31 research outputs found

    Mengen- und wertmäßige Bedeutung des Biomasseimports von Deutschland - Eine detaillierte Auswertung der Importstatistik (KIT Scientific Reports ; 7719)

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    Im Rahmen der Globalisierung der Rohstoffmärkte, der Ausrichtung der Wirtschaft in Richtung Bioökonomie und der Energiewende gewinnt die Biomasse als Nahrungsmittel, Rohstoff und Energieträger für Deutschland zunehmend an Bedeutung. Vor diesem Hintergrund wurde für Deutschland auf Basis der Außenhandelsstatistik ein Überblick über die derzeit mengen- und wertmäßig bedeutendsten Biomasseträger und deren Herkunftsländer erstellt, ausgehend von den Importen für das Jahr 2014

    Bereitstellung und Nutzung von SNG

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    Resonance ionization spectroscopy of thorium isotopes - towards a laser spectroscopic identification of the low-lying 7.6 eV isomer of Th-229

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    In-source resonance ionization spectroscopy was used to identify an efficient and selective three step excitation/ionization scheme of thorium, suitable for titanium:sapphire (Ti:sa) lasers. The measurements were carried out in preparation of laser spectroscopic investigations for an identification of the low-lying Th-229m isomer predicted at 7.6 +- 0.5 eV above the nuclear ground state. Using a sample of Th-232, a multitude of optical transitions leading to over 20 previously unknown intermediate states of even parity as well as numerous high-lying odd parity auto-ionizing states were identified. Level energies were determined with an accuracy of 0.06 cm-1 for intermediate and 0.15 cm-1 for auto-ionizing states. Using different excitation pathways an assignment of total angular momenta for several energy levels was possible. One particularly efficient ionization scheme of thorium, exhibiting saturation in all three optical transitions, was studied in detail. For all three levels in this scheme, the isotope shifts of the isotopes Th-228, Th-229, and Th-230 relative to Th-232 were measured. An overall efficiency including ionization, transport and detection of 0.6 was determined, which was predominantly limited by the transmission of the mass spectrometer ion optics

    Alternative fuels from forest residues for passenger cars - an assessment under German framework conditions

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    Background Due to the available volumes, biogenic residues are a promising resource for renewable fuels for passenger cars to reduce greenhouse gas (GHG) emissions. In this study, we compare three fuels from forest residues under German framework conditions: biogenic electricity, substitute natural gas (SNG), and Fischer-Tropsch (FT) diesel. Methods Fuels from forest residues are compared with regard to their technical efficiency (here defined as ‘pkm per kg biomass’), costs, and environmental impacts with a focus on GHG emissions. We took into consideration the real-life driving conditions and corresponding car classes as well as market penetration scenarios for electric and gaseous fuel cars. Results Our results show that the technical efficiency of biogenic electricity is high, while the economic and environmental results strongly depend on the car size and market penetration assumptions. Furthermore, it is essential to clearly define the main goal of introducing fuels from forest residues. If the goal is to reduce GHG emissions at the lowest cost, SNG (and natural gas) in bigger cars is preferable. For high GHG reductions at the lowest forest residue consumption, biogenic electricity in smaller commuter-type cars are found to be a good solution. This also proves true for the aggregated environmental impact score ReCiPe Total. Conclusions It is important to include mobility patterns and a clear goal definition when comparing biogenic fuels. In Germany, biogenic electricity, SNG, and FT diesel can reduce GHG emissions at reduction costs of around 100 €/t CO2-Eq when used the right way
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