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In the described case, the dust and ash particles are removed in a product gas filter. A scrubber with packed bed was used to clean the product gas from the tar components. The solvent of the scrubber was RME (rapeseed methyl ester), a biodiesel. RME is used because of its good tar separating characteristics. To investigate these tar separation characteristics of RME and the separation efficiency of the scrubber, four enrichment experiments were carried out during this work. These experiments took place at the 'Technikum' nearby the biomass steam gasification plant G��ssing. There, a pilot-scale scrubber and product gas from the gasification plant were used to perform the enrichment experiments. The four experiments are long term experiments with duration of approximately 120 hours each to obtain comparable results, it is necessary to make sure most of parameters are constant during the experiments. Only the RME temperature was changed from 0��C in the first experiment to 40��C in the last experiment. The task of this master thesis was to investigate the removal efficiency of the scrubber for the tar components benzene, toluene and xylene from the gas. During the enrichment experiments, a continuing data recording was fulfilled and in addition discontinuous tar sampling was accomplished. The discontinuous tar samples were taken 0:15h, 1h, 5h, 25h, 120h after the start of the experiments. The tar samples were analyzed in a laboratory and the results give the opportunity to evaluate the efficiency of the scrubber to eliminate benzene, toluene and xylene from the product gas. Using an exponential model, the results were fitted as scrubber efficiency as function of dry product gas volume at standard pressure and temperature. The results give good information about the behavior of toluene and xylene, because they show a good correlation between the temperature of RME and the separation efficiency. The results of benzene do not show this clear correlation. The results show, that, if fresh RME is used, a very good, nearly 100% tar separation is possible. Comparing the results to the CHP's scrubber, it can be concluded, that only a very little fraction of the tar components, which were investigated in this work, are actually removed there. Es wurde im Technikumsma��stab ein Versuchsw��scher mit Produktgas aus dem Biomasseheizkraftwerk G��ssing betrieben. Es wurden vier 120h Anreicherungsversuche bei Temperaturen von 0��C bis 40��C durchgef��hrt, um das Abscheideverhalten zu untersuchen. Die bei den Versuchen betrachteten Teerkomponenten waren Benzol, Toluol und Xylol. Sie wurden ausgew��hlt, da sie die am schwersten abzutrennende Teerfraktion sind. W��hrend der Anreicherungsversuche wurden s��mtliche Parameter m��glichst konstant gehalten, einzig die Temperatur des W��schermediums wurde variiert. Neben einer kontinuierlichen Datenaufzeichnung wurden 0:15h, 1h, 5h, 25h und 120h nach Versuchsstart Teerproben vor und nach dem Versuchsw��scher genommen. Diese Probenahme liefert Messpunkte, um die Effizient des Versuchsw��schers zu beurteilen. Durch ein exponentielles Modell wurden die ermittelten Daten in eine kontinuierliche Funktion des Abscheidegrades umgerechnet. Um die Vergleichbarkeit mit ��hnlichen, mit dem gleichen L��sungsmittel betriebenen W��scher zu gew��hrleisten, wurde das durch den W��scher gereinigte Produktgasnormvolumen in eine Beladung des L��sungsmittels umgerechnet. Somit erh��lt man einen Zusammenhang zwischen dem Abscheidegrad und der Beladung des L��sungsmittels. Die Ergebnisse liefern f��r die Teerkomponenten Toluol und Xylol einen eindeutig erkennbaren Zusammenhang zwischen L��sungsmitteltemperatur und Abscheidegrad. Benzol zeigt diesen Zusammenhang ohne ausf��hrliche Fehlerbetrachtung nicht. Bei geringer Beladung des L��sungsmittels kann ein Abscheidegrad von 100% f��r alle betrachteten Komponenten erreicht werden, mit steigender Beladung nimmt der Abscheidegrad f��r alle Komponenten jedoch stark ab. Die Ergebnisse zeigen des Weiteren, dass sich mit steigender L��sungsmitteltemperatur der Abscheidegrad bei gleicher betrachteter Teerkomponente verschlechtert. Diese Gegebenheiten deuten darauf hin, dass Absorptionsprozesse f��r die Teerabscheidung in einem Biodieselw��scher verantwortlich sind und Kondensation eine untergeordnete Rolle spielt. Ein Vergleich mit dem Kraftwerksw��scher zeigt, dass dieser die beobachteten Teerkomponenten nur zu einem geringen Teil abscheidet.

Die intensive Nutzung in Landwirtschaft und Forstwirtschaft und damit einhergehende Bodendegradation stellen eine enorme Herausforderung für die menschliche Gesellschaft dar. Insbesondere die Übernutzung reduziert die Ernährungssicherheit, führt zur Emission von Treibhausgasen und Aerosolen, treibt den Verlust der biologischen Vielfalt an, verschmutzt das Wasser und untergräbt eine Vielzahl von Ökosystemdienstlei - stungen, die über die Nahrungsmittelversorgung sowie die Wasser- und Klimaregulierung hinausgehen. Die direkten Emissionen durch Entwaldung, Düngung, Reisanbau und Wiederkäuer belaufen sich derzeit auf etwa 25% aller menschlichen Treibhausgasemissionen. Der intensiven Landnutzung zugrunde liegen sowohl das Bevölkerungswachstum, der Anstieg im pro-Kopf-Verbrauch an Kalorien, Holz und Fasern sowie verstärkter Konsum von Fleisch- und Milchprodukten. Dieses Kapitel fasst diese soziökonomischen Aspekte kurz zusammen und führt in die grundsätzlichen Prozesse ein, die der Emission von CO2, CH4 und N2O zugrunde liegen. In verschiedenen Kapiteln in diesem Buch werden diese Prozesse wieder aufgegriffen und unter verschiedenen Gesichtspunkten detaillierter beleuchtet. Socioeconomic aspects of land use change, effects on biogeochemical cycles and greenhouse gas emissions: Intensive agriculture and forestry and associated land degradation, pose an enormous challenge to human society. Overuse of land ecosystems reduces food security, leads to emissions of greenhouse gases and aerosols, drives biodiversity loss, pollutes water, and undermines a wide range of ecosystem services beyond food supply and water and climate regulation. Direct emissions from deforestation, fertilization, rice cultivation, and ruminants currently amount to about 25% of all human greenhouse gas emissions. Drivers of intensive land useare population growth, together with increases in per capita consumption of calories, wood, and fiber, and a shift towards consumption of meat and dairy products. This chapter briefly summarizes these socioeconomic aspects and introduces the basic processes underlying the emission of CO2, CH4, and N2O. Various chapters in this book revisit these processes and examine them in more detail from different perspectives. Aspectos socioeconómicos del cambio de uso de la tierra, efectos en los ciclos biogeoquímicos y emisiones de gases de efecto invernadero: El uso intensivo del suelo en la agricultura y la silvicultura asi como la asociada degradación del suelo representan un enorme desafío para la sociedad humana. En particular, el sobreuso hace peligrar la seguridad alimentaria, conduce a la emisión de gases de efecto invernadero y aerosoles, incrementa la pérdida de biodiversidad, contamina el agua y socava una variedad de servicios de los ecosistemas más allá del suministro de alimentos y la regulación del agua y el clima. Las emisiones directas de la deforestación, la fertilización, el cultivo de arroz y los rumiantes representan actualmente alrededor del 25% de todas las emisiones antrópicas de gases de efecto invernadero. El uso intensivo de la tierra se basa en el crecimiento de la población, el aumento del consumo per cápita de calorías, madera y fibra y un mayor consumo de carne y productos lácteos. Este capítulo resume brevemente estos aspectos socioeconómicos e introduce los procesos fundamentales que subyacen a la emisión de CO2, CH4 y N2O. Estos procesos se retoman en varios capítulos de este libro y se examinan con más detalle desde varias perspectivas.

This Working Paper summarizes the results of a survey and a workshop, which were compiled and discussed by scientists of the research institutes Thünen-Institut, Julius Kühn-Institut (JKI) and Friedrich-Loeffler-Institut (FLI) in autumn 2016. The aim of the workshop and the survey was to analyze the state of knowledge on climate change adaptation in BMEL departmental research and the future challenges of adaptation to climate change in German agriculture and forestry. DOI:10.3220/WP1518167089000

Arable weeds are one of the most endangered species groups in Europe. Modern agriculture and intensive land use management with the application of herbicides and fertilisers, enhanced seed cleaning, simplified crop rotations and abandonment of marginal arable sites are the main causes for the continuous decline of arable weeds. However, besides these changes in land use also global climate change may challenge the adaptability of arable weeds. Most scientists agree that the frequency of extreme meteorological conditions will increase in the future. As a consequence, plants of Central Europe will be subject to higher temperatures and reduced water supply due to longer intervals without precipitation during the growing season. We exposed seeds of five common and five endangered arable weed species to different temperatures and water potentials to study i) how this plant group responds to higher temperatures and lower moisture during germination in general and ii) whether there is a significant difference between common and endangered species in this respect.

Since the establishment of the activited sludge process in everyday life, we are constantly in search of new solutions to optimize the biologic process of sewage purification in a sustinable and economic way. The application of ultrasonic sound, which is investigated in this thesis, manifests itself as a qualified technique. After the influence of ultrasound an optimal morphological modification in the flake structure is achieved and the microbial activity in the activated sludge is enhaced. Furthermore, we can observe a reduction of the excess biomass by pro-rata dissolution of the activated sludge. Seit der Etablierung des Belebtschlammverfahens im Alltag ist man auf der Suche nach neuen Lösungen um den biologischen Prozess der Abwasserreinigung nachhaltig und wirtschaftlich zu optimieren. Der in dieser Arbeit untersuchte Einsatz des Ultraschalls zeigte sich als geeignete Technik. Nach der Ultraschalleinwirkung werden optimale morphologische Veränderungen in der Flockenstruktur erreicht, infolge dessen wird die mikrobielle Aktivität im Belebtschlamm gesteigert. Darüber hinaus durch Auflösung eines Teils des Belebtschlammes wird eine Verringerung der überschüssigen Biomasse beobachtet.

On September 11 and 12, 2017, a symposium on "Irrigation in agriculture", jointly organized by the Thünen Institute, the Julius-Kühn Institute and the University of Applied Sciences Ostfalia took place at the Ostfalia University of Applied Sciences, Campus Suderburg. For this purpose, experts from the field of irrigation were invited to give current assessments on the development of irrigation needs and the irrigation-worthiness of different crops at different locations in Ger-many as well as on the development of irrigation technology. The irrigation of crops in outdoor vegetables or special crops has long been a common practice. The profitability of irrigating agri-cultural crops in Germany has so far been limited to a few, dry locations. As a result of climate change, an increasing average annual temperature and changed precipitation patterns (in partic-ular lower rainfall at the beginning of the vegetation period in spring) have been observed in Germany for some years now. For the future, according to the results of climate models, a fur-ther increase in temperatures and further changes in the precipitation distribution such as a de-crease in the summer precipitation and an increase in winter precipitation are to be expected. The conference proceedings provide an overview of the latest research findings from the field of drought stress and discuss possible alternative sources for meeting the additional water require-ments of agricultural crops. Aspects of the landscape water balance and hydrological correlations in the agricultural landscape are addressed and solutions presented. Insights into possible con-flicts of water use and practical experience with the development of solutions are accompanied by the presentation of the legal framework for water use. The contributions are supplemented by reports of long-term irrigation field trials conducted by the LWK Lower Saxony. On the one hand, the experiments have shown that irrigation can increase the nutrient efficiency of crops and the quality of crops. On the other hand, the present state of the art of irrigation will be explained and limits and possibilities for increasing efficiency in the future will be presented. In order to in-crease the efficiency of irrigation, irrigation control is of great importance; its current status is presented and the trends for the future are shown. The profitability of investments in irrigation technology is presented in two contributions. Here, both the different techniques and their prof-itability in different crops are assessed economically. Possible developments of regional irrigation needs are exemplarily shown for the federal state of North Rhine-Westphalia. The conference proceedings conclude with a chapter on the overview of previous projects in the field of water management and on irrigation of agricultural land in view of future climate change in Germany.

"In this symposium review, three agricultural and environmental researchers discuss the book Nature and the Environment in Amish Life by David McConnell and Marilyn Loveless, both of the College of Wooster in Wooster, Ohio. McConnell is an anthropology professor and co-author of Amish Paradox (2010, Johns Hopkins University Press) and has published his research in Human Organization, Anthropology and Education Quarterly, and the Journal of Amish and Plain Anabaptist Studies (JAPAS) (Moledina, et al. 2014). Loveless is a biology emeritus professor; this is her first academic publication about the Amish. Our reviewers offer a variety of reactions to this book. The first reviewer, historian Steven Reschly, is a founding board member of the Journal of Amish and Plain Anabaptist Studies and is currently assistant editor. He has written on Amish agricultural history in The Amish on the Iowa Prairie (2000, Johns Hopkins University Press) and in articles in Agricultural History, Mennonite Quarterly Review, JAPAS, and others. Scot Long completed his Ph.D. in anthropology at Ohio State University, having conducted extensive research on Amish farm households in southeastern Holmes County, OH. He has also published in JAPAS (Long and Moore 2014) about the impact of the environmental landscape on Amish church districts. Caroline Brock completed her Ph.D. in envirnoment and resources at the University of Wisconsin-Madison. Her research focuses on theoretical models for understanding Amish responses to agriculture and the environment, including organic dairy adoption and water quality conservation practices. Her research has appeared in Environmental Management, Society & Natural Resources, Journal of Rural Studies, Sustainability, JAPAS, and other outlets. She recently worked as a senior research associate at the Ohio Agricultural Research and Development Center in Wooster, OH. This book will certainly generate many conversations and hopefully inspire further research into the Amish relationships with agriculture and the environment. [Abstract by editor]"

In dieser Arbeit sollen zwei verschiedene Membranen in zwei unterschiedlichen Membranmodulen auf ihre Eignung, Aceton, Butanol und Ethanol (ABE) aus einer w��ssrigen L��sung abzutrennen, getestet werden. Au��erdem soll der Einfluss von verschiedenen Komponenten auf die Leistungsf��higkeit gepr��ft werden. Bei der sogenannten ABE-Fermentation werden biofermentativ Aceton, Butanol und Ethanol erzeugt. Diese Komponenten sind wichtige Grundchemikalien und sollen mit diesem Ansatz aus nachwachsenden Rohstoffen produziert werden. Zur anschlie��enden Abtrennung der L��sungsmittel aus dem w��ssrigen Medium ist die Pervaporation eine vielversprechende Technik. Dabei wird die L��sung ��ber eine Membran geleitet, durch die nur die gew��nschten Komponenten hindurchgelangen k��nnen. Zwei Membranmaterialien, die f��r die dargelegte Trennaufgabe sehr vielversprechend erscheinen, sind Polyoktylmethylsiloxan (POMS) und Polydimethylsiloxan (PDMS). Hier wurde eine experimentelle POMS-Flachbettmembran von dem Helmholtz-Zentrum Geesthacht (Deutschland) und ein Hohlfasermodul mit eingebauten PDMS-Membranen der Firma PermSelect - MedArray, Inc (USA) getestet. Die Membranen wurden in eine Pervaporationsanlage im Laborma��stab eingebaut und auf unterschiedliche Parameter untersucht. Nach der Testung der Leistungsf��higkeit mit ausschlie��lich ABE in Wasser, ist anschlie��end der Einfluss von Glucose, Ammoniumchlorid, Essigund Propions��ure auf die Membranen getestet worden. Die Essigund Propions��ure Versuchsreihen sind jeweils bei einem pH-Wert von 7, 5 und 3,5 durchgef��hrt worden, um somit den Einfluss des pH-Werts zu ber��cksichtigen. Alle betrachteten Komponenten sind auch in realen Fermentationsbr��hen enthalten und k��nnen daher bei einer Inline-Abtrennung einen Einfluss auf die Membran aus��ben. Um die Membran zu charakterisieren, sind der transmembrane Fluss, der Trennund Anreicherungsfaktor sowie die Permeanz und die Permselektivit��t berechnet worden. Damit k��nnen sowohl die Leistungsf��higkeit als auch die Wechselwirkungen der Membran mit den einzelnen Komponenten charakterisiert werden. Im Anschluss an die Experimente sind beide Membranen noch mittels Rasterelektronenmikroskop untersucht worden, um ihre Dicke zu ermitteln, damit die Permeabilit��ten berechnet werden k��nnen. Beide Membranen sind im gesamten betrachteten pH-Wertebereich und gegen��ber allen getesteten Substanzen stabil. Die POMS-Membran zeigt einen negativen Einfluss bei der Zugabe von Glucose. Schon die niedrigste gemessene Glucosekonzentration von 50 g/l f��hrt zu einem Sinken des Flusses sowie der Permselektivit��t von ABE zu Wasser. Dieser Effekt ist jedoch reversibel und entsteht m��glicherweise durch eine von der Glucose ausgel��ste Polarisation an der Membran. Die PDMS-Membran hingegen zeigt keinen Effekt durch die Zugabe von Glucose. Daf��r sinkt die Leistungsf��higkeit bei Zugabe der S��uren bei einem pH-Wert von 3,5. Die POMS-Membran zeigt die h��chste Permeabilit��t f��r Wasser und ist somit nicht selektiv f��r ABE. Damit ist die Trennung schlechter als man durch das Fl��ssig-Dampf-Gleichgewicht erwarten w��rde. Aus diesem Grund ist die untersuchte POMS-Membran schlechter f��r die Trennung von ABE und Wasser geeignet als die betrachtete PDMS-Membran. Die PDMS-Membran hingegen ist selektiv f��r Butanol, nicht jedoch f��r Aceton und Ethanol. Da Butanol jedoch das Hauptprodukt ist, ist die Membran f��r das dargelegte Trennproblem geeignet. In this work, two membranes in two different modules are examined on their suitability to separate acetone, butanol und ethanol from an aqueous solution. Furthermore, the influence of different components on the performance is tested. In ABE fermentation, acetone, butanol and ethanol are produced via fermentation. These substances are important base chemicals and can be produced from renewable resources through this process. For the separation of the solvents from the aqueous solution, pervaporation is an interesting technique. The solution is pumped over a membrane that should only let specific components through. Membrane materials that seem to show promise for this separation are polyoctylmethlysiloxane (POMS) und polydimethylsiloxan (PDMS). In this thesis an experimental POMS flat sheet membrane by Helmholtz-Zentrum Geesthacht (Germany) and a hollowfiber module with a PDMS membrane by PermSelect - MedArray, Inc (USA), have been tested. The membranes were built into a lab-scale pervaporation plant and multiple experiments were performed. First the membranes have been brought into contact with only pure ABE in water. Than the influence of glucose, ammonium chloride as well as propionicand acetic acid on the membrane have been examined. Experiments with aceticand propionic acid are carried out at the pH values of 7, 5 und 3.5, so as to also include the influence of different pH values on the membranes. These specific components have been chosen since they are also present in real fermentation booths. The parameters chosen for the characterization of the membranes include the transmembrane flux, separation and enrichment factor, as well as the permeance and permselectivity. Thus, it is possible to draw conclusions on the productivity of the membranes as well as the interactions with the different components. In a next step, scattering electron microscopy has been performed on the membranes to measure their thickness and thus be able to calculate the permeability. Both membranes are stable in the whole tested pH range and against all added substances. The POMS membrane is negatively influenced by the addition of glucose. Even at the lowest used glucose concentration of 50 g/l, there is a measurable decline of the flux as well as the permselectivity of ABE to water. This effect is reversible and may be caused by polarization. Contrary to that the PDMS shows no effect at the addition of glucose. But the addition of the acids at the pH value of 3.5 causes a lower performance. The permeability shows that the POMS membrane has the highest affinity to water and thus is not selective for ABE. Therefore, the separation is worse than predicted by the vapor-liquid-equilibrium. Which is the reason why this membrane is less suited for the separation of water and ABE than the PDMS membrane. The PDMS membrane is selective for butanol but not for acetone and ethanol. Since butanol is the main focus of the separation, this membrane is suited for this separation problem.

Herein, the production of 5-hydroxymethylfurural (5-HMF) from fructose in in a liquid-liquidtubular reactor is proposed. In this intensified reactor in-situ extraction of 5-HMF into a disperse phase consisting of the solvent 2- methyltetrahydrofuran (2-MTHF) is performed. The disperse phase is contacted in a countercurrent flow relative to the continuous phase in which 5-HMF is produced. The design of this novel reactor concept follows a model-based approach. Based on a newly parameterized equation of state, the phase equilibrium of the ternary system 2-MTHF/water/5-HMF as a function of composition and temperature is described. Root mean square deviations for the thermodynamic model compared to experimental data are below 0.02 mol mol−1. From this accurate description of phase equilibria, the transport variables density and viscosity are calculated for both liquid phases within the range of experimental error. The acid-catalyzed dehydration of FRC to 5-HMF is described by a newly developed kinetic model. This kinetic model enables calculation of the temporal change in concentration caused by reaction and mass transport into the organic phase. Sedimentation and mass transport into the disperse phase are investigated in single-drop experiments. Based on these experimental data, parameters for the mathematical description of sedimentation and mass transfer are obtained. The results of the models developed in this work allow a calculation of sedimentation velocities with an accuracy greater than 0.015mms−1. Single-drop mass transfer calculations exceed an overall accuracy of 4%. The herein developed rate model for the description of local and temporal concentration profiles in the liquid-liquid tubular reactor allows a quick evaluation of the potential of this design. Due to the efficient extraction in the countercurrent mode of operation, the 5-HMF yield compared to batch results is increased by 16% at full conversion. Additionally, a validation experiment was carried out in a custom-made pilot plant. A comparison of experimental results and results of the reactor modeling for this validation experiment yields an accuracy greater than 80 %. An extrapolation of the model data to the stationary point of operation shows thata 5-HMF selectivity of 93% at 30% fructose conversion is achieved. The performance of the two-phase 5-HMF synthesis in the liquid-liquid tubular reactor developed in this work thus offers clear advantages compared to operation in a batch reactor. Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2021; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2021). doi:10.18154/RWTH-2021-09547 = Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2021 Published by RWTH Aachen University, Aachen

Phenoxypropanols have been used for some time as ingredients in surface and instrument disinfectants. Since the residual solutions of these preparations are discharged into the waste-water, the biodegradability of the ingredients used is of great importance. Tests by means of the Zahn-Wellens test in accordance with OECD guidelines have shown that phenoxypropanols are biodegradable. In further studies it was investigated whether unwanted intermediate products are formed in considerable amounts. Of particular interest was the question of the possible development of phenol outside the bacterial cells. To test the biodegradability of the aromatic alcohols and to ascertain whether there is extracellular formation of phenol, microorganisms were isolated from the municipal sewage plant at Stellinger Moor, Hamburg, and from water from the River Elbe. Phenoxypropanol-containing solutions were then inoculated with the bacteria and incubated at 30 degrees C. At regular intervals both the concentration of the alcohols was determined and the test for phenol was performed by means of liquid chromatography on reverse phase material (RP 18) and detection with a photodiode array detector. The breakdown of the phenoxypropanols was monitored for a period of up to 4 weeks. During this period a clear breakdown of the aromatic alcohols was observed. No phenol was detected.