Project meeting of STEP at the site of the company ATS - Agro Trading & Solutions in Hardegsen (Photo: DBFZ)

Biomass furnace Biomass technologies sector coupling | CHP

Project ID 03KB122

BioWasteStirling - Power generation from biogenic residuals in a fluidized bed fired stirling engine

Existing CHP-plant (Photo: FAU)


  • 01.09.2017 – 31.12.2020


Friedrich Alexander-University Erlangen-Nürnberg (FAU)
Chair of Energy Process Engineering
Fürther Straße 244f
90429 Nürnberg

Prof. Dr.-Ing. Jürgen Karl
FAU Erlangen-Nürnberg
Fürther Straße 244f
90429 Nürnberg, Germany

Dominik Müller – project leader
Telephone: +49-(0) 911/5302-9024

Tanja Schneider – direct contact / project coordinator
Telepone: +49-(0) 911/5302-9038


03KB122B - SWW Wunsiedel GmbH
03KB122C - Technologie- und Förderzentrum im Kompetenzzentrum für Nachwachsende Rohstoffe (TFZ)

Associated partners

03KB122 - Frauscher Thermal Motors

Cooperation partners



Final report only available in german.


Until now major portions of biogenic solid fuels for small-scale power generation leave unexploited, because they cause big problems in common grate furnaces. The reason for that is above all the crucial high combustion temperature. By using small fluidized bed combustion for mini CHP concepts, an efficient combustion cooling through an integrated stirling engine gets possible. Simultaneously pollution (e.g. caking) at the heat exchanger surfaces is avoided. Thus, high combustion efficiencies are achieved due to low excess air needed, without passing ash melting temperatures and concurrent fuel flexibility.


The objective of this project is the development and field trial of a highly efficient, fuel-flexible and scalable CHP-system consisting out of a fluidized bed combustion and a stirling engine. Thereby, the high demand for solutions regarding power generation out of unexploited residuals should be met, as currently there is no technical solution for this issue.


Development and commissioning of a 5 kWel CHP-plant in the lab environment; preparation of long-term operation at SWW focusing on tests of different biogenic fuels; Analysis of particle separation of horizontal cyclones; load- and application-dependent economic review, evaluation of the utilization potential of different fuels, as well as evaluation of the market potential

SWW Wunsiedel GmbH
Supply of the necessary infrastructure for the field trials; Fuel preparation for the supply of the small fluidized bed combustion; Evaluation of the economic and continuous utilization of the fuel potentials in the service area of SWW based on the results out of the field trials

Analysis of the emissions of particulate matter including particle size distribution depending on bed temperature, air ratio, fuel and condition of the bed material

Frauscher Thermal Motors
Supply of a 5 kWel stirling engine; adaptation and optimization of the heat exchanger to the fluidized bed combustion; Material issues during the analysis of the erosion regarding a proof of service life of the integrated heat exchanger


Development and comissioning of the demo plant, support during field trials with different biogenic fuels, particle separation of horizontal cyclones, profitability analysis and analysis of market potential

SWW Wunsiedel GmbH
Supply of infrastructure and integration of the demo plant at SWW site; field trial operation; fuel pelletization and preparation

Measurement and analysis of emissions (e.g. particulate matter)

Frauscher Thermal Motors
Supply of stirling engine and optimization of the in-bed-heat exchanger


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