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Biokraftstoffe - Eigenschaften und Erfahrungen bei der Anwendung, Biokraftstoffe - Eigenschaften und Erfahrungen bei der Anwendung - Fortschreibung

Dieser DGMK-Forschungsbericht ist eine Fortschreibung des DGMK-Forschungsberichts 611 'Biokraftstoffe -Eigenschaften und Erfahrungen bei der Anwendung', der im Jahr 2002 erschienen ist. Seit dieser Zeit haben sich die Pläne der Europäischen Kommission, den Einsatz von Biokraftstoffen zu fördern, konkretisiert. Die Direktive 2003/30/EC gibt für den Zeitraum von 2005 bis 2010 Zielvorgaben, in welchem Umfang Biokraftstoffe in den Handel gebracht werden sollen. Bei Dieselkraftstoffen wird das im Wesentlichen durch Zugabe von bis zu 5 Prozent Fettsäuremethylestern und nicht durch einen Einsatz in reiner Form geschehen. Bei den Ottokraftstoffen kommen Ethanol und Ethyltertiärbutylether (ETBE) als Beimischungen in Frage. Sowohl bei Diesel- als auch bei Ottokraftstoff sind für den Fall einer Beimischung durch die gültigen Normen Maximalwerte für die sauerstoffhaltigen Verbindungen gegeben. Wegen seiner geringeren Oxidations- und Lagerstabilität besteht ein Interesse an Labortests, die für Biodiesel und Dieselkraftstoffe, die Biodiesel enthalten, eine Vorhersage darüber erlauben, ob der Kraftstoff über eine für den praktischen Betrieb ausreichend große Stabilität verfügt. Die ASTM D 4625-Methode, bei der die Probe bei 43 Grad Celsius gelagert wird und die allgemein als das geeigneste Testverfahren zur Bestimmung der Lagerstabilität von Mitteldestillaten angesehen wird, ist für Fettsäuremethylester und Mischungen mit ihnen weniger gut geeignet. Unter vielen untersuchten Prüfverfahren hat für die Bestimmung der Lagerstabilität die Rancimat-Methode die weiteste Anerkennung gefunden, obwohl auch Ergebnisse vorliegen, die es fraglich erscheinen lassen, ob generell ein Zusammenhang zwischen den Rancimat-Ergebnissen und der Lagerstabilität besteht. Vereinzelt gibt es Dieselkraftstoffe, die für eine Zumischung auch nur einer so geringen Menge wie 5 Prozent Biodiesel schlecht geeignet erscheinen. Für solche Dieselkraftstoffe scheint eine besonders kleine Rancimat-Induktionsperiode kennzeichnend zu sein. Nicht alle für Kohlenwasserstoffe bewährten Antioxidationsmittel sind in Mischungen mit Biodiesel gleich gut wirksam. Nach den bisherigen Erfahrungen kommt es beim Einsatz von Mischungen mit Biodiesel in Kraftfahrzeugen zu keinen Problemen, wenn der Biodieselgehalt 5 Prozent nicht übersteigt, auf Abwesenheit von Wasser geachtet und die Lagerzeit auf 6 Monate begrenzt wird. Der eingesetzte Biodiesel muss den Anforderungen der Norm EN 14214 genügen. Überflüssiger Kontakt mit Luft beispielsweise durch Rühren sollte bei der Lagerung von Biodiesel unbedingt vermieden werden. Auch wenn in dem durch die Norm erlaubten Rahmen Ethanol oder ETBE konventionellen Ottokraftstoffen beigemischt wird, sind im praktischen Betrieb keine Schwierigkeiten zu erwarten. Allerdings muss beim Zusatz von Ethanol auf die Abwesenheit von Wasser im System geachtet werden. Bei einer unkontrollierten Vermischung von ethanolhaltigen und ethanolfreien Kraftstoffen kann der Dampfdruckgrenzwert ...

Zweite Verordnung zur Änderung der Verordnung über die Beschaffenheit und die Auszeichnung der Qualitäten von Kraft- und Brennstoffen

Zur Umsetzung von europarechtlichen Vorgaben sind Anpassungen im untergesetzlichen Regelwerk des Bundes-Immissionsschutzgesetzes erforderlich. Dazu wurde die Verordnung über die Beschaffenheit und die Auszeichnung der Qualitäten von Kraft- und Brennstoffen (10. BImSchV) geändert. Die Änderung der 10. BImSchV dient der Umsetzung der Richtlinie 98/70/EG des Europäischen Parlaments und des Rates vom 13. Oktober 1998 über die Qualität von Otto- und Dieselkraftstoffen und zur Änderung der Richtlinie 93/12/EWG des Rates, die zuletzt durch die Richtlinie (EU) 2023/2413 geändert worden ist. Mit der Richtlinie 2023/2413/EU wird Diesel B10, also konventioneller Diesel, dem bis zu 10 Prozent Biodiesel (Fettsäuremethylester, FAME) beigemischt werden kann, eingeführt. Darüber hinaus sieht die Richtlinie 2023/2413/EU vor, dass die Mitgliedsstaaten verpflichtet sind, die Verfügbarkeit der Bestandsschutzsorte Diesel B7 sicherzustellen. Die Verordnung wurde am 22. November 2023 vom Kabinett beschlossen. Es handelt sich um eine Verordnung auf nationaler Ebene. Der übergeordnete Rahmen ist die/das 10. BImSchV.

Elemental, biochemical, and fatty acid contents for the copepod Temora longicornis (and its diets) fed under laboratory conditions with different nutrient regimes

The two experiments for which data is presented in this record were conducted in the context of RMFS' PhD work. The objective of the experiments was to quantify and qualify the effects of diet quality, herein manipulated in terms of different species (the diatom Conticribra weissflogii and the dinoflagellate Oxyrrhis marina) grown under different nutrient regimes (nutrient replete and Nitrogen-depleted), on the fatty acid (FA) assimilation and turnover of the copepod Temora longicornis. Experiments used field-collected copepods; sampling for experiments I and II took place on May 17th and 30th, 2016, respectively, with a 500 µm mesh-size CalCOFI net which was towed horizontally for 15 minutes at 5 m depth off the German island of Helgoland (54o11'N, 07o54'E), in the southern North Sea. Samples were immediately taken to the laboratory, where intact and active adult females were sorted under an Olympus SZX16 stereoscopic microscope. A total of 1260 females were sorted for each date, 1080 for the feeding experiment and 180 for the determination of in situ elemental and biochemical compositions. This study was conducted concomitantly with that from Franco-Santos et al. (2018). The feeding experiment was initiated after sorting, and lasted for five days. Females were distributed between triplicate 3L plastic beakers (75 females L-1), which were fitted with a 300 µm meshed-bottom cylinder, and kept in a dark, temperature-controlled room (10 ± 0.3oC, a temperature similar to that recorded in the surface water during sampling). Batch cultures of C. weissflogii were started on a daily basis (prior to starting the experiment) for five consecutive days; a stock solution was diluted with fresh f/2 medium (with and without nitrate additions, modified from Guillard, 1975), which contained 13C-enriched sodium bicarbonate (NaH13CO3, 4 mg L-1), and was grown for five days before being used to feed copepods (details in Franco-Santos et al., 2018). The same protocol was followed to culture the cryptophycean Rhodomonas salina, but bicarbonate was added to a concentration of 12 mg L-1. The algae were then used to feed the cultures of O. marina and, thus, create its different nutrient treatments. The dinoflagellate batches were cultured with the same protocol as the diatoms, except that the stock solution was diluted on a daily basis with labelled food (i.e., R. salina) rather than once at the start of the culture with isotopically-enriched medium. Cryptophycean cell quantities given to dinoflagellates were adjusted so that the former was depleted from the cultures on day 5. Diatom and dinoflagellate diets were provided for copepods ad libitum (> 350 µg C L-1; 8 and 2 * 103 cells mL-1, respectively) on a daily basis for five days. Cell density in the cultures was determined with a BD Accuri C6 Flow Cytometer. Beakers were gently stirred three times a day in order to resuspend dietary cells. Immediately before feeding copepods, a partial (approx. 65%) water exchange was conducted, which removed most of the food from the previous day. Copepods were sampled on days 1 (in situ composition, t0h), 3 (t48h), and 6 (t120h) of the experiment. Females were pooled into 10 and 50 individuals per replicate for elemental (body carbon (C) and nitrogen (N) contents and molar C:N ratio) and biochemical (total FA content and profile, and FA-specific content and 13C isotopic signal) analyses. Sampled copepods were gently washed in distilled water, then placed into pre-weighed tin capsules (5x9 mm, IVA Analysentechnik) or pre-combusted lipid vials (for elemental and FA analyses, respectively). Cultures were sampled daily during the experiment (after food was provided to copepods) for determination of cell elemental (C and N contents and molar C:N ratio) and biochemical (total FA content and profile, and FA-specific content and 13C isotopic enrichment) compositions. Subsamples of 5.2 and 0.4 *106 cells (for diatoms and dinoflagellates, respectively) were filtered through pre-combusted (500oC for 24h) Whatman GF/F filters (0.7 µm pore size, 25 mm diameter). Tin capsules and filters with samples for elemental analysis were dried at 60oC for 48 h; filters were folded inside tin foil, and both capsules and foil were stored in a desiccator until analysis. Filters with samples for FA analyses were placed into pre-combusted lipid vials, and vails containing both copepods and filters were stored at -80oC until analyses. The dry mass (DM) and C and N contents of samples were obtained as per Franco Santos et al. (2018). Lipid extraction (modified after Folch et al., 1957) and subsequent fatty acid methyl ester (FAME) quantification were performed as described in Franco-Santos et al. (2019) (and references therein). Temora longicornis does not have significant energy reserves and exhibits triacylglycerols (TAGs) as its primary neutral lipids (Fraser et al., 1989; Peters et al., 2013). Lipid classes were not separated in this study, and it was assumed that FAMEs were composed of TAGs. The FA-specific 13C isotopic composition of FAMEs was measured according to Boissonnot et al. (2016). Lipid C assimilation and turnover were calculated according to the equations used by Boissonnot et al. (2016) and Franco-Santos et al. (2019). Lipid C assimilation efficiency (AE), the percentage of (isotopically-enriched) dietary content ingested by copepods that was assimilated into FAs, was also calculated for (a) TFA, (b) saturation-specific sums of FAs (saturated, monounsaturated, and polyunsaturated FAs), and (c) each individual FA that was both available from the diet and assimilated by copepods (> 1% TFA in copepods). All the equations necessary for these calculations are described in the data sets contained in this bundled publication.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: O2 depletion over time

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. A significant loss of PS beads in pilot studies was traced back to the aeration of the exposure units. Therefore, the aeration was paused during the exposure phase of 2 hours. In a pilot study, the oxygen saturation was measured over 2 hours with mixing every 20 min in four treatment groups: with or without mussel in an aerated or non-aerated (static) set-up. Oxygen saturation lowered to 96.0 % (equivalent to 9.6 mg O2/ml) at the end of the 2 hours of exposure in the non-aerated set-up with mussels due to their respiration.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: clearance rates

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The effect of PS beads on the filtration was assessed by measuring the clearance rates. Clearance rate of the food algae Rhodomonas baltica was measured during the first hour of exposure and standardized by shell length. Since the reproductive status of the mussels can have an influence on the feeding activity, this factor was taken into account. Therefore, the mussels were inspected for the presence or absence of gonads at the end of the experiment. This resulted in four different treatment groups: control group with or without gonads and the microplastic-exposed group with or without gonads. Presence of PS beads and the reproductive status had a significant influence on the clearance rates.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: feces depuration

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. Feces was collected after the exposure phase of 2 hours and after 24 and 48 hours of depuration in filtered sea water and the amount of PS beads was determined.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: fate experiment

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The fate of PS beads within the experimental set up was assessed in four compartments (exposure water, depuration water, feces, softbody) after 2 hours of exposure, 24 hours and 48 hours of depuration in filtered sea water. Additionally, the loss of microplastic as the difference of the sum of all recovered PS beads and the measured concentration at the start of the experiment was determined to obtain a complete mass balance. The total number of PS beads and the number of PS beads per unit as well as the percentage recovery is given.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: softbody depuration

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The number of PS beads in the softbody of the mussels was determined after the exposure phase of 2 hours and after a 48 hours depuration phase in filtered sea water. Depuration in clear water lowered the amount of microplastic in the mussels' softbodies significantly.

Effect and fate study with blue mussels and microplastic in a laboratory experiment: comparison algae and microplastic regression

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. During the first hour of exposure the decrease of particles (algae or PS beads) was recorded every 15 min. The particle concentration is given in particles per milliliter and as a percentage of the starting concentration.

Effect and fate study with blue mussels and microplastic in a laboratory experiment

Adult blue mussels (Mytilus spp.) were exposed to microplastic particles in a controlled laboratory experiment. The study was conducted to investigate I) the effect of polystyrene particles (spherical PS beads, 40µm) on the filtration of mussels and II) the fate of PS beads within the experimental set up. The data was obtained in May and June 2019 with mussels collected from the Kiel Fjord, Germany. The mussels were exposed in a closed system to an intended initial microplastic concentration of 0.4 and 40 PS beads/ml. To correct for deviations from these two concentrations, the measured PS bead concentrations were used. Mussels were exposed to microplastic for 2 hours, followed by a 48 hours depuration phase in filtered sea water. Clearance rate of the food algae Rhodomonas baltica was measured during the first hour of exposure. The fate of PS beads was determined after exposure and after depuration in four compartments: exposure water, feces, softbody, depuration water. Additionally, the loss of microplastic was determined to obtain a complete mass balance.

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