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Biogas, mit geringen Konzentrationen an Methan, entsteht unter anderem bei verschiedenen industriellen Prozessen. Wegen der Umweltschädlichkeit des Methans gilt es dessen Eintrag in die Umwelt zu vermeiden.
Das Ziel des vorgestellten Projektes war die Überprüfung eines umweltfreundlichen Verfahrens zur Reduzierung des Methans durch methanotrophe Bakterien. Die einzelnen Batchversuche liefen über 15 Stunden und zeigten eine starke Reduzierung des Methans von 18 auf 1 Vol.-%.
Comparative analysis of non-natural acceptor glucosylation with sucrase enzymes of family GH 70
(2019)
Mutan- and alternansucrase were analyzed for their non-natural glucosylation potential with catecholic compounds caffeic acid and nordihydroguaiaretic acid (NDGA) as well as with non-catecolic p-coumaric acid and umbellic acid. Mutansucrase accepted both catecholic substrates and high glucosylation yields of 92 % with caffeic acid and 81 % with NDGA were obtained. The enzyme showed a clear regio-preference for the catechol 4-OH, which corresponds to findings from our previous work with Leuconostoc and Weissella derived glucansucrases. The substrate spectrum of the alternansucrase was broader and all substrates were successfully glucosylated with a preference for the catechols. Interestingly alternansucrase possessed a different regio-specificity. With caffeic acid the 3-O-α-D-glucoside was the major product. A similar substrate spectrum and regioselectivity pattern was observed in previous glucansucrase screenings only with glucansucrase from strain Weissella beninensis DSM 22752. Therefore it may be concluded that the W. beninensis enzyme is an alternansucrase type enzyme as well.
Mit Hilfe der Inline-ATR-FTIR-Spektroskopie im mittelinfraroten (MIR) Spektralbereich lassen sich gleich mehrere Prozessparameter für Biogasanlagen in Echtzeit und ohne Probenahme verfolgen. Die gemessenen Absorptionsspektren geben simultan Aufschluss über den Gehalt an flüchtigen organischen Säuren (FOS), die alkalische Pufferkapazität (TAC) und die Ammoniumstickstoff-Konzentration (NH4-N).
Dabei können unter Verwendung intelligenter Datenanalyseverfahren, wie z.B. Partial Least Squares (PLS), Regression oder Support Vector Regression (SVR) sowie in kontrollierter Laborumgebung, Vorhersagefehler (RMSECV) von 0.372 g/l (FOS: R2=0.971), 0.336 g/l (TAC: R2=0.996) und 0.171 g/l (NH4-N: R2=0.992) im Falle der PLS, bzw. 0.386, 0.259 und 0.110 g/l für die SVR erreicht werden.
Erste Inline-Messungen in einer Biomüllvergärungsanlage zeigen, dass die erwarteten Absorptionsbanden auch im Prozessbetrieb wiedergefunden werden können. Sie unterliegen jedoch einem ausgeprägten Temperatureinfluss, der bei der Quantifizierung dieser Prozessdaten berücksichtigt werden muss. Weiterführende Untersuchungen sind notwendig, um die Inline-Tauglichkeit des Messsystems unter Beweis zu stellen.
The introduction of Feed-in tariffs in the German Renewable Energy Act (EEG) fuelled the growth of anaerobic digestion (AD) industry making Germany the country with highest number of operational AD plants. However, the rapid expansion of AD industry resulted in some unwanted side-effects such as food vs fuel debate, increased prices for electricity and the temporal mismatch between supply and demand of electricity grid. Subsequent amendments in EEG has tried to address some of these issues by reduction in Feed-in tariffs, introduction of a cap on cereal based feedstocks and providing premium for energy production in accordance with market demand. Furthermore, the Feed-in tariffs which were introduced for 20 years are soon going to expire. The changes in legal and political discourse is soon going to introduce some new challanges to the AD industry. This paper has discussed some of these challanges and their potential solutions.
The electricity network is undergoing a change due to reducing costs for renewable energy sources. Subsidy programs for renewable energy sources are changing and the funding available is being reduced. This will have an impact on anaerobic digestion which in some cases may struggle financially. Overfeeding is one of the most common mechanisms of inhibition in the process, and by shifting to intermittent feeding for on-demand production, this change will provide more information about the digestion process and could be used to detect the beginning of inhibition due to overfeeding. This paper discusses the shift towards intermittent production and how this change can be used to monitor the anaerobic digestion process.
The synthesis of 17-hydroxy-oleic acid based oligomeric esters was investigated with immobilized Pseudozyma antarctica Lipase B and hexanediol as co-substrate. The effects of different reaction parameters on velocity and product composition at equilibrium conditions were analyzed. The synthesis of oleic acid esters was used as a reference system for initial evaluation of reaction parameters. The reaction with oleic acid and hexanediol was fastest at an enzyme concentration of 5% at 60 °C and high conversions of > 90 % were achieved in non-polar solvents in the presence of molecular sieves. In heptane an oleic acid conversion of 96 % was reached with a final diester to monoester ratio of > 4:1. In syntheses trials with 17-hydroxy-oleic acid the formation of oligomers was verified with GPC, however; conversion was generally lower than with oleic acid. Removal of hydroxyl fatty acid monomers and dimers and the formation ester functionalities could be verified by GC analysis. An increase of the degree of oligomerization was observed simultaneously by GPC analysis. The number-average molecular weight was around 1400 in the best trials corresponding to a degree of oligomerization of around 4 units of hydroxyl-fatty acid attached to a hexanediol core. Though transformations were not complete, the final oligomer size was in the lower range of polyester diols used for polyurethane manufacturing.
Messverfahren zur Erfassung der potenziellen Ökotoxizität in anaeroben und aeroben Abbauprozessen
(2014)
In der vorliegenden Ausarbeitung werden die etablierten Verfahren zur Bestimmung der Ökotoxizität erläutert, mit dem Ziel weitere Bioaktivitätsparameter zur Charakterisierung der biologischen Prozesse bei der Forschungsgemeinschaft :metabolon zu integrieren.
Die Erfassung der Toxizität beruht bei den vorgestellten Methoden auf der Messung der Lumineszenz, der Sauerstoffverbrauchsrate oder der Zellzahl. In Abhängigkeit von den Eigenschaften der Schadstoffe sowie der biologischen Betriebsbedingungen der Behandlungsstufen ist die Auswahl der bestmöglichen Methode erforderlich.
In the last few decades raw material molasses, used in large scale fermentations in the production of bioethanol, citric acid, (baker´s) yeast and yeast extracts, has become more and more expensive. That is why agro-industrial wastes have become an interesting alternative. They are being produced in large volumes every day and represent a serious environmental problem considering its high organic content. The present contribution aims to demonstrate how waste products of wine production can be employed as substrate in bioethanol production. Cultivation of yeast and bioethanol production on molasses and grape pomace extract was studied in flasks in laboratory scale. This work should be regarded as an example of integrated sustainability which demonstrates how the waste from one industrial process is used as feedstock for another.
Der vorliegende Bericht ist ein ökonomischer Vergleich
verschiedener Varianten der Überschussschlamm
(ÜSS)-Verwertung der Sickerwasseranlage
auf der Deponie des Entsorgungszentrums Leppe
mit dem aktuellen Entsorgungsweg. Als Vergleichsparameter
werden die Jahresvollkosten herangezogen.
Der derzeitige Entsorgungsweg über die kommunale
Kläranlage wird hierbei als Basisvariante
betrachtet und mit alternativen Behandlungs- und
Verwertungsmöglichkeiten verglichen. Hierbei werden
verschiedene Varianten mit unterschiedlichen
Ausführungen der Komponenten Lagerung, Entwässerung,
Trocknung, Transport und Verbrennung
gegenübergestellt.
For use in a landfill, a laboratory reactor for safe and environmentally friendly biological utilization of low-concentration methane gas will be further developed. The current principle of denitrification-coupled aerobic methane oxidation will be replaced by methane oxidation under anaerobic conditions. Anaerobic methane oxidation offers the advantage that, in addition to methane, nitrate also undergoes biodegradation. Another advantage is that the oxygen content can be significantly lower. This reduces the risk of the formation of an explosive atmosphere in the reactor. Currently, the principle of anaerobic methane oxidation is known. However, organisms capable of doing so are not yet available as a pure culture. Therefore, several biomasses were probed for the ability of anaerobic methane oxidation. It was found that moor-heavy sediment, activated sludge from the leachate treatment plant and biomass from the local biogas plant oxidize methane after the natural carbon source (C source) was been removed.