Renewable black pellets trialled in Finland
Published: 29 October 2019 - Carly Wills
Clean Electricity Generation (CEG) and Turun Seudun Energiantuotanto (TSE) have announced the successful logistics, handling and combustion trial of over 1,000 tonnes of CEG renewable black pellets at TSE's coal-fired power unit Na2 in Naantali power plant, Finland.
The pellets, produced from sustainably sourced biomass, served as a drop-in substitute for fossil coal in the co-firing trial.
CEG renewable black pellets were produced at CEG's high temperature Torrefaction facility in Derby, UK, and transported by ship to Naantali, Finland. In Naantali, the pellets were stored outdoors, in the power station's existing coal yard, uncovered and exposed to rain and normal autumn weather conditions. The pellets were then conveyed, using legacy coal conveyors, to the unit Na2 power block's coal silos and mills, and ultimately the coal-fired boiler unit Na2. During the trial, TSE employed the plant's existing infrastructure designed for fossil coal; the equipment was not modified for biomass.
The objectives for the trial were to evaluate replacement of fossil coal with torrefied pellets, demonstrate that the fuel switch from fossil to renewable can occur without significant investment at the power station, and prove that CEG pellets can withstand outdoor storage for a certain time, in a similar manner to fossil coal.
CEG renewable black pellets were high-energy and demonstrated hydrophobic behaviour, standard coal handling, efficient combustion and good grindability. TSE is further evaluating the detailed technical performance of the pellets, as the basis for a fuel replacement decision. The trial occurred in Naantali between 23-27 September 2019.