Biogas and Dimethyl ether are providing water fertilizer for an intelligent smart soil ab 13.99 € als Taschenbuch: Akademische Schriftenreihe. Aus dem Bereich: Bücher, Wissenschaft, Geowissenschaft,
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Biogas and Dimethyl ether are providing water fertilizer for an intelligent smart soil ab 13.99 EURO Akademische Schriftenreihe
Diploma Thesis from the year 2012 in the subject Physics - Biophysics, grade: 1,0, University of Vienna (Physik), language: English, abstract: Todays agricultural food production highly depends on the availability of non-renewable resources like crude oil, natural gas and phosphor rocks. Tomorrow's food security can only be ensured by reducing this dependency. There are open questions concerning the methods that can be used for the production of renewable sources in order to achieve this goal. Is it technically and economically feasible, for instance, to produce micro-algal fertilizer in photo-bio reactors to recycle N and P from waste water streams? Is this furthermore possible by avoiding the combustion of non-renewable energies to become energy self-sucient? Relevant examples from literature will be used to investigate the microalgal potential to extract nutrients from urban waste water streams for the re-injection into the food chain of the population. The production of algae and heat will be described in a bio-physical way to calculate the mass- and energy flux in photo-bio reactors, attached to walls of buildings in Vienna. It will be suggested to decompose the generated bio material through anaerobic digestion to increase the N- and P share on one hand and to produce methane as an energy carrier on the other hand. The calculation model will be used to estimate the costs of producing a micro-algal fertilizer in Vienna. Furthermore a possible utilization of the generated fertilizer in vertical farms will be discussed. About 271t micro algae per year could be produced on a 100m*100m wall in Vienna. The combustion of the produced biogas could meet the entire heat and electrical-energy demand of the production process. By demonstrating the technical feasibility of every single part of the energy self-sucient production chain, the technical feasibility of the whole concept is ensured. The costs of this product, however, would be nine times higher than the costs of commercial fertilizer. The bio-re nery in question still has a great potential when it comes to saving a high amount of non-renewable resources, thus making it an attractive alternative to the exclusive use of biomaterial as an energy carrier. This can be further shown by comparing the sunlight irradiation on a photo-bio reactor with the calori c value of the produced micro algae: This calculation yields an energy conversion efficiency of about 4% which could be surpassed by the electricity production of every available photovoltaic system.
In this work, MBT residual waste was used for experimental studies to investigate the influence of crucial parameters influencing biochemical processes in anaerobic degradation in residual wastes from MBT. The moisture content is one of the most critical parameters influencing biogas production in waste as well as nutrient transport. Batch experiments were carried out to correlate moisture content and biogas production in MBT residual waste. Moreover, quantification and monitoring of heterogeneous moisture distribution in a landfill body is critical for mechanical landfill stability and landfill gas emission control. For quantitatively monitoring in-situ moisture distribution in in MBT residual waste, a novel geoelectrical technique was successfully applied and evaluated on laboratory scale. The pH development in leachate from MBT residual wastes and the relating acid buffering intensity was found to be important for facilitating biochemical conversion of solid organic carbon matter to biogas. At unadjusted conditions, a positive correlation between strength of acidification phase and biogas production, especially methane production, could be found. Thereby, the acid buffer intensity of MBT residual wastes proved to be crucial for pH stabilisation. Due to maximum cumulative biogas production at neutral pH, pH regulation at pH 7 is recommended for waste treatment in MBT plants and landfill bioreactors. The bioavailability of metabolic intermediates was investigated with regard to their sorption behaviour on MBT residual wastes. Alcohols of a homologous series with increasing octanol-water partition coefficients POW were used as surrogates for carboxylic acids. Activated carbon was used as a reference sorption system due to its high specific surface area. By determining the distribution coefficient KD, the bioavailability factor Bf was quantified and denotes that bioavailability of the surrogates was practically unlimited. Transferring these results to intermediates of the anaerobic degradation with similar log POW values, e.g. acetic acid and propionic acid, reveals that biodegradation of certain organic substrates e.g. acetic acid or propionic acid can be considered unconfined in MBT residual waste.
Master's Thesis from the year 2008 in the subject Agrarian Studies, grade: Very Good, , course: Tropical Land Resources Management, language: English, abstract: Abstract The study was conducted in North Wollo, Mersa-Chekorsa village, Ethiopia in 2006/2007, where animal dung for biogas production is available. The overall objective of the study was to introduce economically feasible, technically acceptable and environmentally friendly biogas plant to the farming community and other potential users in Ethiopia. The research was carried on two types of biogas plants of 3m3 capacity (1) geo-membrane plastic (two single and two double layered) biogas plants constructed below and above the ground surface and (2) fixed-dome biogas plant. Each bio-digesters was fed with a mixture of 75Kg of cow-dung and 75Kg pure water at equal volume and proportion. Amount of gas and slurry were measured using calibrated biogas burner and weight balance respectively. The quality of the slurry (i.e. total-N and organic matter content) were analyzed in the laboratory using Kjeldahl and ash method respectively. The bio-digesters were compared after gas has completely produced at the end of 40 days of fermentation with respect to amount of gas and slurry produced, quality of slurry in terms of total-N and organic matter content. Economic analysis of the bio-digesters was carried out using cost-benefit analysis. The social aspect of using biomass and biogas technologies and environmental impact assessment of the new geo-membrane plastic biogas technology was also assessed. The emissions of CO2 and CH4 were computed by measuring the production of biogas in the two models of bio-digester. Fermented slurry contained larger nitrogen content than fresh cow dung in both models of bio-digester. The geo-membrane plastic biogas plant gave higher net benefit than fixed-dome biogas plant. So, from this, investment on geo-membrane plastic bio-digester is economically feasible. Environmental impact assessment of the technology was studied and found that 360.04 m3 of CO2 and 600.06 m3 CH4 was prevented from emitting in to the atmosphere and save 0.562 hectare of forest per year. Generally, it was found that, the geo-membrane cylindrical film bio-digester technology was found cheap and simple way to produce gas in the study area and it was recommended to introduce the technology into the rural areas having even and high temperature which is similar to the study area more preferably to an area having mean daily temperature greater than 20 OC. Key words:Geo-membrane ,fixed-dome bio-digester, biogas, quality of fermented slurry,economical feasibility
Bioenergy production from agricultural crop biomass or residues has gained interest recently due to the escalating cost of fossil fuels and the need to mitigate global warming caused by increasing GHG emissions. Of all the different feed stocks used for bioenergy production in Africa, cassava biomass potentially offers multiple benefits for producing biofuels such as biogas. This book, therefore, highlights the bioenergy (biogas) potential of the crop in Africa. The basic agricultural properties of cassava were discussed including its high carbohydrate content and total dry matter. Its ability to thrive in all ecological zones with one of the best blue water-footprints especially in drought conditions and relatively low fertility soils. The crop therefore requires low agricultural input. The various pre-treatment techniques as well as the advantages and disadvantages of each technology for cassava biogas production were analysed. A holistic view on the highly publicised food vs. energy debate were provided. The book recommends cassava and its biomass as the next energy crop for bioenergy production and should be useful to future researchers and government policymakers in Africa.