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Aufsatz
Aqueous Leaching Prior to Dewatering Improves the Quality of Solid Fuels from Grasslands
(2018-04-04)
Renewable energies are necessary to reduce greenhouse gas emissions in energy production, and biomass plays a dominant role in the renewable energy sector. Combustion of biomass constitutes an efficient conversion technique, but is hindered by harmful elements which are frequently contained in residual grassland biomass. We investigated the effect of leaching on solid fuel quality with three independent experiments including the following treatments: (1) with or without leaching, (2) with leaching at various water ...
Dissertation
Entwicklung eines Modells zur Abbildung von Verfahrensketten für nachwachsende Rohstoffe
(2018-12-16)
Neben Nahrungs- und Futtermitteln werden auf landwirtschaftlichen Flächen zunehmend nach-wachsende Rohstoffen erzeugt. Dieser Trend wird durch die deutsche Bundesregierung aktiv gefördert – auch um die gesetzten Klimaziele zu erreichen. Derzeit konzentriert sich das Interesse auf Energiepflanzen und deren Verwertung. Jedoch können nachwachsende Rohstoffe auch in der Industrie eine signifikante Rolle spielen und dort unter anderem konventionelle, endliche Rohstoffe substituieren. Beispielsweise werden bereits heute ...
Aufsatz
Heavy Metals and Polycyclic Aromatic Hydrocarbons in Urban Leaf Litter Designated for Combustion
(2017-03-03)
Vast amounts of leaf litter have to be disposed of by city administrations. This biomass has the potential for energy conversion, but contamination with pollutants can adversely affect this usage. We investigated leaf litter samples from the city of Kassel by analyzing their heavy metal and polycyclic aromatic hydrocarbon (PAH) concentrations. Leaf samples were indeed contaminated with heavy metals and PAHs and contamination was influenced by provenience and collection technique. A simple cleaning system of washing ...
Aufsatz
High-Quality Solid Fuel Production from Leaf Litter of Urban Street Trees
(2016-11-30)
Leaf litter is a growing concern for cities. Due to adherent dirt such biomass is rarely utilized nowadays but may constitute a renewable energy source for communities or private households. Leaf litter from main roads, residential areas and city centres collected by the vacuum technique or the sweeper technique was sampled and analysed for ash content and chemical composition. Ash content of leaf litter collected by the sweeping technique was higher (21.6%–40.1% dry matter, DM) than in material collected by the ...
Aufsatz
Fusion of Ultrasonic and Spectral Sensor Data for Improving the Estimation of Biomass in Grasslands with Heterogeneous Sward Structure
(2017-01-21)
An accurate estimation of biomass is needed to understand the spatio-temporal changes of forage resources in pasture ecosystems and to support grazing management decisions. A timely evaluation of biomass is challenging, as it requires efficient means such as technical sensing methods to assess numerous data and create continuous maps. In order to calibrate ultrasonic and spectral sensors, a field experiment with heterogeneous pastures continuously stocked by cows at three grazing intensities was conducted. Sensor ...
Dissertation
Design of a decentralised camel milk processing plant with integration of renewable energy supply
(2020)
Der Milchsektor trägt zu ca. 4% zum Bruttoinlandsprodukt (BIP) in Kenia bei und ist der größte Teil des Agrarsektors. Kenias Kamelmilch spielt eine wichtige Rolle bei der Deckung des Ernährungs- und Wirtschaftsbedarfs in den ariden und semiariden Ländern (ASALs). Trotz dieser Bedeutung gibt es nur wenige Informationen über die Konservierungstechnologien und langlebige Milchprodukte wie Kamelmilchpulver. Außerdem zeichnen sich ASALs durch eine hohe Sonneneinstrahlung aus, die für die Konservierung von Kamelmilch genutzt ...
Dissertation
Use of organic wastes of Agave processing for bioenergy production
(2018)
Der organische Reststoff, welcher bei der Verarbeitung der Agave S. anfällt (Mezcal-Schlempe), ist aufgrund der hohen Anteile an organischer Substanz, anorganischen Salzen und anderer Inhaltstoffe ein umweltschädlicher Rückstand, der nicht ohne Vorbehandlung in Gewässer oder Böden gelangen darf, ggf. aber für die Bioenergieerzeugung genutzt werden könnte. Im Rahmen dieser Arbeit wurde daher unter Laborbedingungen die Eignung dafür durch drei Versuche zur anaeroben Vergärung und zwei zu mikrobiellen Brennstoffzellen ...
Aufsatz
Using Grass Cuttings from Sports Fields for Anaerobic Digestion and Combustion
(2017-03-18)
Sports fields provide a recreation space for citizens, but also generate grass biomass, which is cut weekly during the main seasons and therefore could be used in energy generation (combustion or anaerobic digestion). To evaluate the technical suitability of the grass cuttings, silage was produced from four sports fields during one vegetation period and investigated for relevant properties. Potential methane yield was determined with batch tests. Mean methane yield was 291.86 lN·kg−1 VSadded (VS, volatile solid). ...
Dissertation
Challenges to ecosystem services of sustainable agriculture in West Africa
(2020)
Food security is still sub-optimal in many parts of West Africa calling for more efficient agricultural practices in mitigating food insecurity. Some of the problems faced in West African agricultural systems are bottlenecks in ruminant livestock supply, inefficiency in commercial poultry production, and loss of arthropod diversity. These issues require proper integration of farming systems, demand the closing of nutrient cycles, need diversi cation of production, and require enhancement of ecosystem services. To ...