18 research outputs found
Installation of a Feed-and-Turn Dryer: An Option to improve Heat Utilization and Economy of an existing Biogas Plant
Feed-and-turn dryers may be installed in order to use excess heat from biogas CHPs especially in agricultural enterprises with otherwise low heat utilization. These dryers can be used for drying a manifold of agricultural produce. In this case draff, maize silage and saw dust were investigated. The focus was on drying effectiveness, economic benefits and probable changes in chemical composition of the materials investigated. Results demonstrate that the installation of the feed-and-turn dryer is a substantial improvement of the biogas plant. In the case investigated it significantly improves the energy efficiency by increasing heat utilization from 6,669 GJ·a-1 in 2007 to more than 27,542 GJ·a-1 in 2009. It provides, in addition, the agricultural enterprise with valuable equipment for producing high quality and high valuable feed and other products. Finally, on-farm drying generates an additional income compared to purchasing equivalent products or to external drying
Results of batch anaerobic digestion test – effect of enzyme addition
The hydrolysis of lignocellulose is assumed to be the rate-limiting step in the anaerobic fermentation process. A fungal hydrolytic enzyme mixture was used to assess the enzymatic impact on different feedstocks for biogas production. The optimal conditions for enzymatic hydrolysis of rye grain silage, maize silage, grass silage, feed residues and solid cattle manure were determined in lab-scale experiments. Finally, the effects of enhanced hydrolysis on anaerobic digestion were investigated in batch digestion tests. Enzyme treatment of substrate showed Michaelis-Menten-like behavior and reached maximum values after 3 hours for reduced sugars as a product of hydrolysis. Methane production potential was determined for specific feedstock mixtures without enzyme, with inactivated enzyme and with active enzyme (with and without buffer). The results obtained show a clear increase in methane production after enzyme application for solid cattle manure (165 LN CH4∙kgODM-1 to 340 LN CH4∙kgODM-1 ), grass silage (307 LN CH4∙kgODM-1 to 388 LN CH4∙kgODM-1; enzyme plus buffer), feed residue (303 LN CH4∙kgODM-1 to 467 LN CH4∙kgODM-1), maize silage (370 LN CH4∙kgODM-1 to 480 LN CH4∙kgODM- 1)and a lower increase for rye grain silage (355 LN CH4∙kgODM-1 to 413 LN CH4∙kgODM-1). The ratios of heating values from methane yields to heating values from the dry materials ranged between 0.3 and 0.7 for the untreated feedstock and increased to levels between 0.6 and 0.9 after the different forms of enzyme application
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Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion
In this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not.
A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9 months for energy, 3 months for greenhouse gases, and 3 years 3 months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis
Energy balance, greenhouse gas emissions, and profitability of thermobarical pretreatment of cattle waste in anaerobic digestion
AbstractIn this study modeled full scale application of thermobarical hydrolysis of less degradable feedstock for biomethanation was assessed in terms of energy balance, greenhouse gas emissions, and economy. Data were provided whether the substitution of maize silage as feedstock for biogas production by pretreated cattle wastes is beneficial in full-scale application or not.A model device for thermobarical treatment has been suggested for and theoretically integrated in a biogas plant. The assessment considered the replacement of maize silage as feedstock with liquid and/or solid cattle waste (feces, litter, and feed residues from animal husbandry of high-performance dairy cattle, dry cows, and heifers). The integration of thermobarical pretreatment is beneficial for raw material with high contents of organic dry matter and ligno-cellulose: Solid cattle waste revealed very short payback times, e.g. 9months for energy, 3months for greenhouse gases, and 3years 3months for economic amortization, whereas, in contrast, liquid cattle waste did not perform positive replacement effects in this analysis
Grünlandenergie: Praxishinweise für die Entwicklung von Gras und Schilf basierten Nutzungskonzepten zur Energiegewinnung
Eine der großen Herausforderungen, die es
in diesem Jahrhundert zu meistern gilt, ist
die gezielte Bereitstellung von nachhaltig
erzeugter Energie.
Die Bundesregierung verfolgt das Ziel, bis
zum Jahr 2020 den Anteil erneuerbarer
Energieträger an der Wärmeerzeugung
auf 14 % und an der Stromerzeugung
auf 35 % zu steigern. Dabei soll die
Energieerzeugung auf ökonomische,
soziale, und ökologische Weise nachhaltig
erfolgen. Dieses gilt in besonderem Maße für die Bioenergienutzung. Vor
diesem Hintergrund hat das Bundesumweltministerium das Programm
über die „Förderung von Forschung und Entwicklung zur klimaeffizienten
Optimierung der energetischen Biomassenutzung“ aufgelegt, durch das die
Entwicklung innovativer Bioenergiekonzepte unterstützt wird.
In diesem Programm wurde das Forschungsprojekt „Grünlandenergie
Havelland“ (FKZ: 03KB035) gefördert. Untersucht wurde die Eignung von
Gras und anderem Halmgut aus der Landschaftspflege zur Wärme- und
Stromerzeugung. Die Stärken der Biomassenutzung zeigen sich in diesem
Projekt besonders klar: Die Energieerzeugung ist in einen regionalen Kontext
eingebettet. Strom und Wärme können bedarfsgerecht bereitgestellt
werden. Durch die Verwertung von Landschaftspflegematerial wird die
Nutzungskonkurrenz zur Nahrungsmittelerzeugung vermieden.
Mit der Nutzung der hier untersuchten Reststoffe sehe ich eine vielversprechende
Möglichkeit unter gegebenen Nachhaltigkeitsanforderungen zu einer
alternativen Energieerzeugung beizutragen. Sie basiert auf heimischen,
nachwachsenden Ressourcen und erzeugt darüber hinaus Synergien zwischen
Klimaschutz- und Naturschutzzielen
Is venous congestion associated with reduced cerebral oxygenation and worse neurological outcome after cardiac arrest?
Possible impacts of global warming on tundra and boreal forest ecosystems - comparison of some biogeochemical models
International audienc
Coupling global models of vegetation structure and ecosystem processes
International audienc
Possible impacts of global warming on tundra and boreal forest ecosystems - comparison of some biogeochemical models
International audienc