A pellet burner directly integrated into the solar storage provides heat and domestic hot water for small
residential applications in an environment-friendly way. The objective of this work was to evaluate the system
performance of a storage integrated pellet boiler in laboratory under transient test conditions. Furthermore, the type
test results according to ÖNORM EN 303-5 [1] of the last decade were compared with monitoring data of systems
with separated boiler and heat storage. The laboratory tests allowed finding relevant parameters and losses, which
influence the system performance. A developed computer simulation model shows the potential to optimize the
performance of the investigated boiler.

Due to the increasing number of different online and offline methods and procedures for sampling at gasification and pyrolysis plants a comparison of the measured values is difficult. About the sampling of tars already a number of detailed guidelines and a common approach are established [2]. In terms of discrete chemical impurities the missing of a guideline for sampling at biomass¬ plants is an obstacle for implementing sampling systems in new plants or experimental assemblies. Nevertheless the knowledge is available at several institutions but it has to be collected. Within this paper the basic challenges of sampling are mentioned, the system at Bioenergy2020+ is explained in detail and about the parameters NH3, H2S & HCN useful results of optimisation are reported. This status should help to point out the need of a reliable library of methods. According the first systematisation of offline and online sampling respectively detection a table of application is proposed. The detailed knowledge for this will be treated and exchanged within an established working group which should lead to a guideline (at least methods library) for sampling of trace components as described.

The utilization of biomass for the substitution of fossil fuels to reduce greenhouse gas emissions in biomass steam gasification plants is a promising technology for the production of electricity, heat, and fuels for transportation. Experience from industrial scale dual fluidized bed steam gasification plants showed a modification of the bed material due to the interaction of the bed material (olivine) with biomass ash components and additives. In this paper the influence of bed material modification on the gasification properties of used olivine from an industrial scale plant in Güssing is compared with the case of fresh olivine. The trials were carried out under similar conditions in a pilot plant at the Vienna University of Technology. The pilot plant trials showed an increase in hydrogen and carbon dioxide in the product gas with the used bed material while the content of carbon monoxide in the product gas decreased. The exothermal water–gas shift reaction is enhanced by the used bed material, resulting in a lower energy demand for the gasification. Tar content was decreased by around 80% for tars detected by gas chromatography–mass spectrometry (GCMS) and the composition of the tar showed less components during the trial with used bed material.

The results obtained with the used bed material at the 100 kW pilot plant are in good agreement with those for the 8 MW industrial plant in Güssing, confirming good scale-up properties from the 100 kW plant to industrial scale plants.

A steam blown dual fluidized bed gasification plant was used to yield a nitrogen (N 2) free product gas (synthesis gas) from various biomass fuels. In addition to the variation of process parameters like temperature, steam to carbon ratio, fluidization rate, and the influence of different bed materials, various feedstock inputs affected the generation of the product gas. This study focuses on the gasification of different biomass feedstock. The variation of biomass implies wood chips, wood pellets, sewage sludge pellets, and straw pellets. The chosen evaluated experimental results are all gained from the uniformly operated "classical" 100 kW "DUAL FLUID" gasifier at Vienna University of Technology at constant gasification temperatures between 800°C and 810°C. In the "classical" design, the gasification reactor is a bubbling fluidized bed. The composition and ash melting behavior of each feedstock is displayed, as well as the ranges of the product gas compositions generated. Beside the main gaseous product gas components, typical content ranges of dust and char are highlighted. The content and composition of tar in the product gas is discussed. Further it is possible to present gravimetrical and gas chromatography coupled with mass spectrometry measured tar values. Not less than five significant component-groups of tar will also be outlined for each feedstock. © 2012 American Institute of Chemical Engineers (AIChE).

Die Verbrennung fester Biomasse gewinnt als nachhaltige Form der Energienutzung zunehmend an Bedeutung. Dabei stellt die Forderung nach einem schadstoffarmen Betrieb von Biomassefeuerungsanlagen bei möglichst hohem Wirkungsgrad eine Herausforderung an deren Regelung dar. Ziel dieser Arbeit ist die Untersuchung und Verbesserung eines existierenden, modellbasierten Regelungskonzepts, welches die Methode der Eingangs-Ausgangslinearisierung zur Regelung sowie einen Erweiterten Kalmanfilter zur Zustandsschätzung vorsieht. Die Arbeiten wurden in Kooperation mit dem Kompetenzzentrum Bioenergy 2020+ anhand einer Versuchsanlage (Flachschubrostfeuerung mit einer Kesselnennleistung von 180 kW) durchgeführt. Dabei lassen sich eine Reihe von Störeinflüssen identifizieren, unter anderem etwa die bei dieser Anlage besonders stark ausgeprägten Schwankungen des abgebauten Brennstoffs. Die geeignete Berücksichtigung dieser Störeinflüsse im Kalmanfilter durch Formfilter wird untersucht. Ebenso erfolgt die Modellierung von variablen Totzeiten und Sensordynamiken, die bei der Messung einzelner Größen auftreten, durch zusätzliche Sensormodelle. Auf Basis dieser Ergebnisse wird ein neuer Kalmanfilter vorgeschlagen und implementiert. Die auftretenden Störeinflüsse führen bei der exakt linearisierten Strecke zu einer Abweichung vom geforderten linearen Übertragungsverhalten. Daher wird auch der Regler dahingehend modifiziert, dass die vom Kalmanfilter rekonstruierten Störgrößen bei der Ermittlung des nichtlinearen Zustandsregelgesetzes verwendet werden. Das modifizierte Regelungskonzept wurde abschließend an der untersuchten Anlage implementiert und experimentell verifiziert. Dabei wurden gegenüber der ursprünglichen Regelung eine deutliche Verbesserung bei der Stabilisierung von Vorlauf- und Sekundärzonentemperatur sowie eine geringere Abweichung des Verbrennungsluftverhältnisses im Brennstoffbett vom vorgegebenen Sollwert erzielt.

In this paper a stochastic cellular automata model is examined, which has been developed to study a "small" world, where local changes may noticeably alter global characteristics. This is applied to a climate model, where global temperature is determined by an interplay between atmospheric carbon dioxide and carbon stored by plant life. The latter can be released by forest fires, giving rise to significant changes of global conditions within short time.

In the last decades certification tests of small-scale biomass systems have impressively shown the improvement of the state of the art. Though, steady state measurements represent results only foroptimal operation. In practice results differ due to varying operating conditions. Therefore, of a test stand measurement method to derive realistic annual system efficiencies and emission factors is developed. The method includes a heat loss model for thermal storages too. It can be used to test automatically fed biomass boiler, manually loaded biomass boilers and boiler / heat accumulator combinations. For the evaluation of the measurement data a calculation method based on mass flows was developed. The results of our experiments show that the newly developed method is a good tool to evaluate small-scale biomass boilers. With this method an easy and reliable instrument to determine annual system efficiencies and emission factors for realistic boiler operation is provided. The application of the method will prove that modern small-scale biomass combustion systems have the potential to significantly contribute to the reduction of air pollutants and to increase overall energy system efficiency.

The processing of heterogeneous waste is a major challenge for waste treatment equipment used in mechanical-biological (MB) waste treatment plants. This conference contribution focuses on the technical feasibility and efficiency of different technologies for the processing of a heavy waste fraction from a MB-plant which contains a high portion of high caloric components. The aim is to meet the requirements for waste to be landfilled in Austria. Also economic considerations with regard to the implementation of an additional separation step and the resulting changes in the waste routing are discussed. The processing technologies looked at comprise sensor-based sorting technologies (NIR, X-ray transmission) as well as traditional mechanical density separation technologies such as a jigger and cross-flow air classification.