SRFSRF – abbreviation of solid recovered fuel – is RDF upgraded to a fuel that consists of smaller fractions and more energy content. Processing RDF further upgrades the waste material, first more recyclables are taking out and then the non-recyclable residue is being used as fuel which is mostly suited to replace primary fossil fuels. Depending on the quality and application, SRF can substitute at least 70% of the primary fuels, used in a kiln or boiler.