Plants based on dual fluidized bed (DFB) gasification are a season- and weather-independent, sustainable and decentralized option to provide electricity, heat and gas. These DFB plants are on the verge of profitability due to high prices for raw materials (e.g. wood chips) and low prices for products (e.g. electricity and heat). In order to be able to maintain, research and further develop this key technology on an industrial scale, its economic efficiency should be increased. One way of doing this is to improve the interaction between the processes by means of control engineering measures.

The MBC-FluBBStGas project, led by BIOENERGY 2020+, was successfully completed in the summer of 2018 and aimed to improve the economic efficiency of these plants by means of control engineering measures. The test was carried out at the HGA Senden of Blue Energy Syngas, where dual fluidized bed gasification is successfully used.

As a result of the research work, the required amount of product gas and thus the required amount of fuel could be reduced by 12% in partial load operation with the same electricity production. At full load, the reduction can be estimated at approx. 7%. Since the fuel accounts for a large part of the operating costs of a DFB plant, the operating costs can be significantly reduced by means of this control engineering measure.

The project was funded by the Austrian Research Promotion Agency (FFG) within the framework of the Brückenschlagprogram_NATS (Bridge Early Phase). Further project partners are the Institute of Automation and Control of Graz University of Technology, the Institute of Chemical, Environmental and Bioscience Engineering of Vienna University of Technology, and REPOTEC.

Due to the success, the project partners started a follow-up project at HGA Senden, in which long-term tests under full load were to show whether the amount of fuel can be permanently reduced by 7%. The results of these long-term tests will be presented at the European Biomass Conference & Exhibition (http://www.eubce.com/) in May 2019. In addition to this reduction in the amount of fuel, further measures to increase the economic efficiency of DFB plants are being worked on.