Waste wood includes industrial and used wood that must be collected and disposed of separately according to Germany's Circular Economy Act(KrWG). In processing biomass and waste wood, efficient purpose-designedmachinery is needed to get the best possible results from different inputmaterials.

Depending on where it comes from, waste wood may be contaminated with non-wood substances like paint,halogen organic compounds and wood preservatives. Consequently, much less waste wood is recycled than is usedfor energy (17 percent to 77 percent in Germany in 2016 ). The Waste Wood Act accords these two uses the samestatus, but that could change. Currently the German government is looking into how legislation on the reclamationof waste wood can be modified to address technical and analytical progress. Komptech is keeping an eye on thisprocess, and is taking it into consideration in refining its waste treatment processes.

Uses of waste wood

Waste wood is divided into four categories based on the hazardousness of the contaminants in it. Category A I iswood in its natural state without significant contamination; Category A IV is used wood treated with preservatives.The category determines the conditions under which the processed waste wood can be recycled or used as fuel in abiomass cogeneration plant, or whether it can only be used in cogeneration plants that have extensive exhaustscrubbing. The most common use for untreated waste wood is the manufacture of wooden construction materialssuch as particle board.


Treatment by particle classes

After a visual check during receiving and manual pre-sorting, the waste wood is shredded down to the grain size thatis most suitable for further use. First the metallic contraries are removed. Particle sizes normally follow thecategories of EN ISA 17225, which defines the particle classes of biogenic solid fuels. If the waste wood is to be usedas a reclaimed material, it is usually reshredded and undergoes another contrary removal step, resulting in finechips for chipboard.


One and two-stage processing (P200, P100, P63)

Komptech’s Crambo and Terminator are suitable for single-stage processing to specifications P200 and P100. Bothare low-speed shredders that are insensitive to metallic contraries. Two-stage processing is recommended forshredding waste wood to particle classes P100 and P63. A star screen downstream from the shredder, such as theKomptech Multistar One, generates a precisely defined grain fraction while returning overlengths to the shreddingprocess. Product quality can be further improved through the addition of an eddy flow separator and overbandmagnet. These machines can be mobile or stationary, and the Crambo and Terminator are also available in e-mobileversions.


Pre- and post-shredding (P100, P63 and P45)

Particle class 45 output is often required for the material reclamation of waste wood. To achieve this, two shredderscan be combined. For example, a Crambo can handle the preshredding, in which combined wood and metal objectsneed to be opened up as fully as possible. Following metal separation, a Komptech Axtor can do efficient post-shredding. The Axtor can be configured to match the material and the requirement.


We have a wide range of compact systems and mobile machines for the effective and economical processing ofevery category of waste wood.