Thermally treated wood pellets is a promising type of biomass which can be used for cost effective co-firing in existing coal power stations. The fuel handling properties alone are enough to make refined wood pellets one of the main contributors to increased future volumes of renewable fuels for Vattenfall.
“There are great opportunities if we act fast now, and BD Renewables is already working to get large volumes of refined wood pellets to Vattenfall,” says Per Kallner, Programme Manager, Biomass R&D.
Time is a factor, as Vattenfall’s new strategic direction is to replace more than half of the hard coal used today with biomass by 2020. Therefore, finding answers to the most critical questions that remain about the utilisation of refined wood pellets is a major R&D focus. Small-scale tests indicate that refined wood pellets offer similar properties to hard coal, and using them as a fuel would therefore require a fraction of the investment that wood pellets would necessitate.
First large-scale tests in the world
“We have performed a lot of laboratory and small-scale tests, which have put us in a position to select fuels for further investigation and to give feedback on the manufacturing processes,” says Stefan Dusan, Project Manager of the BU Biomass Refined Wood Pellets Verification Project.
“However, feasibility can only be proven in large-scale storage and combustion tests. These kinds of tests were successfully performed during the summer of 2011 in the Reuter West CHP hard-coal-fired plant in Berlin. During one week in July the plant generated 20% of its electricity with about 4,000 tonnes of this new type of pellets, i.e. 120 MW of renewable electricity. This was the first test of this scale worldwide, and we are proud to be part of it.”