed marginal reductions. Despite these environmental benefits, no one of the CCHP scenarios was economically viable. Opportunity to generate revenue from conductive cooling was limited by the number of heat stress episodes in New York, while the low value of electricity limited revenue from displaced electricity-driven cooling. This body of work suggests anaerobic digestion is technically viable and environmentally beneficial when properly implemented, however, high capital cost and the lack of high-value revenue streams constitute insurmountable barriers under current market conditions in the U.S.
Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1991 with total page 884 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Anaerobic Digester Fluid Rheology and Process Efficiency written by Luka Šafari? and published by Linköping University Electronic Press. This book was released on 2019-04-08 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the anthropogenic greenhouse gas emissions continue imposing stress on our environment, it is becoming increasingly important to identify and implement new renewable technologies. Biogas production through anaerobic digestion has a great potential, since it links waste treatment with extraction of renewable energy, enabling circular bio-economies that are vital for a sustainable future. For biogas to have an important role as a renewable energy carrier in society, the scale of its production will need to be increased substantially. New substrates need to be introduced along with raising organic loading rates of the reactors to increase the rate of biogas production. This contributes to challenges in maintaining process stability, thus increasing the risk for process disturbances, including problems that were not commonly encountered before. These difficulties may be particularly pronounced when a broad range of new, largely untested substrates are introduced, leading to an increased heterogeneity of organic material entering the reactors. In the case of currently the most common reactor type; the continuous stirred-tank biogas reactor (CSTBR); such problems may include shifts in rheology (i.e. fluid behaviour) of the anaerobic digester sludge. This may lead to increased energy consumption and decreased digester mixing efficiencies, which in turn may lead to inefficient biogas processes, ultimately decreasing the economic and environmental viability of biogas production. Much is still unknown regarding how rheology shifts happen in biogas reactors, particularly when it comes to what role the substrate plays in rheological dynamics, as compared to the microbial community during varying levels of biogas process stability. This thesis elucidates the interactions between substrate type, microbial community and its metabolic activity, and anaerobic sludge rheology. A number of sludge samples from mesophilic and thermophilic CSTBRs digesting a broad range of substrates was analysed for their rheology. The specific effects of individual substrate types on CSTBR sludge rheology and the resulting implications for stirring power requirements and mixing efficiency were investigated. In order to also asses to which extent the microbial metabolism affects rheology at different levels of process disturbance, an experiment with a trace-element-induced inhibition of specific metabolic pathways under mesophilic reactor conditions was performed. This was used to identify the sequence of different interactions that occur in the reactor after the process begins to fail, and to evaluate how these interactions link to changes in digester sludge rheology. Finally, a case study of a disturbed thermophilic anaerobic digestion process was performed, including the monitoring of the response of rheology in relation to process stability, which was modified by changing trace element concentrations. The use of artificial substrate without polymeric compounds in both cases allowed for an evaluation of effects of the microbial community and its metabolic products on rheology without including the effects of complex substrates. The results showed that substrate type has a large effect on how different process parameters correlate with fluid behaviour. This was particularly apparent in the case of total solids and total volatile solids, which correlated well with rheological parameters for samples from reactors digesting agricultural waste, sewage sludge, paper mill waste, or food waste, but not for mesophilic co-digesters. Among the different substrates investigated, food waste was generally observed to lead to the highest limit viscosities (i.e. apparent viscosities at high shear rates, where it becomes linear and constant) of the anaerobic sludge, while digestion of paper mill waste and thermophilic co-digestion led to some of the lowest. No fluid type could be clearly coupled to a specific substrate, but it could be observed that increased solids content could generally be associated with more complex, non-Newtonian rheological behaviour. The differences in fluid characteristics between reactors corresponded to large differences in modelled stirring power requirements and mixing efficiency. The results indicated that fluids with high values of rheological parameters, such as the consistency index (K) or yield stress (?0), would likely require more power or an adapted stirring system to achieve complete mixing. The substrates generally contributed more to the rheology characteristics of the anaerobic sludge than microbial cells on their own. Trace element-induced process disturbance initially led to the inhibition of specific microbial groups among methanogenic archaea or their syntrophic partners, which later escalated to broader inhibition of many microbial groups due to the accumulation of fermentation products. This resulted in microbial cell washout with a corresponding decrease of the contribution of the cells to anaerobic sludge rheology. A recovery of the thermophilic anaerobic digestion process was possible after the supplementation of selenium and tungsten was increased, resulting in increased propionate turnover rates, growing cell densities, and higher viscosity. Major shifts in the methanogenic community were observed, corresponding to the level of process stability. It could be concluded based on these experiments that the specific effect of microbial cells and their activity on sludge rheology were linked to cell density, which corresponded to process stability. A conceptual scheme was developed based on the studies in this thesis, defining complex interactions between substrate, microbial metabolism, and anaerobic sludge rheology in biogas processes. The possible causes of rheology shifts are visualised and discussed. Med anledning av att antropogena utsläpp av växthusgaser fortsätter att påverka vår miljö negativt, blir det allt viktigare att identifiera och implementera förnybara teknologier. Biogasproduktion, genom anaerob rötning, bidrar till att sammanlänka avfallshantering med förnybar energiomvandling samt möjliggör för cirkulära bioekonomier, avgörande för en hållbar framtid. För att biogas ska utgöra en central roll som förnybar energibärare i samhället måste omfattningen av dess produktion ökas avsevärt. Nya substrat behöver introduceras, samtidigt som den organiska belastningen i existerande biogasreaktorer ökas, med syfte att öka produktionshastigheten. Detta bidrar emellertid till utmaningar avseende att upprätthålla processtabilitet, med ökad risk för processtörningar, inklusive nya typer av problem. Dessa svårigheter kan vara särskilt uttalade när nya, i stort sett otestade substrat, introduceras, vilket leder till ökad heterogenitet av organiskt material till reaktorerna. I tankreaktorer med omrörning (CSTBR), som i nuläget är den vanligast förekommande reaktortypen, kan sådana processförändringar innebära förändringar i reologiska egenskaper hos rötvätskor. Detta kan i sin tur leda till ökad energiförbrukning och lägre omrörningseffektivitet, vilket kan försämra biogasprocessens effektivitet samt bidra till minskad ekonomisk avkastning och minskade miljömässiga vinster. Det råder fortfarande oklarheter gällande reologiska förändringar av rötkammarmaterial i biogasreaktorer, särskilt med avseende på val av substrat i jämförelse med mikroorganismernas roll under varierade betingelser av processtabilitet. Denna avhandling belyser interaktioner mellan typ av substrat, mikrobiella samhällen och deras metaboliska aktivitet och reologiska egenskaper av rötslam. Reologisk karaktärisering av rötvätskor från mesofila och termofila CSTBRs, som rötade ett brett spektrum av substrat, genomfördes. De specifika effekterna av individuella substrattyper på korresponderande rötvätskors reologiska egenskaper och dess implikationer för omrörning undersöktes. För att även kunna bedöma i vilken utsträckning den mikrobiella metabolismen inverkar på rötvätskors reologi, vid olika nivåer av processtörning, genomfördes en fallstudie med spårelement-inducerad inhibering av specifika metaboliska vägar, under mesofila reaktorbetingelser. Denna studie användes för att identifiera sekvensen av olika interaktioner som uppträder i reaktorn när processtörningar uppstår och för att utvärdera hur dessa interaktioner kopplar till förändringar i slamreologi. Slutligen genomfördes en fallstudie av en termofil biogasprocess innefattande karaktärisering av reaktormaterialets reologi i respons till förändringar i processtabilitet orsakad av förändrade spårelementkoncentrationer. I båda dessa fallstudier, möjliggjorde användningen av ett artificiellt substrat utan komplexa polymerer, att mikrobiella effekter på förändringar i rötvätskans reologi kunde studeras frånkopplat effekter av komplexa substrat. Resultaten visade att substrattyp har stor inverkan på hur olika processparametrar korrelerar med rötvätskors reologiska egenskaper. Detta var särskilt tydligt med avseende på andelen totala respektive organiska fasta ämnen, vilka korrelerade väl med reologiska parametrar för rötvätskor från reaktorer som rötade jordbruksrester, avloppsslam, avfall från pappersbruk, respektive matavfall, men ej för rötvätskor från mesofila samrötningsanläggningar. Av de undersökta substrattyperna bidrog rötning av matavfall generellt till anaerobt slam med högst uppmätta värdena för gränsviskositet (dvs när viskositeten blir linjär och konstant vid ökade skjuvhastigheter), medan rötning av avfall från pappersbruk respektive termofil samrötning av olika substrat bidrog till de lägsta värdena för gränsviskoistet. Ingen reologisk vätsketyp kunde tydligt kopplas till en specifik substrattyp, men ökad mängd torrsubstans i rötvästkan kunde generellt associeras med komplexa, icke-newtonska, flödesegenskaper. Skillnaderna i flödesegenskaper motsvarade stora skillnader i behov av omrörningskraft och omrörningseffektivitet. Resultaten indikerade att rötvätskor med höga reologiska värden, exempelvis för konsistensindex (K) eller flytgräns (?0), sannolikt kräver mer energi eller ett anpassat system för effektivare omrörning. Generellt bidrog substratet mer till rötvätskans reologiska egenskaper än de mikrobiella cellerna på egen hand. Inducerad spårämnesbrist i genomfört reaktorförök ledde i början till en hämning av specifika mikrobiella grupper inom metanogena arkéer och deras syntrofa partners, vilket i sin tur bidrog till en bredare hämning av flera mikrobiella grupper orsakad av ackumulering av olika fermentationsprodukter. Detta resulterade i ursköljning av cellbiomassa vilket i sin tur minskade deras effekt på slammets reologiska egenskaper. En återhämtning av den termofila biogasprocessen var möjlig efter ökade tillsatser av spårelementen selen och volfram, vilket resulterade i snabbare omsättning av propionsyra, förhöjd celldensitet och viskositet. Stora förändringar observerades samtidigt inom det metanogena samhället, vilka var kopplade till olika nivåer av processtabilitet. Den specifika effekten av mikroorganismerna och deras aktivitet med avseende på slammens reologiska egenskaper var kopplad till celldensitet, vilket motsvarade processtabiliteten. Ett konceptuellt schema utvecklades baserat på resultat av beskrivna studier för att visualisera komplexa interaktioner mellan substrat, mikrobiell metabolism, och reologi av anaerobt slam i biogasprocesser. De möjliga orsakerna till reologiska förändringar visualiseras och diskuteras.
Download or read book Bioenergy Production by Anaerobic Digestion written by Nicholas Korres and published by Routledge. This book was released on 2013-08-29 with total page 627 pages. Available in PDF, EPUB and Kindle. Book excerpt: Interest in anaerobic digestion (AD), the process of energy production through the production of biogas, has increased rapidly in recent years. Agricultural and other organic waste are important substrates that can be treated by AD. This book is one of the first to provide a broad introduction to anaerobic digestion and its potential to turn agricultural crops or crop residues, animal and other organic waste, into biomethane. The substrates used can include any non-woody materials, including grass and maize silage, seaweeds, municipal and industrial wastes. These are all systematically reviewed in terms of their suitability from a biological, technical and economic perspective. In the past the technical competence and high capital investment required for industrial-scale anaerobic digesters has limited their uptake, but the authors show that recent advances have made smaller-scale systems more viable through a greater understanding of optimising bacterial metabolism and productivity. Broader issues such as life cycle assessment and energy policies to promote AD are also discussed.
Download or read book The Microbiology of Anaerobic Digesters written by Michael H. Gerardi and published by John Wiley & Sons. This book was released on 2003-09-19 with total page 189 pages. Available in PDF, EPUB and Kindle. Book excerpt: Anaerobic digestion is a biochemical degradation process that converts complex organic material, such as animal manure, into methane and other byproducts. Part of the author's Wastewater Microbiology series, Microbiology of Anareboic Digesters eschews technical jargon to deliver a practical, how-to guide for wastewater plant operators.
