Subcoal® is a technology to upgrade RDF and SRF into pellets. Subcoal® pellets replace e.g. ligniSubcoal pelletste, bituminous coal and pet coke in power plants and in lime and cement kilns. The chemical composition of Subcoal® pellets is comparable to bituminous coal in terms of heating value and it can be treated the same physical way. The pellets are mostly used as a powdered fuel, ground to a fine powder typically <5mm particle size. Pellets are also used due to their density, in the same way as e.g. TDF is used in cement kilns. Unique about the Subcoal pellets is also that they can be ground together with e.g. coal in a vertical roller mill.