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The sustainable use of natural ressources by saving, reducing, re-using and recycling is one of the pilars of the forest circular bioeconomy. Recycling wood and fibres is therefore a mandatory issue for achieving high levels of rational utilization of forest resources. However, due to its intrinsic characteristics and as a natural biomaterial, used wood or fibres undergo different physical or chemical treatments or biological decay and are rarely available to be used without further traitements, including sorting, decontamination, physical comminition or chemical treatments. These operations must be conducted under strict compliance with legislation relating to all environmental issues while minimisation of the impact of its industrial facilities on their locations and on the environment. Recycling wood and fibres process can be summarized in four main steps: collection, sorting, re-processing and re-using. 

Wood waste can arise from a number of sources, such as municipal, commercial and industrial (C&I), construction and demolition (C&D) and in many different forms. Wood waste can be collected via a number of routes depending on its source, amount and grade. In most of the cases, great variety of different wood-containing material are gathered together, what makes the sorting very difficult. Wood sorting is 'designed in' to the collection system by pricing incoming wood waste according to its content. This gives waste producers and intermediaries price incentives to keep lower grade wood waste separate. The wood waste is then subject to a range of sorting and grading processes. More investment and overheads in processing are required to produce high value feedstocks whereas high throughput and low handling costs are necessary to produce a lower value, higher volume product. Although different classes of recycled wood exist in different European countries, we can basically consider 4 main classes :

• Wood from packaging, pallets, moulds in concrete construction,…
• Wood based panels (OSB, particle board), plywood, coated, painted or glued solid wood, wood from interior fittings without PVC compounds in coatings
• Preserved wood, wood from outdoor application, wood containing hazardous substances, e.g. railway ties, telegraph poles, wooden windows, construction timber, roof beams, timber from demolition,…
• Wood with PVC-coatings, pallets with plastic composites

The first type of recycled wood goes to higher value markets such as animal bedding and panel products as well as in any incinerator. The second one can be used in panel products and WID compliant incineration. The two last types must be used in a WID compliant incinerator (Grade D is hazardous wood waste and only suitable for specialist landfill or WID compliant incineration). The majority of the recovered wood waste goes to the panelboard market, and about equal amounts are used for animal bedding, biomass energy, and exports. Landfill or other 'informal' outlets are the fate of the rest of the recycled wood.

The most important R&D questions related to recycling wood and fibres can be summarized as the following :

• How to efficiently collect and sort different grades of wood to be recycled ?
• How to recycle different waste wood classes? Which applications ?
• How to efficiently (both from technical and economic point of view) decontaminate wood previously treated ?
• How to manage the losses of properties of wooden material during its previous life before giving it a new one ?
• What are the legal requirements of waste wood recycling? How to meet the requirements?