Next Generation Fuel Flexible Residential Biomass Heating Based On An Extreme Air Staging Technology With Ultra-Low Emissions

Although present small-scale biomass boilers, in particular pellet boilers, have already reached a high technology level, still a potential for further improvements exists which shall be used to increase their competiveness on the residential-scale heating market. Increased fuel flexibility towards the utilisation of low-quality ash rich wood fuels and non-wood fuels (agricultural residues), further reduced emissions, especially in terms of particulate matter (PM) emissions, and the integration of advanced flue gas condensers to increase efficiency are seen as development targets for future residential biomass boiler technologies. With the PuroWIN technology, which has been developed by Windhager Zentralheizung Technik GmbH in cooperation with BIOS BIOENERGIESYSTEME GmbH, a concept has been introduced, which allows for an utilisation of softwood pellets and high-quality wood chips at almost zero CO, OGC and PM emissions. Within an ongoing EU funded research project, R&D work is performed to broaden the fuel range applicable as well as to improve its efficiency by the implementation of a novel flue gas condenser concept. In this paper, intermediate results of the project are presented which show that for future biomass boilers a utilisation of various wood and non-wood fuels at almost zero CO, OGC and dust emissions and high efficiencies is possible.