PRO MENTE OBERÖSTERREICH – INCLUSION INSTEAD OF EXCLUSION

pro mente OÖ is one of the biggest organisations offering psycho-social care and treatment. It is a crucial part of the differentiated system of social psychiatric services in Austria. First, the article describes the organization pro mente OÖ, its history and services. Then, a selection of framework conditions of social psychiatric supply is presented. In this respect some existing strengths and weaknesses of the Austrian psycho-social supply system are discussed

Heat transfer challenge and design evaluation for a multi-stage temperature swing adsorption (TSA) process

Functionalized solid amine-based temperature swing adsorption (TSA) processes have recently been proposed as a potential way to reduce the energy-penalty of post-combustion carbon capture processes (1). If TSA is to be carried out at large scale and with high energy-efficiency, continuously operated counter-current contactors are required for thermodynamic reasons. This could, generally, be achieved by using moving bed contactors. However, the heat exchange requirement of TSA is significant and heat transfer is poor in fixed and moving beds. Therefore, multi-stage fluidized bed contactors with counter-current flow of solids and gas phase and immersed heat exchange surfaces may solve the heat transfer challenge while maintaining the thermodynamic process requirements. Experiments have shown that adsorption and desorption kinetics of suitable functionalized amine sorbents are fast and equilibrium loadings are practically reached in the stages (1). Thus, heat exchange is the dominant limiting factor for a practical stage design in multi-stage fluidized bed TSA. The present work rationally develops design requirements for TSA stages based on the necessary heat exchange rates. The considered particles are Geldart Type B (diameter 200-300 µm, particle density 1000-1500 kg/m3). Scalability of the design proposal is considered and vertically orientated heat exchanger tubes are compared to horizontal tube bundles. The net movement and mixing of particles within the bubbling bed stage must be maintained in spite of the emulsified heat exchangers (possible dead zones in the area of the tube bundles). It is shown that the pressure drop of multi-stage fluidized bed TSA units for flue gas CO2 capture is practically determined by the heat exchange requirement and not by the space-time of the solids for the adsorption. Future work will employ a bubbling fluidized bed heat exchange testing device for optimization of the heat exchanger geometry with respect to heat transfer rates and particle residence time distribution in the stage. Heat exchange measurement devices have been presented recently in literature for horizontal tube bundles and Geldart Type A particles (2), but the importance of the heat exchanger issue in continuous fluidized bed TSA requires the detailed investigation for the Geldart B range, potentially considering the macroscopic particle movement relative to the heat exchangers within each individual TSA stage. Please click Additional Files below to see the full abstract

Fluid-dynamic study on a multi-stage fluidized bed column for continuous CO2 capture via temperature swing adsorption

Adsorption based processes have a great potential to significantly reduce the overall costs of CO2 separation from stack flue gas as compared to currently available technologies. One of the main challenges in the development of these processes is certainly the provision of adequate adsorbents. Hence, in the last decade a great effort has been put into screening and testing of various adsorbent materials. However, beside the identification of suitable adsorbent materials it is of equal importance to develop suitable reactor designs that allow for effective and most cost efficient utilization of these materials and so far only little work has been attributed to this subject. Nevertheless, it was shown that for thermodynamic reasons it is essential to provide counter-current contact between adsorbent and gas streams in order to allow for efficient operation of any Temperature Swing Adsorption (TSA) CO2 capture process. It was further highlighted that effective heat transfer with the used adsorbent material is necessary as the reported values of their corresponding adsorption enthalpies are typically rather large. Please click Additional Files below to see the full abstract

A multi-stage fluidized bed system for Continuous CO2 capture by means of temperature swing adsorption – First results from bench scale experiments

Temperature swing adsorption processes have been proposed as an alternative to common amine scrubbing processes for CO2 capture from stack flue-gas streams, as they have the potential to reduce the overall capture costs significantly. In the recent years, researchers have put a great effort into the development of highly selective CO2 adsorbent materials with sufficiently large CO2 transport capacities and cyclic operating stability. However, comparably little work has been attributed to the development of suitable reactor designs or to the experimental study of continuously operated temperature swing adsorption (TSA) processes that utilizes those adsorbent materials. The authors of this work most recently introduced a reactor system that allows for effective and efficient operation of the TSA process. The system comprises two interconnected multi-stage fluidized bed columns that enable counter-current contact of adsorbent and gas streams in both columns whilst allowing for effective heat management through indirect heat exchange in each stage. Based on the proposed reactor design, a fully integrated bench scale unit (BSU) has been constructed and put into operation to deliver a proof of concept and to further study the process experimentally (see Figure 6). Each of the BSU columns comprises five fluidized bed stages that are operated in the bubbling bed regime. Transport of solids between the two columns is carried out in two transport loops consisting of a screw conveyor, a riser and a gravitational gas/solids separator each. An amine-functionalized solid sorbent selectively adsorbs CO2 in the adsorber at low temperature and is subsequently regenerated in the desorber column at higher operating temperature, before it is returned to the adsorber. This work presents results obtained from the first continuous CO2 capture experiment within the unit. Please click Additional Files below to see the full abstract

Assessment of metabolic variability and diversity present in leaf, peel and pulp tissue of diploid and triploid Musa spp.

Banana (Musa spp.) plants produce many health promoting compounds in leaf, peel and pulp. For a robust metabolic analysis of these tissues, leaf at five developmental stages were compared to assess suitable sampling practices. Results confirmed that the common sampling practise of leaf 3 is applicable for metabolic comparisons. The developed work flow was applied to analyse the metabolite diversity present in 18 different Musa varieties, providing baseline levels of metabolites in leaf, peel and pulp tissue. Correlation analysis was then used to ascertain whether similar trends can be detected in the three plant tissues of the diversity panel. The genome group displayed a dominant role in the composition of the metabolome in all three tissues. This led to the conclusion that a correlation between tissues was only possible within a genome group as the different parental backgrounds caused too great a variation in the metabolomes. It also suggests the metabolome could be used to monitor the interaction/hybridisation of genomes during breeding programmes

Post combustion CO2 capture based on temperature swing adsorption - from process evaluation to continuous bench scale operation

Zsfassung in dt. SpracheChemische Absorption von CO2 mittels wässriger Aminlösungen wird derzeitig als das am weitesten entwickelte CO2-Abscheideverfahren angesehen. Dennoch weisen Abscheideverfahren die auf dieser Technologie basieren mehrere prozessbedingte Nachteile auf, die einen großen Prozesswärmebedarf und hohe CO2-Abscheidekosten mit sich bringen. Um die derzeit erreichbaren CO2-Abscheidekosten wesentlich zu reduzieren ist es daher notwendig alternative Abscheideverfahren zu entwickeln. Prozesse basierend auf der kontinuierlichen Adsorption von CO2 wurden kürzlich als potentielle Alternativen zur chemischen Absorption vorgeschlagen da diese die prozessinhärenten Nachteile der Absorption nicht aufweisen und somit geringer In den letzten Jahren wurden daher große Anstrengung unternommen um geeignete Adsorbentien zur Abtrennung von CO2 aus Rauchgasen zu entwickeln. Derzeit gibt es jedoch nur wenige Arbeiten die sich mit der Entwicklung von geeigneten Adsorptions-Reaktorsystemen und damit mit der Umsetzung dieser Technologie befassen. Diese Doktorarbeit beschäftigt sich daher mit der Entwicklung eines neuartigen Reaktorsystems, welches eine effiziente CO2-Abtrennung mittels Temperaturwechseladsorption (TSA) ermöglichen soll. Thermodynamische Untersuchungen am TSA Verfahrens wurden durchgeführt und zeigten, dass eine Gas und Adsorbentien innerhalb des Adsorbers und Desorbers im Gegenstrom geführt werden müssen um eine wirtschaftliche Arbeitsweise zu ermöglichen. Weiterhin wurde festgestellt, dass ein Gas-Feststoff-Kontakt im Wirbelbett zu optimale Wärmeübertragungseigenschaften führt. Basierend auf diesen Erkenntnissen wurde ein neuartiges TSA-System, bestehend aus zwei mehrstufigen Wirbelschichtkolonnen als geeignetes Reaktordesign entwickelt. Ein thermodynamisches Gleichgewichts-Modell wurde verwendet, um das Potential des vorgeschlagenen TSA-Systems zu erfassen und mit dem Stand der Technik zu vergleichen. Simulationsergebnisse zeigten deutlich, dass das TSA-System auch ohne Wärmeintegrationsmaßnahmen einen zumindest vergleichbaren Prozesswärmebedarf aufweist. Die fluid-dynamischen Eigenschaften des vorgeschlagenen mehrstufigen Wirbelschichtsystems wurden in einem Wirbelschicht-Kaltmodell (CFM) untersucht, welches im Verlauf dieser Arbeit entworfen, gebaut und in Betrieb genommen wurde. Versuche im CFM zeigten, dass ein stabiler Betrieb in einem weiten Bereich möglich ist, und bewiesen, dass eine Verwendung des vorgeschlagenen Reaktorsystems aus fluid-dynamischer Sicht möglich ist. Basierend auf den Ergebnissen aus der CFM-Kampagne, wurde ein TSA Laboranlage (BSU) für die kontinuierliche Abscheidung von bis zu 35 kg CO2 pro Tag ausgelegt, gebaut und im Laufe dieser Arbeit in Betrieb genommen. Erste Versuche innerhalb der BSU lieferten einen -proof of concept- für das vorgeschlagene TSA-Abscheidesystem. Ein stationärer Betrieb mit CO2-Trenngraden von über 90% und Abscheideraten von rund 35 kgCO2 pro Tag wurde in mehreren Experimenten erreicht. Darüber hinaus wurde durch umfangreiche Parametervariationen der Einfluss der wichtigsten Betriebsparameter auf die Abscheideleistung untersucht. Erhaltene BSU Ergebnisse zeigten schnelle Adsorptions-/Desorptions-Kinetik innerhalb der Wirbelschichtkolonnen und eine Limitierung der Abscheideleistung durch den erreichbaren Wärmeaustausch mit den Wirbelbetten. Die Einbringung von Wasserdampf, entweder als Strippgas im Desorber oder in Form von feuchten Abgas im Adsorber hatte eine signifikante Auswirkung auf den Wärmehaushalt im System. Dieser Einfluss wurde durch die Co-Adsorption von Wasserdampf auf dem Adsorbent begründet.Chemical absorption by means of aqueous amine solvents can be considered as the currently most mature post-combustion CO2 capture process. However, amine scrubbing technologies exhibit several disadvantages that are intrinsic to the process and result in large process heat demands and CO2 capture costs. Thus, in order to achieve breakthroughs in the reduction of CO2 capture costs the development of alternative capture technologies is required. Adsorption based processes have been proposed as appropriate methods to achieve significant reduction of CO2 capture costs compared to amine scrubbing technologies. Inspired by the excellent CO2 absorption properties of amine-based solvents, researchers immobilized amines onto solid support materials and thereby developed a new class of highly selective CO2 adsorbent materials. In the recent years, a great effort has been made to further develop amine functionalized adsorbents that are optimized for CO2 capture from stack flue gas. However, not much work has been attributed to the development of suitable reactor designs. This thesis is concerned with the development of a novel reactor system that enables efficient CO2 capture with solid amine functionalized adsorbent material by means of TSA. Basic thermodynamic investigations of the TSA CO2 capture process showed, that for economic process operation it is required to provide counter-current contact between gas and adsorbent streams in the adsorber and desorber. Furthermore, it has been concluded that the deployment of fluidized bed technology is crucial to allow for optimum heat transfer characteristics within the system. According to these findings, a novel TSA system consisting of interconnected multi-stage fluidized bed columns has been proposed as suitable reactor design and selected for further investigations. A thermodynamic equilibrium model has been used to quantitatively assess the process performance of the proposed TSA system and to compare it with MEA scrubbing technology performance data. Simulations clearly showed that the TSA system is at least competitive in terms of regeneration energy even if process improvements from heat integration are not considered. The fluid-dynamic characteristics of the proposed multi-stage fluidized bed system have been studied within a cold flow model (CFM) that has been designed, constructed and put into operation during the course of this thesis. Experiments conducted within the CFM showed that stable operation is possible within a broad range and proved that the proposed reactor system is feasible from a fluiddynamic point of view. Basing on the results from the CFM campaign, a fully integrated TSA bench scale unit (BSU) for continuous capture of about 35 kg of CO2 per day has been designed, constructed and put into operation during the course of this thesis. A proof of concept for the proposed TSA process has been delivered within one of the very first CO2 capture experiments conducted. Steadystate operation with CO2 capture efficiencies above 90 % and capture rates of around 35 kgCO2 per day have been achieved in several experiments. Furthermore, the influence of the main operating parameters on the process performance has been assessed through comprehensive parameter variations. Obtained BSU results indicated that adsorption/desorption kinetics are fast and that heat exchange was limiting the performance of the unit. Introduction of steam, either as stripping gas in the desorber or in form of humid adsorber feed gas had a significant impact on the system, which was most likely caused by co-adsorption of steam onto the adsorbent material.15

Assessment of the scale-up and operational design of the fuel reactor in chemical looping combustion

Zsfassung in dt. Sprachewww.chemical-looping.atChemical Looping Combustion (CLC) wird ein großes Potential als zukünftige Technolo- gie für CO2 Trennung und Speicherung (engl.: Carbon Capture and Storage CCS) zuge- sprochen, da im Gegensatz zu anderen Technologien keine parasitären Energieaufwändungen für Gas-Trennverfahren anfallen und daher theoretisch der Gesamtwirkungsgrad einer An- lage nur durch die Kompression des anfallenden CO2 Stromes reduziert wird. Nachdem die Funktion des Verfahrens in Laboranlagen mit Leistungen bis zu 120 kWth nachgewiesen wurde, steht man vor der Herausforderung der Entwicklung des Prozesses im großtechnis- chen Maßstab. Im Gegensatz zu Versuchen in Laboraufbauten die großteils zur Entwicklung der Technologie selbst dienten, ergeben sich beim Versuch der Vergrößerung der Anlage verschiedenste Problemstellungen, wie z.B. limitierte horizontale Mischung gasförmiger und fester Stoffe, modifizierte Festkörper-Strömungsmuster oder erhöhte Aufenthaltszeiten inner- halb des Brennstoffreaktors.Eine dem CLC-Prozess sehr verwandte Technologie ist die (Doppel-) Wirbelschichtver- brennungstechnologie, von der bereits langjährige Betriebserfahrungen als auch validierte Simulationsmodelle vorliegen, welche sich wiederum als besonders hilfreiche Werkzeuge für die Entwicklung industrieller CLC-Systeme eignen.In dieser Arbeit wird die erste Version eines Brennstoffreaktor-3D-Modells einer großtech- nischen CLC Anlage vorgestellt. Die Simulationen basieren auf in der Literatur über großtech- nischeWirbelschichtverbrennungsanlagen validierten Modellen für Feststoff-Gas Fluiddynamik, Feststoff-Gas Mischung undWärmetransport . In diese Modelle werden die aus CLC Laborver- suchen erhaltenen Kinetikdaten für Sauerstoffträger-Gaskonvertierung implementiert, um ein Gesamtmodell eines Brennstoffreaktors zu erhalten.Mit Hilfe dieses Modells soll die Funktion verschiedener Brennstoffreaktor- Konfigurationen und die Einflüsse unterschiedlicher Eingabeparameter, wie Position des Feststoffeintrages im Reaktor (Brennstoff, Sauerstoffträger), fluid-dynamische Eigenschaften frisch zugeführter Feststoffe, allgemeine Betriebsparameter der Wirbelschicht (Fluidisierungsgeschwindigkeit, Druckverlust entlang des Reaktors, durchschnittliche Reaktortemperatur) oder Reaktordesign untersucht werden. Ziel der Arbeit ist es, geeignete großtechnische Brennstoffreaktordesigns bzw. Betriebsstrategien zu finden, insbesondere solche bei denen eine Aufbereitung des Abgasstromes aufgrund unverbrannter gasförmiger Rückstände entfällt.Chemical looping combustion is expected to play a major role as Carbon Capture and Storage technology due to its intrinsic separation of the flue gas stream from the nitrogen contained in the fed air, thus avoiding the energy and capital cost penalty deriving from the presence of any gas separation unit. Having been successfully tested in units ranging up to 120 kWth in the last decade, chemical looping combustion starts to face the challenge of scale-up to commercial scale. While results obtained at lab-scale units are relevant to the initial development of the technology, scale-up implies the appearance of new key phenomena such as limited lateral gas and solids mixing, modified solids flow patterns and increased residence times. Having this, experience from large-scale fluidized bed units is highly valuable for further development of the chemical looping combustion technology through scale-up and is an essential resource to get a more complete understanding of the process.This work presents the first version of a 3-dimensional model for the fuel reactor of a large- scale chemical looping combustion unit. The model is based on validated models available in literature for combustion in large-scale fluidized beds. Thus, expressions for the fluid dynamics of the solids and gas phases, gas-solids contact and heat transfer derived from investigations in large-scale fluidized bed boilers are combined with kinetic data obtained from chemical looping experiments at lab-scale. From this, a model is obtained that is able to describe the performance trends of a large-scale fuel reactor upon variation of different inputs and operational strategies, such as feeding points for fuel and oxygen carriers, physical properties of these, operational conditions (fluidization velocity, pressure drop over the reactor, average operation temperature) and design of the reactor. Such a modeling tool is used to obtain suitable large-scale designs and operational strategies for the fuel reactor, which are presented in this work.9

Optimal Selection of Thermal Energy Storage Technology for Fossil-Free Steam Production in the Processing Industry

Due to increased share of fluctuating renewable energy sources in future decarbonized, electricity-driven energy systems, participating in the electricity markets yields the potential for industry to reduce its energy costs and emissions. A key enabling technology is thermal energy storage combined with power-to-heat technologies, allowing the industries to shift their energy demands to periods with low electricity prices. This paper presents an optimization-based method which helps to select and dimension the cost-optimal thermal energy storage technology for a given industrial steam process. The storage technologies considered in this work are latent heat thermal energy storage, Ruths steam storage, molten salt storage and sensible concrete storage. Due to their individual advantages and disadvantages, the applicability of these storage technologies strongly depends on the process requirements. The proposed method is based on mathematical programming and simplified transient simulations and is demonstrated using different scenarios for energy prices, i.e., various types of renewable energy generation, and varying heat demand, e.g., due to batch operation or non-continuous production Keywords: thermal energy storage; optimization; steam; power-to-heat; renewable energypublishedVersio

Assessment of zeolite 13X and Lewatit® VP OC 1065 for application in a continuous temperature swing adsorption process for biogas upgrading

Two commercially available CO2-adsorbent materials (i.e., zeolite 13X (13X) and Lewatit® VP OC 1065 (Lewatit)) were evaluated for their applicability in a continuous temperature swing adsorption (TSA) process for biogas upgrading. The equilibrium adsorption characteristics of carbon dioxide and methane were determined by fixed bed and TGA tests. While relatively high CO2 capacities were measured for both materials (3.6 and 2.5 mol kg−1), neither of them was found to adsorb significant amounts of CH4. Lewatit showed to be fully regenerable at 95 °C, whereas for 13X, the regeneration was not complete at this temperature. However, 13X showed no degradation up to 190 °C, whereas Lewatit started to degrade at 110 and 90 °C when exposed to N2 and air, respectively. Fluidization tests showed that Lewatit provides a high mechanical stability, while on the contrary, the tested 13X showed considerable attrition. An equilibrium adsorption model was fitted to the measured CO2 adsorption data. The adsorption model was then integrated into an existing simulation tool for the proposed TSA process to roughly estimate the expectable regeneration energy demand for both materials. It was found that depending on the operating conditions, the regeneration energy demand lies between 0.32–0.54 kWhth/m3prodgas for 13X and 0.71–1.10 kWhth/m3prodgas for Lewatit. Since heat integration measures were not considered in the simulations, it was concluded that the proposed TSA process has a great potential to reduce the overall energy demand for biogas upgrading and that both tested adsorbent materials may be suitable for application in the proposed TSA process.Austrian Governments Climate and Energ