Co-firing of biomass
Co-firing is the (partial) substitution of fossil coal by biomass in coal-fired power plants. Torrefied biomass offers the most cost-effective route to significantly increase the use of biomass as a renewable energy source and to lower CO2 emissions from coal power plants.
Today most electricity is produced from coal. Blackwood Technology believes that a significant contribution of the future renewable energy mix will come from replacing fossil coal used for electricity production with biomass, which will cause a major leap forward in the decarbonization of energy production. Leveraging the enormous installed base of current power production assets and invested capital, torrefaction enables an affordable and fast substitution of fossil coal by biomass. Besides the aspect of existing infrastructure, biomass is a non-intermittent renewable energy source.
There is sufficient sustainable biomass in the world to turn it into the most significant and reliable source of renewable energy. However, biomass is a poor fuel. It has a low heating value, is biological active and its fibrous structure makes biomass difficult to grind. This limits the extent to which biomass can be (co-)fired without significant investments into additional infrastructure in current coal power plants.
These limitations are eliminated when biomass is first torrefied. Upgrading the biomass through torrefaction makes it cheaper to transport, store and combust. Blackwood’s torrefaction technology delivers approx. 20% costs savings for utilities using torrefied pellets instead of white pellets. Furthermore, torrefaction enables far higher co-firing rates alongside fossil coal in existing energy plants, while avoiding the additional capital expenditures in such plants for biomass handling and the de-rating of the electricty output associated with burning wood pellets.
In November and December 2013, Topell Energy delivered a total of 2,300 tons of black pellets for a large-scale co-firing test to the Amer power plant of RWE Essent in the Netherlands. The torrefied pellets were successfully transported, handled, co-milled and co-fired to produce green electricity. The co-milling and co-firing took place at a rate of up to 25%. Critical items addressed during the test were dust formation, milling properties and burner stability. No adverse effect on milling and burning was detected in any of the tests. The trial therefore confirmed that high quality ‘biopellets’ can be produced and co-fired at large commercial scale.
To view a video of the pellet production at Topell Energy’s Duiven plant and the co-firing at the Amer power plant, please click here.