Horti-BlueC developed a tool to indicate how to process residual biomass into CO2 fertilizer and building blocks for growing media, i.e. biochar, chitin, fibers, or other materials. We worked on 1 gaseous waste stream (off-gasses from the chimney of a bio-energy installation) to be used as CO2 fertilizer and 4 solid waste streams to be used as replacer for peat and mineral wool in growing media. Some materials may only need defiberization, cutting, milling, … whilst other waste streams or applications require more advanced treatment. The pretreatment from waste to feedstock is documented in a fact sheet to select the best processing techniques. All fact sheets on the processing of these materials are available and linked to the Decision Tool.