Research

A commercial building is being constructed in Engelhartszell that is as sustainable, resource-saving and circular as possible. To this end, research questions regarding the use of materials and the building's energy supply are being investigated. In a first step, the materials and technologies to be used are determined on the basis of a comprehensive literature review. In a second step, various HVAC concepts are developed in combination with a suitable heat distribution system. The next step is to model the building in a building simulation environment in order to simulate different variants of the wall structure and energy generation, but also to be able to map the effects on comfort and the indoor climate. In a final phase, the results are collected and summarized in a final report.

Wood is one of the most important materials for a carbon-neutral future of building products, but it has one major drawback: it is combustible. The ignition of wood is subject to complex mechanisms that are not yet fully understood. Generally, flame formation is always considered to be the same as ignition, but before any ignition of gases, a reactive carbon layer is formed on the surface. Such layers can already form at temperatures significantly below the generally accepted ignition temperatures of wood (spruce 280 °C) and subsequently undergo an oxidation process, which leads to glowing without flame formation. It is known that temperatures below 200 °C are already sufficient for the formation of this charcoal layer, if the exposure time to the temperature is correspondingly long. The exact duration has not yet been scientifically proven. Cases have been documented where wood is said to have ignited by itself after long-term exposure to temperatures far below the ignition point. It is assumed that chemical sorption processes take place which enrich the charcoal surface with additional oxygen atoms and can significantly reduce the activation energy necessary for ignition, thus leading to spontaneous combustion at lower temperatures. The extent to which the presumed influencing variables such as the degree of pyrolisation of the charcoal and the duration of temperature exposure have an effect on surface enrichment with oxygen and lead to ignition at temperatures below 200 °C is the subject of this basic research project. In order to be able to look at the hierarchical structure of wood as holistic as possible, investigations are being carried out on small samples in the micro range as well as on macroscopic samples in the centimetre range. The results should bring clarity to the processes involved in the spontaneous combustion of wood at low temperatures and thus provide the basis for even safer and more efficient handling of wood as a natural building material.

The climate crisis calls for solutions to drastically reduce greenhouse gas emissions and, moreover, to remove carbon dioxide (CO2) from the short-term cycle (negative emission technologies - NET). Technologies that use sustainably produced biomass for energy and simultaneously capture CO2 and make it available for storage can make a relevant contribution here. The dual fluidized bed technology developed in Vienna, which has recently undergone significant further development, can be used both for the production of renewable gases and for the process-inherent capture of CO2 according to the chemical looping principle. For scale-up towards a commercial plant, a design process is necessary concerning the optimal dimensioning of the geometrical proportions of such a plant. In order to enable a rational system design on a scientific basis, the Fluid4NET project adapts and equips an existing fluid dynamic cold model of a two-bed fluidized bed pilot plant in such a way that the investigation of gas flow and chemical looping becomes possible. In the course of targeted measurements of gas and particle flows in the fluidized bed system, the design on the cold model can be optimized with respect to the gas-solid contact quality and the desired operational stability. The aim of the project is to arrive at a rationally based fluidized bed system design for a possible, scaled-up plant through a deep understanding of the fluid dynamic processes.