Energie-Umweltmanagement
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Browsing Energie-Umweltmanagement by Author "Bauer, Alexander"
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- PublicationBiogas Production from Steam-Exploded Miscanthus and Utilization of Biogas Energy and CO2 in Greenhouses(Springer, 2013)
;Menardo, Simona ;Bauer, Alexander ;Theuretzbacher, Franz; ;Nilsen, Paal Jahre ;Balsari, Paolo ;Pavliska, OksanaAmon, ThomasThe costs of producing protected vegetables comprise up to 78 % of the total operating costs in greenhouses. These expenses mainly result from energy consumption. Increasing energy efficiency and expanding the use of renewable energy sources are essential for global competitiveness. The aim of this study is to optimize methane production from miscanthus and to evaluate the potential use of miscanthus as a source of electrical energy, heat, and CO2 in vegetable greenhouses. To optimize methane yield, miscanthus was pretreated by steam explosion using different time/temperature combinations. Pretreatment resulted in a more than threefold increase of methane yield from anaerobic digestion (374 lN kgVS−1) compared with untreated miscanthus. Based on technical parameters from two greenhouses (in Northern and Southern Europe), four different energy balances were established. The balances showed that using methane produced by pretreated miscanthus in vegetable greenhouses can enhance the entire process and therefore make it more sustainable.68 1Scopus© Citations 62 - PublicationCorn stover for biogas production: Effect of steam explosion pretreatment on the gas yields and on the biodegradation kinetics of the primary structural compounds(Elsevier, 2017)
;Lizasoain, Javier ;Trulea, Adrian ;Gittinger, Johannes ;Kral, Iris; ;Schedl, Andreas ;Nilsen, Paal Jahre ;Potthast, Antje ;Gronauer, AndreasBauer, AlexanderThis study evaluated the effect of steam explosion on the chemical composition and biomethane potential of corn stover using temperatures ranging between 140 and 220°C and pretreatment times ranging between 2 and 15min. Biodegradation kinetics during the anaerobic digestion of untreated and corn stover, pretreated at two different intensities, 140°C for 5min and 180°C for 5min, were studied in tandem. Results showed that pretreatment at 160°C for 2min improved the methane yield by 22%. Harsher pretreatment conditions led to lower hemicellulose contents and methane yields, as well as higher lignin contents, which may be due to the formation of pseudo-lignin. The biodegradation kinetics trial demonstrated that steam explosion enhances the degradation of structural carbohydrates and acid insoluble lignin.59 1Scopus© Citations 74 - PublicationEffects of the Antibiotics Chlortetracycline and Enrofloxacin on the Anaerobic Digestion in Continuous Experiments(Springer, 2014)
;Bauer, Alexander ;Lizasoain, Javier ;Nettmann, Edith ;Bergmann, Ingo ;Mundt, Kerstin ;Klocke, Michael ;Rincón, Maria ;Amon, ThomasSignificant quantities of antibiotics are used in modern livestock husbandry and are found in livestock waste. Such waste has been reported to exert inhibitory effects if used as a substrate in biogas facilities. The goal of this study is to analyze the inhibitory effect of the antibiotics chlortetracycline (CTC) and enrofloxacin (EFX) on biogas production with pig slurry. Antibiotic concentrations up to 8,000 mg kg−1 dry matter (DM) pig slurry were added in continuous fermentation tests. Impacts on methane production and on the microbial community structure were analyzed. The results clearly show that chlortetracycline and enrofloxacin negatively affect biogas production. Higher concentrations of antibiotics led to lower methane production. The addition of 200 mg kg−1 DM of CTC or EFX reduced the specific methane yields up to 49 and 44 %, respectively. The microbial community did not show any changes at this concentration. When chlortetracycline was added at a concentration of 8,000 mg kg−1 DM, the biodiversity changed slightly compared to the control without antibiotics.63 1Scopus© Citations 25 - PublicationEffizienzvergleich von automatischen Lenksystemen mit manueller Lenkung während der Grünlandernte auf Basis von Prozessparametern der Zugmaschine(Gesellschaft für Informatik e.V., 2017)
;Kral, Iris ;Mauch, Marie ;Barta, Norbert; ;Bauer, Alexander ;Bauerdick, Josef ;Bernhardt, HeinzGronauer, AndreasDer Nutzen von automatischen Lenksystemen wurde bisher vor allem im Ackerbau untersucht. In der vorliegenden Studie soll daher der Nutzen zwischen manueller Lenkung (mL) und automatischer Lenkung (aL) in der Grünlandwirtschaft durch Feldversuche verglichen werden. Die Prozessparameter wurden aus CANund ISO-Bus der Zugmaschine während des Mähens, Wendens und Schwadens erfasst. Die größten Abweichungen zwischen mL und aL wurden im Bereich der Feldarbeitszeit beobachtet. Hier war die Bearbeitung mit aL im Mittel 42,6% während des Mähens und 30,0% während des Wendens langsamer als mit mL. Neben unterschiedlichen Fahrstrategien war dieser Umstand auf einen mangelhaften Wechsel von mL auf aL nach der Wende zurückzuführen. Im Gegensatz dazu konnte mit der aL während des Schwadens um 15,6% schneller gearbeitet werden als mit mL. Dies ist auf einen Wendevorgang mittels Schwalbenschwanzwende während mL zurückzuführen.74 1 - PublicationEnvironmental Effects of Steam Explosion Pretreatment on Biogas from Maize—Case Study of a 500-kW Austrian Biogas Facility(Springer, 2016)
;Kral, Iris; ;Saylor, Molly K. ;Gronauer, AndreasBauer, AlexanderPotential environmental impacts of biogas electricity from agricultural residues (maize stover) with steam explosion (SE) pretreatment were compared to a typical Austrian biogas system (maize silage) using the method of life cycle assessment. Besides the biogas plant, the system includes substrate production, a combined heat-and-power (CHP) unit, digestate management, and transportation. The stover scenario (including construction and operation of the SE unit) results in lower total climate change impacts than those of the typical biogas system (239 g CO2-eq/kWh electricity vs. 287 g CO2-eq/kWh electricity; 100-year global warming potential (GWP)), and this holds also for the other impact categories (e.g., cumulative energy demand, acidification, eutrophication). While uncertainties in other areas could change the results, based on the uncertainty information considered, the overall results for the two scenarios were significantly different. Methane slip emissions from the CHP exhaust account for the largest GWP share in both scenarios. Other large GWP contributions are from substrate production and grid electricity for plant operations. The findings were robust against worst-case assumptions about the energy requirements of the SE pretreatment.61 1Scopus© Citations 11 - PublicationEnvironmental hot spot analysis in agricultural lifecycle assessments – three case studies(University of Zagreb, 2016)
; ;Bauer, Alexander ;Gronauer, Andreas ;Saylor, Molly K. ;Stampfel, AngelikaKral, Iris82 1Scopus© Citations 5 - PublicationErratum to: Effects of the Antibiotics Chlortetracycline and Enrofloxacin on the Anaerobic Digestion in Continuous Experiments(Bioenerg. Res., (2014), DOI 10.1007/s12155-014-9458-0)(Springer, 2016)
;Bauer, Alexander ;Lizasoain, Javier ;Nettmann, Edith ;Bergmann, Ingo ;Mundt, Kerstin ;Klocke, Michael ;Rincón, Maria ;Amon, Thomas; Winckler, ChristophThe original version of this article unfortunately contained mistakes in the authorship. The author’s name, “ Christoph Winckler ” as the 10th author, is missing. The correct version is presented above.68 1Scopus© Citations 1 - PublicationLife Cycle Assessment of Biogas Production from Unused Grassland Biomass Pretreated by Steam Explosion Using a System Expansion Method(MDPI, 2020)
;Kral, Iris; ;Saylor, Molly K. ;Lizasoain, Javier ;Gronauer, AndreasBauer, AlexanderReforestation is a threat to permanent grasslands in many alpine regions. Using these areas to produce biogas energy may help to preserve these important landscapes and save fossil fuels by adding a renewable local heat and electricity source. This case study compares (a) a status quo (SQ) reference scenario with heating oil, wood-chips, and grid electricity as municipal energy sources, and (b) a hypothetical local biogas (LB) scenario (to also be used as a municipal energy source) based on a 500-kWel biogas plant with steam explosion pretreatment. Here, hay from previously unused grassland is the main biogas substrate, whereas, in the reference SQ scenario, these grasslands remain unused. Life cycle assessment (LCA) results for LB and SQ scenarios are significantly different at p < 0.05 in all six impact categories. In three categories, the LB scenario has lower impacts than the SQ scenario, including climate change (0.367 CO2-eq kWhel-1 versus 0.501 CO2-eq kWhel-1). Dominant contributions to climate change in the SQ scenario are from the extant municipal energy sources that the LB biogas plant would replace; in the LB scenario, important contributions include unburned methane from the biogas plant, as well as CO2 emissions from hay production machines. In summary, important environmental impacts can be reduced and alpine grasslands can be preserved by biogas production from that grass. The advantages of integrating a local biogas plant in municipal energy and waste systems depend strongly on the extant municipal energy system characteristics.140 1Scopus© Citations 6 - PublicationPotential of different Sorghum bicolor (L. moench) varieties for combined ethanol and biogas production in the Pannonian climate of Austria(Elsevier, 2013)
;Theuretzbacher, Franz ;Bauer, Alexander ;Lizasoain, Javier ;Becker, Manuel ;Rosenau, Thomas ;Potthast, Antje ;Friedl, Anton; Gronauer, AndreasThe objective of this study is to estimate the energetic yields of a combined ethanol and biogas production from three different sorghum varieties, and to compare them to a similar estimate for maize in order to demonstrate the suitability of sorghum as an alternative biomass source. The sorghum varieties “SG1” (Sugargraze I) and “SG2” (Sugargraze II), which produce fermentable sugars, as well as the grain variety “C” (Chopper), which produces starch, were grown on experimental plots in eastern Austria. The harvested biomass was analysed for its contents of cellulose, hemicellulose, lignin, crude protein, crude fats, starch and sugar. For the calculation of the energy output, ethanol and biogas yields were calculated corresponding to accepted standard methods. The potential of sorghum for energy production has been demonstrated. The highest energy outputs were achieved by the SG1 and the C varieties, delivering approximately 150 GJ ha−1 and 156 GJ ha−1. Compared to data obtained from different maize varieties in the same year and under similar conditions, this means an equal or even increased energy output per hectare. The SG2 variety only yielded 121 GJ ha−1 worth of ethanol and biogas. Bioethanol and biogas production were unequally distributed between sugar and starch varieties: SG1 provided 70% of its energy output as methane and the rest as bioethanol, whereas the grain variety C yielded 46% methane and 54% bioethanol.65 1Scopus© Citations 14