RWE builds up pellet power1 August 2010
RWE is making significant investments in the biomass supply chain for its power plants, notably in wood pellet production, both conventional and Topell “biocoal.”
The first commercial-scale plant for the production of Topell biocoal pellets (pictured above right) – a new type of biomass fuel with similarities to coal and therefore well suited to co-firing (see MPS, August 2008) – is underway in the Netherlands, at Duiven in the province of Gelderland.
The foundation stone laying ceremony was held on 28 June for the
€ 15 million project, which is being implemented by Topell Nederland, a joint venture of RWE Innogy (49.9 %) and Topell Energy (50.1 %).
The new plant, which will have a production capacity of 60 000 tons per year, is due to be commissioned in early 2011.
A couple of years ago, RWE Innogy took a 25% stake in Topell Energy, which is a Dutch start-up company, as part of the German utility’s new policy of investing in promising young technology enterprises (other beneficiaries being: CeramHyd (ceramic membranes for H2 production); Heliatek (organic solar cells); Mantex (scanning system for determining biomass properties such as moisture content, ash and impurities); StirlingDK (Stirling-engine-based solid-biomass-fuelled CHP); Quiet Revolution (small vertical axis wind turbines); Revolt Technologies (batteries); and Voith Hydro Ocean Current Technologies (tidal stream turbines)).
Topell Energy’s technology combines torrefaction (a form of pyrolysis involving rapid heating of the biomass to about 320°C in the absence of oxygen, to eliminate water) with pelletisation. The resulting biocoal pellets have high energy density compared with conventional biomass, and better combustion properties, more like coal. Biocoal is more easily transported than biomass in conventional form, and when co-fired with conventional coal requires no additional facilities such as separate handling, storage and milling.
The process developed by Topell Energy (formed by a merger of Polow Energy Systems BV, developer of the Torbed reactor, a key enabling technology, and Topell BV) enables the continuous production of biocoal pellets on an industrial scale. The manufacturing process is also highly flexible in terms of raw material input.
Dr Leonhard Birnbaum, member of the Executive Board of RWE AG, speaking at the foundation laying ceremony, said: “Our commitment to Topell was the very first venture capital investment of RWE Innogy. Today shows that our decision was right. Our intention was to commercialise a new process for the production of efficient biocoal, which significantly improves and extends the potential applications of biomass. As a leading operator of coal-fired power plants, we consider it to be our responsibility to reduce the CO2 emissions of electricity generation as much as possible. The plant whose foundation stone we are laying today is another major step in this direction.”
The first power plant to use the new pellets will be the Amer coal station in Holland (two units of total capacity 1245 MWe and 600 MWt), which is owned and operated by Essent, now part of RWE.
World’s largest pellet plant
In addition to the venture capital investment in Topell Energy, RWE Innogy is also investing in conventional biomass pellet production capacity, with the aim of helping to secure the raw materials supply chain for the growing biomass market it sees developing in Europe. In fact, the company is investing some 120 million euro in what will be the world’s largest wood pellet production facility, currently under construction at Waycross, Georgia, USA, with a capacity of 750 000 tons per year. These pellets will be used by RWE in Europe for both dedicated biomass power plants and for co-firing at coal-fired power plants.
The ground-breaking ceremony for the Waycross pellet plant was held on 25 March 2010, with the first pellets due to be produced in the third quarter of 2011.
About 1.5 million tonnes of fresh wood will be needed each year to produce the pellets, but this is of course easily accommodated by Georgia’s sustainably managed forests, which are vast, even by US standards. Carbon dioxide emissions associated with bulk sea transport are relatively small in per tonne terms and RWE Innogy is investing in the development of port facilities in Savannah through its subsidiary Georgia Biomass LLC.
The biomass pellets from Waycross will also be used, at least initially, in the Amer coal fired units, which are already co-firing up to 30% of biomass. The additional supply from Waycross will allow the co-firing rate to be increased to as much as 50% over the medium term.
In the longer term RWE envisages the use of the pellets at other plants in the Netherlands and elsewhere, including Germany, Italy and the UK.
Currently the world’s largest operating wood pellet production plant is the 560 000 t/y Green Circle Bio Energy Inc facility in Cottondale, Florida, USA, which started up in 2008.
The significance of this plant, and of biomass in general, was recently recognised by Eurelectric, which gave one of its two 2010 awards to J Christer Ericsson, chairman of JCE Group AB of Sweden, founder of Green Circle Bio Energy. (The other Eurelectric 2010 award went to Luis Echavarri of the OECD Nuclear Energy Agency.)